Analysis of Distribution Patterns and Spatial Variability of Soil Salinity Affecting Factors in Topsoil Layer of Salinized Soil in Jinghe Oasis

Salt content, electrical conductivity (EC) and pH of soil are the major factors in assessing salinization degree of the soil, so the study to quantify their spatial heterogeneities is the precursor of solving the problem of rapid diagnosis of soil salinization. The authors chose the Jinghe Oasis as their study area, and used the "3S" technology combined with the Google Earth in field survey. Results show:(1) salt content and electrical conductivity in topsoil (0-10 cm) varied vigorously with variation coefficient being 1.053 and 1.146, respectively; soil electrical conductivity in the >10-20 cm soil layer reached 2.385, indicating strong variability, too. However, pH was less than 10% in variation coefficient in both the 0-10 cm and >10-20 cm soil layers, indicating mild spatial variability; (2) the performance of the spatial interpolation method indicates that soils high in electrical conductivity and salt content in the 0-10 cm and >10-20 cm soil layers were concentrated mainly in the parts southeast and northwest to Lake Ebinur, where the soils were quite high in soil electrical conductivity, and salt content and in soil salinization degree too, as affected by natural and human factors; while the soils low in salinization degree were in the part west to Lake Ebinur, and the farmland-dominated center of the oasis, thanks to the high vegetation coverage. The distributions of pH values in the two soil layers did not exhibit any specific rule of variation, but an interlacement of high and low pH values; (3) spatial autocorrelation index of soil salt content increased from 0.306 in the 0-10 cm soil layer to 0.527 in the >10-20 cm soil layer; and soil salt content in the study area displayed a trend of increasing gradually from southwest to east, regardless of soil layer, and spatially soil salt contents were strongly mutually-dependent. All the findings of the study demonstrate that the study is of great significance to timely following changes in salinization degree and soil salt content distribution, formulating reasonable land use policies and ecology improvement measures for land use and realizing sustainable development of the region.