Esmaeil Nasrabadi
Abstract
Analyzing the changes in the characteristics of daily precipitationis very important in water resources planning and cultivation patterns. In this research, the changes of the most fitting frequency distribution and its parameters over time are investigated. To this end,thenetworked daily precipitation ...
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Analyzing the changes in the characteristics of daily precipitationis very important in water resources planning and cultivation patterns. In this research, the changes of the most fitting frequency distribution and its parameters over time are investigated. To this end,thenetworked daily precipitation data of the Middle East Aphroditeprecipitation database with a latitude and longitude of 0.25, 0.25 degreeswere used.The daily precipitation data of this database in Iran, during the period of22.03.1951 to 20.03.2007 (20453 days) was extracted using Grads software. To track the changes over time, the data was divided into two 28-year periods. The precipitation data of the first period from 22.03.1951 to 20.03.1979 was placed in an array with a dimension of 10226*2491 and the data of the second periodfrom 21.03.1979 to 20.03.2007 was placedin an array with a dimension of 10227*2491(the rows and columns represent the number of days and cells respectively).The Kolmogorov-Smirnov Goodness-of-Fit test was used to identify the most fitting distribution of rainy days. The normal and gamma type distribution functions onindividual cells of the precipitation were fitted by programming in Matlab software environment. The theoretical two- parameter and exponential gamma distribution function has been able to attain the required statistical conditions for the Goodness-of-Fit test at a 95% confidence level as the most fitting distribution in both periods.The extensive spatial and temporal changes in precipitation distribution are not confirmed as one of the components of climate change tracking. The calculation of the most fitting distribution parameters by linear torque method shows slight variations in the spatial dispersion pattern of these parameters. But, these changes do not follow a specific pattern. The mapping of the standard deviation variation indicates that in a vast part of central and western Iran, the confidence in precipitation has decreased in recent decades.
Milad Salehi; Jamal Asgari; Alireza Amiri Simkooei
Abstract
Coordinate systems transformation has an important role in mapping activities, geodesy and spatial science. New and efficient methods are needed in order to increase the accuracy in the transformation between these systems.The main purpose of this article in the first part, is a local coordinates transformation ...
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Coordinate systems transformation has an important role in mapping activities, geodesy and spatial science. New and efficient methods are needed in order to increase the accuracy in the transformation between these systems.The main purpose of this article in the first part, is a local coordinates transformation in Isfahan City to UTM coordinates and vice versa. This method is based on the combined scale factor. So, the coordinates of 500 GPS stations in Isfahan City were used,and with reduction of distanceson the surface of the earth to the map, coordinates of the GPS points in the local system were calculated.Study on changing of combined scale factor for the GPS points of Isfahan City shows that if a unit scale factor is used for whole the city, in long lengths occurs a few decimeter differences and it is not suitable for accurate mapping. LIDAR is a mature remote sensing technology which can provide accurate elevation data for both topographic surfaces and above-ground objects. So in the second part of the article, we presented an algorithm to provide height interpolation for the points in the passage network of Isfahan City by using LIDAR data,because the inverse transformation from local system to UTM using new methods such as Rational Functions, needs vertical component in addition to horizontal position of points.A height bias of 30 centimeter has been detected in the LIDAR data using GPS control points. After removal of this systematic component, the final RMSE of LIDAR heights is 43 centimeters.
Seyyed Yaser Hakimdoost; Shahbakhty Rostami; Mahmood Moradi; Abdolhamid Nazari
Abstract
Abstract
The present study is seeking to identify the spatial pattern of habitability of rural settlements in Hirmand’s border regions in order to identify the hazardous areas. The research method in this study is of applied type, and the governing approach to the research is descriptive and analytical. ...
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Abstract
The present study is seeking to identify the spatial pattern of habitability of rural settlements in Hirmand’s border regions in order to identify the hazardous areas. The research method in this study is of applied type, and the governing approach to the research is descriptive and analytical. In order to analyze the distribution pattern of the habitable villages at three optimal, moderate and undesirable levels spatially, spatial statistics tests will be used in the GEO DATM and GIS software environment to identify the spatial pattern of the habitability of the villages and ultimately the hazardous and vulnerable zones to be identified. The results of the research show that 16 villages are in the optimal, 16 in the moderate and 12 in the undesirable range. Also, the results of using the Moran Anselin’s Algorithm in the region indicate that 7 cold clusters (low habitability) and 11 hot clusters (high habitability) were identified in the region. The largest hot spot is located in the south of the city and the villages located on this spot are highly habitable and adjacent to each other, and the largest cold spot is located in the south-east and center of the city. The results of the study indicate that the villages near the borderline have a weaker habitability and cold clusters are concentrated in these areas, and the rural regions of the northern part of the city are less habitable due to their dependence on the agricultural economy and the shortages of resources of the Hamoon’s Abūroud in the north of the city. Hazardous spots from the unstable situation of rural settlements perspective can endanger the region from the security aspect, and consequently, habitats with more appropriate habitability located in the vicinity of the spots with low habitability will also be endangered in terms of security and will eventually overwhelm their habitability.
Fatemeh Jahani Cherebargh; Mehdi Akhoondzadeh Hanzaei
Abstract
Extended Abstract Aerosols are small (sub-micron to several microns) suspended particles in the solid or liquid phase in the atmosphere. The main origins of aerosols are natural and anthropogenic. They can be directly emitted as particles (primary aerosols) into the atmosphere namely, mineral aerosol, ...
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Extended Abstract Aerosols are small (sub-micron to several microns) suspended particles in the solid or liquid phase in the atmosphere. The main origins of aerosols are natural and anthropogenic. They can be directly emitted as particles (primary aerosols) into the atmosphere namely, mineral aerosol, sea salt, volcanic eruptions, organic aerosols, industrial dust, soot, biomass burning, etc. They can also be the result of chemical reactions (secondary aerosols) namely, sulfates from biogenic gases or volcanic and nitrates from transportation and diffusion of aerosol particles from the source region depend on wind vector and wind strength. Aerosols are ever present and highly varying constituents of our atmosphere. They play roles in many physical and chemical processes that shape the composition of the atmosphere and thereby affect cloud formation, visibility, and air quality. They interact both directly and indirectly with radiation and thus affect the amount of radiative energy reaching the surface and reflected to space. The shortwave part of the radiative energy at the surface (insolation) is an important component of the surface energy budget, and a necessary input to models of land-surface processes. Aerosol Optical Thickness (AOT) is calculated by measuring light absorption at specific wavelengths of the visible spectrum. For the most widely used AOT data product, the absorption at 550 nm is the preferred wavelength for measurement (In the visible spectrum, humans perceive a light wavelength measuring 550 nm as a shade of green). AOT is a dimensionless quantity, expressing the negative logarithm of the fraction of radiation (e.g., light) that is not scattered or absorbed on a path. High AOT indicates a large quantity of aerosols, and thus a significant amount of absorption and scattering of radiation (i.e., light). Low AOT indicates clearer air with fewer aerosols and increased transmission of radiation. Increasing aerosol concentrations can thus affect global temperature and the radiation balance of the globe by reducing the amount of radiation reaching the Earth’s surface, and that reduction can result in lower air temperatures. Penetration of the large particles into the atmosphere in certain cases leads to decreasing the particles mobility and then dropping the conductivity, which will increase the electric field but aerosol measurements in the seismically active zones are more complicated due to the mosaic character of the gas emanation in the seismic zones and the uncertainty of aerosol origin in gas probes. Some remote sensing satellites due to their suitable temporal, spatial and spectral resolutions provide useful information of time and spatial distributions of Aerosols. This leads to creating an appropriate database for statistical study of the seismic atmospheric effects. The AOD measurement is taken by the MODIS sun-synchronous instrument onboard Terra and Aqua satellites every day. The satellites provide more continuous coverage nearer to the poles but there are more gaps in the coverage of the satellite nearer to the equator. AOT can be determined by implementing different methods on satellite images, but it is a difficult task to achieve it because solar lights are reflected by the atmosphere and the whole solar lights do not hit the ground. The most famous methods used to derive aerosol parameters are Dark Dense Vegetation (DDV), deep blue algorithm and synergy of Terra and Aqua MODIS (SYNTAM). SYNTAM approach can remove limitations in deriving AOT by combining data from two sensors of MODIS of TERRA and AQUA satellites and this method gives the right results. In this study, SYNTAM method has been applied over a region of Iran to produce an AOT map. The comparison between our results and NASA AOT products for the same time and location shows a good agreement. The result of comparing NASA data and SYNTAM approach with Newton iteration algorithm for the wavelength of 0.55 µm, gives the RMSE equal to 0.253. Therefore SYNTAM could be a robust method to derive AOT map over regions without AERONET ground stations. In the next section, SYNTAM method was combined with nonlinear parametric adjustment model. In this case, the results are more accurate than implementation of SYNTAM method alone. The result of comparing NASA data and SYNTAM approach with nonlinear parametric adjustment model for the wavelength of 0.55 µm, gives the RMSE equal to 0.207.
Saeid Maleki; Reza Ahmadi; Sajad Monfared; Mohammad Matougi
Abstract
Many developing countries are over-concentrated in a few urban areas. Such a situation leads to many problems. In this countries, the quality of people's is experiencing huge regional inequalities which are increasing rapidly in many cases. Environmental problems are one of the most fundamental issues ...
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Many developing countries are over-concentrated in a few urban areas. Such a situation leads to many problems. In this countries, the quality of people's is experiencing huge regional inequalities which are increasing rapidly in many cases. Environmental problems are one of the most fundamental issues in modern cities and are the result of conflict and confrontation with the natural environment. The result of this process will be the imbalance and incompatibility between man and nature and the collapse of the ecosystem relationship. The purpose of this research is to identify the variables of sustainable environmental development and assessment of sustainability in the cities of Khuzestan province. This is an applied and descriptive- analytical method research. The results of the research show that the cities of Izeh, Dezful, Andimeshk,Lali and MasjedSoleiman are at a higher level than other cities in terms of environmental development in khuzestan province. Also, the results of statistical tests indicate the superiority of the North of province to its south in terms of environmental development. However, there is no sensible difference between the east and west of the province despite the relative superiority of the east of the province to the west. The results of the Pearson correlation coefficient show that there is no meaningfulcorrelation between environmental development and population size of the cities and their Urbanization rate. This means that, there is no meaningful relationship between population size and urbanization rate with environmental development.
Mohsen Ahadnejadroshti; Ashraf Azimzadeh Irany; Saeed Najafy
Abstract
Abstract
physical growth and development of border cities with regard to defense and security structures, migration and population movements, communication and transportation infrastructure, urban management, sources of livelihood, diversity of cultural customs and…, have undergone changes and ...
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Abstract
physical growth and development of border cities with regard to defense and security structures, migration and population movements, communication and transportation infrastructure, urban management, sources of livelihood, diversity of cultural customs and…, have undergone changes and developments under the influence of internal and external communication over the years. The main objective of this research is to compare adaptively the physical development of Eastern and Western border cities of the country with a case study of Zabol and Piranshahr cities. For this purpose, ETM, TIRS, and OLI sensor images of Landsat satellites 5, 7, and 8 were selected for the period of 1986-2015 (1365-1394), and Holdren models and Shannon Entropy were used. After geo-referencing the images, Fuzzy method has been used to classify the changes of development, and the urban expansion was foreseen for the year 2030 (1409) using the combination method of Markov chains and automated cells. The results show that during the 29 years of study, the lands constructed in Zabol city has reached from 2578.10 hectares in 1986 (1365) to 3419.92 hectares in 2015 (1394), and in the city of Piranshahr from 612.10 hectares in 1986 to 1785.90 hectares in 2015. During this period, the greatest land use changes in Zabol were observed in agricultural lands with 58.76 % and the least changes were in gardens with 0.42 %. In the city of Piranshahr, however, the highest rate of land use changes were observed in agricultural lands with 67.88% and the least changes in wastelands with 2.16%. According to the entropy model, it has been shown that in the last 29 years, the physical expansion of cities has been growing sporadically and non-densely. But the rate of shapelessness has decreased in the city of Piranshahr compared to the year of 1986. Between the years of 1986 and 2015, about 85% of physical growth in Zabol city was related to population growth and 15% of the city growth was related to the horizontal and spiral growth of the city, while in the city of Piranshahr, all the city's physical growth has resulted from the population growth during the aforementioned years due to the negative gross per capita. Considering the projected population during these 15 years, it is expected that 364.4 ha in the city of Zabol and 15.94 ha in the city of Piranshahr will be added to the urban constructed lands. The adaptive comparison of the cities with regard to the population growth has led to an uneven development of the cities, which requires the guidance, growth and development of the cities with appropriate and desirable plans.
shahabadin isalou; Gholamreza Latifi; VAHID GOODARZY
Abstract
Abstract
Confronting natural disasters and managing that by using the most efficient means, have always been subjected to deliberation, investigation and examination from various aspects. But, a comprehensive and locative analysis on the spur of the moment is always an essential act that must be taken.In ...
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Abstract
Confronting natural disasters and managing that by using the most efficient means, have always been subjected to deliberation, investigation and examination from various aspects. But, a comprehensive and locative analysis on the spur of the moment is always an essential act that must be taken.In this field, geographic information system is capable through integrating information of providing a comprehensive analysis and identification of the zones which require attention and have been very effective. Among natural disasters, earthquake is very unpleasant and leaves the highest mortality rates, hence, its management is very important, especially in the urban context. Most injuries from the earthquake due to the physical resistance of tissue, the impossibility of relief and incapability of reversibility had been in direct or indirect connection with undesired structural situations. This paper tries to offer the most effective strategies to achieve a higher quality of physical safety against potential earthquakes through assessment of physical vulnerability and determine vulnerable zones.
Materials & Methods:
Using the five indicators, (population density, land use risks, quality of buildings, age of buildings, access to the centers of relief and rescue) information layers of each of these variables were produced and these layers were integrated using the Analytic Hierarchy Process IHWP in Arc GIS environment, and the location of district 1 was evaluated against earthquakes.
Results & Discussion:
Findings show that the physical texture of district 1 in Tehran is relatively safe against possible earthquakes, districts 9, 7 and 5 are very safe,districts 4, 6 and 10 are safe, and districts 2 and 8 are moderately safe. Districts 1 and 3 were assessed as areas with low safetyand subjected to disaster. In general, the north of this area has narrow passageways and streets, high-rise buildings, worn out textureand ruined sites, which is unsafe and vulnerable to earthquakes.
