土壤渗透参数空间变异性及其影响因子研究

土壤渗透参数的空间变异性是地形因子以及土壤理化性质综合作用的结果,是影响水以及溶质迁移转化的关键因素。在坡地随机布设24个点位,测定30cm土壤的渗透参数、地形指数、容重、颗粒组成、有机质、交换性钠、CEC(阳离子交换量)和ESP。在经典统计学以及Kolmogorov—Smiromov(K—S)正态分布检验概率(Pk—s)检验基础上对数据进行了空间结构分析。结果表明,Kfs、容重、砂粒、黏粒、有机质、CEC等符合正态分布,交换性钠和ESP等属于对数正态分布;粉粒属于均匀分布;Kfs、容重、砂粒、黏粒、有机质、交换性钠和ESP等空间结构明显,CEC空间变异性较大;并以相关分析和主成分分析相结合的方法,分析了土壤渗透参数空间变异的主要影响因子。

Spatial Variability and Its Influencing Factors of Soil Hydraulic Parameter

The spatial variability of soil hydraulic properties influenced by topographic and soil physical and chemical factors is one of the key factors which have considerable effects on water flow and solute transport.An experiment was conduced on a 80m @ 40m plot.Saturated conductivity,Kfs,was measured at a depth of 30 cm,and soil physical and chemical properties were also considered,such as wetness index,bulk density,particle composition,organic matter,exchangeable sodium,CEC and ESP in the 24 sampling sites selected randomly.Based on classic statistics and the Kolmogorov) Smiromov(K)S) normality test,spatialst ructure was analyzed using the GIS+ for Window 5.The result indicated a normal distribution for Kfs,bulk density,organic matter,sand,clay and CEC,a lognormal distribution for exchangeable Na+ and ESP,and auniform distribution for silt.Kfs,bulk density,organic matter,sand,clay,exchangeable sodium and ESP showed the spatial correlation characteristic,but CEC had more distinct spatial heterogeneity than other factors.The influencing factors were also analyzed based on the correlation and PCA method.