Mahmud Mohebbi
Volume 17, Issue 67 , October 2008, , Pages 69-74
Abstract
The database management system (DBMS) is comprised of a set of related data, and a set of computer programs for access to those data. A data set is usually called a database, and a set of programs is usually called database management. Due to the importance of information in all plans at all levels the ...
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The database management system (DBMS) is comprised of a set of related data, and a set of computer programs for access to those data. A data set is usually called a database, and a set of programs is usually called database management. Due to the importance of information in all plans at all levels the database is considered a valuable source. Consequently, its concepts and principles need to be developed. The purpose of this article is to present the overall features of the database system. In addition, the features and capabilities of the database system are expressed.
Seyyede Ameneh Sajjadi
Volume 21, Issue 82 , September 2012, , Pages 71-78
Abstract
Determining parameters like precipitation-snow, snow depth-discharge and temperature are especially important in predicting flow in mountainous areas and studying activities of river system. Regarding snow hydrology, determining appropriate snow melting models of the area are important. Therefore, the ...
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Determining parameters like precipitation-snow, snow depth-discharge and temperature are especially important in predicting flow in mountainous areas and studying activities of river system. Regarding snow hydrology, determining appropriate snow melting models of the area are important. Therefore, the present article studies effective factors in snow melt, investigates different models of snow melt and introduces the best snow melt model.
Abdollah Seif; Tayyebeh Mahmoodi
Volume 23, Issue 89 , May 2014, , Pages 72-80
Abstract
During the last three decades, the process of producing topographic information has observed a development in data producing technology, from traditional and land mapping toward inactive methods of surface measurement and registration (like photogrammetry and remote sensing), and more recently toward ...
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During the last three decades, the process of producing topographic information has observed a development in data producing technology, from traditional and land mapping toward inactive methods of surface measurement and registration (like photogrammetry and remote sensing), and more recently toward active methods (like radar and Lidar). Lidar is a technique used to gather information from the surface which works by measuring distance with laser. Measurement in Lidar is based on this principle: with defined coordinates of the laser sending point, it is possible to measure coordinates of any point on the ground by measuring the oblique distance between pulse sending point and the ground surface and measuring the angle of wave sent between the pulse sending point and ground level. Images produced using Lidar data have a 472*697 pixel dimension. In fact, Lidar is a supplementary tool for collecting 3 dimensional information which aid spatial photogrammetry and remote sensing. The most important information received from this device is the distance between sensor and ground level which is measured by calculating the time period between pulse impact with earth surface and its return to the sensor. Moreover, the distance between ground surface and flying level of the airplane is repeatedly measured which determines ground surface and vegetation. Digital elevation model and digital surface model are products of Lidar. Features like plot parameters, average elevation of trees, surface of vegetation crown, elevation of the vegetation crown, diameter at breast height, single trees and jungle structure can be exploited by Lidar. The present article seeks to introduce Lidar and investigate its functions and applications.
Sadegh Karimi Khajehlangi
Volume 21, Issue 83 , November 2012, , Pages 73-76
Abstract
The relation between ENSO and fluctuations in monthly precipitation patterns of Iran
ENSO phenomenon is a combination of El Nino-Southern Oscillation and an important telecommunication patterns in southern hemisphere which affect weather condition all over the globe through changing temperature and ...
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The relation between ENSO and fluctuations in monthly precipitation patterns of Iran
ENSO phenomenon is a combination of El Nino-Southern Oscillation and an important telecommunication patterns in southern hemisphere which affect weather condition all over the globe through changing temperature and precipitation patterns.
Different researchers have studies the influence of this phenomenon on temperature and precipitation patterns of different areas of the world, including Iran in different cold and hot phases and found significant differences. Different areas react differently to ENSO with different time lags. Thus, the present article studies the relation between ENSO and seasonal/monthly precipitation in Shahr-e Kord.
The present article analyzes the relation between these patterns through a 44 year period (1957-2000) of precipitation in Shahr-e Kord synoptic station and temperature anomaly in Nino 3.4 region. Results indicate that Shahr-e Kord precipitation pattern during the mentioned period in May, June, August, October and November is related with ENSO, yet the level of this relation differs. Therefore, the correlation between ENSO and Shahr-e Kord monthly precipitation pattern is more significant in June, May (spring season), October, and November (autumn). According to the findings, we recognized a negative correlation between ENSO and precipitation in Shahr-e Kord. Results indicate that the most significant relation is between temperature anomaly in Nino 3.4 and Shahr-e Kord precipitation with a four month lag.
Seyyed Eskandar Seydaii; Hosseinali Kazemi
Volume 19, Issue 73 , May 2010, , Pages 83-85
Abstract
Experience of new cities in Iran has a long history. Cities like Abadan, Shushtrano, Zahedan, Noshahr and various industrial cities are among its examples. The strategy of new cities began after the approval of the Cabinet of Ministers in 1986, and the responsibility for the construction of these cities ...
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Experience of new cities in Iran has a long history. Cities like Abadan, Shushtrano, Zahedan, Noshahr and various industrial cities are among its examples. The strategy of new cities began after the approval of the Cabinet of Ministers in 1986, and the responsibility for the construction of these cities was delegated to civil engineering companies. However, the policy of locating new cities in our country has not been favorable and has been more concerned with the fact of state ownership of the land, neglecting other regulations of locating such as urban development capability, proximity to major economic centers, accessibility to roads, desirable distance from the mother city, paying attention to the population centers of the region, attention to the geographical and natural criteria of the region and ... As a result, the new cities have not succeeded in achieving their goals. Shahr-e-Jadid (new city) of Baharestan is one of the four new towns of Isfahan, which has a relatively good location, and has therefore succeeded in some way in attracting and settling the population.
Ali Mohammadpoor; Saied Zarghami
Volume 23, SEPEHR , July 2014, , Pages 89-93
Abstract
Throughout history, locating urban facilities has always been necessary. Especially in the present era, it seems to be more important. Urban facilities are located using GIS, fuzzy model, overlap index, and etc.
In this regard, requirements must be observed with consideration of passive defense. Urban ...
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Throughout history, locating urban facilities has always been necessary. Especially in the present era, it seems to be more important. Urban facilities are located using GIS, fuzzy model, overlap index, and etc.
In this regard, requirements must be observed with consideration of passive defense. Urban facilities are among vital urban centers and the first target of enemies whose damages paralyze the city and result in its fall. In regard to their sensitivity, the present article investigate urban facilities and propose some suggestions for finding appropriate locations considering passive defense requirements.
Mohammad Rahimi; Ali Akbar Damavandi; Vahid Jafarian
Volume 22, Issue 88 , January 2014, , Pages 115-128
Abstract
Due to the increasing complexity and development of dynamic phenomena like land degradation and desertification in the present century, new technologies have focused on their evaluation and monitoring (Alavi panah, 2003). Remote sensing, Geographic Information System and Global Positioning System are ...
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Due to the increasing complexity and development of dynamic phenomena like land degradation and desertification in the present century, new technologies have focused on their evaluation and monitoring (Alavi panah, 2003). Remote sensing, Geographic Information System and Global Positioning System are among the most important technologies based on spatial information (geoinformatics). In fact, investigating spatial and temporal changes of complex phenomena like land degradation and desertification with the aim of ongoing evaluation and monitoring for proper management and exploitation is inevitable. With the emergence of such modern technologies, it is expected that better and more accurate investigation of land phenomena become possible. Remote sensing, which is based on collecting spatial information (in specified time intervals) by airplanes and satellites, plays a very important role in land degradation and desertification evaluation and monitoring in local, regional and global scale. Multiple capabilities created by this technology (being multi-spectral, inexpensive and digital, having wide field of vision, increasing spectral, land, temporal, radiometric resolution capability, duplicate coverage and spectral variety, easily available data, quick access to distant points and high accuracy) have resulted in the development of a new approach in the studies on the evaluation and monitoring of desertification.
Marzeyeh Mokarram; Ali Darvishi; Saeed Negahban
Abstract
Extended Abstract
Introduction
Watershed is an area of land that surface water of rain and melting snow conduct towards a single point, which is usually out of the basin. Check of watershed is one of the main strategies for integrated management of natural resources and sustainable development. Recently, ...
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Extended Abstract
Introduction
Watershed is an area of land that surface water of rain and melting snow conduct towards a single point, which is usually out of the basin. Check of watershed is one of the main strategies for integrated management of natural resources and sustainable development. Recently, the availability of remote sensing (RS) data and Geographical information system (GIS) technologies has allowed for improved understanding of the morphometric properties and surface drainage characteristics of many watersheds in different parts of the world (Parveenet al., 2012; Nayar& Natarajan, 2013). For example, Shrimaliet al. (2001) presented a case study of the 42 km Sukhana lake catchment in the Shiwalik hills for the delineation and prioritization of soil erosion areas. In addition, Srinivasaet al. (2004) used GIS techniques for morphometric analysis of subwatersheds in the Pawagada area, Tumkur district, Karnataka. Nookaratnamet al. (2005) carried out a study on dam positioning through prioritization of microwatersheds using the sediment yield index (SYI) model and morphometric analysis. Khan et al. (2001), used RS and GIS techniques for watershed prioritization in the Guhiya basin and sub-watersheds in Odisha, India respectively.
Materials & Methods
The study area is one of the subwatersheds of the river of Urmia (Nazloochaei) that is located in North West of Iran with an area of 948.75 km2. The study area was selected for detailed morphometric analysis using Geography information system (GIS). The input data for morphometric analysis was DEM with resolution of 30 m from ASTER satellite. The steps of stream extraction consist of:
1. Extraction of drainage networks from the DEM using the flow direction method, which consists of the following steps (O’Callaghan & Mark, 1984):
i. Fill Sinks: A sink is an uncompleted value lower than the values of its neighborhood. To ensure proper drainage mapping, these sinks were filled by increasing elevations of sink points to their lowest outflow point.
ii. Calculate Flow Direction: Using the filled DEM produced in Step1, the flow directions were calculated using the eight-direction flow model, which assigns flow from each grid cell to one of its eight adjacent cells in the direction with the steepest downward slope.
iii. Calculate Flow Accumulation: Using the output flow direction raster created in Step2, the number of upslope cells flowing to a location was computed.
iv. Define Stream Network: The next step is to determine a critical support area that defines the minimum drainage area that is required to initiate a channel using a threshold value.
v. Stream Segmentation: After the extraction of drainage networks, a unique value was given for each section of the network associated with a flow direction.
Morphometric analysis of the study area consist of:
Stream number (Nu)
Nu is number of segments in order U
Stream order (U)
Cumulative length of streams (L), L = ∑Nu, L is calculated as the number of streams in each order and total length of each order is computed at sub-watershed level (Horton, 1945).
Bifurcation ratio (Rb)
Rb=Nu/N (u+1) N (u+1) = Number of segments of the next higher order (Schumms, 1956),
Watershed relief (Bb), Bb = Hmax – Hmin, Bb is defined as the maximum vertical distance between the lowest and the highest points of a sub-watershed. Hmax and Hmin are maximum and minimum elevations respectively (Schumms, 1956)
Drainage density (Dd)
Dd=Lu/A, A=Watershed area (km2), L (u) is total stream length (Horton, 1932)
Stream frequency (Fs), Fs = Nu/A, Fs is computed as the ratio between the total number of streams and area of the watershed (Horton, 1932)
Form factor (Rf)
Rf =A/Lb2, Rf is computed as the ratio between the watershed area and square of the watershed length. 𝐿 is the watershed length (Horton, 1932)
Circularity ratio (Rc)
Rc= 4π*A/P2, P is the watershed perimeter (km)
Elongation ratio (Re)
Re= (2/Lb)*(A/π) 0.5
Results and discussion
The results showed that according to the high number of streams (489 waterways), the existence of first, second and third degree streams, the high length of the streams, the high proportion of length of the streams in relation to the basin area, high coefficient of relief which indicates high elevations and slopes, the area is erodible and requires more management. Also, Landform studies in the studied area showed that with the help of morphometric characteristics, the sensitivity of landforms to erosion can be determined in the area. So, after the mapping of landforms using topographic position index (TPI), and considering the erosion-sensitive areas through morphometric characteristics, erosion-sensitive landforms in the study area were determined, So that the increase in the number of waterways and their length in the watershed indicates an increase in erosion. Comparing the map of the landforms and the map of the streams in the studied area, it was determined that class 4 (U-shaped valleys) and class III (high drainage) landforms have the highest erodibility. The results showed that, with increasing drainage density, the erodibility increases and the highest erodibility was observed in Class 4 (U-shaped valleys) and Class 6 landforms due to the high drainage density.