Conclusion:
Based on the principles of urban management,non-standard sales of building density by the municipality of Tehran in this area and the growing trend of population is considered to be the main problem and a serious threatening alarm to the life of the region.
Farideh Sabzehee; Mohammad Ali Sharifi; Mehdi Akhoondzadeh hanzaee
Abstract
Extended Abstract
Electrondensity is one of the significant parameters for monitoring and describing the ionosphere.The ionosphere is a consequential source of errors for the GPS signals that traverse through the ionosphere on their ways to the ground-based receivers, because there is a high concentration ...
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Extended Abstract
Electrondensity is one of the significant parameters for monitoring and describing the ionosphere.The ionosphere is a consequential source of errors for the GPS signals that traverse through the ionosphere on their ways to the ground-based receivers, because there is a high concentration of free electrons and ionsreleased by the ionizingaction of solar X-ray and ultraviolet radiation on atmospheric formers. Radio Occultation(RO) is one of the most modern satellite techniques to study on vertical profiles of neutral density, temperature, pressure and water vapor in the stratosphere and troposphere and ionospheric electron density profiles with high vertical resolutions.Since the RO technique using the GPS signals was employed for the first time by the Global Positioning System Meteorology (GPS/MET), the low-earth-orbit-based GPS RO technique has been proven as a successful method in exploring the earth’s lower atmosphere and ionosphere.
Abel transformation is the basic hypothesis made in the retrieval of radio-occulted ionospheric parameters.The Abel inversion is a powerful tool to retrieve high-resolution vertical profiles of electron density from GPS radio occultation collected by satellites into Low Earth Orbit(LEO).
COSMIC satellite records measurements during the whole day and is not limited to the specific times and special atmospheric conditions.It should be noted that the GPS radio occultation techniques provide continuous and useful ionospheric layers information and are not obtained from the point wise measurements by other satellites.
COSMIC satellite also records the altitude for the measurements of the electron density profile. COSMIC satellite provides more than1000 electron density profiles per day with approximately global coverage and also parts of them cover IRAN .In this approach, the LEO-GPS line of sight is occulted by the Earth’s limb with the setting(or rising) motion of the LEO satellite. The GPS-LEO radio connection successively records the atmospheric layers at different altitudes. The ionosphere is highly variable in space and time. Thus, for modeling the electrondensity profile the time changes(diurnaland seasonal) and location changes(geographical position of station), must be considered. In this research, the input space includes the day number (seasonal variation), hour (diurnal variation), latitude, longitude, height and F10.7 index (measure of the solar activity). The output of the model is the ionospheric electron density profile(Ne).The COSMIC observations and IRI-2007-based data of electron density profiles were also analyzed during the solar minimum period. In this research, we used a feedforward Artificial Neural Network (ANN) with 55 neurons in hidden layer for modeling profiles of electron density of COSMIC satellite performance of the ANN models was evaluated using correlation coefficient (R=92%),R-Squared(0.83). It was found that the ANN model could be applied successfully in estimating the electron density profiles retrieved from the FORMOSAT-3/COSMIC.The comparison of the IRI model electron density profile with the COSMIC RO measurements during each month of the year 2007 over IRAN is performed.The electron density profile from all three International Reference Ionosphere (IRI) models, namely IRI-NEQ,IRI-2001, and IRI-01-Corr are used.
The results showed that the results of the IRI2007 model electron density is not satisfactory over IRAN and ANN model electron density profile is in very good agreement with COSMIC RO measurements. It was concluded that IRI-NEQ model is more appropriate thanthe other two models.
The results showed that the differences between the modeled profile electron density and theobserved profile electron density are very lower than the differences between the IRI-2007 models.Maximum changes occurred in January and December at analtitude of about 450 km and minimum changes were recorded in November at the height of 250 Km and in April at the height of 450 Km. The differences also decreased in the summer at higher altitudes and in winter at lower altitudes.
Ehsan Modiri; Gholam Ali Kamali; Sohrab Hajjam
Volume 22, Issue 88 , January 2014, , Pages 75-80
Abstract
Solar radiation is one of the most important and influential parameters in thermal balance of the atmosphere and thus it is considered to be the basis of many climatic studies. Evapotranspiration is defined by the amount of available energy for evaporation. Since energy at ground level is mostly supplied ...
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Solar radiation is one of the most important and influential parameters in thermal balance of the atmosphere and thus it is considered to be the basis of many climatic studies. Evapotranspiration is defined by the amount of available energy for evaporation. Since energy at ground level is mostly supplied by the sun, many researchers have been interested in the influence of solar radiation on agriculture and especially irrigation sciences. Main research variables include total radiation received at ground level and the slope of radiation changes which are calculated and analyzed using data quality control and routing methods recommended by World Meteorological Organization, and measured at two different geographical points with semi-arid climate. Regarding Pearson correlation coefficient, the significance level of Kermanshah station was set at 99% and Tabriz was set at 95%. Total annual radiation and statistical period are positive related. With an increase in statistical years, annual radiation increases with an appropriate slope which shows the ascending trend of annual radiation in stations.
Mehdi Najafi Alamdari; Masoud Torabi Azad; Ali Hakimi
Abstract
Extended Abstract
Introduction
The Mean Dynamic Topography (MDT) of the seas is a quantity which comes from subtracting the Geoid Height (GH) from the Mean Sea Surface (MSS) at every point on the sea. The direction of geostrophic currents is obtained through the calculation of the MDT slope relative ...
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Extended Abstract
Introduction
The Mean Dynamic Topography (MDT) of the seas is a quantity which comes from subtracting the Geoid Height (GH) from the Mean Sea Surface (MSS) at every point on the sea. The direction of geostrophic currents is obtained through the calculation of the MDT slope relative to the Geoid. In this research, a series of GOCE geopotential coefficients resulted from the 4 year collection of GOCE observations was used to estimate the reference geoid height in the Persian Gulf, the Oman Sea and the Indian Ocean, i.e., in the area of interest. Two MDT models data were available at the time of performing this research: Denmark Technical University’s model, named ‘Mean Dynamic Topography of Denmark Technical University 2010’ (MDT_DTU_2010) which has been available on a geographical grid of 2 arc minutes spacing (Knudsen & Andersen, 2010). This model is based on the mean sea surface topography model MSS_DTU_2010 and the 2 month of GOCE geopotential data for the Geoid as the reference surface. The second model is the Mean Dynamic Topography Centre National d'Etudes Spatiales collecte localisation satellites 2009 (MDT_CNES_CLS09) with 15 minutes resolution (Rio et al, 2011). This model contains the east-west and north-south geostrophic current components with itself as well. It is based on MSS_CLS01 (Hernandez and Schaeffer, 2001) and 4.5 years of GRACE geopotential data used for the reference geoid.
Materials and Methods
In this research a new Mean Dynamic Topography (MDT) model with the name of MDT_IAU_TN_2014 is presented. Also, the surface permanent current vectors in a grid with 2 minutes resolutions is computed in the Persian Gulf, the Oman Sea and the north of Indian Ocean. This MDT is formed by a Mean Sea Surface (MSS) model computed from 6 altimetry satellites data (Topex/Poseidon, Jason 1 and 2, ERS 1 and 2 and Geosat Follow-On) and GOCE satellite data with 21 and 4 years ranges in 1992-2013 are calculated. The first step for the Mean Sea Surface (MSS) computation is to calculate the mean of Sea Surface Heights (SSH) along the repeated (in time) sub-tracks of altimetry satellites over the years available in the area of interest. The mean value of SSHs over time in a same track is then called Mean Height (MH). The Basic Radar Altimetry Toolbox (BRAT) version 3.1.0 was used for the MH computation. The correction term includes the tidal periodic variations, physical earth corrections such as troposphere, ionosphere, and sea state biases. All of these corrections are considered from the satellite handbooks T/P (AVISO/ALTIMETRY, 1996), J1 (AVISO and PODAAC USER HANDBOOK, 2012), J2 (OSTM/Jason-2 Products Handbook, 2001), ERS (RA/ATSR products - User Manual, 2001), GFO (GEOSAT Follow-On GDR User's Handbook, 2002). Among altimetry satellites, T/P (J1 and J2) has the highest orbit and longest data sets so it has been selected as a reference for corrections.
Results & Discussion
To homogenize the spectral of MSS and the Geoid, a truncated Gaussian filter with 1.386 degree radius has been used. MDT results have been compared with two global model and have 0.033 and 0.051 RMS of differences in order. Among altimetry satellites used in this research, J2 and GFO satellites have the ability to measure shallow waters. Hence, the data provided by these satellites in shallow waters, i.e. Persian Gulf are valuable. MHS differences between E1 and T/P are larger than the MHS of other satellites, because there are differences between the two missions, i.e., there are 8 km distances between E1 sub-tracks at equator but long repeatability period of 35 days of data acquisition time and T/P sub-tracks spacing are 315 km at equator and short repeatability period of 9.9 days. Also, the orbit elevations are different: T/P at altitude of 1336 km and E1 at altitude of 785 km. Inclusion of E1 data in the MSS_IAU_TN_2014 solution would globally decrease the RMS difference of the solution relative to the MSS_CNES_CLS_2011 model from 0.4 m (without E1 data) to 0.1 m. This improvement by the E1 data is probably due to the higher resolution of the data in the region of interest.
Conclusion
Changing the filtering radius of 1.386 degree down to lower degrees until 1 degree would increase the MDT_IAU_TN_2014 differences (relative to the MDT_DTU_2010) and MDT_CNES_CLS09 from 0.033m and 0.051m RMS up to larger values. At the 1.386 degree, the differences are minimum. For filtering radiuses of more than 1.386 degree the MDT surface would become unreasonably much smoother and the RMS difference would increase. Geostrophic and Ekman velocity currents using 22 years data of surface wind has been calculated. Total currents of the released model in this research have been compared with OSCAR in-situ data and have 0.047 and 0.031 meter RMS of differences in North-South and East-West current components. The total currents from MDT_IAU_TN-2014 model vary between 0 to 0.61 m/s in the north Indian ocean region. The comparison shows that all three models show almost the same range of variations in the region of interest. SLA an In-Situ data could be used to make the MDT_IAU_TN_2014 independent from any other models. The lack of In-Situ data in the region of interest forced MDT_IAU_TN_2014 to use MDT_DTU_2010 to cover filtered parts. Also using other gravity models with higher Spherical harmonic coefficients degree and orders such as EIGEN-6c and EGM08, would make filtering not needed in the dynamic modeling.
Hossein Mohammadi; Mohammad Hasan Mahoutchi; Mahdi Khazaei; Esmaeil Abbasi
Abstract
Probability analyses are useful methods for recognizing and predicting phenomena such as precipitation. One of these methods is the Markov chain. The Markov chain model is a special state of the models in which the current state of a system depends on its previous states. With this method, it is possible ...
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Probability analyses are useful methods for recognizing and predicting phenomena such as precipitation. One of these methods is the Markov chain. The Markov chain model is a special state of the models in which the current state of a system depends on its previous states. With this method, it is possible to calculate the probability of the occurrence andthe return period of climatic phenomena such as precipitation.Therefore, in the present research,using the 58 year daily precipitation data (1956 - 2013) ofShiraz synoptic station, the frequency and the continuity of rainy days in this city were studied by the use of the Markov chain model. The above statisticswere arranged based on the matrix of counting the changes of the occurrence states of the dry and wet days (days without precipitation and precipitation days), then, the situation change matrix was calculated based on the maximum likelihood estimation method. The matrix was evaluated and analyzed with repeated, constant power, and daily rainfall return period. Next, the return periods of 2 to 5 day rainfall days and the return period of1 day dry days, were also evaluated. Then,the return period of the continuation of 2 to 5 day precipitation days for twelve months of the year was calculated. The results showed that the probability of precipitation occurrence (wet days) per day was %0.1167 and the probability of no precipitation occurrence (drydays) was %0.8833. It was also determined that the most probable occurrence of rainy days was during the winter, especially in January and February. For example, the return period of 2 consecutive rainy days in January was estimated to be nearly 5 days. Therefore, it was observed that Shiraz precipitation has a heterogeneoustime distribution. In other words, precipitation is not uniform and concentrated in Shiraz.
Ahmad Sahraei Juibari; Issa Ebrahimzadeh
Abstract
Basically, land use planning is the most important issue of sustainable urban development and is one of the main priorities in urban planning. District 47 of Zahedan city has been inadequate in terms of the proportionality and optimal distribution of uses, therefore, the present study was conducted to ...
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Basically, land use planning is the most important issue of sustainable urban development and is one of the main priorities in urban planning. District 47 of Zahedan city has been inadequate in terms of the proportionality and optimal distribution of uses, therefore, the present study was conducted to identify these shortcomings in order to implement social justice that should be realized at all levels of the city and among all citizens. In order to achieve this, effecient methods have been devised that can help planners in optimal decision-making.In this research, in addition to reviewing theoretical perspectives, the use of these efficient techniques in planning for urban land use was undertaken and planning support systems such as "what-if", which is one of these methods, were used as a dynamic planning system based on GIS. In this method, three analytical phases of land feasibility, predicting the demand for urban uses, and allocating lands for land use demands were performed, and various future shapes of each area were analyzed through different allocation scenarios.Finally,with the formation of the UAZ layer and weighting by AHP method, the best places to deploythe required uses for the provision of urban services inZahedandistrict 47 were proposed as the final map. The finding results obtained from the produced maps of the performance range and the inconsistencies indicate that the level of provision of services and urban facilities for the residents of this neighborhood is appropriate comparedto the current standards within the country.In order to optimize new applications with regard to the standards and functions required, these functional points were proposed and mapped, which should be used as a priority for the deployment of new uses in this district.
Seyyed Vahid Razavi Termeh; Mohammad Reza Malek
Abstract
Extended Abstract
Introduction
Over time, spatial data has evolved from paper maps to Web GIS through digital mapping and finally to the current generation of GIS. Although this new interface has enhanced user’s insights about spatial information, it still needs more tangible interface that ...
