Mohsen Shaterian; Seyed Hojjat Mousavi; Zahra Momenbeik
Abstract
Extended Abstract Introduction Knowing type and percentage of each land use and land cover are considered to be a fundamental need for understanding and managing an area. Given the ever-increasing changes in land use, managers and experts need to be aware of past changes and developments. This is because, ...
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Extended Abstract Introduction Knowing type and percentage of each land use and land cover are considered to be a fundamental need for understanding and managing an area. Given the ever-increasing changes in land use, managers and experts need to be aware of past changes and developments. This is because, policy making and solving existing problems require detecting changes and determining the trend of changes over time. Satellite data is one of the quickest and least expensive methods available based on which researchers can produce different land use map. In this regard, Landsat Satellite imageries are one of the most important data sources used to study different types of land use and land cover changes, such as deforestation, agricultural expansion and urban growth. Extracting information from satellite imagery through classification is one of the most widely used methods. One of the most important applications of remote sensing data is for investigating and discovering changes in phenomena with a spatial-temporal nature (i.e. phenomena whose position and status changes over time). In fact, change detection is the process of identifying and determining the type and extent of land cover or land use in a given period of time based on remote sensing images. The present study seeks to monitor land use changes in Shahr-e Kord during the period of 1985 to 2017, and to prepare land use maps of the area using Landsat satellite imageries. Materials & Methods In the present study, satellite imageries received from TM, ETM+, and OLI sensors of Landsat satellites in 1985, 2000, 2015, and 2017 were extracted from the United States Geological Survey (www.usgs.gov) and analyzed using different remote sensing software and geographical information systems like ENVI 4.7 and ArcGIS 10.4. In order to produce land use changes map, error correction was first performed. Then, images were processed using supervised classification method and maximum likelihood algorithm, which based on previous studies have a higher accuracy compared to other algorithms. In order to classify land use/land covers, a training sample was produced for each land use based on field observations, topographic maps (1:25000) produced by Iran National Cartographic Center, Google Earth imageries, and visual study of the imageries. Then, classification results were corrected using auxiliary data, visual interpretation, experiential knowledge, and GIS techniques. Prior familiarity with the region, visual study of imageries, previous experience and field operations revealed that following land uses exist in the region and are detachable on the images as well: a) urban, b) agricultural, c) industrial, d) meadow, e) airport, and c) other land uses (including pasture, rocky areas and areas without any specific land cover). Confusion or error matrix –including overall accuracy, producer’s accuracy, user accuracy and kappa coefficient- was also used to evaluate the accuracy of the classification. Also, urban land use changes were monitored using image differentiation functions. Results & Discussion After production of land use maps based on imageries received in 1985, 2000, 2015, and 2017, area of the six land cover classes was obtained. Results indicate that during these four periods (1985 to 2000), urban, industrial, agricultural and airport land uses have increased to 13, 111.7, 5.2 and 3.4 km2 (1.26, 10.16, 0.51 and 0.4 % increase) respectively, while meadows and other land uses have faced a decreasing trend. In other words, it can be concluded that most changes during this 15-year period occurred in meadows and other land uses. Since development of the airport have resulted in destruction of a large part of meadows, this land use have faced more severe changes. Land use changes from 1985 to 2017 indicate that 7.8 km2 of agricultural lands were transformed into urban land use, 1.4 km2 to industrial land use, 1.08 km2 to airport and 7.7 km2 to other land uses. Also, 20.5 km2 of other land uses were transformed into urban land use, 203.1 km2 to agricultural land use, 0.03 km2 to dried meadows, 0.17 km2 to airport and 14.5 km2 to industrial land use. 2.8 km2 of meadows were also transformed into agricultural land use, 0.05 km2 to industrial land use and 2.04 km2 to airport. During this period, urban and industrial land uses have remained unchanged. Conclusion Generally, results indicate that urban, industrial and agricultural land uses have developed over time, and these land uses have always had a positive increasing trend. While meadows and other land uses have had a decreasing and negative trend. This is due to the construction of Shahr-e Kord Airport, uncontrolled exploitations, digging wells and drought phenomena, which have led to a decrease in the level of water in aquifers and destruction of natural ecosystem in this region. In this way, previous meadows have turned into the source of intense dust generation in the city, which is a sign of desertification and ecosystem destruction. Due to drought and water scarcity in recent years, new deep wells have been dug with the aim of supplying water. This have occurred despite the critical condition of the meadows, and thus, have resulted in repeated protests by farmers and livestock farmers. Dramatic decrease in other land uses, including pastures, can also be attributed to recent droughts in Iran and intense dust generation. Increased population, increased human pressure on natural resources and also development of agricultural lands are among other causes of the present situation. Based on existing maps and satellite imageries, Shahr-e Kord is developing towards North and North West. In some areas, this development has occurred in pastures. Therefore, due to very high population density in the region which is still increasing, and also ongoing migration of villagers to the city, supplying appropriate accommodation and occupation for this population requires finding new suitable locations for urban and industrial development of the city. This development process should happen with correct management and according to the goals of sustainable development.
