采用ＧＩＳ的方法，建立了环县数字高程模型（ＤＥＭ），研究了本区地表水流方向、集流能力、子集水区的划分及水系网络空间分布等水文特征．以栅格化径流系数法为基础，模拟了该区多年平均产流量的空间分布，以及降雨量分别为１０、２０、３０、４０、５０和６０ｍｍ时，环县各自然集水盆地内可产生的径流量．研究结果表明，利用ＤＥＭ不仅可模拟地表大型水系网络的空间分布，而且可模拟小型水道的空间走向；利用栅格化径流系数法，可快速分析子集水盆地产流量的空间分布．这些研究结果，对半干旱区集水农业工程的规划与决策具有重要的意义． Using the method of GIS, a ring-county digital elevation model (DEM) was established, and the hydrological characteristics such as the direction of surface water flow, the current collecting ability, the division of sub-catchment area and the spatial distribution of water network were studied. Based on the gridded runoff coefficient method, the spatial distribution of annual average runoff in this area was simulated. When the rainfall was 10, 20, 30, 40, 50 and 60 mm respectively, Of runoff. The results show that the use of DEM can not only simulate the spatial distribution of surface water network, but also simulate the spatial trend of small watercourse. Using rasterization runoff coefficient method can quickly analyze the spatial distribution of sub-catchment flow. These findings are of great significance to the planning and decision-making of water-harvesting agricultural engineering in semi-arid areas.