GIS-Based Evaluation Sand Diffusion Risk By Mind In Wuliangsuhai

With the development of human society, severe sandstorm disaster hampering the development of human society. Inner Mongolia is located in the north of China, the sand disasters affecting the ecological environment of this provinces for a long period. Wuliangsuhai is located in the western arid desert region of Inner, its ecological environment degradation and desertification expansion under the influence of climate change and human activities. The study area of 2010 TM image as the data source, on basis of 3S, to extract the sand source of study area of 30 years and analyze the characteristic of the spatial distribution pattern and its change under the the theory of raw sand disaster and risk evaluation theory, and the theory of natural disasters. Selection land use type, vegetation coverage, soil organic matter content, soil type and soil wetness as main assessment indicator of sand diffusion environment, using analytic hierarchy process and linear model to quantitative evaluation of Sand diffusion risk. The following is the main research contents and results:The result that the source of sand distribution to the east of lake, the area of sand is174.87 km2 in 1987, the area of sand is 217.37 km2 in 2000, the area of sand is 147.83 km2 in 2010; from 1987 to 2000, the area of sand had the greatest increasing of 42.5km2 in the past 13 years; from 2000 to 2010, the area of sand had reduced of 69.54km2 in the past 10 years.The area of extremely serious risk area is 64km2, and the percentage of it is 5%; this region land use type is given priority to with sand and saline-alkali land, soil type is given priority to with calcium soil, saline soil, low vegetation. The area of serious risk area is 374km2 and mainly distributed in the extremely serious risk area surrounding, accounting for 29.4% of the total area, the soil type is given priority to saline soils and gleysol; the area of moderate risk area is 517km2, and the percentage of it is 40.6%; the area of low-level risk area is 298km2, and the percentage of it is 23.5%; the area of weak risk area is 19km2, and the percentage of it is 1.5%, the low-level risk and the weak risk area located in the southeast of the lake district and the west.The results indicate:divide study area for the source of sand, serious disaster area, moderate disaster area, low-level disaster area, weak disaster area, and the proportion of corresponding land areas are 18%,24%,21%,19%and 18% respective. Sand diffusion simulation results show that:the area of extremely serious risk area is 301km2, and the percentage of it is 24%, and easily affected by the weather of sand source; the area of moderate risk area is 263km2, and the percentage of it is 21%; the area of low-level risk area is 242km2, and the percentage of it is 19%, the region is the sand disaster degree of transition area; the area of weak risk area is 228km2, and the percentage of it is 18%.This study by means of RS technology for large area monitoring, basis of spatial analysis functions of GIS, the 3S technology combined with natural disaster risk theory to simulate sand diffusion to provide theoretical for Wuliangsuhai sand prevention and control.