Seyed Hojjat Mousavi
Abstract
Introduction About one quarter of world’s deserts are covered with quick sands, whereby, sand fields are the most common landforms. The movements of the sand fields are considered as a threat to the roads, natural resources, urban areas, agriculture and infrastructure.Factors such aspoverty of ...
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Introduction About one quarter of world’s deserts are covered with quick sands, whereby, sand fields are the most common landforms. The movements of the sand fields are considered as a threat to the roads, natural resources, urban areas, agriculture and infrastructure.Factors such aspoverty of vegetation, increasing of drought due to global warming have led to the dynamic of sand fields with different speeds in manydirections that threat the transportation, health, economic and human activities. Thus, the spatial-temporal monitoring of sand fields dynamic behavior and identifying their directions of development are of great importancein the management of dry regions and conservation of natural resources. Therefore, the aim of this research is the Multi-temporal monitoring of sand field dynamic behavior in the west of Damghanplaya from 1972 to 2016, in the form of three 15-year period through data and remote sensing methods. Materials and Methods Damghanplaya Basin with an area of 18070.918 km2issituated between Toroud-ChahShirin Horst and the Alborz Mountains with an elevation of 2319 and 3884 meters respectively. Its general slope is towards the center of Damghan desert with an elevation of 1028m. Damghan playa is a tectonic-sedimentary hole, which is presently influenced by different geomorphic and climatic morphogenetic processes. Because of the vegetation and precipitation shortage,the wind morphogenetic systems dominate other processes. Thus, several types of wind erosion landforms can be observed in this region. The study area is the western erg of Damghanplaya with an area of 71.155 Km2 which is situated in Damghan Basin in the north of Iran’s great central desert. The region is located between latitudes 35° 51´ to 35° 58´ N and longitudes 54° 13´ to 54° 25´ E. This is an applied research and its methodology is a combination of remote sensing analyses. In this regard, topographic maps with a scale of 1: 25,000, geological maps with a scale of 1: 100,000 and Google Earth’s satellite images were used first to determine the position of the study area. Then, spatial database was completed through receiving Landsat satellite images during the period 1972 to 2016. Sinceseveral series of remote sensing satellite images belonging to multiple time periods are needed for monitoring the dynamic behavior of the sand field, four series of Landsat satellite images, MSS, TM , ETM+ and OLI sensors related to three 15 year periods of 1972,1987, 2002 and 2016 respectively, were used in this research. The aforementioned images were obtained from the Landsat satellite archive on the American geological organization website (http://earthexplorer.usgs.gov/). Then,color combinations, IHS transformation, and supervised classification of Maximum Likelihood methods were used to enhance the spatial area of the sand field, and the method of images difference and the calculation of the changing classes level were used to examine the type and trend of the changes.. Findings and Results The results show that the maximum and minimum area of the sand filed are observed in 2002 and 2016 with an area of 92.2641 and 49.2803 km2 respectively. The results of change detection show that there are three types of changes including increasing, decreasing, and no-changes. As it can be observed,the maximum area of the classes of change belongs to the no change class that the periods of 1972 to 1987 and 2002 to 2016 with the amounts of 