ANALYSIS OF CHARACTERISTICS OF SALINE SOILS AND INFLUENCING FACTORS IN DEBRIS FLOW DISASTER PREVENTION ENGINEERING AREA OF SHACHE COUNTY

This paper intends to systematically sample the topsoil within 2 m of the debris flow prevention area in Shache County and analyze its saltness. The distribution characteristics of saline soils in the area,the impact on the prevention area,the causes of saline soils and the factors influencing salinization are discussed in depth. It is found that the study area is mainly medium and weakly saline soils,with very small areas of strong saline soils and no hyper saline soils. The relative content of each ion in the soil salinity in the study area changes regularly due to the increasing saltness,under a combination of meteorological,topographical,groundwater and formation lithology factors. The planimetric distribution showed a gradual increase from south to north,with increasing salinization towards the Yarkant River. Upwards,saline soils showed a clear zonation and superficial aggregation,with a general accumulation of salt in the surface layer and a general downward trend in the salinity of eutectic salts throughout the region. Soil pH changes enhance with increasing depth in the vertical direction. The engineering diseases in the study area are structural cracks,which are divided into two categories: surface cracks and deep deformation cracks. The salt intrusion damage to the project is the cause of surface cracks in the prevention and control works. The salt swelling and dissolution characteristics of saline soils lead to the production of deep deformation cracks. Regression analysis of the factors influencing salinity using SPSS25 yielded that the spatial distribution patterns of salinity and mineralization,groundwater depth and elevation in the study area coincided well. Mineralisation enjoys the highest spatial correlation with soil salinity in the study area and showed a direct effect. The results of the study can provide reference for the prevention and mitigation of geological hazards and regional development and construction in Shache County,which provide reference for the study of saline soils in other similar areas.