渭-库绿洲土壤盐渍化空间分布特征研究

Spatial Distribution Characteristics of soil Salinity in the Ogan-Kucha River Oasis

为了研究渭-库绿洲土壤盐渍化空间分布特征,根据野外调查取样土壤数据,应用地统计分析方法中的普通克里格插值完成半变异函数计算以及理论模型的拟合,分析研究区土壤盐分空间分布特征。以土壤中的SO4^2-、Cl^-、HCO^-3、CO3^2-、Mg^2+、Na^+、Ca^2+、K^+等盐分离子作为解释变量,以土壤含盐量,电导率,纳吸收比,pH等作为响应变量,对土壤土层进行冗余分析(Redundancy Analysis,RDA),解析解释变量和响应变量的对应关系。最后利用Moran散点图和LISA集聚图,来探索研究区土壤含盐量空间自相关性特征。研究结果表明:研究区随土壤深度的增加,含盐量逐渐减少,呈重盐渍化到非盐渍化趋势;土壤含盐量东部高于西部,各土层盐分分布呈现出一定的区域差异性;Na^++K^+是阳离子中主控离子、SO4^2--Cl^-是阴离子中主控离子;土壤含盐量较高的区域和土壤含盐量较低的区域呈现出两极集聚。

In order to study the spatial distribution characteristics of soil salinization in Ogan-Kucha river oasis,the spatial distribution characteristics of soil salt in the study area were analyzed by calculating the half-variation function and fitting the theoretical model based on the soil data sampled from the field survey and the ordinary kriging interpolation in the statistical analysis method.Taking the equivalent salt ions of SO4^2-、Cl^-、HCO^-3、CO3^2-、Mg^2+、Na^+、Ca^2+、K^+in soil as explanatory variables,,soil salinity,electrical conductivity,absorption ratio,and PH as response variables,the paper carried out Redundancy Analysis(RDA)on soil layer,and analyzed the correspondence between explanatory variables and response variables.Finally,Moran scatter map and LISA cluster map were used to explore the spatial autocorrelation characteristics of soil salt content in the study area.The results show that with the increase of soil depth,the salt content of the study area decreases gradually,and it presents a trend from heavy salinization to non-salinization.The salt content in the eastern part of the soil is higher than that in the western part of the soil.The analysis of soil salt ion showed that it was the main ion in the cation and the main ion in the anion.The regions with high soil salt content and those with low soil salt content showed polar agglomeration.