坡面土壤水分特性的空间变异及其水库贮量

利用地统计学方法研究了我国西南丘陵区坡面土壤水分特性的空间变异。结果表明:西南丘陵区坡面土壤水分特性在不同的剖面深度具有一定的空间结构,可用纯块金效应模型、线性模型、指数模型和球状模型进行拟合;土壤水分特性变异为含水量>萎蔫含水量>田间持水量>饱和含水量>容重,变异系数都介于1%～100%之间,均属中等变异;水分特性随剖面深度表现出一定的变化规律,但半方差模型各参数随土壤深度无明显变化规律;土壤水库容为:有效水库容>通透库容>无效水库容,其空间分布主要受土层厚度和地形影响。

Spatial Variability of Soil Water Properties and Its Volumetric Capacity in Hill Slope

Research to spatial variability of soil water properties was conducted with geo-statistical method in upland of the southwestern China. Results show that soil water properties have different spatial structure in different soil layers in our study area. They can be simulated with pure nugget effect model, linear model, exponential model and spherical model. The variable degree of the soil water properties is water content>wilting point>field capacity>saturation>bulk density. The coefficiency variance is among 1%~100%, which belong to moderate variability. Water properties are changing with the soil layers, but the semivariogram models have not apparent changing rule. The volumetric capacity of soil is available water-storage>transmission volumetric capacity>unavailable volumetric capacity. Its spatial distribution is mainly affected by the soil layer thickness and terrain.