Conclusion
Ridge landforms such as those in high altitude (landforms in class 9 and 10), had the highest erosion and were therefore the most sensitive landforms. The drainage density features as the most important factor for determination of erosion and its relation to landforms were used. The results showed that by increasing the amount of drainage density the erosion increases which were for landforms Class 4 and Class 6. This study has demonstrated that morphometric characteristics can be used to predict other watershed characteristics.
Elham Ghasemifar; Somayeh Naserpour
Abstract
Extended Abstract Introduction An extreme event is an event that rarely occurs in other than normal conditions. Extreme events, stimulate changes in natural and human systems to more than the average climatic conditions (Peterson et al, 2008). Extreme days (veryhot and cold days) have impacts ...
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Extended Abstract Introduction An extreme event is an event that rarely occurs in other than normal conditions. Extreme events, stimulate changes in natural and human systems to more than the average climatic conditions (Peterson et al, 2008). Extreme days (veryhot and cold days) have impacts on human and natural systems such as agriculture, ecology, etc. A heat and cold wave is a hot and cold period which lasts from a few days to a few weeks and may be accompanied by high humidity for heat waves, andextreme wind for cold waves. The impacts of heat waves that have occurred in the world are as follows: heart pains, severe shortage of water, heat stroke, rising food prices, power outages, increased natural disasters, outbreaks of insects such as mosquitoes, fire, loss of life and living organisms. Also, frost, frost damages to crops and mortality are the results of the cold waves. By far, there are many studies about this climatic events in the world which have been done for example by Panmao and Xiaohua, 2003, and Peterson et al., 2013. Many studies have confirmed that heat and cold waves are increasing and decreasing respectively in recent years. In Oklahoma, the results of the effects of heat island after a heat wave in the year of 2008 showed that the heat-island at the core of the city is 5 degrees Celsius (during the day)and 2 degrees (during the night) warmer than the rural areas and due to the presence of humidity and heat waves, higher value of heat is generated (Basara et al, 2010). Studies about this extreme events weredone also by few meteorologist and climatologist researchers in Iran, for example Lashkari (2009) did the case study of cold wave which took place over Iran from December 11 to 16, 2003. He found that Siberian high pressure and low temperature are responsible for the extreme cold wave (Lashkari, 1387). By far, cold waves and heat waves have not been studied on coastal regions of the Caspian Sea. The objective of this research is to provide a general overview of heat and cold waves in this area. Methodology This research has studied heat and cold wave events using minimum and maximum temperature which was received from Iran meteorological organization. After sorting the data and examining them for selecting threshold, cold waves with 0.02 percentile and heat waves with 0.98 percentile were evaluated during 1961-2010 in Southern coastal regions of the Caspian Sea over five stations namely Bandar- E -Anzali, Rasht, Ramsar, Babolsar and Gorgan. For better interpretation, wave periods were divided into three periods as follows: long-term waves (more than 6 days), medium term waves (3 to 6 days) and short term waves (less than three day). For synoptic analysis, NCEP/NCAR reanaly data including sea surface pressure and geo-potential height at the level of 500 were received from the website with 2.5x2.5 resolution for an area covered from 20 to 70 N and 10 to 80E in this region. All the data were analyzed in GRADS software. Then, all the results were interpreted with respect to warm and cold waves. Results and discussion Overall, the results showed an increasing trend for minimum temperature and a decreasing trend for maximum temperature. Maximum frequency of cold wave have took place in the years of 1963, 1964, 1969, 1972, 1973, 1989, 1991 and2008.But, continuity of the waves is observable in the year of 1964 and 1972. Maximum frequency of heat wave have taken place in 1962, 1966, 1980, 1983, 2000, 2009 and 2010, while continuity of the waves have been recorded in the year of 1966 and 1971. Ramsar station has recorded maximum frequency of both cold and heat waves. Gorgan has recorded minimum frequency of heat waves, while Rasht and Anzali are specified by minimum frequency of cold waves. The synoptic analysis of NCEP/NCAR sea surface pressure andgeo-potential height at the level of 500 showed that high pressure inEastern Europe, Siberian anticyclone, high pressurein Alpine Mountain and low pressure in Ural Mountains caused the cold waves. Low pressure in Saudi Arabia, Pakistan, andthe Persian Gulf have created heat waves. Conclusion So far, no research has been done onheat and cold waves on coastal regions of the Caspian Sea with maritime climate. This research addressed these waves in 1961 to 2010 period, using weather stations and reanalyzed data at five stations with the most comprehensive weather data. Different results were obtained for stations which are linked to synoptic conditions. In addition to weather and NCEP/NCAR data, it is suggested that the use of ERA-interim and satellite data such as MODIS land surface temperature which have different resolution, can be a great help in filling the gaps between stations and improving the obtained results.
Hossein Mohammadi Hossein Mohammadi; Ghasem Azizi; Faramarz Khoshakhlagh; Mahdi Khazaei
Abstract
Abstract
Accurate and timely estimation of evapotranspiration has a significant and critical impact on the planning of water resources and agriculture. In this research, the estimation of evapotranspiration of sugarcane in Khuzestan province has been studied, and the data used, have been air temperature, ...
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Abstract
Accurate and timely estimation of evapotranspiration has a significant and critical impact on the planning of water resources and agriculture. In this research, the estimation of evapotranspiration of sugarcane in Khuzestan province has been studied, and the data used, have been air temperature, relative humidity, wind speed and sunny hours since the establishment of synoptic station until 2014. For this purpose, the evapotranspiration values of the reference plant were first calculated using the FAO Penman-Monteith standard method and then, using available plant coefficients, the amount of sugarcane evapotranspiration was estimated at different stages of growth. The results of this study show that the average sugarcane evapotranspiration in Khuzestan province has been 3.35 mm / day in June and in the early stages of growth, 10.46 mm/day in the middle stages of growth, and 6.26 mm / day in the final stages of growth. The value of this parameter in July was estimated 3.59 mm/day in the early stages, 11.23 mm/day in the middle stages and 6.74 mm/day in the final stages of growth. Finally, the amount of evapotranspiration of sugarcane in August was estimated 3.56 mm per day in the early stages of growth, 11.12 mm/day in the middle stages and 6.67mm per day in the final stages of the growth. The maximum daily and monthly evapotranspiration has occurred in July and the minimum in June. Also, the highest daily and monthly fluctuations of sugarcane evapotranspiration have occurred in the middle stages of growth and the lowest in the early stages of growth.
mostafa mohamadi dehcheshme; Hadi Alizadeh
Abstract
Extended Abstract
Introduction
Today, given the increasing trend of urbanization and the progressive growth of city and citizens’ risk-taking in relation to accidents and hazards, the necessity of addressing the security issue as one of the key determinants of a good city is felt more than ever, ...
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Extended Abstract
Introduction
Today, given the increasing trend of urbanization and the progressive growth of city and citizens’ risk-taking in relation to accidents and hazards, the necessity of addressing the security issue as one of the key determinants of a good city is felt more than ever, and this challenge has led theorists to find a definition of a healthy, safe and sustainable city. In its report on strengthening the urban safety and security in 2007, the United Nations has made human security and safety equivalent to supporting the vital needs of human, namely, freedom from undesirable conditions of life and bringing people closer to their aspirations and ambitions. This Interpretation of Human Security and Safety in the Copenhagen Declaration of 2005 was completed with the emphasis on efforts to eliminate hunger and malnutrition, creating food security, development and livelihoods, health services including safe drinking water, proper sanitation and shelter, and participation in social and cultural life. However, attempts to establish urban security on a global scale have generally confronted the offender rather than focusing on crime and the causes of security threats in urban areas. It can be argued that there is a certain amount of violence in every given city, but violence at the city level has not been randomly distributed and for a better attitude towards security topic, the factors creating insecurity in urban spaces should be sought and identified. Considering the mentioned issues and the necessity to pay attention to the security in urban spaces, in the present study, the city of Urmia has been evaluated as the basis of the study. Over the last few decades, the city as the capital of the province of West Azerbaijan, with the acceptance of various Kurdish ethnicities, Assyrian and Armenian Christians to live in the city and increasing the marginalization in the north, northwestern, and southern regions of the city, has become an appropriate context for creating insecure and anomalous spaces due to increasing ethnic and ideological prejudices among Azeri and other ethnic groups, and conflicts and increasing crime rates in the city. Ethnic bias, the lack of balanced distribution of resources and facilities at the city level, ideological bias among ethnicities, the lack of sustainable physical infrastructure in marginalized areas with ethnic diversity that has led to insecurity and dissatisfaction among residents and finally, distrust of citizens and ethnicities to influential institutions and urban policymakers in collaborative discussions on ideological issues has caused insecurity and dissatisfaction among citizens and reduced security in the cities and districts mentioned, for example, the formation of insecure urban areas such as Zurabad and Muftabad indicate the anomalous and unsafe situations in these areas in Urmia. The issue of the security crisis and the increase of social anomalies and ethnicity along with the issue of marginalization have made this challenge in the city to be considered as one of the challenges of urban management in terms of security and social issues. Considering the above mentioned issue, in the process of achieving urban security in Urmia, the issue of security realization has been evaluated through studying the components of structuralist approach in urban security of Urmia in this study.
Material method
The present study was conducted with the applied targeting and “descriptive-analytical” method to analyze the security situation in urban spaces of Urmia city with regard to the structuralist approach in urban security. In order to achieve the set goals, to collect the descriptive part of the research, library studies and documents on the topic of research were used, and for the analytical part of the research, a survey method and a questionnaire were used to analyze the security of Urmia urban spaces in three fundamental, dynamic and safety dimensions from the citizens’ points of view. To analyze the research data, considering the components of the structuralist approach in the form of SPSS software, Pearson statistical correlation test was used to assess the internal relation of the security components in Urmia, T test was used to assess the priority of the security components in Urmia and the Diagnostic analysis model was used used to predict the implementation process of security in Urmia city.
Results & Discussion
The obtained results are the outcome of proper internal correlation among the components of security assessment in Urmia urban spaces. These results show that, firstly, the internal correlation of the components, in terms of the sample population, is meaningful at the level of 0.99. The final analysis of the priority of urban security components from a structural viewpoint in Urmia shows that the fundamental component with the difference between the lower mean and the two other components with the level of 0.0858 and the lower T, have a more inappropriate situation than the other two components in the city of Urmia from the citizen’s points of view. On the other hand, the final statistics of the diagnostic analysis shows that in order to predict the security in Urmia urban spaces, the safety component in continuation of confirming the preliminary results of the diagnostic analysis with a general prediction level of 0.522, has a stronger prediction for security in Urmia urban spaces. The results obtained in predicting urban security in Urmia show that, these conditions, in the present status, with the more obvious conditions, can be very important in the quantity and quality of security and its realization or non-realization in Urmia. These results show that considering the basic and fundamental factors in urban security issue in urban spaces of Urmia from the citizens’ viewpoints can be very helpful in establishing safe urban spaces in this city.
Conclusion
The structuralist approach to security, with regard to its theorizing process, addresses the assessment of the security category based on the conditions of developing countries. Its constituent parts also show root problems and challenges that can lead to insecurity in urban spaces in these countries. With this background, the components of this approach were evaluated in Urmia. In fact, in order to assess the state and accuracy of the definition of security in urban spaces of Urmia, the internal connection of selected components from the structuralist point of view was first measured. This assessment was aimed at demonstrating whether or not the components and indicators selected for the purpose of explaining the urban security category in Urumia had a coherence and intrinsic connectivity to illustrate this explanation. Secondly, the reason for assessing the priority of safety components from the point of view of structuralist approach in Urmia was to address planning to improve the level of security in urban spaces in Urmia by recognizing the importance of the components due to their weaknesses and strengths. Finally, our goal was to respond to this question that, which one of the selected components could better fulfill the security process in the urban environment of Urumia in accordance with the existing conditions.
