基于GIS的黄土高原小流域土壤水分时空分布模拟——以定西安家沟为例

土壤水是黄土高原生态环境的主控因素,进行土壤水时空分布的模拟对黄土丘陵区农业生产、植被恢复和土地合理利用及配置具有重要的指导意义。从水量平衡的角度出发,采用GIS软件Arc/Info的GRID数据结构,对定西县安家沟小流域影响土壤水分时空分布的要素:降雨、径流和蒸散(发)进行了空间分布的模拟,并利用实测土壤水分数据进行检验,合格率达到83.146%。结果表明,利用水量平衡原理并对参数进行一定的化简进行黄土高原土壤水分的模拟是可行的。

GIS-assisted Modeling of Temporal and Spatial Distribution of Soil Water Content in Loess Plateau- A Case Study in Anjiagou Catchment

Soil water content is a key factor influencing the ecological environment in the Loess Plateau of China.Thus,modeling temporal and spatial distribution of soil water content in loess hill region is of theoretical significance in the ecological restoration and also of practical signifi-cance in land use management.This study is accomplished by employing water balance-based model.The research uses GRID data structure in the GIS software of Arc/Info and uses its AML (Arc Macro Language)to program to model the spatially distributed soil water content every ten days from April to October.First,the spatial distribution of precipitation is considered uniform according to the situation of the study area.Second,the SCS model is employed to calculate the distributed spatial runoff.Third,Butikle method is employed to model the distributed spatial actual evapotranspiration and the Hargreaves equation is used to model the spatial distribution of potential evaporation.Finally,we obtain the spatial distribution of soil water content in Anjiagou catchment area.The eligibility ratio of the simulated soil moisture is 83.146% through the measured soil data,which shows the method of dealing with the parameters of the water balance-based model is reasonable.