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Extended Abstract
Introduction
Over time, spatial data has evolved from paper maps to Web GIS through digital mapping and finally to the current generation of GIS. Although this new interface has enhanced user’s insights about spatial information, it still needs more tangible interface that can be usable to the public and enhance human interactions with the environment and spatial objects. Combining real and virtual worlds, Augmented Reality (AR) systems can make more tangible experience with real world objects. These activities relies on the dynamic working environments. Therefore it is important to consider the users environment and its changing through context-awareness. Context-awareness is any kind of information about user’s status and its estimation allows to integrate the context with the happening changes. AR is a combination of real vision with virtual content in real–time and acts as an interface to increase user insight of the real world and interaction with it. With increasing information in the AR, the usefulness and readability of information decreases and the details and their display should also be subject to certain conditions. To overcome this problem, we offer the combination of AR with context-awareness. Hence, in this study, The AR representation varies according to the user’s context. The increasing use of sensors, their hardware and software enhancements, and growth and development of communication networks have led to development of context-aware computing. Context-aware computing is rooted in processing anywhere and anytime, and aims at understanding environmental changes in computer systems so that computers can understand and respond to their environment. The small screen, low bandwidth, interaction problems, and user’s quick need to obtain response from service have driven services to provide information based on users and their environments. Nowadays, in most location planning applications, they try to use directional data besides location data. By using this information, better interaction and information are provided to user. The activities performed depend on user’s dynamic work environment, so by using context-aware knowledge, the environment and user environment changes receive more attention. The output of old programs was based on specific input and did not consider context change.
Materials & Methods
By increasing the amount of realistic information, simultaneous provision of all information will not only reduce the usefulness and readability of information, but also details and their presentation. In order to overcome the problem, we have used a context-aware augmented reality that displays the necessary information according to actual increase in user’s context. Specially in the domain of spatial services, given the massive amount of the available information and simultaneous provision of data in real-time due to small display of associated equipment make visual distraction for user, so by using context-awareness, useful and proper information can be provided to the user. Having the vulnerability maps, specifically about buildings in the region of interest is a necessary requirement for any rescue and relief teams after earthquake. Due to the lack of immediate access to earthquake vulnerability maps, it is necessary to provide an intelligible context information system for displaying vulnerabilities of building with the help of augmented reality. In general, any type of navigation issue, information about building vulnerabilities to select safe paths or temporary accommodation is required. In order to implement such information system, three contexts, i.e. distance, direction and time for presenting information in augmented reality was studied. To this purpose, after zoning vulnerability caused by earthquake in Tehran, Donyaye-Noor business complex was used as the case study and information system was considered with three contexts for given site. In order to evaluate the presented system, our context-aware augmented reality system was compared with an augmented reality system alone.
Results & Discussion
Results of evaluation show that combination of augmented reality and context-aware can reveal suitable information by considering the user context, while data presentation in augmented reality is monotonic and there is no dynamism in changing information display. The results of evaluating combined augmented reality system with context-awareness compared with augmented reality alone show that context-aware augmented reality system is more active and always reveals more adopted information to the user regarding environmental dynamics. While information is uniform and does not change in augmented reality.
Conclusion
Using the context-aware spatial information system, the user can take different decisions under different circumstances or gain extra information about other context such as time, velocity, acceleration. To better understanding augmented reality, certain graphical forms can be used. Displaying vulnerability by augmented reality can be a tool for ordinary users or specialists in the field of urban design and management, without the need for mapping and map reading knowledge in managing important centers and building in low-risk areas. The results of integrated system evaluation from various users indicate the system’s performance is superior to augmented reality system alone.
Zohreh Fanni; Seyyed MohammadReza Ghashami
Abstract
Extended Abstract
Introduction
The natural behaviors of the human life environment where the settlements are constructed without recognizing and studying these behaviors are called hazards. The distinctive features of natural hazards are the changes in the hazard severity in different locations, as ...
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Extended Abstract
Introduction
The natural behaviors of the human life environment where the settlements are constructed without recognizing and studying these behaviors are called hazards. The distinctive features of natural hazards are the changes in the hazard severity in different locations, as in the urban environments, human activities along with greater vulnerability in the environment, aggravate the hazard and the extent of its occurrence. The city and its infrastructure development in providing security and various needs of human are of the most substantial areas for the development of social life. In general, identifying areas prone to hazards is a key tool for decision makers to reduce the damages caused by natural hazards. On the other hand, abstract study of the nature’s behaviors in the form of flood, earthquake, land slide and subsidence has always made managerial decision-makings difficult, so that avoiding the aggravating factors of a hazard has caused to get close to another hazard.
Objectives
The main objective of this study is to evaluate areas affected by these four natural hazards in all 22 Districts of Tehran City. In other words, this research with the aim of comprehensive and integrated zoning of hazards such as flood, earthquake, landslide and subsidence has proceeded to identify, evaluate and adjust the findings in the form of a comprehensive map of the susceptibility of these behaviors under the title of four environmental hazards within the 22 districts of Tehran city.
Discussion
Multiple-risk analysis, including a range of data, provides a more realistic model of the natural environment management. In this regard, studies have been conducted on the various approaches to analyze spatial data, how to create a combination of environmental hazards and how to determine their risk and vulnerability levels. To generate a probabilistic model, the basic assumption is that the risk level is determined by risk factors and possible hazards in the future, and with an emphasis on the past events. In this study, the creating and effective factors in environmental crises are related and calculated with each other with respect to several risks.
Research Methodology
One of the usual algebraic methods is the Analytic Hierarchy Process (AHP), which, as a weighted evaluation method, evaluates different scenarios and selects the best option by combining the qualitative and quantitative factors. The Analytic Hierarchy process as one of the multi-criteria decision-making methods provides the ground for performing applied spatial analyses by examining the effects of different factors in contradiction with each other. The research method is quantitative-analytical, and all the factors affecting the occurrence of each hazard have been identified and digitized in ArcGIS environment and modeled using Frequency Ratio (FR) model. Then, each of the four susceptibility maps was combined in fuzzy method and the final susceptibility map was classified into 5 classes of very high, high, moderate, low and very low susceptibility, and was extracted and presented as a map and a table.
Results
This research resulted in the production of the susceptibility zone map for more probable hazards including flood, earthquake, landslide, and subsidence of Tehran City in the separation of 22 Districts. This map includes several factors such as slope degree, slope direction, slope shape, elevation layers, distance from the river, distance from the road, distance from the fault, geology, land use, and the rain The result show that the effective factors in flood are the distance from the river, and the slope; the most effective factors in the destruction are the wasting of groundwater and eliminating the geotechnical properties of the soil; the most effective factors in the occurrence of earthquake are the distance from the major and minor faults which determine the length of major and minor faults. Based on the results of this research and their analyses in Tehran’s districts, areas with very high, high, moderate, low and very low susceptibility were observed. Then, considering this study, their percentages were calculated in each class and reported in the form of a table. Among the 22 districts of Tehran city, districts 1, 3, 18, 5, and 4 are more susceptible than the rest of districts and districts 9, 10, 11, 12, and 17 are less susceptible in terms of the four aforementioned hazards.
Therefore, it is recommended that the process of reinforcement and standardization of existing facilities and infrastructure to be implemented by prioritizing hazardous zones. Concerning the construction and development of new infrastructure and facilities, the occurrence and exacerbation of these natural hazards within the hazardous areas may be prevented by imposing restriction or not issuing construction permits.
Mojtaba Rahiminasab; Yazdan Amerian
Abstract
Extended Abstract Introduction Rain is one of the most important atmospheric phenomena affecting human life. Rainfall prediction is important for various purposes such as planning for agricultural activities, forecasting floods, monitoring drought and providing resources for consumable water. The rapid ...
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Extended Abstract Introduction Rain is one of the most important atmospheric phenomena affecting human life. Rainfall prediction is important for various purposes such as planning for agricultural activities, forecasting floods, monitoring drought and providing resources for consumable water. The rapid expansion of using artificial neural networks (ANNs) as an experimental and efficient model in various sciences including meteorology and climatology implies the high value of studying these types of models. Materials and methods The purpose of this paper is to predict the monthly rainfall in Iran, using the combination of artificial neural networks and extendedKalman filter. For this purpose, the monthly average rainfall data of about 180 synoptic stations spreading across the country were used during the years 1951 to 2016, then, the monthly rainfall was predicted for the year 2017 using the article’s method. Artificial neural networks are a method for the approximation of the functions and prediction of the future state of various systems. Artificial neural networks discover the law latent in them and transfer it into the network by processing the experimental data. The smallest processing unit of information in the artificial neural network is neuron that builds the bases for the application of neural networks. Each neural network consists of a number of nodes which are the neurons, and the communication weights that connect the nodes together. Input data is multiplied by their corresponding weights, and their sum is entered into the neurons. Each neuron has a transfer function. This input data passes through the transfer function and specifies the output value of the neuron. The back propagation algorithm is one of the most commonly used algorithms for teaching these networks, but the back propagation algorithm depends on the selection of the number of hidden neurons. Also, the convergence speed of the back propagation algorithm is very slow comparing with the proposed method in this paper, and is very sensitive to the noises present in the input and output data set, which is used for teaching the neural network. In addition, it has a poor performance in modeling the complex processes. One of the most famous methods to eliminate the aforementioned defects is the use of the Kalman filter. The Kalman filter contains a set of mathematical equations that performs a repeated process, prediction and updates, and is also an optimal tool in minimizing the covarianceof the estimated error. The leading neural network can be considered as a nonlinear dynamic system with synaptic weights and equate the teaching of the neural network with the problem of estimating the state of the nonlinear system. Therefore, the extended version of the Kalman filter can be used to estimate the adjustable parameters of the artificial neural network like the neural network weights. Results and discussion The climatic zonation of Iran was used for the data separation by the method of Coupon-Geiger which has been conducted by other researchers, and Iran was divided into eight climatic zones. This zonation divides Iran into dry and hot desert, dry and cold desert, dry and hot semi-desert, dry and cold semi-desert, moderate with dry and hot summers, rainy moderate with warm summers, snowy with dry and hotarm summers, snowy with dry and warm summers climates. This artificial neural network which has been taught by the extended Kalmanfilter, was used for the prediction in each of the climatic zones. A multi-layered artificial neural network with two hidden layers has been used. There are 10 neurons in each of the hidden layers, and 7 neurons in the input layer, which are the same numbers as the network inputs. The methodology is that the year and number of months, the average monthly temperature, the average monthly wind speed and the geographic location of the synoptic stations are considered as the input parameters, and the average monthly precipitation as the output parameter. The difference between the observed and the predicted values of the monthly precipitation in 2017 was calculated for all stations and was considered as an error. The Root Mean Square Error (RMSE) of these differences was calculated for the 8 climatic zones. The RMSE is lower for dry and hot desert climate than for dry and cold desert climate. This RMSE is lower for dry and cold semi-desert climate than for dry and hot semi-desert climate. The RMSE is lower for moderate climate with dry and hot summers than for moderate rainy climate with warm summers. The RMSE is lower for snowy climate with dry and hotsummers than for snowy climates with dry and warm summers. Conclusion In most cases, the RMSE for hot climates is less than others that represents the efficiency of the proposed method for the prediction of monthly precipitation in hot climates.
Mojtaba Yamani; Shahnaz Alizadeh
Abstract
Landfill location is one of the most important aspects of municipal solid waste management. Geomorphology is of great importance in optimal location due to its nature, which relates to the origin and development of landforms and their formation processes. Hashtgerd region with an area of 398 km2 is located ...
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Landfill location is one of the most important aspects of municipal solid waste management. Geomorphology is of great importance in optimal location due to its nature, which relates to the origin and development of landforms and their formation processes. Hashtgerd region with an area of 398 km2 is located south of Savojbolagh city of Alborz province. Due to its location on the alluvial cones of permanent rivers (Kordan) and high permeability of lands, the presense of surface water and groundwater layers sometimes at a low depth (less than 50 meters), population areas (urban and rural) and abundant agricultural lands, optimal landfill location in this area in a way that does not damage the surrounding environment is of great importance and necessity.The purpose of this research is optimal location of landfill in Hashtgerd area using AHP method and considering the geomorphologic parameters. The research method is analytical-comparative method. In this research, topographic maps of 1:25000 and geological maps of 1: 100000, as well as data related to groundwater in the study area were used and ArcGIS software was also used for analysis. In the present article, based on four main criteria, namely geology, hydrology, topology and land use, five areas were obtained for locating the landfill. The result of the research shows that the areas are perfectly suitable for landfill in the eastern and southern parts of the area around Mohammad Abad Afshar village and the areas in the western parts of the region are entirely inappropriate for landfill because of the location of population and agricultural areas and the groundwater low depth (7 to 32 m) in this part of the region.
Kia Bozorgmehr; Seyed Yaser Hakimdoost; Ali Mohammadpour Zeidi; Zahra Seydi
Abstract
Daily increase in the production of municipal waste is one of the most important factors threatening the health of the global environment. At present, burying the municipal waste is the most significant method of waste disposal in many countries, including Iran. The type of the research is developmental ...
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Daily increase in the production of municipal waste is one of the most important factors threatening the health of the global environment. At present, burying the municipal waste is the most significant method of waste disposal in many countries, including Iran. The type of the research is developmental and applied, and the method of investigation is descriptive and analytical.In this research, SPSS, 10 and ARC / GIS software were used for spatial and statistical analysis. The information gathering in this research was a library collection consisting of: sources of books and note-taking and the use of Internet articles, seminars and theses.The purpose of this paper is to determine the suitable location for burying municipal waste materials in Tonekabon city. In the process of locating land suitable for landfill, 9 information layers including layers of distance from urban and rural areas, groundwater level, distance from the river, land use, soil type, rainfall, distance from communication routes, land use and classified slope , were used in location operation using the overlapping process and the hierarchical analysis process (AHP) by extracting effective weights.Based on the results obtained in this research, 12.34 hectares of the total area of Tonekabon city is of extremely strong importance, which possess 0.12% of the area. Also, 1827.90 hectares of the area is of very strong significance, which holds 6.95% of the area. This is despite the fact that. 9904.82 ha of the area has a low priority in terms of importance which holds 37.70% of the area with medium importance and 7233.63 hectares of about 27.53% of the area.The region with a strong significance with an area of 7267.37 and 27.66%, and the region with very strong significance with an area of 1827.99 and 6.9%, have been taken into consideration for proposing landfill for the municipal solid waste materials.