Marzieh Mokarram; Saeed Negahban
Abstract
Extended Abstract
Introduction
Investigating the spatial andTranslation errorInvestigatingiiiii temporal variations of soil salinity plays a major role in managing the watershed and preventing the development of salinity (Mohammadi, 2007). Also, the study of groundwater salinity due to the complexity ...
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Extended Abstract
Introduction
Investigating the spatial andTranslation errorInvestigatingiiiii temporal variations of soil salinity plays a major role in managing the watershed and preventing the development of salinity (Mohammadi, 2007). Also, the study of groundwater salinity due to the complexity of hydrological processes, characteristics of the aquifer, and their variability is a difficult task. However, these problems exacerbate by external factors such as atmospheric conditions and human activities affecting the permeability and hydrological processes (Mirzaee and Hassan-Nia, 2013). Because of the costly nature of experiments involving salinity sampling, as well as the computational models not being calibrated and the complexity of these models in order to overcome these limitations and to determine salinity in the depths of the soil, determination of models consistent with natural behaviors and the use of existing models, Increase day by day. On the other hand, considering the fact that many lands are under cultivation in the northwest of Fars province, it is important to study the chemical properties of the soil and water in the region, including salinity.
There are various methods for studying the salinity of water and soil, for example, Syringes et al. (2006) predicted the salinity of soil profile and the drainage outlet in a research using neural networks in an experimental area in India. Arfin et al. (2003) used an artificial neural network model and linear regression model to predict the soil and water salinity. Topographic index is a measure of the extent of flow accumulation at the given point of the topographic surface. As catchment area increases and slope gradient decreases, topographic index increases. Like other combined morphometric variables, topographic index can be derived from a digital elevation model (DEM) by the sequential application of methods for local and nonlocal morphometric characteristics, followed by an arithmetic combination of the results of these calculations.
Materials & Methods
The studied watershed is located in the west of Shiraz, between the cities of Shiraz and Kazeroon. The most important urban center in this basin is the city of Bayza. The geo-location of the studied area is N 29° 12´to 29° 48´and E 52° 06´ to 52° 36´ (Figure 1). The area of the study region is 623.63 KM2. The highest and lowest altitudes in the study area are 1630 and 3083 meters respectively. The average temperature in the region is 16.8 degrees varying from 4.7 to 29.2. The study area is very rich for cultivating crops. It is also a very rich in terms of topography, geology and biodiversity. Regarding the presence of agricultural lands in this region as well as the significance of irrigation water quality and the type of soil in terms of electrical conductivity (EC), the study of the soil and water characteristics of the region is very important in terms of salinity.
The data used in this research include electrical conductivity of water and soil samples provided by Fars Agricultural Jihad Organization (2013). This region was selected considering the importance of the study region for agriculture. The zoning maps for each of them were prepared in the ArcGIS environment with the help of these sample points which were selected randomly. Then, the EC data of water and soil was homogenized and ranged from 0 to 1 with the help of membership functions. Finally, the relationship of the amount of water and soil salinity with the watershed rough terrain was investigated.
Discussion and Results
According to the interpolation maps, it was determined that the lowest and the highest values for water salinity in the study area were 0.42 and 3.07 respectively, while for soil salinity were 0.87 and 8.75 respectively. According to the salinity zoning map prepared for soil samples in the study area, it is determined that the highest soil salinity is in the southwest of the study area, while the north and center of the study area have lower soil salinity. Also, the results of water salinity obtained by IDW method showed that the highest salinity of water is in the north of the region, while the lowest salinity of water is observed in parts of the south of the study area. The fuzzy map values of the study area are between 0.08 to 0.99, that except for a very small part of the study area located in the southeast, the rest of the area contain saline water. Also, the results of soil salinity fuzzy map of the studied area showed that the soil salinity values were between 0.61 and 0.92. In fact, the soil in the study area has a lot of salinity.
Conclusion
After finalizing the fuzzy map of water and soil salinity by fuzzy method, the final salinity map was classified into four classes. Values less than 0.25, between 0.25 and 0.5, 0.5 to 0.75 and more than 0.75 were classified into inappropriate, moderate, good and very good grades, respectively. (The low values: < 0.25 (inappropriate for drinking), moderate: 0.25 – 0.50, high: 0.50 – 0.75, very high: > 0.75 (a-ppropriate for drinking)). Using fuzzy method for soil salinity, it was determined that 24.31% of the area was in poor class (inappropriate), 11.78 in the moderate class, 25.74 in the good class and 38.16% of the area was in the very good class, while for water salinity, it was found that 36.6% was in the moderate class, 31.69% in the good class and 31.65% was in the very good class. At the end, the relationship between the Landform map and the salinity map of the soil and water in the study area was determined. The results showed that salinity of the water in the valleys is very high, while soil salinity in the upstream drainage has shown the highest values. The results also showed that the minimum salinity of the soil and water are in the plains.
Hossein Asakereh; Hasan Shadman
Abstract
Abstract
Hotdays are temperature extreme states and are considered to be one of the important climatic phenomena. Long term changes (trends) of thisphenomenon arethe consequences and evidences of thermal-climatic changes. Also, these days can affect the ecosystems and human life. Therefore, recognizing ...
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Abstract
Hotdays are temperature extreme states and are considered to be one of the important climatic phenomena. Long term changes (trends) of thisphenomenon arethe consequences and evidences of thermal-climatic changes. Also, these days can affect the ecosystems and human life. Therefore, recognizing the behavior of hot days can be the source of many topics. In this research, we tried to investigate the long-term trend of Iran's hot days using the network data of the country’s average maximum temperature from 1961 to 2007 and statistical methods. For this purpose, the hot day profile was studied based on the percentile of ninety for each pixel from the network and was estimated on each day of the year. Thus, a threshold of heat occurrence was obtained for each pixel every day. Then, the days whose temperatures equaled or exceeded this threshold, were considered hot days.The average number of hot days in the country is 39 days. The cold season months, as well as April, have the highest frequency of the average hot days.The frequency of hot days is increasing. The number of hot days has made a positive trend for about half of the country. Also, the average temperature of hot days has also been checked. The trend of the average temperature of hot daysin more than half of the countryhas been positive and in around one third of the country has been negative.The hot days’ temperature-related events of Iran have a 3 to 4 year cycle. Toanalyze the trend in data, linear regression was used with least squares error method and a spectral analysis method was used to investigate the existence of significant fluctuations in the data.
Yaghob Abdali; Ahmad Pourahmad; Milad Amini; Isaac Khandan
Abstract
Extended Abstract: Introduction: Natural disasters have always been considered to be a great challengefor sustainable development throughout the world. Consequently, the paths to this development through the vulnerability reduction patterns are very important. Therefore, it is particularly important ...
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Extended Abstract: Introduction: Natural disasters have always been considered to be a great challengefor sustainable development throughout the world. Consequently, the paths to this development through the vulnerability reduction patterns are very important. Therefore, it is particularly important to reduce the risks of these disasters and necessary to consider a proper position in the national policy-making of countries in order to provide an appropriate condition for the effective reduction of the risks in different levels. Most of the plans made in the field of earthquake management are limited to the time interval during and after the occurrence of the crisis and less attention is paid to the pre-disaster planning. Among the plans for the risk reduction, resilience can be considered a more accurate and successful plan due to its consideration of social, institutional, economic, and physical aspects of a city. In fact,it aims to reduce the vulnerability of the communities and prepare people to face the risks caused by natural disasters. The management of natural disasters requires understanding their nature, accurate assessments, planning and finally providing proper strategies. Hence, it is very important to explain the relationship between resilience in natural disasters (such as earthquake) and reducetheir impact given the results that it might have and the emphasis of this analysis on the aspect of resilience. Materials & Methods:The present study is an applied study in terms of purpose and is adescriptive survey type in terms of research method. Documentary method based on library studies and survey approach with a questionnaire tool was used to collect the research data. The assessment criteria for the resilience of urban communities were first determined in the present study. Then, a questionnaire was designed and distributed among the residents of Nourabad and Maskan-e Mehr in order to prepare the initial matrix for these criteria. The study population consists of the residents of Nourabad and Maskan-e Mehr of this city. Cochran's formula was used to estimate the sample size. According to the initial results of the census conducted in 2016, the population of Nourabad, including the residents of Maskan-e Mehr, was 66417. Therefore,given this population, the sample size was obtained to be 384 for the city of Nourabad using Cochran’s formula and the sample size for Maskan-e Mehr was obtained to be 500 households with household dimension of 5.5, given the number of households settled in Maskan-e Mehr until the end of 2017. The sample size was estimated to be 340 people for Maskan-e Mehr using Morgan’s table,. The scoring basis of the criteria was based on Likert 5-point scale with1 representing very low, 2 low, 3 medium, 4 high, and 5 very high. Finally, the average point of this questionnaire was considered as the initial matrix for VIKOR model. In the proposed method, the final weight of the criteria was determined based on AHP pair-wise comparison matrix. Finally, the criteria were ranked based on VIKOR technique procedure. In general, the findings of the current research were analyzed through hierarchy analysis and integration of the indices using VIKOR technique. Results & Discussion:In the first step, the raw data of each criterion associated with the resilience of Nourabad County and Maskan-e Mehr, which were extracted from the questionnaire, were used and the decision-making matrix was created. In the second step, Equation (1) was used to obtain the weight normalization matrix for Nourabad and Maskan-e Mehr. In the third step, AHP method was used for the weighting of the normalized matrix and determining the weight of the indices. The weights of the proposed indices were determined by the residents of Nourabad County and Maskan-e Mehr and were calculated using the AHP method in Excel 2013 software and were assigned to each index. After determining the weight of the criteria, the values of the normalized matrix for each option was multiplied by the weight of the criteria and consequently, the weighted normalized matrix was obtained. In order to determine the best and worst values for the criteria, equations (2) and (3) i.e. determining the positive and negative ideal points were used. Equations (4) and (5) were used to calculate the distance of the options from the ideal solution. Finally, VIKOR index (Qi) was used to rate the resilience of Nourabad County and Maskan-e Mehr based on the distance from the ideal solution. Generally, the views of the residents of Nourabad and Maskan-e Mehr were combined through VIKOR method to determine the value and importance of the criteria and the final weights of the criteria were determined using the AHP method. Applying the obtained weight on the initial values of the criteria and combining the weight indices, Nourabad County and Maskan-e Mehr were prioritized in terms of resilience. Conclusion:The results obtained from VIKOR technique showed that this method, as one of the multi-criteria decision-making method, has capabilities including multi-attribute utility theory or non-ranking methods. On this basis and after calculating the weights through hierarchy analysis process and using VIKOR technique, the difference in the resilience of Nourabad County and Nourabad Maskan-e Mehr was determined. Based on the calculations and the associated indices, Nourabad County has the highest resilience level with S=0.763, R=0.49, and Q=0.966, whilethe Maskan-e Mehr of this city has the lowest resilience with indices S=0.666, R=0.272, and Q=0.626. Given the Q index, Nourabad County (pre-created communities) has a more favorable condition in terms of resilience against natural disasters (earthquakes) compared to the Maskan-e Mehr of this city (planned communities) in social, institutional, economic, and physical aspects.
Sonia Mehry; Khadije Haji; Voria Alizadeh; Raoof Mostafazadeh
Abstract
Introduction
Drought as a natural deficiency of precipitation over aperiod of time is a serious hazard to environment andthe lives of living species. Spatial-temporal variability of wetand dry spells will affect availability of water resources andmanagement plans. Therefore, the lack of opportunity ...
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Introduction
Drought as a natural deficiency of precipitation over aperiod of time is a serious hazard to environment andthe lives of living species. Spatial-temporal variability of wetand dry spells will affect availability of water resources andmanagement plans. Therefore, the lack of opportunity and sufficient resourcescauses serious damage in the time of drought occurrence. Droughtdisaster management includes a set of reactive responses which canreduce or mitigate the consequences of drought events. Thus, theanalysis of drought indices is necessary to predict and assessthe spatial and temporal variability of this phenomenon. The StandardizedPrecipitation Index, as a well-known meteorological drought indicator, isthe capability of estimating various drought characteristics and can beused to analyze past droughts and predict future droughts returnperiods. The Standardized Precipitation Index was selected due to itssimplicity and ability of calculating the duration of droughtevents and the severity of drought and mildew.
