Risk Degree Evaluation Of Soil Salinization Based On GIS In Oasis Irrigated Area Of Dry Inland River

Xinjiang Yanqi Basin is a large-scale semi-closed intermountain basin, which is a folded fault mountain system of the south TianShan Mountain. The climate of Yanqi Basin has transitional feature from south to north in Xingjiang; The Bostan Lake is located at the southeast of Yanqi Basin. Because of the water level effect of setup of Bostan Lake, it makes the condition of groundwater runoff worse in the basin. At the same time, due to unreasonable irrigation of lasting diversion surface-water, and a mass of field are dilapidated for secondary salinization, which do harm to agriculture and economic sustaining development. Therefore, this paper takes Yanqi County of plant irrigated area as an example, through field investigation and laboratory analysis, analyzed the genesis of soil salinization in oasis irrigated area of dry inland river; Based on GIS, carried on spatial analysis to the lithology of soil, buried depth of the groundwater, degree of mineralization of groundwater and soil salinization status; It adopted the Gray correlation model, analyzed and calculated the incidence degree of the lithology of soil, buried depth of the groundwater, degree of mineralization of groundwater and soil salinization, then selected three indicators of the lithology of soil, buried depth of the groundwater, degree of mineralization of groundwater and soil salinization to create a soil salinization evaluation system index system of risk evaluation; Based on the artificial neural network model-BP model, got by the training sample and fitting sample, derived the risk assessment model in Yanqi County, as well as assessed and predicted the soil salinization risk degree in Yanqi County of plant irrigated area.The paper through evaluating the soil salinization of quantitative risk assessment in Yanqi County of plain irrigated area, the safest and most insusceptible salinization land area is 12.3% of the total land; the safer and more mild salinity land area is 5.2% of the total land,the dangerous and moderate salinity land area is 44.6% of the total land,the more dangerous and severe salinization land area is 24.0% of the total land, the dangerous and very serious salinization land area is 13.9% of the total land. The land prone to soil salinization accounted for 82.5%. Thus it can be seen that Yanqi County plain irrigated soil salinization has great criticality.For researching the risk assessment of soil salinity has very important significance to rational utilization the land resources, preventing and curing the soil salinization, improving the crop growing environment, protecting the fragile ecological environment.