Reza Aghataher; Mohammad Fallah Zezoli; Mehrdad Zarafshar; Mohsen Jafari
Abstract
The present research was conducted with the aim of locating the susceptible military centers and determining the favorable areas for its construction in a part of dense forests in Golestan province-Ali Abad Katoulcity, using the Analytical Hierarchy Process (AHP) and Geographic Information System (GIS). ...
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The present research was conducted with the aim of locating the susceptible military centers and determining the favorable areas for its construction in a part of dense forests in Golestan province-Ali Abad Katoulcity, using the Analytical Hierarchy Process (AHP) and Geographic Information System (GIS). For this purpose, using defense experts’ opinions, university professors, military experts and resources review, information layers, slope percentage, slope direction, elevation classes, distance from the canal network, distance from the road, distance from villages, lithology, density of vegetation and distance from urban areas as factors affecting the location of susceptible military centers in forest areas were identified and the aforementioned maps were prepared and digitized in the GIS environment.In the next step, standard AHP forms were prepared and assigned to different experts in order to weight and prioritize effective factors. Weighted forms were collected and each of them was analyzed separately in Expert Choice software and AHP module in Arc GIS 9.3 software. Finally, the weight of each of the criteria and sub-criteria related to the target was determined. The results of the evaluation showed that the three factors of distance from the city (0.321), distance from the road (0.217) and lithology (0.176) have had the most impacts on the location of the susceptible defense centers of the study area, while the density of the vegetation (0.023) and direction of slope (0.017) have had the least effects. Eventually, the final potential map of the susceptible defense centers was prepared using the AHP model in the GIS software environment, and was divided into four subcategories of low potential (9.07%), medium (41.8%), high (30.01%) and very high (19.13%).
Yunes Khosravi; Hassan Lashkari; Aliakbar Matkan; Hossein Asakareh
Abstract
Introduction
Survey of spatial relationships of environmental data is considered as one of themost important goalsof spatial statistics for analyzing the spatial patterns and understanding the spatial dependencies. In this context, the Exploratory Spatial Data Analysis (ESDA) could well provide methods ...
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Introduction
Survey of spatial relationships of environmental data is considered as one of themost important goalsof spatial statistics for analyzing the spatial patterns and understanding the spatial dependencies. In this context, the Exploratory Spatial Data Analysis (ESDA) could well provide methods for distinguishing betweenspatialrandomandnon-random patterns. Using the ESDA for analyzing the spatial autocorrelation of climatic elements is necessary to distinguish their changes and spatial distribution. The present research is aimed at explaining the use of ESDA to describethe spatial patterns ofwater vapor pressureas one of the most important climatic parameters. Water vapor pressure plays a crucial role in climate system as an important feedback variable associated with the earth’s energy balance and hydrologic cycle. This climatic parameter has an important rolein explaining the climate change or changes in climatic parameters, because: 1) It is the main sourceof rainfall in allweathersystems, 2) It suppliesthe latent heatin this process and controls the heat inthetroposphere, 3) It is the booster of the storm's speed and 4) It plays a major role in the dynamics of atmospheric circulation. So, determination and interpretation of the likely reasons of Water vapor pressure changes and its variability are vitally important for human as well as other living-beings.
Materials & Methods
The studied area, with about 360,200 km2 area, is located in the South and the Southwest of Iran and approximately between 25° 00'N and 34° 25'N latitudes and between 45° 38'E and 59° 17'E longitudes. Southern and southwestern parts of the studied area are located beside two massive sources of moisture, i.e. Persian Gulf and Oman Sea. The main mountain chain in the studied area is Zagros that extends from the northwest to the Southern part of the studied area. The Zagros mountainrange is responsible for the major portion of rain-producing air masses that enter the region from the Western and Northwestern sides, with relatively high amounts of rainfall. In this study, water vapor pressure data in pixels (dimension of 9×9 km) inthe time interval of 1981-2010 were collected by the Iranian Meteorological data website (http://www.weather.ir).To interpolate the water vapor pressure, Kriging Inverse Distance Weighting (IDW) and Radial Basis Functions (RBF) were tested and so after theerror validation, the optimum method (Ordinary Kriging with Gaussian method) was chosen. Considering the aim of this study, analyzing the spatial variability of WV in regional and local scale, the most important geographical features such as elevation, longitude, latitude, slope and other aspects were chosen. Topographical maps of the studied area were collected by the Geological Survey of Iran (http://www.gsi.ir). The Digital Elevation Model (DEM)with a 10 Km cell size was derived by mosaicking, geo-referencing, and editing these maps in Arc GIS 10.2 software, and the geographical features were prepared based on it. Moran's I, local Moran'sAnselin, and LISA were used asESDA’s approaches to analyze the spatial autocorrelation of water vapor pressure patterns based on climate parameters.
Results & Discussion
According to the cross validation, it was cleared thatthe optimum method for interpolation of water vapor pressureis Ordinary Kriging with Gaussian method. The results of Moran’s Istatistic showed that the water vapor pressure hasspatial structure and is distributed in cluster patternin the South and the Southwest of Iran. The monthly surveys showed thatthe spatial autocorrelation of water vapor pressure in warm months is higher than the cold months and therefore hasa greater tendency to cluster. The results alsoshowedthat the water vapor pressure is tending to disperse and non-clusterinspace in the South and SouthWest of Iran. The bivariate Moran's Istatistic for relation of water vapor pressure and longitude showed thestrong and positive spatial autocorrelation and also clustered pattern.
Conclusion
The monthly surveys showed that the spatial autocorrelation of water vapor pressure in warm months is higher than the cold months and is more tending towards clustering. The existence of such situation in most regions of the studied area in the warm seasons reflects the consistency and homogeneity in this seasons in relation to other seasons. The main reason for these circumstances may be the lack of non-diversification of input pressure systems in these seasons, climate uniformity and sustainability and effects of local systems. Over the time, the water vapor pressure in the South and Southwest of Iran has tended to be more dispersed and less clustering in space. The reason for this incident is not fully revealed but it may be attributed to topographical effects, changes in system positioning, land use changes, etc.Investigating the relationship between spatial distribution of water vapor pressure and geographical parameters showed that the relationship betweenwater vapor pressureand latitude,elevation and slope suggested adispersed and heterogeneousspatial distribution between them. The results of the bivariaterelationship betweenwater vapor pressureand other aspects suggested a discontinuous and random relation.
Amir Aghabalaei; Hamid Ebadi; Yasser Maghsoudi
Abstract
Extended Abstract Introduction Monitoring and assessment of the biosphere are two essential tasks at any scale. Based on this, forests play an important role in controlling the climate and the global carbon cycle. For this reason, biomass and consequently forest height are known as the key information ...
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Extended Abstract Introduction Monitoring and assessment of the biosphere are two essential tasks at any scale. Based on this, forests play an important role in controlling the climate and the global carbon cycle. For this reason, biomass and consequently forest height are known as the key information for forest monitoring. In the recent decade, several studies have shown that the Synthetic Aperture RADAR (SAR) imaging systems in Compact Polarimetry (CP) mode can overcome the disadvantages of Full Polarimetric (FP) SAR imaging systems and provide a good performance in various remote sensing applications such as monitoring and managing the important natural resources like forests. In this regard, a novel technique named Polarimetric Interferometry SAR (PolInSAR) has been further considered as a powerful tool for forest height estimation. Materials & Methods In this research, the performance of the Compact PolInSAR (C-PolInSAR) data in Dual Circular Polarization (DCP) mode has been investigated in order to retrieve the forest height. For this reason, the common methods which are used for forest height estimation including Digital Elevation Model (DEM) differential method, coherence amplitude inversion, and phase & coherence inversion methods were applied and implemented on these data. In all of the aforementioned methods, LL+RR and LR polarizations were considered as the selected channels for estimating the volumetric and ground coherences, respectively. Then, the estimated coherences were considered as the input parameters for all of the mentioned methods. Results & Discussion To evaluate the performance and the efficiency of C-PolInSAR data in DCP mode, the results obtained from these data were compared with those obtained from Full PolInSAR (F-PolInSAR) data. The results obtained in this study in two datasets simulated from PolSARProSim software in both L and P bands showed that the C-PolInSAR data in DCP mode yielded a similar result compared to the F-PolInSAR data for forest height estimation (when the HH+VV polarization is adopted as the ground backscattering), because, in this case the LL+RR and the LR polarizations are equal to the HV and the HH+VV polarizations, respectively, particularly, the C-PolInSAR data in DCP mode yielded 0.78 m and 0.55 m improvements for forest height estimation in L and P bands, respectively. In addition, all of the employed methods provided better and closer results compared to the real forest height (i.e. 18 m) in L band compared to P band, because the electromagnetic (EM) waves have a more penetration into the canopy in L band compared to P band. Thus, the attenuation of these waves is low and consequently the height estimation is more accurate. Without considering the used bands, the DEM method provided the lowest precision compared to other methods, because the HV (or LL+RR) phase center can lie anywhere between half the tree height and top of the canopy. The exact location of this phase depends on two vegetation parameters which are the wave mean attenuation and the vertical canopy structure variations. In this case, the trees have very thin canopies, and consequently, the attenuation is small, but the phase center is high due to the structure. In other words, when the canopy extends over the entire forest height, then the phase center can be at half the true height for low density (low attenuation), through to the top of the canopy for dense vegetation (high attenuation). This ambiguity is inherent in single baseline methods, and in order to overcome this, model-based correction methods need to be employed. It was also observed that the coherence amplitude method is among the weak algorithms due to ignoring the phase and its sensitivity to the attenuation and structural variations but it can be used as a backup solution when other approaches fail. Finally, the phase and the coherence inversion method had better results than two aforementioned methods for the forest height estimation. In this method, selecting the factor ‘’ is very important and it should be selected in a way to be strong towards the attenuation changes. In this study, = 0.4 was adopted to maintain the height error variations. Conclusion As the final result, the C-PolInSAR data can be an efficient strategy due to its performance, when the full polarimetric imaging systems are either limited or not available. Moreover, utilizing these data in long wavelengths (e.g. P band) is more appropriate due to the effect of the Faraday rotation on the transmitted polarization.
Bahram Choubin; karim solaimani; Mahmoud Habibnejad Roshan; Arash Malekian
Abstract
Extended abstract
Introduction
Management of watersheds requires understanding of watershed conditions both in gauged and ungaugedbasins. The classification of watersheds by similarcharacteristics for the implementation of coordinated watershed operations and flood control as well as giving priority ...
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Extended abstract
Introduction
Management of watersheds requires understanding of watershed conditions both in gauged and ungaugedbasins. The classification of watersheds by similarcharacteristics for the implementation of coordinated watershed operations and flood control as well as giving priority to sub-basinsis of great importance. The need for a classification framework in hydrology is not an entirely new subject. In fact, this subject has long been discussed and several studies have also attempted to advance this idea. So far, no acceptedcomprehensive protocol has been presented for the classification of watersheds,and questions can be raised regarding why this has not happened. More efforts must be made in order to develop such a classification.Previous studies have used hard clustering methods more, for the classification of watersheds but, the present study used fuzzy approach as asoft method. In general, the purpose of this research is to focus on the characteristics of the watersheds including morphological characteristics, soil and land use for the identification of similar watersheds. These parameters can facilitate the watershed classification scheme and our understanding ofthe watershed conditions.
Materials & Methods
The dataset for this study includes is base maps (sub-watersheds boundary, streams and rivers, digital elevation model (DEM), soil and landuse which have been collected from Iran Water Resources Management Company. To classify the Karkheh watershed, 35 spatio-physical indices including topographic, morphological, landuse characteristics and soil parameters were considered. These indices have been calculated for each watershed. The dimension reduction of the variables was an important part, because 35 indices were quite large for the classification of 38 watersheds. Therefore, factor analysis for each group of indices wasusedseparately to reduce the number of variables.
After reducing the variables and selecting the final indices, the fuzzy clustering approach was conducted to classify the watersheds into homogenous groups. The number of optimal clusterswas determined through trial and error and the functions of partition coefficient and partition entropy evaluation.
Results & Discussion
Kaiser-Meyer-Olkin (KMO) test statistics for each group of the morphological, landuse and soil indices were 0.71, 0.69 and 0.76 respectively, indicating that the data was suitable for factor analysis. Factor analysis was conducted using Principle Component Analysis (PCA) method and the results revealed that among 35 spatio-physical indices, 9 indices (4 morphological indices, 3 land use indices and 2 soil parameters) had a higher load factor than other indices. Therefore, indices of the watershed surface, basin elongation, average length of drainage network and total topographic indexamong the morphological indices;percentage indices of rangelands, agricultural lands and wastelandsamong the land use indices; and indices of water holding capacity in the soil layer and saturated hydraulic conductivity among the soil parameters were selected as the ultimate criteria for grouping the watersheds.
Theselectedfactors were normalized between zero and one before the classification. Then, sub-watersheds were classified using fuzzy C-mean (FCM) approach. The trial and error method was used to find thenumber of optimum clusters. The maximum amount of evaluation function of partition coefficient equal to 0.76 and the minimum amount of partition entropy function equal to 0.49 occurred in three clusterstherefore,the number of optimum clusters equal to 3 clusters was determined through trial and error.The results of classification indicated that the triple groups included the sub-watersheds of the northeastern regions and parts of central regions of the Karkheh watershed (group 1), the northwestern- southeasternalong with the southern regions of Karkheh watershed (group 2) and the central regions and parts of southwestern regions of Karkheh watershed (group 3).
Conclusion
Watershed classification with similar characteristics can be used as a method for watershed management, flood control and giving the priority to critical sub-basins. However, watershed classification is only completedwhenit is understood why some catchments belong to certain groups of hydrological behavior, so as to be possible to classify gauged and ungaugedwatersheds through it.
Finally, it is important to remember that classification of watersheds is not the “be-all and end-all” of research on watersheds, but rather only a means towards achieving broader aims of planning and management of our ecosystems, environment, water resources, and other relevant earth systems and resources. However, watershed classification certainly allows us to study catchments more effectively and efficiently and develop more appropriate strategies in terms of simplification in models/model development, generalization in our modeling approach, and improvement in communication both within the hydrologic community and across disciplines, as much as possible.