Materials & Methods
In this study, drought condition and its spatial-temporal variations were investigated in Kurdistan province, Iran, using the Standardized Precipitation Index (SPI) calculated by DrinC software in different 3, 6 and 12 month time scales. Toward this attempt, the monthly precipitation data of nine synoptic stations in Kurdistan province including Sanandaj, Saghez, Zafarabad, Marivan, Baneh, Ghorveh, Bijar, Kamyaran and Dehgolan were obtained. The maximum available recorded data were used for analysis. The maximum and minimum values of the SPI index in the 3, 6, and 12-month scales were defined in the study period. Also, spatial distribution of drought condition based on the 12-month index was presented alternately in some years of the study period. Then, the most important characteristics of wet and dry periods, including the total number of wet and dry months, were determined in different drought classes. In this research, the inverse distance weighting method was used to determine the spatial pattern of drought characteristics in the study area and zoning maps.
Results & Discussion
The results of the study indicated that the severe drought in the three time scales has occurred across Dehgolan station in 2005-2006. The longest period of drought occurrence with high severity level with 17-month length was related to Qorveh station. The results of the study approved the variability of drought occurrences across the study area in different time scales.
Table. Some characteristics of wet and dry spells based on 6-month SPI values in the selected stations of Kurdistan province
Station
statistics
Sanandaj
Saghez
Zafarabad
Marivan
Baneh
Ghorveh
Bijar
Kamyaran
Dehgolan
Max
1.3
2.0
2.2
1.8
1.5
1.6
1.7
2.0
1.3
Min
-2.2
-2.6
-1.7
-2.3
-2.0
-1.7
-2.2
-3.0
-2.2
Average
0
0
0
0
0
0
0
0
0
Dry months
10
17
7
15
9
9
14
13
10
Wet months
6
11
9
11
7
7
14
11
6
Exceptionally wet months
0
0
1
0
0
0
0
0
0
Extremely wet months
1
1
1
2
1
2
1
1
0
Severely wet months
4
3
0
2
3
0
5
2
2
near normal months
20
20
12
17
10
10
17
19
11
Severely dry months
2
1
1
2
1
3
1
0
1
Extremely dry months
0
2
1
2
1
1
3
1
1
Exceptionally dry months
2
1
0
1
0
0
1
1
1
Finally, the zoning maps of the study area indicate that, there is a higher wet spell occurrence in the North and West regions, while the Eastern parts of the province experienced more severe droughts. Accordingly, Dehgolan station has the first priority in terms of drought severity among stations and the lowest drought severity was defined in the Zafarabad (Dyvandreh) station.
Conclusion
It can be concluded that, the Dehgolan and Divandareh stations were identified as the highest and lowest priority in terms of drought hazard occurrence in considered temporal time scales. As a result, drought crisis management and prediction can be one of the effective measures in reducing the damages of this climatic phenomenon, especially in drought-prone areas. It is suggested that other drought indicators be used to identify drought characteristics and the results be compared to obtain a comprehensive understanding on the drought severity and extent over the study area.
mohammad Rezaei; Elham Ghasemifar; Chenour Mohammadi
Abstract
Extended Abstract Introduction Vegetation plays an important role in the cycle of energy, carbon, hydrology and bio-geochemistry. The climate and vegetation have a mutual effect on each other. For example, the surface vegetation affects atmospheric patterns by affecting the surface albedo (which ...
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Extended Abstract Introduction Vegetation plays an important role in the cycle of energy, carbon, hydrology and bio-geochemistry. The climate and vegetation have a mutual effect on each other. For example, the surface vegetation affects atmospheric patterns by affecting the surface albedo (which determines the amount of radiation available for global warming, low atmosphere and evaporation as well). Therfore, the long-term study of the effect of the remot linking patterns on the varibility of vegetation is essential. So far, no study has been done on the effect of remote linking patterns on the varibility of vegetions.Therefore, the main objective of this study is to detect the vegetation changes in the month of May in Iran in relation to the remote linking patterns of the North Atlantic Oscillation. In this regard, remote linking patterns, such as El Nino have a significant effect on the surface climate with their periodic oscillations (Glantz, 1991). Many studies have been carried out in relation to the remote linking patterns and climatic elements on regional scale, but the role of remote linking patterns in the vegetation changes is a new topic which has been brought up lately (Wang et al., 2004). The normalized difference vegetation index (NDVI) obtained from the remote sensing satellite data is widely used to examine the vegetation features. Vicent Serrano et al. (2004) identified the positive and negative trends between NDVI and NAO in the Northern and Southern parts of Iberian Peninsula, respectively, by investigating the relation of NDVI, the North Atlantic Oscillation index (NAO) and the precipitation. Gouveia et al (2008) extracted the NAO correlation in the winter with vegetation activity in the spring and summer seasons by the combination of NDVI and luminosity temperature. Cook et al. (2004), Stockli and Vidale (2004), Sarkar and Kafatos (2004), Mennis, (2001), Erasmiet et al., (2009) also showed that there was a relationship between the remote linking patterns and vegetation in different parts of the world. Lu et al. (2012), showed that the vegetation impressibility in china in El Nino phase is greater than that of La Nino phase. Materials & Methods In order to investigate the relationship between the North Atlantic Oscillation and vegetation changes in the month of May in Iran, the normalized vegetation index products of MODIS sensor (MOD13A3) were used during the statistical period of 2001-2014. By applying the NDVI 0.2 threshold on the average long-term map of the vegetation index for the month of May in Iran, the area with larger and equal vegetation of the desired threshold was separated. Then, due to the severity and weakness of the NDVI values, the aforementioned area was divided into 3 areas based on the values of NDVI in order to assess the sensitivity of each area with regard to the remote linking patterns of the North Atlantic Oscillation which, helps identify the relationship between each vegetation category (namely, thinned, medium and dense vegetation) and the North Atlantic Oscillation index. Results & Discussion Due to the existence of vegetation-free deserts in Iran, an area susceptible to vegetation was first separated based on the threshold of at least 0.2 of the NDVI values. This region has about 38.2% of the country’s total area. Due to the high spatial variations in the NDVI values, the area was divided into 3 classes of thinned, medium and dense vegetation based on 0.2 to 0.5, 0.5 to 0.7 and higher than 0.7 ranges. It was assumed that the area with thinned and dense vegetation had the highest and lowest sensitivity respectively, with regard to the changes of the remote linking patterns. The positive and negative phases of the North Atlantic Oscillation (NAO) have significant effects on the climate of Iran. For example, the amount of vegetation, precipitation and humidity advection in many parts of the West, Northwest, and Northeast of Iran in the February 2010 (as a negative phase), were much higher than that in the February 2014 (as a positive phase). A 14-year time series was prepared from the NDVI values of the May for 18363 points in Iran and, each point was calculated with the variations in the values of the NAO index of January to May in a Pearson correlation coefficient matrix (assuming that the NAO changes in January influence the vegetation of May in Iran). The results showed that the positive and negative correlation values in terms of spatiality can be observed in all regions without a regular spatial pattern however, the maps showed that negative correlation values have covered a wider range of Iran in January and February. This indicates that, in the positive phase of the pattern, the higher values of sea level pressure in the Azore region, coinciding with the poor moisture transfer and precipitation systems, have caused less vegetation in a few months later (May) in Iran. Conclusion Given the highest coefficient of determination obtained in February(0.77) in East Azerbaijan province, the vegetation values of May can be estimated for the index points located in the Northwest and western provinces using the state of NAO in the months of winter.
Maryam Arjmand; Alireza Rashki; Hossein Sargazi
Abstract
Extended Abstract Introduction Dust cycles are an integral part of the Earth system, which emits about 2000 tons of dust every year (Shao et al., 2011) and plays an important role in the global climate changes (Park & Jong, 2008). The frequency of dust events in the arid and semi-arid regions is ...
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Extended Abstract Introduction Dust cycles are an integral part of the Earth system, which emits about 2000 tons of dust every year (Shao et al., 2011) and plays an important role in the global climate changes (Park & Jong, 2008). The frequency of dust events in the arid and semi-arid regions is much higher, meanwhile, dried lakes have the largest ration in dust emission (Goudie and Middleton, 2006). Hamoun e Jazmurian is a dried lake located in an homonymous topographic-low basin in southeast Iran and a main source for high dust emissions under favorable weather conditions, but so far limited studies have been carried out in this area, especially on dust. Remote sensing provides useful information about spatiotemporal variability of dust storms over the arid environment of the world. So the present study examines the spatiotemporal variability of dust activity over the region by identifying the dust events from the satellite data. Materials & Methods In this work, spatial and temporal variability of dust aerosol were analyzed over the arid environment of Jazmurian region and surroundings located on southeast of Iran by means of monthly mean data, including Absorption Aerosol Index (AAI), values products of TOMS-Nimbus7 (N7) (1979-1984), TOMS-Earth Probe (EP)(1990-2005) and OMI (2005-2014) as well as Deep Blue AOD of MODIS-Terra (2000-2007) and MODIS-Aqua(2002-2014) and Aerosol Optical Depth (AOD555nm) of MISR (2000-2013). Results & Discussion The results indicated that several hot points of dust including Sistan/Hamoun, Rootak, a region in Pakistan near the border with Iran, Makran coast, Gwadar Bay ion the southeast corner of Iran and the Jazmurian region. Overall, the annual trend of both AAI and AOD values obtained from all sensors, are increasing during the periods expect MODIS retrievals which has negative partial amounts, the time periods of 2002-2004, 2008-2009 and 2011-2012 are the peak of dust storms over the Jazmurian region because of human activities and severe droughts. Seasonal variations of AAI and AOD values showed the major dust activities occur during spring and summer and it is minimum in autumn over Jazmurian region. high activity of dust storms are in four months of May, June, July and August and low in the four months of November, December, January and February Conclusion Hamoun e Jazmourian is one of the active dust emission regions in south east of Iran. The amount of dust and affected areas have increased in recent years. Severe droughts in recent years and numerous dam construction are one of the main factors of dust emission increase in this region.
Mahmood Ahmadi; Hasan Lashkari; Ghasem Keikhosravi; Madjid Azadi
Abstract
Abstract
The present study was conducted to simulate precipitation and temperature with the RegCM4 and LARS dynamic model in two states, with and without using the statistical post-processing technique of direct model output in the north-east of Iran (Great Khorasan) and the statistical period of 1987-2011 ...
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Abstract
The present study was conducted to simulate precipitation and temperature with the RegCM4 and LARS dynamic model in two states, with and without using the statistical post-processing technique of direct model output in the north-east of Iran (Great Khorasan) and the statistical period of 1987-2011 in the annual time period. Based on the results, the annual bias average raw precipitation is equal to 53.63 millimeters and the post-processed is -11.25 in the LARS model in the study area during the 2007-2013 verification period. In summary, performing post-processing technique has been effective at 84% of the study stations in annual time scale and has reduced severely the bias error rate in most stations. Based on the results obtained from the RegCM4 model, the annual bias average raw rainfall of the RegCM4 model is calculated to be 85.3 millimeter and the post-processed to be 61.04 during the 2006-2011 verification period. Therefore, error values in most stations are very high before and after processing and the model results are not acceptable. In summary, performing post-processing technique has been effective at 75% of the research stations in annual time scale. Therefore, the absolute value of the bias error of the average annual rainfall post-processing of the LARS and RegCM4 models are equal to 13.6 and 61 respectively. The annual bias average raw temperature of the LARS model is equal to 0.096 degrees Celsius and the post-processed is -0.432. Practically, this is larger than the bias without post-processing, so post-processing operation is not effective in all stations and is only well defined in 46% of the stations. Simulation of 2 meter temperature data at the meteorological stations using the RegCM4 model as well as MA operations showed high efficiency.The annual bias average raw temperature of the RegCM4 model was -2.78 degrees centigrade which fell to -0.05 after applying post-processing technique. At all stations, the modelled annual temperature is different from observational data less than 0.1 ° C. Therefore, in the simulation of annual rainfall data, the LARS model is even more responsive than the RegCM4 model. And, in simulating the annual temperature data, the RegCM4 dynamic model shows a much better reality than the LARS statistical model.
Mostafa Khabazi; Ali Mehrabi; Javad Arabi
Abstract
Extended Abstract Introduction Digital elevation model (DEM) is the raster representation of the ground surface so that the information of each cell on the image has a value equal to the altitude from the sea level corresponding to the same spot on the ground. DEM is an appropriate tool for the generation ...
