ranking of vulnerable villages against wind erosion and movement of running sands using fuller triangle and orestemodels (case study: villages in shahdad, west lut desert)

1. introduction wind erosion is a major geomorphological force, especially in arid and semi-arid regions. it is also a major source of land degradation, evaporation, desertification, harmful airborne dust, and crop damage especially after being increased far above natural rates by human activities such as deforestation, urbanization, and agriculture. wind erosion removes sediment, damage crops, fences, buildings, and highways. fine sediment particles are lost along with nutrients, which can result in reduced crop yield. eroded sediment particles are a nuisance for many people and can adversely affect the health of some individuals. there are also circumstances where eroded dust can obscure visibility. such conditions can lead to fatal traffic accidents. above 80 percent of iran is currently located in arid and semi-arid to dry and sub-humid climates and they have sensitive conditions given the climatic conditions and natural characteristics of these regions and improper utilization methods, hence, they are potentially and actually subject to the phenomenon of desertification. the central and southeastern parts of iran are always under the influence of wind hazards due to their location in arid and semi-arid regions of the world and existence of sand areas. this process each year makes damage to the rural housing in the area. the running sands have great influences on the settlements and facilities. the roads and transportation facilities are greatly affected by the hazards. the networks play an important role in making relations between neighboring villages as well as passenger and cargoes transportation. these networks are sometimes disrupted by the sand masses. 2. study area the lut desert is located in the south-east of the country. between june and october, this arid subtropical area is swept by strong winds, which transport sediment and cause aeolian erosion on a colossal scale. consequently, the site presents some of the most spectacular examples of aeolian yardang landform. it also contains extensive stony deserts and dune fields. the property represents an exceptional example of ongoing geological processes. the study area of this research is located in east kerman and west part of lut desert. it is located in from 57:52:15 e to 57:53:15 e longitude and from 32:27:00 n to 32:28:00 n latitude at 298 meters above sea level. this area is in takab of kerman county near hojatabad and islamabad. there are vast sand areas in the vicinity of the area. the average precipitation in the shahdad station is 35 mm and most of the rainfall is in winter. the average temperature is 40 c and the average of maximum temperature is 46 c in july and the average of minimum is 34 c in december. 3. material and methods this is a descriptive analytical research in a survey. the research is carried out in two quantitative and documentary parts. in documentary section, we have used library and literature review, and in quantitative part we have also used statistical data to make required maps. in the method of this study, we initially found vulnerable villages and the areas susceptible to the sand movements. the villages have been observed in the field and then their border has also been specified on the map. how the villages are affected by ted sand have been determined to find the vulnerable parts of the rural areas. the most important parameters affecting the sand movement have been identified and entered into arcgis software. fuzzifications have been made on the layers and they have been prioritized by fuller triangle. in the next stage, the villages have been ranked in their vulnerability using oreste model. 4. results and discussion the ranking of the villages have indicated that some villages are more affected by the sands and some others are less influenced. the villages in southeast part are more affected due to more severe winds, less ground water level, and less soil thickness. the villages of deh ghazi and zaman abad are in the 1st and 2nd ranks, respectively. the villages in northwest are less influenced by the sands due to more ground water level, less wind severity, and more surface water. the villages of shojaabad, dehnosalar, and salarabad are, in order, less affected by the sands. 5. conclusion the results of the research have indicated that the villages located in the southeast part are more affected by the sands and that the cultivated areas, roads, and facilities in these areas are more threatened by the sand effects. on the other hand, the villages in northwest including shjabadmohamadali, deh no salar and salarabad due to the parameters listed better than elsewhere in the region is less affected. generally, natural factors can influence these rural areas differently.