Mohsen Bakhtiari; Ali Darvishi Bolorani; Ataollah Abdollahi Kakroodi; Kazem Rangzan
Abstract
Extended Abstract Introduction Remote sensing has introduced new fields in monitoring and modeling environmental variables on different levels. One of the major advances of remote sensing is the use of quantitative algorithms to estimate the earth’s surface variables. Therefore, it can be regarded ...
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Extended Abstract Introduction Remote sensing has introduced new fields in monitoring and modeling environmental variables on different levels. One of the major advances of remote sensing is the use of quantitative algorithms to estimate the earth’s surface variables. Therefore, it can be regarded as a research and application framework in order to forecast and counteract devastating effects of environmental crisis. Meanwhile, capabilities of MODIS sensor in terms of its various products to estimate the environmental parameters have been explored more than any other remote sensing instruments. Optical remote sensing modeling techniques are robust and strong enough for modeling the relationship between land surface variables and the quantities measured by remote sensing data. Materials & Methods This research focuses on developing and introducing a new spectral index for modeling the Land Surface Temperature (LST) and vegetation, simultaneously. Land surface temperature is a key parameter in the balance physical processes of the Earth’s water and energy on different levels including from regional to local scales. On the other hand, studying the temporal and spatial variations of vegetation and temperature in different areas as an indicator showing the environmental conditions has the great importance for current and future behaviors of the surface. Therefore, combining these two parameters can lead to high synergies in the use of satellite data for studying the environmental status of the west Asia as the area is experiencing one of the most horrifying environmental degradations of the world. In order to evaluate the developed index, the spatial-temporal relationship of the Normalized Health Environmental Index (NHEI), in relation to the behavior of dust sources in the west Asia is investigated. The main steps of this study include the developing and introducing the remote sensing index that reflects the simultaneous behavior of environmental variables, trending the index based on its changes for the west Asia and finally applying that in studying dust sources of the studied region. The Normalized Health Environmental Index, (NHEI), is developed using MODIS products consisting of MYD11A2, MYD13A2 and MOD44W products. The developed index considers the spatiotemporal behavior of Land Surface Temperature (LST), and vegetation cover, simultaneously. This index is useful for monitoring the environmental health situation of lands by masking the surface water bodies. NEHI is a dimensionless parameter and the range of its values is between -1 to 1. The smaller values indicate that conditions in the region in terms of land surface temperature, vegetation, water and the environmental relevant phenomena are more critical. Results & Discussion NHEI was used to analyze the trend changes of the most important dust sources in the West Asia during last decade. Due to the high correlation between the results obtained from NHEI and the activities of the origins of dust storms, it can be adapted as a basis for modeling the behavior of these phenomena while such relationship has not been confirmed through applying the conventional indices such as NDVI. NHEI is developed and analyzed for 2002 to 2013. The trend of changes was detected by linear trending process and its relationship with dust sources has been evaluated. Since NHEI shows the changing trend of key elements of the environment, i.e. temperature, vegetation and humidity simultaneously, the results of trending reveal the general decrease of severity and extend of the index. While the distribution of dust storm hot spots in terms of the index values is showing more scattering for the whole of the west Asia. Although NHEI is not a pure physical parameter with certain and standard unit, however, because of reflecting the combined effects of NDVI and LST as well as its simplicity and strong correlation with environmental parameters, it can be used as a reliable reference index in the environment research at local and macro-scale. Then the values of NHEI within specific land covers were determined, so it has distinct values for different land covers. Conclusion This study emphasizes on NHEI capabilities in monitoring and modeling environmental variables associated with dust sources, therefore, the average of NHEI in dust sources individually and totally was significantly less and more critical than the value of NHEI in other areas of the study area. Generally, the results of this study can open a new horizon in the field of land surface variables modeling and investigation by developing new remote sensing indices especially in land degradation and dust storm investigations.
Geographic Data
Mostafa Mohamadi dehcheshme; Sohrab Ghaedi; Fereshteh shanbehpoor
Abstract
Extended AbstractIntroductionClimate change is the greatest threat to humanity, because it is the main factor in increasing the frequency and severity of atmospheric events such as droughts, floods, heat waves, etc. that are experienced today. Climate change can cause a wide range of environmental problems, ...
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Extended AbstractIntroductionClimate change is the greatest threat to humanity, because it is the main factor in increasing the frequency and severity of atmospheric events such as droughts, floods, heat waves, etc. that are experienced today. Climate change can cause a wide range of environmental problems, including severe drought and water scarcity, crop loss, and increased socioeconomic consequences. One way to identify climate change is to evaluate climate and temperature indicators. Based on statistical tests and time series of occurrence of these parameters in the long run, the status of change and its trend can be identified. Given the importance of the impact of climate change on all sectors, the study of the consequences of these changes requires the study of all sectors and effective factors with a systemic approach. One of the concerns of human society is the changes that have caused climate change due to global warming. In this regard, given the importance of climate change on all sectors, the study of the consequences of these changes requires the study of all sectors and factors with a systemic approach. Considering the importance of climate change and its effects, this study seeks to answer the following questions by considering important climatic parameters and vulnerable urban dimensions (economic, social, political, environmental):1- The trend of climate change changes (Temperature and rainfall, humidity, wind speed) what is it like in Ahvaz?2- What is the causal relationship between the causes of climate change and vulnerable sectors in the city of Ahvaz? 3- What are the effects and consequences of climate change on the city of Ahvaz?Materials & MethodsThe research methodology is based on statistical tests and qualitative modeling with a systemic approach. The present study analyzes the trend of changes in climatic parameters including temperature, precipitation, relative humidity, and wind speed for a period of 30 years (1991-2020) in Ahvaz using the statistical Mann-Kendall Test was examined. Then, using the science of system dynamics, the causal relationships between variables and structural modeling of the consequences of climate change in Vensim software are investigated. The main stage of using the system dynamics approach is to try to understand and identify the feedback loops of the system under study, for which purpose diagrams of causal loops are drawn. In this study, inputs are the factors that shape climate change are factors that affect the city system. System outputs will be the consequences of climate change.Results & DiscussionBased on the results of the analysis of the trend of climatic parameters, the city of Ahvaz in the study period has faced an increase in temperature, increase in relative humidity, decrease in wind speed, and decrease in rainfall. During the 30-year trend (1991-2020), the average rainfall has been (226) mm, each year (1.32) mm, has decreased and followed a downward trend. The average temperature has been (25.38) degrees Celsius, it has increased every year (by 0.051) degrees, which shows an increasing trend over 30 years. Based on the results, the average relative humidity was (41.1), which increased every year (0.007). Also, according to the results, the average wind speed is (2.65 m/s) and has decreased by about (0.018) every year. Therefore, the wind speed shows a decreasing trend over 30 years. Given that climate change refers to the spatial-temporal changes in the long-term average of climatic elements, the results of this study clearly showed that climatic parameters (temperature, relative humidity, precipitation, wind speed) in the study area have undergone fundamental changes. The consequences of climate change on all economic, social, political, and environmental aspects were evaluated. The results of qualitative modeling and causal relationship showed that climate change in Ahwaz has a direct impact on different sectors of water resources, agricultural production, and energy consumption. Variables of (reduction of water reserves upstream, extreme heat waves) are the most important leverage points of the model. Different outcomes have complex interactions with each other in such a way that they affect different economic, social, environmental, and political dimensions and ultimately intensify each other's effects on reducing the quality of life and increasing climate migration.ConclusionAs a result, climate change has consequences such as increasing unemployment, reducing the quality of life, reducing urban resilience, and ultimately increasing climate migration in the city of Ahvaz, and the urban environment is not equipped to adapt to climate change.
Seyedeh Sareh Dabiri; Mohammad Taleai; Ghasem Javadi
Abstract
Introduction
The study of the areas with geothermal energy potential is of particular importance in realizing the goals ofsustainable development. Areas with geothermal potential areof great importance in terms of application as renewable energy resources, tourist attraction, greenhouse construction, ...
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Introduction
The study of the areas with geothermal energy potential is of particular importance in realizing the goals ofsustainable development. Areas with geothermal potential areof great importance in terms of application as renewable energy resources, tourist attraction, greenhouse construction, etc.Generally, in geothermal exploration projects, studies are initially carried out with regard to the existing indicators, and the outcome of the primary location is used for more detailed studies. The identification of the areas with geothermal potential, which is the first phase of geothermal energy exploration, is complex and difficult.
Determining areas with geothermal energypotential as a basis for clean and environment friendly natural energyexploration studies, is important for achieving sustainable development. The purpose of this paper is to identify the areas with geothermal potential with regard to the characteristics of the northwest regions of Iran and the application of Geospatial Information Systems and Multi-criteria analysis methods, which have many advantages in the field of exploring the regions with geothermal potential.
In this study, the spatial Multi-criteria analysis package of ILWIS software and also the decision-making method based on the Ordered Weighted Average (OWA) in TerrSet(IDRISI) software have been used
Different scenarios of decision-making were implemented in the case study area and, the results were compared with the location of hot water springs in the region. The results indicate that the location of the determined sites is close to the hot water springs, which confirms the results of the proposed model of the paper.
Materials & Methods
The study of geothermal energy with the help of the spatial information system has drawn the attention in recent years. The purpose of this paper is to study areas with geothermal potential in the northwestern regions of Iran. These regions have different effects on the Earthand the researchers of this field use these effects to find new methods for measuring geothermal resources (Yousefy, 2006). Nowadays, GIS-based MCDM techniques are effectively used in these types of studies. Therefore, it has been tried to use some of these techniques in this research. In addition to the novelty of the topic of the geothermal studies in Iran, the issue of modeling different decision-making scenarios has been taken into consideration fromthe pessimistic view (with low risk) to the optimistic one (with high risk). Therefore, in this research,areas with geothermal potential have been identified and compared, with the help of study with the help of spatial data and Multi-criteria decision-making methods. In this study, decision-making criteria are evaluated and selected usinglibrary studies from previous researches. Also, based on the weighting methods and the integration of criteria, 8 scenarios were produced and their results were compared with each other. Meanwhile, the weight of the criteria was calculated using questionnaires and the analytic hierarchy process (AHP) method. The Ordered Weighted Average (OWA) method was applied to create various scenarios. Figure-1 shows the stages of this research.
Results & Discussion
The two software (ILWIS and TerrSet), provide powerful tool for standardizing, weighting and integratingthe standard maps associated with the decision-making process. In the implementation stage, the maps are standardizedafter the preparation of thestandard maps in the acceptable format of each software. In this study, fuzzy and AHP methods were used for standardization and weighting,respectively. Finally, the input factors are integrated according to different scenarios. The results are shown in Fig-8. In order to evaluate the results, the geothermal map produced based on the model proposed in this article has been compared with the location of hot water springs. The results of most scenarios show that, hot water springs are generally located in two classes with high suitability which confirms the results of the research. In Fig-9, hot springs are located in the classes with high suitability, as it was expected. This means that the results of this research are acceptable. Adaptation and compatibility of the geothermal map and the existing situation provide the possibility of using the results of the case study area in the exploration studies of other regions.
Conclusion
In this research, multi-criteria decision-making based on the use of GIS tool was used as a feasibility study in the first phase of geothermal exploration. The layers were processed and using theAHP-OWA integration methods in the 8 scenarios, they were integrated and the obtained results were investigated and compared. In most scenarios, hot water springs are in suitable or very suitable classes. This reflects the acceptable results obtained from the proposed modeling of this research.
Kourosh Mohammadkhani; Samaneh Nazif
Abstract
Extended Abstract Introduction Topographic maps are source mapson whichdetails of geographical features and ground-based phenomena are displayed. To exhibit these phenomenaand visualize their geometric shapes, contour lines are used. In archaeology, topographic maps are used to exhibit not only relief, ...
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Extended Abstract Introduction Topographic maps are source mapson whichdetails of geographical features and ground-based phenomena are displayed. To exhibit these phenomenaand visualize their geometric shapes, contour lines are used. In archaeology, topographic maps are used to exhibit not only relief, but also layout of ancient structures and remains, buildings, archaeological excavation trenches, layout of squares used for geophysical data collection and, in general, location and layout ofanyinformation necessary for different interdisciplinary studies, including the layout of electrical catheterization profiles, geological sectionslayout, and botanical pollen sampling locations. Topographic maps are also usedto systematically study ancient sites and hills and prepare a dispersion and distribution map of sherdsremaining from ancient potteries.However, the application of topographic surveys in archaeology is muchmore extensive than only preparation of topographic maps. With an engineering and technical perspective, surveyors only collect visible geographic features, whereas the smallest features on an ancient site can be a possible sign of architectural structure. Thus in general, all reliefs or ditches are important in an ancient site. Materials & Methods Pasargadae World Heritage Site, in which the first scientific research beganin 1928, contains monumentsstill hidden from all archaeologists’ sights. Since then, many maps have been preparedfor this site by Herzfeld, Sami, Stronach, Pasargadae Parse Research Foundation, etc.all of which were confined to the layout of existing buildings and hills. The first topographic surveys in an ancient site were carried out at the Pasargadae World Heritage Site by ajoint Iranian - French board in 2015. In the first season, surveys were performedusing Theodolite and Total Station Camera, but because of the limitations of these types of cameras, Differential Global Positioning Systems (DGPS) with 2 and 3 frequency bands andreal time correction possibility were usedin the second and third seasons of the surveys. Inductive research method was used in this research, and data was collectedbased on library research and field observations. First, a brief history of Pasargadae Tol-e Takht and the archaeological activities carried out on this site is provided. Then, discussing GPS and topographic maps, related advanced equipment is introduced. Afterwards, topographic surveys in this historical site are discussed. Results & Discussion As mentioned before, anarchaeologically-minded surveyor looks at hills or ancient sitesfrom a regional perspective. In addition to ancient hills, surveyors collect information about all natural and artificial geographical features in the environment, including agricultural lands, water resources, geological structures, region’s erosive dynamics such as gullies, and dispersion of all rubbles, megaliths and slate rock.For example, the presence of several stones in close proximity is usually not very important to surveyors, but can be a sign of an architectural structure or a grave structure for an archaeologist.In topographic surveys, we simultaneously carry out mapping and archaeological activities; we are archaeologists carrying out a systematic archaeological survey on the site, and producing map of the area. An archaeologically-minded surveyor, moves around a site, pays attention to the remains of walls and architectural structures, remains of graves and ancient fireplaces, outcrop of large slate rock in ancient hills, remains of canals built in the site at the present or in the past, areas in which there is an aggregation of pottery and stone pieces, and in general, the smallest slopes and features, and collect these points using GPS.In fact, techniques of topographic survey help archaeologist toproduce accurate maps and discover hidden elements that are notusually noticed in mapping. Conclusion Results indicate that with the help of the topographic survey team and advanced technologies,some structures were identified in the Pasargadae World Heritage Site that had been hidden from archeologists to this day, despitethe long history of the presence of reputable and world renowned archaeologists in this site.In fact, one of the main questions of archaeologists was related to empty spaces among the structures in Pasargadae site. Topographic surveys of the area have led to the discovery of new walls and architectural structures on the southern and northern slopes of Tol-e Takht. In addition, the discovery of some regular buildings behind Tol-e Takht, the new rampart and several graves around Tol-e Takht and scattered walls on the hill opposite Solomon’s Prison and inside the site, are also results of topographic surveys at Pasargadae. Also, with the help of these surveys, two areas used forhuman settlementwere identified at Pasargadae site.
