Research On Soil Erosion And Efficient Utilization Of Water And Soil Resources Based On "3S" Technology In Arid Zone

This thesis takes the upstream of Wuliangsuhai lake, an arid area, as the study object, and carries out the research on water and soil resources efficient use to solve the problem of soil erosion, water environmental degradation, land contamination, agricultural non-point source, etc. Based on soil and water conservation theory, water resources science, fractal theory and Feed-Animal Balance theory, this study adopts the methodology of field investigation, experimental observation, system analysis and3S techniques(Remote sensing, Geography information systems. Global positioning systems), and puts forward configuration mode and key techniques of high-efficiency utilization of water and soil resources. The findings provide a scientific reference for problem of soil and water loss control and efficient use. The main results are as follows:1) The evaluation method of spatial and temporal dynamic changes of oil erosion was established based on3s technology. Using3s technology and Markov models to construct transfer matrix of different soil erosion area, and applying geo-fractal theory, this study analyzes the change rate of intensity, fractal characteristic and Stability of different soil erosion intensity. The results show that, the annual erosion intensity levels in1985were ranked as light, tiny, strong. In2000. tiny, light, moderate, ultra strong, strong. In2011, intense, tiny, strong, extremely strong, light, moderate.From1985to2011, the stability of tiny-eroded soil decreased, and the stability of light-eroded increased, which indicate that plaque stability is good. While the stability of moderate erosion stayed unchanged. The sharp change takes place in the strong erosion and ultra strong erosion areas, which call for urgent treatment and protection.2) The soil erosion model is established based on GIS and RUSLE. The automation of RUSLE calculation process is realized on GIS platform. This will provide scientific basis for quality evaluation, utilization, planning and configuration of water and land resources.3) The main factors that contribute to land resources and vegetation degradation are analyzed and the quantitative analysis method is discussed.The results show that. high coverage grassland area decreased sharply during1985-2000, from882.38km in1985to462.55km in2000.The area has reduced by47.57percent.From2000to2011the area declined by122.48km,the main reason is overgrazing and other unsuitable farming techniques. Saline-alkali land area showed a fast increase of122.48km from1985to2011. the main cause is unreasonable irrigation.4) The balance relationship between Water supply and Water demand of Agriculture, industry and human and animal in the object area was carried out with the method of quantitative analysis.The results show that, a) The total water demand is9115.90×10-m3/a. while the total recharge is4521.67×104m3,b) Water tables are falling at an average speed of0.87m/a. local area the speed of1.56m/a due to the serious exploitation of groundwater resources, which alarmed the serious deterioration of ground water environment.5) Considering regional topography, soil and water resources utilization and water loss and soil erosion characteristic and fanning non-point source pollution, the study area can be divided into three functional areas, they are Source water conservation and soil conservation area, Agriculture and animal husbandry production and windbreak and sand-fixation areas, Pollution control and ecological water. According to the attributes of three functional areas and the problems of soil and water resources use in areas. The measures for water and soil resources utilization configuration mode and key technology were put forward combining with the comprehensive control of soil erosion, ecological restoration, water-saving irrigation, sandstorm area management and non-point source pollution control technology.