Information statistical analysis of influencing factors of soil salinization in Yanqi basin.

Secondary salinization of soil as one of the most important environmental problems in the oasis of arid inland basins is usually measured by the salt content in top soil layer. Salt content in top soil layer is affected by climate,land use,soil lithology and depth to groundwater. In order to understand the problem of soil salinization in the northwestern area of Yanqi Basin,the relationships between salt content in top soil layer and land use type,soil lithology and depth to groundwater at different times were assessed by information statistical method. Results showed that the land use type is the largest contributor to accumulation and spatial variant of salt content in top soil layer,with the lowest salt content in the farmland area and highest in wilderness. Soil lithology is the least contributor to the accumulation of salt in top soil layer among the selected factors,with the highest salt content in top soil layer in the loam area and lowest in the silt area. The depth to groundwater played a very important role to the salt content of top soil layer with remarkable lag effect.