Mohsen Rezaee Arefi
Volume 21, Issue 84 , February 2013, , Pages 95-104
Abstract
Watershed management and water and soil preserving activities are used to eliminate the ill-effects of improper utilization of natural resources. But evalution of watershed management treatments in targeting goals has not yet been scientifically and logically conducted in Iran. In this article watershed ...
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Watershed management and water and soil preserving activities are used to eliminate the ill-effects of improper utilization of natural resources. But evalution of watershed management treatments in targeting goals has not yet been scientifically and logically conducted in Iran. In this article watershed management activities in part of Bande-qora watershed of kashmar which comprises almost 1200 hectares and a population of 834 people was studied. Watershed management activitied in the area started in 1379 and was finished in 1383 with regard to budjet allocation to Khorasan. Watershed management activities in Band-e-qora watershed caused flood control, ground water feeding, decreasing water turbidity and finally caused increased crop rate in the region. These activities affect, crops, migration rate and uncultivated lands utilization. In the study case, watershed management activities include biological and biomechnical operations. Mechanical watershed activities were successful but biological activities did not succeed. Biomechemical activities were also successful.
Extraction, processing, production and display of geographic data
Qadir Ashournejad
Abstract
Extended AbstractIntroductionRemote sensing is considered as the most important source of spatial data in the current era, which we witness its increasing development in different dimensions. The release of global products of these data in recent years with the aim of easier access and use by experts ...
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Extended AbstractIntroductionRemote sensing is considered as the most important source of spatial data in the current era, which we witness its increasing development in different dimensions. The release of global products of these data in recent years with the aim of easier access and use by experts in geospatial science is one of the dimensions of this development. The land cover product is one of these products that is used more than other remote sensing products. When presenting these products, their qualitative and quantitative characteristics, including their global accuracy, are also published. Expressing the accuracy of these products globally makes it necessary and necessary to re-evaluate their accuracy regionally for the users of these products in different regions of the world.Materials & MethodsIn this research, the accuracy of the European Space Agency's Copernicus Global Land Service (CGLS), GlobeLand30 and Esri's land cover product were evaluated for regional use in the north of Iran - Mazandaran province. After calculating the area of the classes for each of the land cover products, Pearson's correlation coefficient was used to calculate the correlation between them. For quantitative evaluation, the error matrix was used as one of the most common ways to evaluate the accuracy of land cover products. This method is based on the comparison of classified data and ground reality data. Also, the categorized random sampling method was used to select 1329 evaluation samples in Mazandaran province. For visual evaluation, three areas with dimensions of 6 x 6 km were selected.Results & DiscussionThe regional accuracy evaluation of the studied products shows opposite results compared to the global accuracy of these products. Based on the global accuracy reported for the studied products, the highest accuracy is calculated for the Esri product at 86%, followed by GlobeLand30 and CGLS at 83-85 and 80%. Meanwhile, based on the regional accuracy obtained from the results of this research, the highest regional accuracy for the CGLS product has been calculated at 84% and then for GlobeLand30 and Esri products at 81 and 75%. In evaluating the regional accuracy of the classes, all three studied products (CGLS, GlobeLand30 and Esri) have acceptable accuracy (above 90%) in the classes of snow and ice (100, 100 and 100%), forest (90, 95 and 98 percent), water (96, 94 and 90 percent) and impervious surface (94, 91 and 90 percent). For the agricultural class, accuracy equal to 92, 69 and 84% was obtained for CGLS, GlobeLand30 and Esri land covers.In the 3 classes of shrubland, Impervious surface and wetland, the accuracy results are less than other classes for all three land cover products and in the amount of (29, 0 and 13 percent), (65, 66 and 42 percent) and (67, 38 and 0 percent).Conclusion By evaluating and comparing the regional accuracy of three CGLS products, GlobeLand30 and Esri, this research answered the question of whether the accuracy stated in global land cover products can be trusted for regional studies and planning. The results show that the regional accuracy of CGLS, GlobeLand30, and Esri are 84, 81, and 75 percent, respectively, compared to their global accuracy (80, 83, 85, and 86 percent). These results show the difference obtained for the Esri product more than the two products CGLS and GlobeLand30. Meanwhile, the remote sensing data used for the Esri product (Sentinel-2 data) and its pixel size (10 meters) are of higher quality and quantity than the other two products. In fact, these results show that only paying attention to the type of data used and the global accuracy is not enough to use products in regional scales and requires evaluations before using them.In addition, by evaluating the classes of each product and comparing them, the need for this evaluation before using these products seems necessary. The results showed that in the evaluation of the regional accuracy of the classes, all three studied products had an accuracy of over 90% in the classes of snow and ice, forest, water areas and human construction. For the agricultural land class, accuracy equal to 92, 69 and 84% was obtained for CGLS, GlobeLand30 and Esri land covers. In the 3 classes of shrubland, herbaceous cover and wetland, the results show lower accuracy than other classes for all three land cover products. Significant results were also obtained in the visual evaluation, and it seems necessary to pay attention to this evaluation before the applications where it is important to pay attention to a particular class.
Mohammadtaghi Rahnamaei; Bahman Ramezani; Sahar sadat Ziabary
Volume 22, Issue 85 , May 2013, , Pages 97-109
Abstract
Gilan is on the most important tourism province, it has more touristy potentials and for its efficiency has needed to recognize and introduce to friendly ecotourism society and adventuring tourism, Nowadays Cave tourism is a scientific and cultural research, such as adventure tourism, Cavelogy. Cave ...
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Gilan is on the most important tourism province, it has more touristy potentials and for its efficiency has needed to recognize and introduce to friendly ecotourism society and adventuring tourism, Nowadays Cave tourism is a scientific and cultural research, such as adventure tourism, Cavelogy. Cave touristy in Gilan is less studied but it can causes to more income and occupation this area. The aim of this paper is recognition potentials touristy and limitation problems of Aveeshoo cave in Masal.
The method of this paper is descriptive analysis with field observation and library documents. The result of this paper has shown that, the Aveeshoo Cave has more potential in development of ecotourism, economical and social culturaing in the area and in the Country.
Spatial planning with regard to military defense
Ebrahim Amou; Ahmad Pourahmad; Seyyed Abbas Rajaei
Abstract
Extended abstractIntroductionCivilians and cities have always been affected by war. However, World War II was the first war in which military strategies succeeded in systematically destroying cities and killing civilian populations on a large scale. It was no coincidence that atomic bombs were also dropped ...
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Extended abstractIntroductionCivilians and cities have always been affected by war. However, World War II was the first war in which military strategies succeeded in systematically destroying cities and killing civilian populations on a large scale. It was no coincidence that atomic bombs were also dropped on cities. In the eyes of policymakers and experts, urban safety and security is one of the most basic assumptions of the global community for human-centered planning. Humans have always faced threats in their lives and constructions and have experienced all kinds of accidents throughout history. One of the basic ways to prepare for crises is to be aware of the degree of vulnerability of the city, especially residential buildings, in case it occurs. Therefore, knowing the degree of vulnerability of urban buildings caused by threats, it is possible to increase the preparedness against any threat to a great extent by adopting strategies. Identifying the risk of possible damages plays an important role in prevention and preparation to face and deal with the negative effects of urban threats and is very important in terms of controlling human and financial damages.Materials & MethodsIn this research, considering the theoretical issues and the examination of global experiences regarding the vulnerability of residential areas against invasion, vulnerability criteria were extracted and completed using the Delphi method. After selecting the criteria and sub-criteria for weight calculation, using the Dematel method, factors that are effective in residential vulnerability have been used. The main goal of the Delphi method is to achieve the most reliable consensus of a group of experts' opinions through a series of focused questionnaires with controlled feedback. By obtaining the consensus of a group of experts through this process, researchers can identify and prioritize issues and develop a framework for their diagnosis. In this research, Delphi panel members were selected as non-probability and combination of targeted or judgmental and chain methods. In this research, Kendall's correlation coefficient was used to determine the level of consensus among panel members. The value of this scale is equal to one when there is complete coordination and zero when there is no complete coordination. Kendall's correlation coefficient for this research was equal to 0.67, which can be trusted as a relatively moderate to high value according to the order of its factors. Building a network analysis process model requires knowing the relationships and interactions between the criteria and sub-criteria of the problem in order to create the most realistic state of the network, which was extracted in the previous stage through Dematel and with the opinions of experts. ANP includes determining the final weights using the method of extracting weight vectors and forming hypermatrix. Results & Discussion,The way of distribution of buildings in terms of floors and especially high-rises has created a special spatial system that has overcome all other urban elements and has turned the city into a compact structure. In terms of the quality of the houses, it can be said that due to the presence of dilapidated structures in the central part of the city as well as informal settlements in the peripheral areas, these houses are not of good quality and are highly vulnerable.From the point of view of passive defense, the passageways and the ability of the network to access the space and the conditions of sheltering are of special importance. Examining the map of vulnerability caused by the access network and access to open spaces in the residential areas of Tabriz shows that the central areas have narrow roads and high density and have high vulnerability. In discussing the vulnerability of residential areas in this research, population density and building density have been considered. By increasing population density in vulnerable areas with specific dimensions, the number of vulnerable population increases. According to the vulnerability map caused by the density of residential areas in Tabriz city, the population distribution is not the same throughout the city and dense population tissues are often located in the central areas and in the range of peripheral tissues (northern parts of the city) and are of high vulnerability. Has Distance and proximity to danger centers is very important in terms of passive defense. The location of these risk centers in the vicinity of human settlements makes it necessary to respect the privacy of these centers. The map of the privacy of dangerous centers in Tabriz shows that the residential areas of Tabriz are not in a good condition in terms of respecting the privacy of high-risk centers and will be highly vulnerable in the event of an attack. The access map of residential areas to relief centers in Tabriz city shows that the distribution of these centers is not balanced in all parts of the city and is mostly concentrated in the central parts of the city, which causes many problems with the influx of people in the event of a crisis. will face these centers. After the occurrence of crises, especially air raids that destroy people's shelters, the temporary accommodation of people is very important. One of the temporary accommodation centers that are considered are educational centers. Also, nowadays spaces are considered as multi-purpose parks and sheds that are used in normal conditions and are considered as temporary accommodation centers in times of crisis. The map of temporary accommodation centers in the city of Tabriz shows that, firstly, these centers are not evenly distributed in all parts of the city, and secondly, they do not have enough numbers according to the existing population. ConclusionMaps and research findings show that the residential density criterion with a weight of 0.356 is in the first place among residential vulnerability factors in Tabriz city. The second rank is assigned to the criterion of residential context with a weight of 0.257. Access criteria, access to relief centers, privacy of danger centers and temporary accommodation are in the next ranks respectively.
Remote Sensing (RS)
Heshmat Karami; Zahra Sayadi
Abstract
Extended AbstractIntroductionCoral reefs are one of the most diverse and ecologically important areas in the world. However, with increasing ocean temperatures, many coral reefs are severely threatened by bleaching events. When the water is too warm, corals expel the algae that live in their tissues, ...
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Extended AbstractIntroductionCoral reefs are one of the most diverse and ecologically important areas in the world. However, with increasing ocean temperatures, many coral reefs are severely threatened by bleaching events. When the water is too warm, corals expel the algae that live in their tissues, causing the coral to turn completely white. When a coral bleaches, it is not dead, and corals can survive a bleaching event, but they are more stressed and at risk of dying. Today, in order to predict and identify areas at risk of coral bleaching, data based on satellite remote sensing are used. In this research, using 35-year data trends, the sea surface temperature in 2022 was predicted using ArcGIS Pro tools for the Persian Gulf area and possible areas exposed to thermal stress leading to coral bleaching were identified.Materials & Methods In order to predict the bleaching of corals, the research data archive of the American National Center for Atmospheric Research (NCAR) has been used. In this analysis, the harmonic method was used to fit the trend line. A harmonic trendline is a periodically repeating curved line that is best used to describe data that follows a cyclical pattern. For anomaly analysis parameters, the average monthly temperature in each location was compared with the overall average temperature to identify anomalies. There are three mathematical methods for calculating anomaly values with the Anomaly function, in this research, the method of difference From mean was used. At the end, the dimension value or band index was extracted, in which a certain statistic is obtained for each pixel in a multi-dimensional or multi-band raster, and the final map of coral bleaching prediction was prepared, and then using the data and global maps of the National Oceanic Administration NOAA , it was evaluated.Results, discussion and conclusionThe preliminary results showed that the sea surface temperature has changed in the Persian Gulf. The range has experienced higher average temperatures since 1996, which could put the area at risk of coral bleaching. The minimum average temperature in the studied time period is 298.758 degrees Kelvin in 1991 and the maximum average temperature in 1399 is 300.737 degrees Kelvin. The parameters that were chosen for multidimensional data trend analysis include water surface temperature variable (SST) and time dimension. The obtained trend map (1980-2015) indicated that the northwestern regions of the Persian Gulf and a part of its south are more exposed to prolonged heat. In this study, frequency parameter 2 was used in the harmonic model, which uses the combination of the first-order linear harmonic curve and the second-order harmonic curve to fit the data. The accuracy of data trend fitting by harmonic regression function provided statistical parameters, R2=0.78 and RMSE=0.5. The value of R2 indicates that the observed value of sea surface temperature (SST) was predicted by the harmonic regression model by 78% and the rest remains undefined. This value of the determination coefficient confirmed the accuracy of the trend map. Another statistical parameter is the root mean square error, the lower the value, the better the fit. In the obtained results, the mean of this error is 0.5, which shows that the harmonic regression model can accurately predict the data. In this study, forecast data was analyzed to find locations where water temperatures remain warm for extended periods of time. In this context, first, anomalies in the data were calculated, anomaly or anomaly is the deviation of an observed value from its average value, and in the analysis, it shows areas that have a temperature higher than the average. As a result of this step, the anomalies in the data were calculated and the areas with higher temperature than the average were identified. In the predicted annual time frame (2022), the north-west and a part of the south of the Persian Gulf region will face a longer period of high temperature. To evaluate the accuracy of the results obtained from the analysis and the method used in predicting sea surface temperature and identifying anomalies (2022-09-03), they were compared with the maps of Nova organization on the same date and were confirmed. It is suggested that responsible organizations use methods based on remote sensing and trend analysis to assess the situation and prepare a risk map of coral reefs.
