基于原位测定的坝上地区河流地貌耕地土壤盐分的空间变异分析

Spatial Variability Analysis of Soil Salinity on Arable Land in Fluvial Landforms of Bashang Region Based on In-situ Measurement

土壤盐分的空间变异一定程度上反映了耕作层土壤盐渍化的程度和状态。运用原位测定法,更准确高效地研究河流地貌耕地不同深度土壤盐分的空间分布特征。结果表明:河漫滩各土层盐分具有中等变异强度和较强的空间自相关性,而河流阶地各土层土壤盐分具有弱变异性,深层土壤盐分的自相关效应显著。Kriging插值图中,研究区土壤盐分的空间分布表现为条带状、同心圆状和均匀分布。河流阶地表层土壤盐度与测定点坡度呈现弱负相关关系。地形、水文及土壤质地是影响研究区土壤盐分空间变异的主要因素。研究区尚未发生盐渍化,但河漫滩耕地具有更高的盐渍化风险,需加以重视和防范。

Spatial variability of soil salinity reflects the salinization and status of arable layer of soil. In order to observe the spatial distribution of soil salinity in different layers of arable land in fluvial landforms, the in-situ detecting method was adopted. The results showed that the soil salinity of each layer on the flooding plain had moderate variability and strong spatial autocorrelation, while the variability of soil salinity on river terrace was weak, the spatial autocorrelation of deeper layer was significant. The Kriging interpolation figure showed that the spatial distributions of salinity in the study areas were in the shape of stripe, concentric ring or uniform distribution. The salinity of surface layer on river terrace had a weak negative correlation with the gradient of sample sites. Terrain, hydrology and soil texture were the major factors that affected the spatial variability of soil salinity. The soil of these study areas was not salinization now, but salt accumulation of several measured sites on the flooding plain had higher risks of salinization, more attention should be paid to prevent the possible salinization.