山前平原地下水侧向补给潜力空间变异模拟

SWAT模型利用分辨率较高的DEM数据,可以估算山前地下水侧向补给的空间变异,并可以计算不同降水年型下补给量的差别。模拟需要对研究区进行填洼、流向确定、汇流和河网水系的提取四步运算,并对河道临界支撑面积的取值进行分析。分别模拟了平水年和丰水年两种降雨年型下研究区13个出水口的地下水侧向补给潜力。在研究区,由于地形的变化,导致山与平原交接断面上出水口的集水面积变异非常大,因此山前平原所接受的地下水侧向补给量的空间变异也非常大。不同的降雨年型下,降雨量转化为地下水侧向补给量的比例也不同。平水年的转化比例较小,丰水年的转化比例较大。应用SWAT模型时,与ArcView的拓展模块有机结合,可以更方便提取完整的大流域,划分出合理的子流域。

Spatial variation simulation of lateral recharge potential of groundwater in piedmont regions

Based on the high-precision DEM,the SWAT model can be used to simulate groundwater lateral recharge in the piedmont regions,and to compute the recharges for years of different precipitations.In the simulation,the following steps must be carried out: sink filling,flow direction determination,flow accumulation,river network extraction,and the analysis of CSA value.The groundwater lateral recharges of thirteen outlets in the research area in normal year and wet year were studied respectively.The water catchment area of the outlet in the connection sections of mountain and plain differs greatly because of the change of topography,thus the spatial variation of groundwater lateral recharge in the piedmont regions is obvious.The rate of precipitation transforming into groundwater lateral recharges is different in different precipitation years,which is large in wet year and small in normal year.The combination of SWAT model with the extended module of ArcView is successful for the extraction of a whole basin and the rational division of sub-basins.