Geodesy
Seyyed Reza Ghaffari-Razin; Navid Hooshangi; Behzad Voosoghi
Abstract
Extended AbstractIntroduction The ionosphere extends from an altitude of 80 to more than 1000 km above the earth. Due to its electrical properties, this layer of the atmosphere has very important and fundamental effects on the electromagnetic waves passing through it. A parameter that can be used to ...
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Extended AbstractIntroduction The ionosphere extends from an altitude of 80 to more than 1000 km above the earth. Due to its electrical properties, this layer of the atmosphere has very important and fundamental effects on the electromagnetic waves passing through it. A parameter that can be used to study the ionosphere is the total electron content (TEC). This parameter is the sum of free electrons in a cylinder with a cross section of one square meter between the satellite and the receiver on the ground. The unit of TEC is electron per square meter (ele/m2). The TEC in the vertical direction is called VTEC. Usually, TEC is expressed in terms of TECU, which is equal to 1016 ele/m2.Different methods have been developed to model the TEC. The simplest and most practical method is to use observations of two-frequency receivers. If there is a proper station distribution, it is possible to obtain accurate TEC and model the ionosphere. The main innovation of this paper is in the long-term prediction of TEC in the period of severe solar activity, as well as the modeling of the ionosphere time series with the long-short term memory (LSTM) neural network model in the Iranian region. This model is used for the first time in Iran to model and predict the time series of the ionosphere. To check the capability of the new model in prediction of TEC in the conditions of severe solar activity, observations from 2007 to 2016 are used for training and the TEC in 2017 is predicted. All the observations are related to the Tehran GPS station, which is one of the stations of the IGS network. To evaluate the accuracy of the model presented in this paper, statistical indicators of relative error, correlation coefficient and root mean square error (RMSE) are used. Materials and MethodsLong-short term memory modelLong short-term memory (LSTM) neural network is a special type of recurrent neural network (RNN). RNN is a type of neural network that has internal memory; in other words, this network is a normal neural network that has a loop in its structure through which the output of the previous step, along with the new input, is entered into the network at each step. This loop helps the network to have the previous information along with the new information and can calculate the desired output based on this information’s. One of the problems of RNNs is the vanishing of the gradient when learning from long-term sequences, which reduces the ability to learn in the algorithm. LSTM networks are actually a type of RNNs that have had a change in their block (RNN Unit). This change makes LSTM recurrent neural networks able to manage long-term memory and not have the problem of gradient vanishing. Results and DiscussionAfter the training step, using the trained models, the VTEC value for 2017 has been estimated and compared with the VTEC values obtained from GPS as a reference observation, GIM and NeQuick models. For the test step, the parameters of correlation coefficient, RMSE and relative error were calculated and presented in table (1). It should be noted that the average of all days of 2017 is showed in this table. Also, VTEC values obtained from GPS are considered as reference observations in this table.Table 1. Statistical values of correlation coefficient, RMSE and relative error in the test step of 2017 for GRNN, LSTM, GIM and NeQuick models.The correlation coefficient value of LSTM model is higher than other models. Also, the values of RMSE and relative error of LSTM model are lower than other models. This model has the ability to show the ionosphere time series variations with an accuracy of about 87%. ConclusionAnalysis of the results of the correlation coefficient in 2017 for LSTM, GRNN, NeQuick and GIM models compared to the GPS-TEC was obtained as 0.84, 0.72, 0.77 and 0.71, respectively. The average annual relative error for these four models was calculated as 16.98%, 25.69%, 29.89% and 51.05% respectively. The results of the analysis showed that in the conditions of severe and quiet solar and geomagnetic activities, the accuracy and precision of the LSTM model is higher than the other models evaluated in this paper. The analysis of the coordinate components of Tehran station with PPP method showed that by using the model proposed in this paper, an improvement of about 5.19 to 56.23 mm can be seen in the coordinates of the station compared to other models.
Remote Sensing (RS)
Kolsoom Shokrilahizadeh; Hamed Naghavi; Morteza Ghobadi; Rahim Maleknia
Abstract
Extended Abstract
Introduction:
Urban green spaces constitute a pivotal component of urban ecosystems, offering a plethora of ecological benefits and services to cities. Augmenting these green patches within urban landscapes and establishing interconnected ecological networks therein represent viable ...
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Extended Abstract
Introduction:
Urban green spaces constitute a pivotal component of urban ecosystems, offering a plethora of ecological benefits and services to cities. Augmenting these green patches within urban landscapes and establishing interconnected ecological networks therein represent viable strategies to mitigate the adverse repercussions of inadequate urban development while bolstering urban environment resilience. In the past few decades, the landscape ecology paradigm has introduced innovative methodologies aimed at comprehending the intricacies of urban green space dynamics and how landscape configurations wield influence over the environmental processes within cities. This research, consequently, sets out with the intention of quantitatively assessing and dissecting the transformations transpiring within Khorramabad's urban green spaces. It does so by harnessing remote sensing data and leveraging landscape metrics to gain deeper insights into the urban landscape's evolution.
Materials & Methods:
The focus of this research centers on Khorramabad city, which serves as the capital of Lorestan province and holds the distinction of being the province's largest city in terms of both population and geographical expanse. Municipally zoned into three distinct regions, the study unfolds across two main phases. Initially, the endeavor involved the creation of comprehensive synoptic maps capturing Khorramabad city's green spaces. This process relied on satellite imagery, followed by a subsequent phase of scrutinizing these maps through the application of landscape metrics.
To execute this, satellite images from various sensors—namely TM, ETM+, and OLI on Landsat 5, 7, and 8 satellites—were harnessed for the years 1987, 2003, and 2019, respectively. These images underwent meticulous preprocessing, culminating in their classification using the maximum likelihood method within the ENVI software environment. To validate the accuracy of the resultant maps, an error matrix was employed. In order to model the quantitative alterations and patterns within Khorramabad's urban green spaces, landscape metrics were harnessed. Notably, the Fragstat software facilitated the analysis of selected landscape metrics, which encompassed four key measures: class area (CA), number of patches (NP), percent of landscape (PLAND), and mean Euclidean nearest neighbor distance (ENN-MN).
Results:
The analysis of spatial-temporal changes in Khorramabad city's green spaces reveals an evident declining trend in their overall pattern. The outcomes underscore a substantial reduction both in the quantity of green patches and the area they encompass, dwindling from 703.8 hectares in 1987 to 629.88 hectares in 2019. Additionally, the investigation into landscape metrics' composition and distribution underscores an absence of cohesive dispersion on the city-wide scale. Within Khorramabad city, regions 1 and 3 exhibit inadequate green space composition and distribution. The computed metric for Class Area (CA) reflects a decrease from 195.66 hectares in 1987 to 191.63 hectares in 2003, further diminishing to 170.145 hectares by 2019. Correspondingly, the metric for Number of Patches (NP) indicates the lowest count of patches (33) in 1987, which escalated to 122 patches in 2003, and ultimately reaching 183 patches by 2019. Moreover, Proportion of Landscape (PLAND) data highlights that regions 3 and 2 demonstrate the highest (19.45%) and lowest (7.18%) green area proportions, respectively. Notably, the PLAND metric underwent modification from 229.81 meters in 1987 to 88.47 meters in 2003, further diminishing to 78.65 meters in 2019. The findings underscore deficiencies in Khorramabad city's urban green spaces, indicating a lack of favorable conditions for their development.
Conclusion:
The research conducted an assessment of urban green spaces within the urban areas of Khorramabad, utilizing remote sensing data and landscape metrics. The findings indicated a consistent downward trend in the overall extent of green spaces in Khorramabad city over various years. The distribution of green patches within the city was deemed relatively inappropriate, lacking an optimal arrangement. To enhance the status of green spaces, there is a need to establish continuity between discrete green patches and smaller green areas. This study underscores the significance of prioritizing sustainable management for Khorramabad's urban green space, aiming to prevent its degradation. The study's limitation lies in its reliance on medium-resolution Landsat image data. Overcoming this constraint through the incorporation of high-resolution data holds promise, particularly for fragmented green spaces in urban areas.
Ali Baratian
Volume 11, Issue 44 , February 2002, , Pages 19-24
Abstract
Today, considering the many problems that drought has caused, the need to conduct studies to anticipate and counteract it seems critical. A careful study of this phenomenon requires comprehensive and specialized studies that will include all the factors that affect it. In this paper, the role of synoptic ...
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Today, considering the many problems that drought has caused, the need to conduct studies to anticipate and counteract it seems critical. A careful study of this phenomenon requires comprehensive and specialized studies that will include all the factors that affect it. In this paper, the role of synoptic factors that have created dry and wet periods in Hamadan province has been studied and synoptic maps are used to predict drought. In this research, the intensity of drought was determined using Gibbs and Moher method and rainfall indices and it was found that there was a good agreement between ICC coefficients and monthly intensities of drought occurred in Hamadan province within 500-850 HPA range.
Volume 1, Issue 4 , May 1992, , Pages 21-25
Abstract
Since religious places of Iran has been a specialty of the learned author and the producers of the encyclopedia, a special study in terms of geographic time in such places has been implemented, and the result of this study has been displayed through two graphs in the page 19, in one of which the number ...
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Since religious places of Iran has been a specialty of the learned author and the producers of the encyclopedia, a special study in terms of geographic time in such places has been implemented, and the result of this study has been displayed through two graphs in the page 19, in one of which the number of religious places at each half longitudinal degree, and in the other one at each half lattitudinal degree have been displayed.
Ali Sa'iidi
Volume 11, Issue 41 , May 2002, , Pages 24-26
Abstract
The country of the Islamic Republic of Iran has a very diverse climate due to geographical conditions such as changes of altitude, distance from the sea, and the long distance between north and south, which extends from latitudes of 30 degrees to 60 degrees of the north. Consequently, the humidity conditions ...
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The country of the Islamic Republic of Iran has a very diverse climate due to geographical conditions such as changes of altitude, distance from the sea, and the long distance between north and south, which extends from latitudes of 30 degrees to 60 degrees of the north. Consequently, the humidity conditions in this land range from ultra-dry to very wet areas. The rainfall level fluctuates in different parts of the country and varies greatly from year to year. Sequential droughts that are sometimes broken with exceptional rainfalls, cause the shortage and limitation of water resources.
Currently, due to the country's climate and water resources, population growth, demand for public welfare, urban and industrial health, as well as the allocation of water to the environment in recent years, water assumption in the country has increased, and today the main problem in our country is the chronic water shortage due to frequent droughts accompanied by increase in population. According to studies on water consumption structure in this research, water per capita changes and irrigation efficiency in agricultural lands based on comprehensive water plans of the country, the limitations and scarcity of water resources do not allow any increase of the area under cultivation. At the moment, saving and optimization of consumption is essential to meet the country's water needs.
Hosein Hataminejad
Volume 14, Issue 55 , November 2005, , Pages 26-33
Abstract
Looking at the history of Mashhad, it is noted that this city had been frequently invaded; therefore the construction of fortifications and guarding towers was essential for its protection against the attacks of enemies. Most geographers, tourists and military-political agents of foreign states have ...
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Looking at the history of Mashhad, it is noted that this city had been frequently invaded; therefore the construction of fortifications and guarding towers was essential for its protection against the attacks of enemies. Most geographers, tourists and military-political agents of foreign states have described Mashhad only in terms of its general appearance, and they have at most enumerated its defensive characteristics. Among various reports, sometimes we find the physical tissue of the city, which was disorganized, and we notice the street as the only public and important passage built on a regular basis. Considering the political-defensive role of Mashhad and the establishment of the governor or ruler of the whole region in this city, it is noticed that in addition to physical prominence of the shrine of Imam Reza, the governor's palace which was usually located in the Ark of this city, has been also distinctive in comparison with other urban structures.
Esmaeil Shahkouei
Volume 11, Issue 42 , August 2002, , Pages 27-33
Abstract
Flood means a sudden overflow of water due to hydro-climatic and hydrological conditions, severe rains, and damages to dams in different areas of the earth.Evidence suggests that life and financial losses caused by flood are more than other natural disasters. Today the estimation of maximum flood and ...
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Flood means a sudden overflow of water due to hydro-climatic and hydrological conditions, severe rains, and damages to dams in different areas of the earth.Evidence suggests that life and financial losses caused by flood are more than other natural disasters. Today the estimation of maximum flood and its prediction before occurrence are among the important issues discussed in hydrology; nevertheless, with increasing population growth and development of industry and the subsequent occupation of the lands adjacent to rivers, the losses caused by flood have not only not diminished, but are constantly increasing.What is certain is that flood is caused by rain, but studies show that there is no linear and direct relationship between these two factors. Climate, natural and geographical conditions of a region are among the main factors that contribute to the disruption of this relationship.
Robin Crodd
Volume 3, Issue 12 , February 1994, , Pages 28-34
Abstract
Launching into space The countdown is running out. Check seat belts, attachments and connections. Five-four-three-two-one-zero- with hearing a tremendous sound, feeling the heat of rockets, we pass their fire, and start the journey into space. In less than a minute, the clouds are split and the sky changes ...
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Launching into space The countdown is running out. Check seat belts, attachments and connections. Five-four-three-two-one-zero- with hearing a tremendous sound, feeling the heat of rockets, we pass their fire, and start the journey into space. In less than a minute, the clouds are split and the sky changes from blue to black. As the rockets work, it speeds up and goes up, and when they stop, we are in space.
