关键词: DEM, 水文地形因子, 降雨径流模型, 三维模拟, 柳沟流域

Abstract: Soil erosion in the Loess Plateau is stupendous,which has become the main obstacle to economic and social development,and among which water erosion is the most serious as it happens in more than half of the whole land.It can provide scientific basis for preventing loss of water and erosion of soil at the root to learn and grasp the rain-runoff principles and fundamental laws.In this paper,Liugou net watershed of Caijiachuan watershed in the Loess Area in the Western Shanxi Province is taken as the study area.Firstly,hydrological terrain factors are extracted on GIS platform,which shows the exact DEM and the channel location information.Then,the rainfall-runoff model is divided into four stage models-canopy interception,litter interception,soil infiltration and runoff yield and concentration,just as its actual progress.Through improving the predecessors' distributed hydrological models respectively,four stages of the rainfall-runoff model construction and computing work are implemented.At last,single heavy rainfall in Liugou basin is taken to examine the accuracy of the models.The relative error of each step is less than 0.3,and the total error is 0.28.The models can finish the actual simulated rainfall runoff process perfectly.Based on the different runoff volumes of different periods,the three-dimensional virtual simulation of the heavy rainfall-runoff on GIS platform is performed.Using the model and method,the previous rainfall-runoff process can be repeated,and the future can be predicted if the rainfall amount is known.Thus models and simulation can bring scientific reference for the relevant staff members of soil and water conservation to lay down appropriate soil and water conservation measures.

Key words: DEM, hydrological terrain factors, rainfall-runoff model, 3D simulation, Liugou basin