58.3506 and 48.2841 km2 respectively,have the highest and lowest areas, while, the minimum area of the classes of change belongs to the class of incremental changes that the periods of 1987 to 2002 and 2002 to 2016 have the highest and lowest areas with the amounts of 38.2833 and 1.0359 km2 respectively. The maximum and minimum areas of decreasing class of changes belong to the periods of 2002 to 2016 and 1987 to 2002 with the amounts of 43.9829 and 14.2693 km2 respectively. In this regard, the no-change and increasing change classes with the standard deviation of 5.0445 and 19.4699 respectively, have the minimum and maximum range of changes during the entire period of 44 years. The results obtained fromstudying thetemporal trend of changes indicate the existence of a decreasing trend in the no-change and increasing change classes, and also the existence of an increasing trend in the class of decreasing changes.Descending trend of no-change class is uniform and continuous. In contrast, the trend ofincreasing and decreasing classes of changehas a periodic jump in the second time period (1987-2002), but their overall trend is almost uniform. Discussion and Conclusion Western erg of Damghanplaya has decreased by approximately 6.7225 km2 in 1987 compared to 1972. Most of this reduction has occurred in the southwestern and eastern parts of the sand field. The southwestern contraction of the erg is in accordance with the pediment and the sand harvesting area, the causes ofwhich are the sand transfer by local winds blowing from the southwest to the northeast, as well as the formation of the desert pavementfacies. In contrast, the eastern contraction of the erg is due to the increase in moisture content from the Haj Aligholiplaya and the increase in humidity caused by agricultural lands adjacent to the erg. In the second period, the trend was completely reversed and the sand field was expanded in 2002 by approximately 17.3659 and 24.0885 km2in 2002 compared to the years 1972 and 1987 respectively. This period is considered to be the most risky periods in terms of environmental hazards. In this period, major spatial expansion of the erg has taken place to the east and especially to the northeast. This expansion can be due to the increased drought severity and the continuation of dry periods and the release ofthe agricultural lands in some cases. In the third period, the situation has improved and the dynamic of sand has reduced, so that the extent of sand field has decreased in 2016 by 25.6178, 18.8952 and 42.9837 km2compared to the years 1972, 1987 and 2002 respectively, which represents the negative balance in the erg. In other words, the amount of the sand entering the erg is far less than that of the sand going out. In terms of location, the contraction of this period on the margins of the ergextends continuously and almost uniformly, but the largest contraction isobserved in the eastern, northeastern and southwestern parts. This decrease is due to the implementation of desert greening plans in the form of quick sands stabilization projects by planting Haloxylon. This indicates the positive and successfulfunction and role of desert greening projects. Also, due to the favorable natural and climatic conditions, the species of Haloxylon has been able to regenerate naturally in the area under cultivation. This has had a positive impact on the stabilization of quick sands and the reduction of erg changes.
Sedighe Kianisalmi; Seyyed Hojjat Musavi; Parisah Yeganeh Dastgerdi
Abstract
1- Introduction
One-sided, unbalanced and unplanned development of cities, population and activity in the area, has left a great deal of the country's capacity useless, and has imposed a lot of problems on planners at different levels (ahmadi et.al,1389: 94). In order to achieve sustainable development, ...