Fatemeh Razi'ei (Translator)
Volume 8, Issue 29 , May 1999, , Pages 30-41
Abstract
OEEPE has participated in preparation and implementation of tests for comparison of different geocoding methods, ERS-1 SPR data and application of geocoded SAR. ESA has presented data and confirmed the tests. DRL has collected and distributed data.
EFAE presented other data of the second phase of project; ...
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OEEPE has participated in preparation and implementation of tests for comparison of different geocoding methods, ERS-1 SPR data and application of geocoded SAR. ESA has presented data and confirmed the tests. DRL has collected and distributed data.
EFAE presented other data of the second phase of project; these data included: KF-1000 images, Thematic Mapper data and DEM (digital elevation model). The location of the test was in Frankfurt, Germany and the images of four ERS-1s along with two DEMs and ground control information can be presented.
Twenty organizations from European and North American countries expressed interest in testing data. These data were sent to fourteen different organizations. Reports by A number of these organizations were presented at the fourth Geo SAR station.
These reports clarify the aims of the test and describe presented data. The methods and results are summarized and participants and supplementary articles examine the case thoroughly. It was concluded from the test that Geocoding can provide high precision in comparison with maps in cases where the volume of information related to surveying is limited.
Alireza Azmudeh Ardalaan
Volume 1, Issue 2 , February 1990, , Pages 30-31
Abstract
TM sensor information is a peerless tool for ecologists, including in the estimation of the damage caused by fire. The two pictures that can be seen show the US Yellowstone National Park. These images result from the combination of data for band 7 (within the range of the red spectrum), 5 (within the ...
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TM sensor information is a peerless tool for ecologists, including in the estimation of the damage caused by fire. The two pictures that can be seen show the US Yellowstone National Park. These images result from the combination of data for band 7 (within the range of the red spectrum), 5 (within the range of the green spectrum), and 3 (within the range of the blue spectrum). By comparing these two images, it is possible to estimate the damage caused by the fire of the summer of 1988. In the image on the left which was received on July 31, 1988 (before the fires took place at the hot spring of Old Faithful), the basin of this spring is easily recognizable by the area in the north of the central part of the image, which has high radiation levels.
Mozaffar Kazemizad
Volume 21, SEPEHR , February 2013, , Pages 31-35
Abstract
The concept of globalization is studied in different scientific fields. Globalization began in the realm of economy and draws to political and cultural realms. Different scientific fields see globalization as the idea of eliminating geographic borders and reducing distances and there is a consensus that ...
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The concept of globalization is studied in different scientific fields. Globalization began in the realm of economy and draws to political and cultural realms. Different scientific fields see globalization as the idea of eliminating geographic borders and reducing distances and there is a consensus that development in communication and information technology are important factors in the formation of this inclusive phenomena. The modern approach to globalization enters the realm of natural systems and analyzes challenges facing human society from the view point of structuralism as the environmental philosophy of geography. The spread of this system in the world, absence of geographic borders limiting their function and their systematic relation can be considered among similarities and common features of economic-political systems and natural systems. Though these systems were present in this planet before human beings, interaction with human activities disturbed their behavioral procedure. They appear as a serious challenge facing human beings and with the present trend of human economic and industrial activities, their integrity and functional scale increase every day. In this way, they are turning into important and critical challenges facing the world. With the appearance of modern challenges like climate changes and environmental crisis in the field of environment, the issue of exploiting and protecting natural environment and its systems has changed into a global concept. Geography considers such natural and environmental crisis as a natural topic for its studies. It can be successful in introducing natural systems to citizens and different groups using its comprehensive knowledge of phenomena behavior and relations and human function. It also has the capability of providing influential solutions, preventing and solving global challenges.
Hossein Hatami Nejad; Hadi Hakimi
Volume 15, Issue 58 , August 2006, , Pages 31-34
Abstract
Postmodernism has been interpreted as a broader concept than modernity, and it is the offspring of modernism. The era of modernism, which was based on trust to human intellect and did not accept a world beyond reason, was influenced by philosophers such as Hegel, Kant, Rene Descartes, and before that, ...
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Postmodernism has been interpreted as a broader concept than modernity, and it is the offspring of modernism. The era of modernism, which was based on trust to human intellect and did not accept a world beyond reason, was influenced by philosophers such as Hegel, Kant, Rene Descartes, and before that, Francis Bacon, which caused profound changes in various areas of human life, and perhaps it was only in this period that mankind reached full self-confidence and considered itself to be ruler over its own destiny. But modernism, as it originally seemed to have succeeded, had major effects on crises such as the first and second World Wars and the racial, gender and environmental crises in the twentieth century. These factors led the philosophers and thinkers of the second half of the 20th century to doubt the wisdom of pure reason, and those like Karl Raymond Popper believe that rationalism must itself be criticized. Therefore, a period in the name of postmodernism has come to the fore which has had profound effects in various scientific and artistic fields. In this paper, we have tried to understand the concepts and definitions of modernism and postmodernism to the extent possible, and to analyze the similarities and differences between them and the impacts that each period have had on different urban areas, both physical and non-physical.
Khosrou Khajeh (Translator)
Volume 13, Issue 51 , November 2004, , Pages 31-35
Abstract
For geographic applications such as surface flow models, 3D visualization, simulation and analysis of visibility potential gaining information about land features (land’s lay) is a necessity. Basically, the Digital Terrain Model (DTM) includes sampling few points of the real world. Interpolation ...
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For geographic applications such as surface flow models, 3D visualization, simulation and analysis of visibility potential gaining information about land features (land’s lay) is a necessity. Basically, the Digital Terrain Model (DTM) includes sampling few points of the real world. Interpolation is still a difficult task in order to reconstruct a continuous surface of sample points. In this paper, the author attempts to discuss current issues of DTM production and interpolation technology including continuous advancement in information technology and increasing need of users to digital land models.
Saeed Sadeghian
Volume 13, Issue 49 , May 2004, , Pages 31-35
Abstract
The history of the city of Karbala in Islamic Era begins since the martyrdom of Imam Hussein. Image (1) shows the space image of IKONOS, taken on January 3, 2003, from the shrine of Imam Hussein, along with the shrine of Abolfazl al Abbas and the spaces surrounding these two sites that form the central ...
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The history of the city of Karbala in Islamic Era begins since the martyrdom of Imam Hussein. Image (1) shows the space image of IKONOS, taken on January 3, 2003, from the shrine of Imam Hussein, along with the shrine of Abolfazl al Abbas and the spaces surrounding these two sites that form the central core of the city.
Zoleikha Bagheri (Translator)
Volume 9, Issue 34 , August 2000, , Pages 31-38
Abstract
The planet of Mercury, famous in myths as gods’ messenger, is very small compared to other planets in Solar System. This planet has the shortest span of year (eighty-eight days) and the highest orbital speed. Mercury revolves like a flame of fire around the Sun with a speed of about 48 km/s and ...
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The planet of Mercury, famous in myths as gods’ messenger, is very small compared to other planets in Solar System. This planet has the shortest span of year (eighty-eight days) and the highest orbital speed. Mercury revolves like a flame of fire around the Sun with a speed of about 48 km/s and is attracted by the Sun’s gravity.In terms of outer structure, Mercury is similar to the Moon, and its internal structure resembles that of the Earth. It is probable that this planet has collided with a body like the Moon in past ages.
Hosein Ghahra'ei (Translator)
Volume 8, Issue 32 , February 1999, , Pages 31-35
Abstract
It was previously thought that the probability of existence of life on Mars is more than other places in the space. Although Mars is half the size of Earth, it is similar to our planet in other aspects. Days in Mars are half an hour longer than our days, and it has a cloudy atmosphere. There are ice ...
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It was previously thought that the probability of existence of life on Mars is more than other places in the space. Although Mars is half the size of Earth, it is similar to our planet in other aspects. Days in Mars are half an hour longer than our days, and it has a cloudy atmosphere. There are ice caps there that melt during summer and expand over winter. There are also plains in there. Most interesting of all are the signs that change every year in terms of size and shape and look almost like plants that are growing. Some of astronomers have even thought that they could see canals dug by Mars residents to transfer water from poles to plains.Space explorations have revealed many facts on Mars, but no sign of life has been discovered there. First, it is very cold there; even in a summer day the temperature will not rise above the freezing point of water. Second, the thickness of air layer on this planet is similar to thickness of air layer at an elevation of about 35 kilometers (22 miles) from Earth’s surface, so it is not possible to breathe in there. Ultraviolet radiations of the Sun reaching the surface of Mars are so strong that they would destroy every living being.There is water on Mars’s surface, but it is not in liquid form. This water lies in frozen state under the surface and within ice caps. However, water has probably existed in liquid form in the past. Some of the signs over the planet look like dried-up rivers. Maybe Mars have been warmer in the past, so that water could have been melted.River beds are not like canals on Mars. They are apparently illusions that deceived astronomers when looking through their telescopes. The dark points that once were supposed to be plants are in fact areas of dark rocks and dust. They change every year in terms of size, because dusts are dispersed by winds.
Mohammad Amin Arefzadeh (Translator)
Volume 8, Issue 31 , November 2009, , Pages 31-43
Abstract
The release of large amounts of CO2 and heavy metals from nickel and copper smelting plants in the Kola Peninsula in Russia has caused extensive destruction of vegetation in the surrounding areas over the past few decades. In an attempt to illustrate the changes in the vegetation situation around Monchegorsk ...
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The release of large amounts of CO2 and heavy metals from nickel and copper smelting plants in the Kola Peninsula in Russia has caused extensive destruction of vegetation in the surrounding areas over the past few decades. In an attempt to illustrate the changes in the vegetation situation around Monchegorsk smelting factories, MSS Landsat satellite images were prepared for a visual analysis of the years 1989, 1986, 1980, 1978 at several stages. By comparing and assessing the NDVI (Normalized Difference Vegetation Index) numerical values in different years, the destruction in the green and fresh vegetation during the measured period can be clearly identified. The monitored classification in examination of the images confirms the same trend: vegetation around the smelting factories has undergone severe annihilation. A large combination of continuous (complementary) images by the TM sensor from Channels 6, 4 and 1 was covered by Sulfur Dioxide (SO2) using the distribution model which clearly showed that the area with an annual average density of 40-60μm of Sulfur dioxide has been severely damaged.
Faramarz Khosh Akhlagh; Mohsen Soltani
Volume 20, Issue 78 , August 2011, , Pages 32-38
Abstract
One of the main pillars of agricultural planning is the identification of agricultural climatic units. An agricultural climatic unit is a unit in which the ground features and climatic elements are considered as integrated units, and each unit can have different characteristics. In this regard, the condition ...
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One of the main pillars of agricultural planning is the identification of agricultural climatic units. An agricultural climatic unit is a unit in which the ground features and climatic elements are considered as integrated units, and each unit can have different characteristics. In this regard, the condition of Sari station was considered as a sample strawberry cultivating area in Mazandaran province. For this purpose, climatic and environmental data and statistics of Mazandaran province were collected in terms of layers of ground and climatic factors and evaluated using Excel software. GIS software (1) has been used to draw up climatic and descriptive maps of the province. From ground factors, topographic layers, land use, slope and type of soil and from climatic elements, precipitation and annual temperature are considered. Using the special functions of the GIS system, first a weighted value was given to the layers according to the potentials of strawberry cultivation, and then they were combined in a final map. The final map indicates the ability of different regions of Mazandaran province to grow strawberries. The results indicate the accuracy of the map and the ability of the GIS to help provide an integrated analysis and homogeneous agricultural climatic units.
Seyyed Hassan Sadugh Vanini; Jamileh Tavakkolinia; Omid Zare'ee
Volume 18, Issue 72 , February 2010, , Pages 32-39
Abstract
Considering that the growth trend of urbanization in Iran, following the deep economic and social changes of past decades, has in recent years led to the unbridled growth of cities with national and regional role and, without regard to the natural capacities and facilities of the region has brought about ...
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Considering that the growth trend of urbanization in Iran, following the deep economic and social changes of past decades, has in recent years led to the unbridled growth of cities with national and regional role and, without regard to the natural capacities and facilities of the region has brought about unpleasant consequences for the physical-biological environment of the city, the growth of the population with the occupation of urban space has created imbalances in the construction and texture of the city and has caused irreparable damage to the urban environment. As a result, the zoning of land for the physical development of cities has always been of interest to urban geographers and planners, and therefore it is essential to locate suitable lands for the physical development of cities. In this paper, using the AHP model in ARC GIS software, land zoning for physical development of Shiraz city was evaluated based on 8 criteria (slope, ground, static surface of groundwater, land capability, river boundary, the distance from fault, height and texture of soil) and a zoning map of the land was obtained. The zoning map shows three areas of high suitability (21516 hectares), low suitability (23069 hectares) and unsuitable (23289 hectares) in terms of priority for physical development, and can be used by urban managers and planners.
Nasrallah Mowla'ei Hashjin
Volume 12, Issue 45 , May 2003, , Pages 32-40
Abstract
The nomadic animal husbandry system of Iran is one of the oldest and most important methods of animal husbandry breeding in the country. The basic features of this system include its main reliance on natural pastures, so that livestock is fed naturally in the territory of the Ile (tribe) using summer ...
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The nomadic animal husbandry system of Iran is one of the oldest and most important methods of animal husbandry breeding in the country. The basic features of this system include its main reliance on natural pastures, so that livestock is fed naturally in the territory of the Ile (tribe) using summer and winter ranges.Change of rangeland ecosystem as a result of the grazing of various types of animal husbandry is inevitable, and if this change is not supervised and controlled, it will lead to soil erosion, a steady decline in the vegetation surface cover of rangelands and risk to the natural environment and life of nomads.Grazing management has been seeking to interfere in the changes through control of intensity and time of grazing in order to maximize the production yield by achieving quantity and plant composition, minimizing environmental degradation and profitability for livestock breeders.Considering the importance of natural grazing of animal husbandry in rangelands on the one hand and the necessity of preserving the natural environment and watershed management on the other, and with the aim of paying due attention to livestock grazing management in watersheds, in this paper, based on descriptive research method and using documentary and secondary methods as well as field studies in the form of observation and analysis of questionnaires, analytical survey of livestock grazing and watershed management have been conducted.
