省域尺度土壤水气热参数空间变异特征及主控因子分析

Provincial-scale spatial variation of soil water-air-thermal parameters and its main controlling factor analysis

为了研究土壤物理基本参数、水气热参数在省域尺度上的空间分布特征,以实地调研测量的数据为基础,结合GIS技术与统计学原理对陕西省13处采样点的土壤物理基本参数进行空间变异特征分析.运用方差分析和回归分析将土壤质地、土壤类型和土地利用方式对土壤水气热参数的影响做出评价.结果表明:反距离加权插值法(IDW)构建的空间变异分布图显示陕西省自北向南土壤中砂粒含量逐渐减少,黏粒含量逐渐升高;土壤饱和导水率、导气率和热导率随砂粒含量的减少而减小;土壤质地、土壤类型和土地利用方式均与土壤水气热参数空间分布有着较强的关联性;土壤类型对土壤水气热参数空间变异的解释能力大于土地利用方式且小于土壤质地;建议在省域尺度上对土壤水气热参数进行空间分布预测时,应将土壤质地、土壤类型和土地利用方式3因子结合分析,从而提高对土壤水气热参数空间变异的预测准确性.

The basic soil physical parameters and water-air-thermal parameters measured at 13 sampling points in Shannxi province are analysed to study their provincial-scale spatial distribution characteristics by making use of GIS technology and statistical methods. The effects of soil texture,soil type and land use on the water-air-thermal parameters spatial distributions were assessed by means of variance and regression analyses. The inverse distance weighted( IDW) interpolation results show that sand content decreases while clay content increases from north to south in the province. Soil saturated hydraulic conductivity,soil air permeability and thermal permeability decrease with declining sandcontent. Soil texture,soil type and land use are the main controlling factors of water-air-thermal parameters spatial distribution. Explanatory power of soil type on water-air-thermal parameters spatial distribution is better than land use,but weaker than soil texture. It is advisable that soil texture,soil type and land use should be analysed in a combined manner in the provincial-scale spatial distribution prediction of water-air-thermal parameters to improve the accuracy of prediction.