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1- Introduction
One-sided, unbalanced and unplanned development of cities, population and activity in the area, has left a great deal of the country's capacity useless, and has imposed a lot of problems on planners at different levels (ahmadi et.al,1389: 94). In order to achieve sustainable development, describing and assessment of the state of the environment and resources is necessary before any planning (movahhed, 1385: 11). Tourism, especially ecotourism is also no exception. Ecological potential assessment of tourism areas to use have been identified as a tool to achieve sustainable development (jowzi et al. 1388:71). In order to achieve sustainable development, land planning is essential and the infrastructure of this planning is environmental assessment, ecological potential assessment, measurement and potential of land with clear and pre-planned criteria. In this regard, from the 1960s, the geographic information system was established with a tangible progress in the spatial planning of land use to accelerate the development of various methods for determination of land ability for different uses.
In this study we have tried to define ecotourism potential, using assessment of Environmental Ecological potential in Chaharmahal and Bakhtiari Province to provide a dynamic setting for the development of the region. Therefore, because of an abundance of natural attractions such as wetlands, lakes, waterfalls, springs, rivers, mountains and peaks, caves, plains and forests, as well as historical- cultural attractions, such as bridges, villages and castles, there is a great potential to attract many visitors. In this study,it is attempted that with the use of GIS and ecological potential assessment model for establishment of tourism in the region, the potential can be investigated. The necessity and importance of this research is the factthat despite the unique characteristics of the province, especially in terms of nature, which can play a more active role in the economic, social and cultural area, and despite these diverse and valuable attractions, unfortunately less attention has been paid to this attractions so with a good planning and suitable using of available resources, the region can be developed sustainably.
2- Material and Methods
In Makhdoom systemic approach, ecological tourism model is provided for intensive and extensive outing (firoozi et al, 1392: 159). At this stage, by using collected data in the phases of analysis and conclusions in the environmental units with ecological models built for the user, the most appropriate activities are selected. Based on the results of investigations in Iran and the countries that are ecologically similar to Iran, a set of ecological models have been produced inIran which can be compared and measure ecological information about the model and determine the type of actions which should be taken. The model was used to determine the usages of the ecological models of agriculture - pasture, forestry, rural-, urban-industrial development, ecotourism, intensive tourism and aquaculture (Makhdoom, 1385: 185-212). This study seeks to find areas suitable for ecotourism (suitable Class A, suitable Class B and inappropriate). Therefore, suitable areas for loading the proposed activities appropriate to the potential of the region's stability have been identified, taking into account variables such as slope, rock and soil, aspect, water, plants, climate and weather and also preparation of needed maps.
3-Result and Discussion
In order to determine the ecological potential for ecotourism development in Chaharmahal and Bakhtiari Province, according to the preference of parameters in terms of importance in Makhdoom model (makhdoom, 1380: 203), first, slope map was developed in 9 classes using digital elevation model map and using the capabilities of ArcGIS. In the next stage, soil and rock condition was evaluated and the map was prepared. After determining the soil groups in the province, suitable areas for ecotourism class A, with suitable soil which is placed in Inceptisoils category, was separated. Climate is another factor considered in the assessment of ecological potential. In this context, the average temperature in warm period in the provinceis calculated. Since proper temperature during warm period for extensive recreation class A is 21-25 degrees Celsius, this feature was introduced in the attribute table. The next parameter is the number of sunny days. For extensive recreation class A for spring and summer seasons, the number of sunny days have to be more than 15 days per month. The last parameter is water. For extensive recreation class A, water level must be 5-12 liters per person. Citing the fact that the province, in terms of water resources is rich and has good precipitation, water levels parameter in the province was considered desirable.
In the last stage, all obtained maps, are mutually overlaid and finally a map is obtained,in which all the necessary conditions for an extensive recreation class A are introduced and shows all the suitable areas for extensive tourism.
4-Conclusion
After overlaying Maps and finishing ecological potential assessment process, it was found that a rather wide region of the province is suitable for developing ecotourism. According to the calculations done, about 32.1961square kilometers of the province is found suitable for extensive recreation (class A), the city of LORDEGAN has the largest share of the relevant regions and the city of BOROUJEN has the lowest share, respectively.