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Extended Abstract Introduction Digital elevation model (DEM) is the raster representation of the ground surface so that the information of each cell on the image has a value equal to the altitude from the sea level corresponding to the same spot on the ground. DEM is an appropriate tool for the generation of topographic maps and contour lines, access to the information of surface roughness, three dimensional vision, etc. (Jacobsen, 2004). The accuracy of the digital elevation model is effective on the accuracy of the information from which it is obtained. This is why researchers are always looking for a way to increase the accuracy of digital elevation models. Among the information resources that are used to generate this model are ground mapping, aerial photography, satellite images, radar data, and Lidar. Some of these data generate the digital elevation model with little accuracy due to the insufficiency of the elevation information. The aim of this paper is to investigate the accuracy of DEMs derived from ASTER satellite images and SRTM data with 30 and 90-meter pixel dimensions and the digital elevation model derived from the topographic 1:25000-scale maps with Differential Global Positioning System (DGPS) in different landforms including plains, hills and mountains. Materials and Methods The study area is a part of the project of dam and water transfer system from the Azad dam to the plain of Ghorve-Dehgolan (with the goal of transferring water from the catchments of Sirvan River into the country) in the province of Kurdistan and the city of Sanandaj. In this study, the Real-Time kinematic method (RTK) was used to locate the points. In this method, assuming that the coordinates of the reference station are known and comparing it with the location obtained from the GPS receiver, a correction value is obtained that is applied to the coordinates obtained for the Rover Station, which is known as the relative or differential method. In this method, the corrections are calculated asreal-time during the observations and are considered in the determination of the Rover location.The Leica GS10 GNSS receivers were used in this study. First, two reference stations were determined using the Fast Static method and then, the Real-Time kinematic (RTK) method was used. In order to investigate the extent of the data compliance and relation, the Pearson linear correlation analysis was used and the accuracy assessment of the extracted digital elevation models was carried out using the RMSE, mean error and standard deviation. Results & Discussion The statistical parameters such as root mean square error (RMSE), bias (µ) and standard deviation () were used to assess the accuracy of each one of the investigated digital models. By comparing different sources that create DEMs, it can be seen that the minimum error is first related to the digital elevation model extracted from the contour lines of the 1:25000-scale map (27/6 = RMSE) and then to the ASTER digital elevation model with the pixel size of 30 meters (RMSE=7.43). The 30-meter pixel size DEM has always led to better results than the 90- meter pixel size DEM. Based on the mean error standard, the minimum bias is related to ASTER30 m (bias of 2 m) and then to the 1: 25,000 DEM (2.17). The maximum bias was related to 30-and 90-meter models extracted from the SRTM data. The results of standard deviation error were in compliance with the RMSE results, which confirmed the superiority of 1:25000-scale map and ASTER30 m DEMs. The results showed that the determination coefficient of relationship between the ground data and digital elevation models is between 97 and 99. The maximum compliance is related to the digital elevation model extracted from the 1:25000-scale topographic data and the ASTER30 m DEM, while the minimum compliance is related to the SRTM90 m data. In general, the compliance of the digital elevation models with the ground data decreased as the field's conditions became more difficult, i.e. from plain to mountain. Conclusion The results of DEMs accuracy assessment showed that the minimum error was primarily related to 1:25000 contour lines DEM (RMSE=6.27) and then, to the ASTER30 m DEM (RMSE=7.43). The pixel size of 30 meters has always been better than the pixels size of 90 meters. Based on the mean error standard, the minimum bias is related to the ASTER 30 m (bias of 2 m) and then, to the 1: 25,000 DEM (2.17). The maximum bias was related to 30-and 90-meter models extracted from the SRTM data. The results of the standard deviation error were consistent with the RMSE results, which confirmed the superiority of the digital elevation models extracted from the topographic 1:25000-scale maps and the ASTER30 m DEM.
Abdolreza Kazeminiya; SedighehMeimandiParizi SedighehMeimandiParizi
Abstract
Extended abstract
Introduction
Given that, the tourism industry can play a significant role in the economy of any country, therefore, it can multiply the income generated by this industry through planning and providing tourists and travellers with easy access to tourist sites and service locations ...
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Extended abstract
Introduction
Given that, the tourism industry can play a significant role in the economy of any country, therefore, it can multiply the income generated by this industry through planning and providing tourists and travellers with easy access to tourist sites and service locations in any region or country. The necessity of paying attention to tourism and using modern technologies to expand it, and utilizing its numerous economic benefits for countries, research on the relationship between the expansion of information and communication technologieshasmadethe development of tourism necessary. Using the technology ofWeb GIS eliminates constraints such as the lack of sharing of data and different information between centers, the lack of easy access to the information needed at different times and locations, and the problems associated with updating them in the database. This researchhas investigated the role of GIS and the use of its Web environments (Web GIS) for wider, faster, cheaper access of tourists and guiding them to tourism and service information in the city of Kerman.
Materials and methods
To inform tourists and respond to their different needs such as informing about recreational places, ancient sites, cultural and service centers of the city of Kerman, roads (streets), as well as the implementation of the analytical functions required by any user on the city’s tourism map, such as searching for a place, question and answer from the related map (query), determining the best path, turning layerson and off, identifying the features, selecting, storing and printing parts of the map, in cooperation with the Statistics and Information technologyOrganizationofKermanmunicipality, designing and execution of WEB GIS system of tourism in the city of Kerman was carried out. The stages of performing this research for implementing and operating such system are as follows:
1. Collection, compilation and providing data, hardware and software required
2. Creating a GIS database
3. Drawing and preparing the required maps in GIS
4. Correction of maps using aerial photos, satellite images of the study area and GPS
5. Preparing and completing the description table of the required maps
6. Hyperlinking of data with relevant features
7. Drawing the final tourism map of Kerman city
8. Uploading the tourism map of Kerman city on the web and determining the access level of each user
Results and discussion
In this research, the existing maps, corrected aerial photographs with the scale of 1:5000 related to the year 2013, and satellite images and GPS were used to collect the recreational, historical, cultural, religious, service and the roads of Kerman city. After collectingthe tourism features and identifying the type of GIS software (Arc GIS10.2), the required tourism data with an appropriate format for storing and designing the land-referenced database using the ArcSDE software was entered from the GIS environment into the created spatial database of SQL Server. After designing the database, maps of the features related to tourism of the study area were prepared and drawn in the GIS environment. In the tourist map, for better guidance of travelers and tourists, for all related features, an image of them in the GIS environment was attached to the related feature which is referred to as the Hyperlink. By moving the mouse over the features, and by clicking on the feature’s area, the appendix which is attached will openon the map.To facilitate the arrival of tourists and travelers to their destinations by the network analyses map, the streets map was edited first and then, the topology was determined for them and finally, the geometric network of the streets of Kerman was designed. Every tourist or traveler can, by specifying his/her origin and destination on the map, determine the route of reaching his/her destination with respect to the parameters such as traffic, the type of the street, etc., and chooses the shortest access path in terms of time on the map.Finally, to load the tourism map of Kerman city on the Web, the required software and hardware wereprepared. With regard to the hardware,an appropriate server device and high-speed Internet lines were taken into consideration. Regarding the software, ArcGIS Server 9.3.1 and ARC GIS Desktop 10.2 were selected.
Conclusion
The most practical capabilities of the WebGIS in tourism that will cause the tourism development and more revenue for Kerman are the users’ access to the spatial and descriptive information of the cultural heritage sites, optimal routing for visiting places, planning and proposing the best tourism tour in a given time, searchingbased on the descriptions and finding the nearest tourism facilities, connection to documents and management capabilities.The most important issues that led to the implementation of Kerman’s tourism map Web GIS are the goals, the use and response to different requests of several users simultaneously. Presenting information in this way can provide a solution for distributing and disseminating data required on the Web and for public use. The advantages of using the Web GIS include online and updated access to maps and data via Internet connection, the possibilityof printing maps of a location, and more.
Bakhtiar Faizizafeh
Abstract
Introduction
Nowadays, detailed land cover and land use information is considered to be an important research topic in geosciences, environmental changes and natural resources. In this regard, monitoring agricultural land-use provides essential information for land use planners and decision makers. ...
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Introduction
Nowadays, detailed land cover and land use information is considered to be an important research topic in geosciences, environmental changes and natural resources. In this regard, monitoring agricultural land-use provides essential information for land use planners and decision makers. Multiple methods are used for monitoring agricultural land use from remotely sensed images. Object-oriented techniques used for processing satellite images makes high accuracy recognition of various land use patterns possible. Compared to traditional pixel-based approaches, these techniques reach a higher accuracy in extracting land-use information from satellite imageries using geometric information and features of different phenomena. In fact, object oriented methods relay on processing unit or image objects made by the integration of homogenized pixels in the segmentation process. Once segments are formed, various indices and spatial information like texture, pattern, form, content, and etc. are applied on processing units. In this way, identifying appropriate land use classes based on geometric features becomes possible. As compared to traditional pixel-based methods, these methods are more flexible and thus can apply a combination of spectral and spatial information. The main goal of the present article is to develop land-use maps and to evaluate agricultural activities in eastern basin of Urmia Lake using object-oriented processing techniques.
Study area and martial
The study area was chosen based on a mixture of agricultural land use, human settlements, and salt marshes in Urmia lake eastern margins. The main goal of the present study was to produce accurate maps of agricultural systems in Urmia lake eastern margins. Thus, various agricultural land uses were extracted from satellite imageries with an emphasis on orchard land use classes. Training data were collected through field operation using GPS. Moreover, 1:25000 scale topographic maps were used for geometric correction and rectifying of the satellite images.
Methods and techniques
Various agricultural and orchard land use were extracted from Aster satellite imageries received in 2016. In pre-processing stage, geometric correction including geo-referencing, orthorectification and atmospheric corrections were performed on imageries. In processing stage, detection functions were applied and images were then classified according to the research goals based on pixel-based and object-oriented algorithms. In this regard, maximum likelihood, parallelepiped, and minimum distance algorithms were used to classify images. Segmentation process was performed based on homogeneity, shape and compactness parameters. Accordingly, the geometric and spectral algorithms were used for modeling each class in object-oriented environment and object-oriented classification was applied based on nearest neighbor algorithm.
Results
Using object oriented and pixel based processing techniques, four land use maps were extracted. In order to evaluate and compare final results, overall accuracy and Kappa coefficients were extracted for each algorithm. Results indicate that among pixel-based classification algorithms, maximum likelihood algorithm with overall accuracy of 87.67 percent and kappa coefficient of 0.86 is more accurate than other methods. However, with a Kappa coefficient of about 0.93 and overall accuracy of 94.20 percent, this algorithm has a lower accuracy level as compared to object-oriented methods.
Discussion and conclusion
Results indicate that compared to pixel based techniques, object oriented processing techniques possesses a higher potentiality for extracting agricultural land use. The main advantage of object oriented methods is that they employ a combination of spatial information, spectral information and integrate them with GIS and remote sensing datasets. Moreover, using texture and shape algorithms in object based classification leads to improved accuracy of land use maps. Besides, it is possible to improve the accuracy of results using effective techniques in object oriented classification. According to research findings, object oriented techniques provide an effective method for classification of satellite imageries and extraction of land use maps. It is possible to use these techniques in landscape planning, natural resources, regional land-use and land-cover changes, sustainability of land cover, and etc.
Mohammad Reza Hafeznia; Meysam Mirzaei Tabar
Abstract
Extended Abstract Introduction Conflict represents a dispute or war between two or more actors on a local, national, regional or global scale. Geographical factors and values play a fundamental role in conflicts. Actually, conflicts occur due to a combination of geographical, political, and power-related ...
