砂质土壤持水特性空间变异特征传递函数模型

为探讨土壤持水特性的空间变异特征,采用Vereecken和Campbell模型预测辽宁西部风沙土的田间持水量(θ60 cm)和萎蔫含水量(θ15 000 cm),并借助传统统计学和地统计学方法预测其空间变异,结果表明:两个模型预测θ60 cm的精确度均低于θ15 000 cm;Vereecken模型的精确度高于Campbell模型.Vereecken模型预测的20 cm~40 cmθ60 cm和θ1 5000 cm半方差模型参数和分形维数较Campbell模型更接近于实测数据,但无法描述0 cm~20 cm的空间结构;因此,Vereecken模型可预测砂质土壤20 cm~40 cmθ60 cm、θ15 000 cm及其空间变异特征.

Spatial variability of water retention capability in aeolian sandy soil and its pedotransfer function

In order to investigate the spatial characteristics of water retention capacity in soil,this study applied Vereecken and Campbell models to predict field capacity(θ60 cm) and wilt point(θ15 000 cm) of aeolian sandy soils in western Liaoning.In addition,their spatial variations were analyzed using traditional statistics and geostatistical methods.The results show that Vereecken and Campbell models result in a lower accuracy and precision for θ60 cm than that of θ15 000 cm,while Vereecken model provides more precise results than that of Campbell prediction.Although the semi-variance model parameters and fractal dimension for 20~40 cm predicted by Vereecken model are closer to the measured data than that of Campbell model,it cannot describe the spatial variability structure of θ60 cm and θ15 000 cm in 0~20 cm depth intervals.Therefore,Vereecken model may predict θ60 cm and θ15 000 cm in 20~40 cm and its spatial variation.