数字高程模型在半干旱区径流模拟中的应用

Application of Digital Elevation Model to Runoff Simulation in Semi-arid Land of China

采用GIS方法构建了甘肃省某地数字高程模型 (DEM),研究了区域内地表水流方向、集水能力、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,模拟了该集水区年均产流量及其空间分布。研究结果表明,利用DEM不仅可模拟地表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。不同的降水年型和降水保证率对径流的空间分布及变化有很大的影响。该文的研究结果对半干旱区集水农业工程的规划和管理具有重要意义。

By means of GIS method, the digital elevation model (DEM) was established in Chankou Village of Dingxi County in Gansu Province. The runoff direction, runoff accumulation, sub-catchment boundaries and the spatial distribution of stream networks were studied. Based on the rasterized runoff coefficient method (RRCM), the annual average runoff and its spatial distribution in Chankou Village were simulated. The results indicate that the spatial distribution of large stream networks and the small water path can be simulated by DEM and the runoff in each sub-catchment can be quickly calculated by RRCM. The spatial distribution and the variation of runoff in each catchment were significantly influenced by different precipitation and its probability. It is important for the planning and management of the rain-harvesting agriculture in semi-arid land of China.