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Extended Abstract Introduction Conflict represents a dispute or war between two or more actors on a local, national, regional or global scale. Geographical factors and values play a fundamental role in conflicts. Actually, conflicts occur due to a combination of geographical, political, and power-related parameters, which can be explained within the framework of geopolitics. Africa has long been involved in a variety of conflicts most of which relate to the 0-15-degreeNorthernlatitude of the continent. From 29 countries in the region, 15 are involved in 11 boundary and territorial conflicts. The present study seeks to find an answer for the question that what the geopolitical roots of boundary and territorial conflicts in the 0 – 15-degree north belt of Africa are? Materials & Methods The current study is considered to be a ‘Basic theoretical Research’ in terms of goals, and a “descriptive” study in terms of nature and method. In terms of attitude, it is classified as a “descriptive-analytic” research. Data collection is performed by documentary method using library resources. Qualitative method of data analysis is applied. Results & Discussion In 0 – 15-degree north belt of Africa, the following variables are discussedas rootsof boundary and territorial conflicts: “Territorial conflicts among different ethnical groups and tribes in border areas of different countries” are considered to be among the effective causes of conflicts in 5 countries and 4 cases including Somalia and Kenya; Kenya and Ethiopia; Kenya, South Sudan and Uganda; and the northern half of Kenya bordering Ethiopia, South Sudan and Uganda. “Territoriality and territorial expansionism of statesand their endeavor to conquer space and control its resources” are considered to be causes of conflicts in 12 countries and 6 casesincluding Ethiopia and Eritrea; Sudan and South Sudan; Cameroon and Nigeria; Ghana and Côte d’Ivoire; Equatorial Guinea with Gabon; and Uganda and area around the Albert lakein theDemocratic Republic of Congo. “Dispute over a strategic border area between countries” has been an effective variablein 8 countries and 4 casesincluding between Ethiopia and Eritrea over Assab port; Ethiopia with Egypt and Sudan over Nile; Cameroon and Nigerian over the Bakassi Peninsula; and Eritrean and Yemen over Hanish-Zukar archipelago. “Actions of colonial powers which result in determining and mapping territorial boundaries of countries” are considered to be among roots of conflicts in 18 countries and 10 casesincluding conflicts between Ethiopia and Eritrea; Ethiopia with Egypt and Sudan over Nile; Eritrea and Djibouti; Sudan and South Sudan; Cameroon and Nigerian over the Bakassi Peninsula; Ghana and Côte d’Ivoire; Equatorial Guinea and Gabon; ethnic and tribal conflicts in boundary regions of Somalia and Kenya; Eritrean and Yemen over Hanish-Zukar archipelago; and Uganda and area around the Albert lake in the Democratic Republic of Congo. “Settling of a minority group from the neighboring country in a disputed border region” has been among the causes of conflicts in 4 countries and 2 cases including conflicts between Cameroon and Nigerian, and Uganda and the Democratic Republic of Congo. “Historical mentality and Nationalism” have been among effective variables in conflicts of 6 countries and 3 cases including conflicts between Ethiopia and Eritrea; Sudan and South Sudan; and Uganda and the Democratic Republic of Congo. “Weak performance in dividing and exact demarking ofboundary” has been among influential causes of conflicts in 6 countries and 3 cases including conflicts between Ethiopia and Eritrea; Sudan and South Sudan; and Uganda and the Democratic Republic of Congo. “Climate condition and climate change” has been among the causes of conflicts in 5 countries and 2 cases including conflict of Ethiopia with Egypt and Sudan over Nile; and ethnic and tribal conflicts in boundary regions of Somalia and Kenya. “Remote areas and Marginalization” have been among the causes of conflicts in 5 countries and 2 cases including ethnic and tribal conflicts in border regions of Somalia and Kenya; and the northern half of Kenya bordering Ethiopia, South Sudan and Uganda. Conclusion Geopolitical roots of boundary and territorial conflicts in the 0 – 15-degree north belt of Africafrom the end of the Cold War in 1991 to 2014 have been ranked based on their influence as follows: 1. Actions of colonial powers which results in determining and mapping territorial boundaries of countries; 2. Territoriality and territorial expansionism of statesand their endeavor to conquer space and control its resources; 3. Dispute over a strategic border area between countries; 4. Territorial conflicts among different ethnical groups and tribes in boundary regions of different countries; 5. Historical mentality and Nationalism; 6. Weak performance in dividing and exact demarking of boundary; 7. Climate condition and climate change; 8. Remote areas and Marginalization; 9. Settling of a minority group from the neighboring country in a disputed border region These roots are geopolitical in nature and the role of geopolitics, along with a combination of mutual relationshipsamong politics, geography and power is observedin each one of them. Due to the inclusiveness of the present study in introducing geopolitical causes of boundary and territorial conflicts, which have the potential of creating this type of conflicts in other regions of the world, the results of the present research are generalizable. Therefore, the results are generalizable to boundary and territorial conflicts in other parts of the worldwithin the framework of “the geopolitical theory of boundary and territorial conflicts”.
Geographic Data
Elham Forootan
Abstract
Extended Abstract
Introduction. In recent years, the population growth, the increase in irrigated land and economic development have caused the increase in the demand for groundwater resources all over the world. In arid and semi-arid regions where surface water does not have a significant amount ...
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Extended Abstract
Introduction. In recent years, the population growth, the increase in irrigated land and economic development have caused the increase in the demand for groundwater resources all over the world. In arid and semi-arid regions where surface water does not have a significant amount due to low rainfall and high evapotranspiration, people lives mainly depend on groundwater. As a result, it is necessary to identify the groundwater potential areas and determine its recharge areas using accurate technologies. So, the aim of this research is to compare the method of multi- influencing factors with the fuzzy method for determining the potential of groundwater in a part of Kebar-Fordo watershed, Qom city, Iran.
Materials & Methods. For this purpose, a part of Kebar-Fordo watershed located in Qom province was selected. Six factors layer, viz. slope, annual rainfall, distance from river, geology, soil, and landuse were considered and classified based on groundwater potential susceptibility in different scales. Multi-influencing factor method can determine the groundwater potential of the region by assigning appropriate weight to different effective factors. In this approach, the layers were combined in Arc-GIS after determining the weight of the layers. In the fuzzy method, the layers of six factors were converted to fuzzy based on the linear function, and then the layers were incorporated using the gamma function. Finally, the statistics of observation points and accuracy index were used in order to evaluate the models,
Results & Discussion. The slope map represents that most part of the studied area (78.56%) has a "0-1" class while "1-3", "3-9" and "9-25" slope classes could be observed in 19.97, 1.29 and 0.18% of the total area, respectively. The soil texture has a significant effect on the infiltration and percolation of the surface water movement towards the groundwater. Therefore, in this research, the soil factor has been investigated as one of the input factors to the models. Soils with high permeability are more suitable for groundwater recharge and vice versa. The soil texture of the area consists of sandy loam, loam, sandy clay loam, and clay loam textures, which cover 3.73, 90.72, 0.23, and 5.32% of the total area, respectively, with a rank of four to one for groundwater potential. In this study, geology map showed that Qft2 formation has the largest area (88.98%) and Plc formation is in the second rank (4.9%). Qft1, Qs.d and Mur units have an area of 2.22, 2.12 and 1.10% and the smallest area belongs to OMq formation (0.68%). Also, different types of land use in the study area were agriculture, garden, rangeland, bareland, and resendential area. The land use map showed that the largest area of this area was ariculture landuse (77.18%), while garden and rangeland covered 0.07 and 6.5% of the total area, respectively. Bareland and residential area comprise 2.94%, 13.31% of the total area, respectively. Among the different landuses, agriculture and residential area have the highest and lowest ranks in groundwater recharge. The rainfall map was categorized with four classes. The classes of 140-156, 156-168, 168-182, and 182-203 mm layers include 14.15, 48.92, 21.84 and 15.09% of the total area with the rank of one to four for groundwater recharge, respectively. The map of distance from the stream was divided into four categories: "0-659", "659-1480", "1480-2675" and "2675-4939" meters, which comprise 46.33%, 34.15%, 15.72% and 3.8% of the total area, respectively. In the method of multi influencing factor, the distance from the stream (8.33%) and the geological factor (25%) were the lowest and highest weights. In this regard, the factors of rainfall, slope, soil, landuse have 20.83%, 16.67%, 16.67% and 12.5% weights, respectively. Then, the groundwater potential map was prepared through overlaying in ArcGIS and the studied area was classified into suitable and unsuitable classes. The suitable class covers 75.15% of the studied area and the unsuitable class covers 24.85% of the total area. In the fuzzy method, the unsuitable class comprises 43.63% and suitable class covers 56.37% of the area. In order to evaluate the models, the statistics of the observation points were applied which the accuracy of the multi- influencing factor and fuzzy models was calculated as 71.42 and 78.57%, respectively.
Conclusion. Preparation of groundwater potential map is necessary to adopt management measures of rainfall storage and groundwater recharge in arid and semi-arid regions and it can be used for sustainable management of groundwater resources. The findings of this research revealed both model's accuracy in the studied area.
Abdollah Seif; Majid Naji
Volume 13, Issue 51 , November 2004, , Pages 46-51
Abstract
Today, thousands of satellites revolve around the Earth with diverse aims, and each of these satellites is at a certain distance from the Earth depending on the purpose it pursues. Satellite plays an important role in scientific research and communication, and it might be said that these satellites have ...
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Today, thousands of satellites revolve around the Earth with diverse aims, and each of these satellites is at a certain distance from the Earth depending on the purpose it pursues. Satellite plays an important role in scientific research and communication, and it might be said that these satellites have made the Global Village a reality, and thus play a crucial role in present-day civilization. Contrary to common ideas about satellites, they are not immune from effects of environmental factors in their surroundings, and are indeed influenced by factors such as the Sun and solar activities and other atmospheric influences, including the coronal material of the sun, solar flares and .... In this paper, we intend to briefly describe some of the factors producing disorder in the work of satellites or affecting their life-span. Among the strengths of the paper is the up-to-date quality of most of content, including the fact that most of these materials have been discovered in recent decades, and we have obtained them from the latest Internet websites and articles.
Mahdi Mo'meni
Volume 11, Issue 44 , February 2002, , Pages 46-49
Abstract
Since distant past, there were a number of scholars in different regions of Iran which, according to the geographical situation of each place, used certain methods for protection and maintenance of the Qanats (underground aqueducts), which sometimes were significantly efficient.With the construction ...
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Since distant past, there were a number of scholars in different regions of Iran which, according to the geographical situation of each place, used certain methods for protection and maintenance of the Qanats (underground aqueducts), which sometimes were significantly efficient.With the construction of first deep wells that were dug by the Americans in the year 1949 with the aim of providing water for their camps and with no attention to their negative impact on Qanats, the number of Qanats was reduced, so that from the 62,932 Qanats of Iran, 20,967 have been abandoned.There is no detailed information on the history of excavation of the first Qanats in Iran, but Megasthenes, in the year 300 BC, has reported on the existence of Qanats in Baluchistan.
In this paper, the major causes of decline of Qanats have been studied as follows:- Digging deep and semi-deep wells- Decrease in the stable level of groundwater- Government and people's neglect of the importance of Qannats
At the end of the paper, using field methods, a successful case of using modern and traditional methods for optimization and exploitation of Qanats has been studied. The traditional way of creating dams on waterways in the vicinity of a head well and on the path of Qanat, terracing the land along the natural slope and along the Qanat route are carried out in order to prevent the flow of rain water and its penetration into ground and to increase the water-provision by Qanat, and the modern method includes the transfer of water by a pump engine to a distance of 1000 meters and its distribution through pipe network to the farm side. The three major results of the implementation of the plan are as follows:
- Use of total volume of aquifer and 50% increase in rate of water provision- Use of the upstream areas of the Qanat head well and cultivation of about 100 hectares of fresh land- Creation of nutritional conditions for aquifer using soil mound, terracing and tree plantation method.
Bahman Ramezani; Ali Ba'dollahi
Volume 11, Issue 41 , May 2002, , Pages 46-50
Abstract
The distribution of precipitation on the surface of a basin is influenced by various processes. Part of the water penetrates into ground and joins ground waters or flows out of the basin in the form of sub-surface flows. Another part is consumed by transpiration, evaporation, interception and depression ...
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The distribution of precipitation on the surface of a basin is influenced by various processes. Part of the water penetrates into ground and joins ground waters or flows out of the basin in the form of sub-surface flows. Another part is consumed by transpiration, evaporation, interception and depression storage. The combination of these facts act as blocking factors and prevents precipitation from running off the basin totally.
Part of precipitation that is neither evaporated nor absorbed by plants or penetrated into the soil flows out on the sloping surfaces of the waterways of basin. This water is called runoff.
There are many factors that affect the amount of runoff in an area. Some of these factors are due to the characteristics of the basin itself, such as basin physiography, geology, vegetation, soil condition, etc. other factors intensify runoff through the interference of human activities in the natural environment of the region and disturbing the natural environment balance, and so cause irreparable losses in the region. In this paper, we have tried to evaluate the factors affecting the runoff of a basin by investigating precipitation and runoff in the basin of Masouleh.
Hosein Sarami
Volume 8, Issue 30 , August 1999, , Pages 50-56
Abstract
The importance of environment as the dynamic context of human activities is still the major topic of sciences especially geography, and the environmental causality is active along with human abilities in creation of landscapes and living places. The terms “environmental coercion” and “cultural ...
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The importance of environment as the dynamic context of human activities is still the major topic of sciences especially geography, and the environmental causality is active along with human abilities in creation of landscapes and living places. The terms “environmental coercion” and “cultural coercion” represent sharp aspects of causal attitudes which have been modified in today’s scientific geography in which every environmental factor and human being have been given their real position, leading to creation of the term “environmental causality”.Today human tries to turn this physical planet into a “cultural planet”, and to provide every person with a healthy life, organize the environment and keep it as human being’s “abode.”The subject studied in this paper is the environmental causality which, one the one hand, requires other discussions as prerequisite due to scientific approach and sensitivity of determination of the problem’s limits, and on the other, its breadth and delicacy necessitates keeping content of any research about it within certain limits and avoiding marginal and descriptive discussions; therefore, we mostly pay attention to fundamental and major points which have received less attention, and sort our material according to the following list:Introduction, lexical examination, causality, determinism and free will, determinism, free will, environmental causality, conclusion and sources.
Aliakbar Sarmadi Seyfi; Ahmad Adib
Volume 21, SEPEHR , February 2013, , Pages 51-53
Abstract
The present article investigates influential factors in land sliding phenomena in Qozlu village. According to the investigations and field studies, Qozlu village is located on an old land sliding zone and settlements in southern, western and central village have been damaged due to the activities of ...
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The present article investigates influential factors in land sliding phenomena in Qozlu village. According to the investigations and field studies, Qozlu village is located on an old land sliding zone and settlements in southern, western and central village have been damaged due to the activities of a sliding mass heel. Main factors influencing land slide in Qozlu village include undercutting and elimination of lateral supports by distributaries of Anguran Chay River, increasing discharge of springs along the drift limit of Qare Naz-Qozlu fault, irrigation of gardens in the sliding mass heel and domestic sewage entering the sliding mass and lower permeability horizon of Qom formation Conglomerate.
Hamid Reza Ershadmanesh
Volume 11, Issue 42 , August 2002, , Pages 51-54
Abstract
Most employers, whether they belong to public or private sections, have more or less a clear picture of what they want to implement. They often cannot properly convey their wishes to the people who are to carry them out. At this stage, the need for consultant engineering services who have capable experts ...
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Most employers, whether they belong to public or private sections, have more or less a clear picture of what they want to implement. They often cannot properly convey their wishes to the people who are to carry them out. At this stage, the need for consultant engineering services who have capable experts in employment becomes clear.The above-mentioned relationship between employer and consultant has almost the same nature in Europe and other countries, with the difference that in non-European countries the consultant and the employer are usually of different nationalities and it is their historical past that links them together.
Hasan Shamsi
Volume 1, Issue 4 , May 1992, , Pages 52-55
Abstract
A) In measuring distance by new rangefinders the following methods are used: 1) Phase comparison method 2) Pulse method (measuring travel time of a pulse until it returns) 3) Interferometry method These methods all depend on the fact that the speed of travel of electromagnetic waves is in the order of ...
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A) In measuring distance by new rangefinders the following methods are used: 1) Phase comparison method 2) Pulse method (measuring travel time of a pulse until it returns) 3) Interferometry method These methods all depend on the fact that the speed of travel of electromagnetic waves is in the order of the speed of light, and this speed must be precisely known. In electronic rangefinders, the first two methods are used more frequently. The third method is used to measure very small distances.
Khosrou Khajeh (Translator)
Volume 9, Issue 34 , August 2000, , Pages 53-55
Abstract
GPS, despite its all advantages over other surveying methods, shows weaknesses in certain conditions of field operations. When implementation of part of surveying operations by GPS is not possible, there will be need for another tool, such as Optical Total Station machines.In this paper, it is tried ...
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GPS, despite its all advantages over other surveying methods, shows weaknesses in certain conditions of field operations. When implementation of part of surveying operations by GPS is not possible, there will be need for another tool, such as Optical Total Station machines.In this paper, it is tried to mention the potentials of utilization created by combination of the two methods. In this paper, all emphasis was placed on field operations of surveying process. Following implementation of a research plan for preparation of planimetric maps through combination of two technologies, we have achieved results which show clear temporal improvement of surveying process. The results obtained from this plan show a temporal improvement between 27 to 73 percent compared to the same task of surveying implemented by only one of the technologies.
Hossein Klantari Khalil Abad; Hossein Hataminejad; Aref Agha Safari
Volume 16, Issue 61 , May 2007, , Pages 54-60
Abstract
Most of the buildings in the historical texture of Yazd have not been adequately resistant to earthquakes, and the rules, regulations and criteria have not been observed in their design. Most of these buildings are old and some of them are newly-built. The occurrence of earthquake entails serious and ...
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Most of the buildings in the historical texture of Yazd have not been adequately resistant to earthquakes, and the rules, regulations and criteria have not been observed in their design. Most of these buildings are old and some of them are newly-built. The occurrence of earthquake entails serious and irreparable damages to buildings, facilities, equipment, natural resources, social order, historical and cultural heritage, activities, employment and income, organizations and executive agencies, transportation system and business, therapeutic, health, educational, religious, etc. functions, and will lead to crisis. The crisis management process requires implementation of measures before, at the beginning, during and after the crisis.
Mahsa Beik Mohammadi
Volume 15, Issue 58 , August 2006, , Pages 54-59
Abstract
The Caspian Sea is the largest closed lake in the world located in one of the most strategic energy production areas in the world. This sea is of great importance for the countries of the region in terms of management and legal issues due to its vast oil and gas resources, communication and commercial ...
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The Caspian Sea is the largest closed lake in the world located in one of the most strategic energy production areas in the world. This sea is of great importance for the countries of the region in terms of management and legal issues due to its vast oil and gas resources, communication and commercial water lines, marine products, as well as environmental conditions, ecological balance, preservation of the environment and creation of beautiful tourist and natural landscapes in surrounding regions. Since the collapse of the Soviet Union, the four Treaties of the years 1921, 1931, 1935 and 1940 had established a solid legal framework between Iran and the Soviet Union, based on principles such as equality, monopoly, non-military identity of the sea, cooperation and ... However, after the collapse of the Soviet Union and the emergence of the issue of succession in that country and the formation of new states of Turkmenistan, Kazakhstan and Azerbaijan, legal problems have occurred and the policy of some of these newly independent states regarding the sea have raised doubts about the legal status of the Caspian Sea which can bring about undesirable political and economic consequences. The author, after referring to the legal status of this sea, has analyzed the problems created in its legal regime after the collapse of the Soviet Union using analytical and documentary methods, with conclusion that the existence of a valid, clear and firm legal regime based on previous (existing) treaties, while resolving the existing problems, will strengthen the sovereignty of Iran over the part of the sea in its vicinity.
Shahab Ghahramani
Volume 12, Issue 45 , May 2003, , Pages 54-57
Abstract
In this paper, we investigate the role of geomorphology in locating and implementing Mullah Sadra dam and power plant in the Tang-e-Baragh area on the Kor River. Determination of the final location of the implementation of this design and construction of the main body of the dam has been directly influenced ...
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In this paper, we investigate the role of geomorphology in locating and implementing Mullah Sadra dam and power plant in the Tang-e-Baragh area on the Kor River. Determination of the final location of the implementation of this design and construction of the main body of the dam has been directly influenced by geomorphological study of the area. The upstream strait has been selected as the location of the project due to appropriate morphology of its floor and side banks compared to the main strait, which has an inappropriate morphology with faults, seams and gaps.
Volume 1, Issue 1 , May 1990, , Pages 54-57
Abstract
The foundation and start of this project has been based on trade and technical advice from the University of Hanover in Federal Germany, which has accumulated enough experience in one of the newly-founded cities called Neustadt, and which has benefited from the guidance of the renowned Professor Kuncheni, ...
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The foundation and start of this project has been based on trade and technical advice from the University of Hanover in Federal Germany, which has accumulated enough experience in one of the newly-founded cities called Neustadt, and which has benefited from the guidance of the renowned Professor Kuncheni, and at least three papers In this context exist in the documents and sources of the 15th Congress of the International Association of Photogrammetry for Remote Sensing (ISPRS). However, our news report is based on the latest report by Mr. Kyuozu Ikeda from the Asia Aerial Surveying Company from Japan, which is presented in the fourth volume of the Sixteenth Congress (1988). The project has been scheduled for six years and so far one fourth of the system’s input data collection (in Japan) has been prepared and delivered to the Kuwaiti municipality.
Mohammad Hasan Ganji
Volume 1, Issue 3 , August 1991, , Pages 55-61
Abstract
One of the highly valuable geographic books, published in Iran in 1988, but not yet criticised or paid due attention (as far as the author is informed), is the book entitled " Iran's Encyclopedia of Villages and Religious Places" written by Dr. M.H. Papeli Yazdi and published by the Astan-e-Ghods Razavi ...
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One of the highly valuable geographic books, published in Iran in 1988, but not yet criticised or paid due attention (as far as the author is informed), is the book entitled " Iran's Encyclopedia of Villages and Religious Places" written by Dr. M.H. Papeli Yazdi and published by the Astan-e-Ghods Razavi Islamic Research Institution.
Khosrou Khajeh (Translator)
Volume 13, Issue 52 , February 2004, , Pages 56-58
Abstract
The widespread use of GPS has been accompanied with great deal of success and has already evolved into a true 3D instrument. Therefore, the major attempt to complete a GPS project is often focused on elevation issues. This paper examines the GPS elevation-determination limits, including GPS measurements, ...
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The widespread use of GPS has been accompanied with great deal of success and has already evolved into a true 3D instrument. Therefore, the major attempt to complete a GPS project is often focused on elevation issues. This paper examines the GPS elevation-determination limits, including GPS measurements, geoid issues and datum. Next, the GPS elevation-determination is described with a look at three applications of deformation control, GPS mapping with instantaneous processing, and device control and guidance.In practice, GPS elevation-determination usually involves three aspects:1 - Oval height measurement with GPS2 - Applying the geoid model3 - Adjustment of the orthometric (or normal) height so that the altitude base is appropriate.All of these issues create limitations, and the importance of each one, depending on the breadth and magnitude of the GPS mapping, is different, so here some of these limitations are studied in greater details.
Seyyed Ramin Ghaffari
Volume 12, Issue 47 , November 2003, , Pages 56-60
Abstract
Undoubtedly, geography is one of the most applied sciences in today's world, yet it is still isolated and somewhat unknown in our country. The mentality and knowledge of the majority of people toward this science is limited to the definitions of purely descriptive nature related to the 17th Century and ...
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Undoubtedly, geography is one of the most applied sciences in today's world, yet it is still isolated and somewhat unknown in our country. The mentality and knowledge of the majority of people toward this science is limited to the definitions of purely descriptive nature related to the 17th Century and before.Many people do not even understand the most obvious and most basic definition of geography, while geography is associated with lives of people, is as old as human being, and in a sense is the knowledge of living.The term geography is, in the minds of many people in our country, mistakenly synonymous with the names of mountains, rivers, capitals, races, etc., and has been associated with a higher level of knowledge of climatic status.This is such that, once encountered with any person educated in the field, they seem to have encountered a massive database or encyclopedia that has a high capacity for storing names of natural and human habitations. Therefore, answering such questions is the scientific task and outcome of any graduate or student studying in the field.
According to the author, in the emergence and development of such a wrong attitude toward geography, not only the experts and specialists of this field are guilty of not providing public awareness, but also the media which, despite diverse programs including some shows of geographic nature concerning one of the branches of this discipline, nevertheless avoids speaking of such mistakes consciously or unknowingly. In this paper, it is attempted to briefly describe the historical developments in the definition and content of geography from beginning to the present day, and to clarify the importance and current status of applied geography in natural and human sciences by mentioning the various branches of the aforementioned fields in the European and American countries as well as in our country, Iran.
Esma'eil Shahkou'ei
Volume 8, Issue 31 , November 2009, , Pages 56-61
Abstract
In this study, using the statistical information of twenty-one years (during the period of 1964-1985) available in ten meteorological stations in Gorgan Province, the trend of potential evapotranspiration has been calculated according to various formula by the help of computer programs. In addition, ...
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In this study, using the statistical information of twenty-one years (during the period of 1964-1985) available in ten meteorological stations in Gorgan Province, the trend of potential evapotranspiration has been calculated according to various formula by the help of computer programs. In addition, after comparison of potential evapotranspiration with the evaporation from the tank, its equations have been calculated and analyzed for all studied stations.
Hasan Shamsi
Volume 1, Issue 2 , February 1990, , Pages 56-59
Abstract
In describing electronic and electro-optic distance measurers, the word signal and the subjects of modulation and anti-modulation are frequently encountered. In this article we want to explain the concepts of these three terms to the readers of the journal.
Signal is the general name for any voltage ...
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In describing electronic and electro-optic distance measurers, the word signal and the subjects of modulation and anti-modulation are frequently encountered. In this article we want to explain the concepts of these three terms to the readers of the journal.
Signal is the general name for any voltage or variable current whose variation indicates a change in another natural phenomenon; for example, when speaking at the front of a microphone, the changes in the intensity of sound are converted into changes in an electronic voltage at the two outlets of the microphone circuit, which is called sound signal.
In telecommunication and radio communications devices, through the act of modulation, news, messages, audio and video signals are conveyed from one location to another using radio waves.
Seyyed Ali Ebadinejad; Ali Osanlou
Volume 20, Issue 78 , August 2011, , Pages 57-59
Abstract
The lack of active participation of the police in the urban planning process is one of the problems that the country's police now face, and this itself leads to a series of problems, including inappropriate location of police stations and offices, regardless of the three basic factors of geography, population ...
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The lack of active participation of the police in the urban planning process is one of the problems that the country's police now face, and this itself leads to a series of problems, including inappropriate location of police stations and offices, regardless of the three basic factors of geography, population and crimes. This problem is rooted in the attitude of the top managers of the Naja (Iran’s police force) and the country, while the city is the most important venue for police missions. The purpose of this article is to study the causes of the emergence of this problem, and further provide and mention grounds for police involvement in urban planning, so that a suitable solution can be devised to end this situation.
Saeed Akbarian Ronizi; Hassan Javaheri
Volume 15, Issue 59 , November 2006, , Pages 57-60
Abstract
This paper examines the various aspects of feasibility of developing electronic residences in order to help decision makers and planners to have a realistic view of the subject. Feasibility studies are tools that can further clarify the conditions for the planners. Feasibility studies attempt to optimize ...
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This paper examines the various aspects of feasibility of developing electronic residences in order to help decision makers and planners to have a realistic view of the subject. Feasibility studies are tools that can further clarify the conditions for the planners. Feasibility studies attempt to optimize the existing conditions by eliminating a part of the instability. In this paper, the reasons for the study of electronic residences, the concept of electronic residences (villages and cities), the dimensions of feasibility analysis of the development of electronic residences and suggestions for improving the process of feasibility examination of electronic residences. Consideration of the various dimensions of feasibility studies (economic, technical, political, social, etc.) are among the other matters mentioned in this article.
Ali Asghar Esma'eilpour Rowshan
Volume 14, Issue 55 , November 2005, , Pages 57-59
Abstract
This discussion examines the changing relationships between population and development, and in the first stage it represents the quantitative aspects of population such as size, density and migration’s rate of growth in relation to the issue of nomadism, a matter which obviously plays a very important ...
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This discussion examines the changing relationships between population and development, and in the first stage it represents the quantitative aspects of population such as size, density and migration’s rate of growth in relation to the issue of nomadism, a matter which obviously plays a very important role in the level and nature of development in the region. In the second stage, the quality aspects of the population such as the role of human resources in the development process have been discussed. This section mainly focuses on health and education issues, but nowadays human rights issues receive greater attention. Finally, there is no solid evidence of a strong causal relationship between various factors of population and the level of development, but the continuation of this discussion shows what needs are to be met in order to improve the quality of life of the majority of people living in the developing world.
Susan Mesgari (Translation)
Volume 9, Issue 35 , November 2000, , Pages 57-58
Abstract
Although data digitization methods have changed the basic rules of cartography, nevertheless the preparation and printing of maps always faces a complex set of changes and conversions. On the one hand, the GIS has provided new features and made the provision of related products easier, and on the other, ...
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Although data digitization methods have changed the basic rules of cartography, nevertheless the preparation and printing of maps always faces a complex set of changes and conversions. On the one hand, the GIS has provided new features and made the provision of related products easier, and on the other, it has caused problems in case of new products. Basically, automatic mapping involves four steps that include:- Understanding the meanings- Data entry- Data processing- Data transmission
Hasan Beik Mohammadi
Volume 8, Issue 32 , February 1999, , Pages 57-64
Abstract
Migration is one of the demographic and population analysis characteristics that is related to residential movement of people from one place to another. This movement takes place under the effects of attractions and repulsive facts of different areas, and creates especial economic-social and cultural ...
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Migration is one of the demographic and population analysis characteristics that is related to residential movement of people from one place to another. This movement takes place under the effects of attractions and repulsive facts of different areas, and creates especial economic-social and cultural effects on either of migrant’s sending and receiving places.Isfahan Province has experienced intense demographic transfer over the past decades due to imbalance in economic planning and concentration of industrial investments in a small part of the province as well as polar development and inattention to spatial development, so that between the years 1986 to 1996 more than 591,000 people (about 15% of the province’s population) have entered this area or moved within it, from which about 40% have been from other provinces, 3% from other countries and the remaining 57% were related to urban or rural transfers within the province. Study of inter-province migrations in Isfahan Province shows that this province has change from a migrant-sender to a migrant-receiver province due to high industrial, commercial, cultural and service potentials. The share of different cities from these migrations have not been equal, and the growth rate of some of them has reached 19.5% (Shahin Shahr).In this paper, using historical and analytical methods, the author has examined demographic transfer in Isfahan Province in the past as inter-province, outward and inward movements in connection with economic, social, political and cultural factors that affect them, and has investigated the positive and negative economic and social effects of these transfers on both migrant-receiving and sending areas of the province.Finally, courses of actions have been proposed to urban and demographic planners of the province for prevention of unbridled urban migration, control of the phenomenon of migration and organization of urban and rural demographic movements.
Mehrdad Hoseini
Volume 12, Issue 48 , February 2003, , Pages 58-61
Abstract
Rainfall is a climatic element that changes year by year, and in fact rainfall is a random variable over time. If the long-term rainfall data are available, the probability of occurrence of precipitation can be determined by statistical methods.In this study, the city of Semnan has been selected in order ...
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Rainfall is a climatic element that changes year by year, and in fact rainfall is a random variable over time. If the long-term rainfall data are available, the probability of occurrence of precipitation can be determined by statistical methods.In this study, the city of Semnan has been selected in order to determine the probability of annual, seasonal and monthly precipitation. Precipitation data in this city have been analyzed using computer software and statistical methods. Wet and dry periods, seasonal and monthly variations in precipitation and the probability of occurrence of seasonal and monthly precipitation have been determined.
Esma'eil Nasrabadi
Volume 12, Issue 46 , August 2003, , Pages 58-61
Abstract
The study of the evolution of human life over the centuries indicates that the type of life and livelihoods, physiological and physical characteristics, types of settlements and the degree of dependence on them ... have been different in various fields of the planet. Without bias and without geographic ...
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The study of the evolution of human life over the centuries indicates that the type of life and livelihoods, physiological and physical characteristics, types of settlements and the degree of dependence on them ... have been different in various fields of the planet. Without bias and without geographic force, one cannot deny the role of natural and climatic factors in life. Therefore, any change in these factors can transform various aspects of human life.Although it is difficult to make a definitive statement about climate changes because of the complexity of the various factors that confront the Aerial, Aquarius, Ice and Biosphere systems of the Plant, but the consensus among scientists based on numerous studies shows the undeniable role of human being along with environmental factors in the global warming process. However, the final judgment on the role of these factors is not possible considering the information available today. A problem that will be less significant in future owing to current progress.
In a general division, meteorologists and climate scientists can be classified into four categories. 1. Studies in relation to the proof of the Earth's trend of change and reduction of existing CO2; in this regard, comparison of statistics and information on meteorology, examination of past bio-climatic records, tree growth rings assessment, study on glaciers and surface water of the oceans and so on. 2- Investigating the factors affecting climate change; cases such as studying the effects of positive and negative interaction, aerosols, airborne particles, solar spots and their cycles, volcanic explosions, effects of greenhouse gases and ... can be noted. 3. Forecasting future changes using climate models; scientists' efforts to predict the future climate using the general circulation model, energy budget model, radiation transfer model, etc. can be mentioned. 4. Synthesis of the study of climate change and application of these studies in order to adapt human life and activities to new conditions.
With this attitude, the first three categories of studies together can be considered as a tool for more accurate and proportionate synthesis. In this paper, we try to identify the factors influencing these changes and predict the future conditions by demonstrating the process of climate change through mentioning examples. Clearly, the proposed solutions are mere suggestions and can become much broader.
Esma'il Shahkouei
Volume 8, Issue 29 , May 1999, , Pages 58-64
Abstract
In this research it has been tried to form a common statistical basis based on available statistical data for studied stations. Then, using the average of meteorological data for a period of twenty-one years (1964-1985) and various coefficients and formula for climatic classification, Gorgan Province’s ...
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In this research it has been tried to form a common statistical basis based on available statistical data for studied stations. Then, using the average of meteorological data for a period of twenty-one years (1964-1985) and various coefficients and formula for climatic classification, Gorgan Province’s climate has been classified.
Asghar Nazarian
Volume 2, Issue 6 , February 1992, , Pages 58-64
Abstract
The profound changes that have occurred today in geographic perspectives and studies have made revision of the pattern, spatial visualization models and regional-district study methods necessary. The rate of the process of transformation in concepts and thoughts of regional-district geography, its design ...
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The profound changes that have occurred today in geographic perspectives and studies have made revision of the pattern, spatial visualization models and regional-district study methods necessary. The rate of the process of transformation in concepts and thoughts of regional-district geography, its design and planning requires that the spatial distribution of each of the organizational factors, the replacement of the main poles and points of gravity, the network of central places and their hierarchical order in the form of regions and districts be reviewed.
Marziyyeh Motarjemi
Volume 14, Issue 54 , August 2005, , Pages 60-64
Abstract
Geomorphology is one of the branches of geosciences which is related to forms of terrain (topographic reliefs) of the Earth's Crust. The contact area studied by geomorphology is affected on the one hand by internal forces such as tectonic forces and volcano, and on the other by exogenous forces, i.e. ...
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Geomorphology is one of the branches of geosciences which is related to forms of terrain (topographic reliefs) of the Earth's Crust. The contact area studied by geomorphology is affected on the one hand by internal forces such as tectonic forces and volcano, and on the other by exogenous forces, i.e. erosion, which originate in the hydrosphere of the atmosphere. Geomorphology forms one of the largest natural units which has a very close relationship with other natural units. Identifying the principles of these relationships in order to understand them and consider and utilize them in developmental plans is one of the goals of geomorphology. As the term “geomorphology” suggests, the study of landforms and their changes and changing factors are among the topics and objectives of this science.In the morphogenetic domain of Sahand, important changes in topographic shapes, which are among the prominent features of this region, can be caused either by sequential function of internal and external factors or simultaneous operation of these forces, hence in this study attention has been paid to each of the internal and external factors. Clear effects of these changes can now be observed in the present appearance of Sahand. The study of natural environments and environments occupied by human beings is carried out by many sciences in order to exploit them more and more correctly. In this study, a part of this objective has been fulfilled by relying on Sahand geomorphologic study to identify the factors affecting evolution and morphogenesis.The content of this research does not at all include all the issues of the Sahand Mountain Range, and it can not be said that this study ends here, but there are many discussions concerning the high mountainous regions and the low basin areas that remain and require further studies.Today, due to the increasing number of population, in order to use natural areas ever more, as well as create new living environments and recreational places for humans, mountainous regions (in spite of the many difficulties) should be paid attention so that they become able to respond to some of the economic and residential needs.
