GIS & RS assisted precipitation-flow generation simulation in a typical watershed of Chinese Loess Plateau

In this research, GIS technology was used to deal with the data preparation of the land use and soil type in the whole watershed. The spatial difference of the time-step based on typical precipitation was calculated by the interpolated method of the Inverse Distance Weight (IDW) provided in the GIS software Arc/info 9.0. The vegetation interception capacity was calculated based on the LAI (leaf area index), which was gained through remote sensing ways. The classical Horton theory of infiltration was used to calculate the infiltrated rainfall in view of the excess overland flow generation mechanism in semi-arid regions. After the calculation of the above, the water quantity balance function was used to calculate the overland flow generation. All of the variables involved in the hydrological portions calculation were ensured according to the results of the experiments in outside fields. Because of the small scale of the watershed, a high resolution of the DEM was selected. The result shows that the simulation methods above can be used to simulate overland flow generation in a basin-scale in the semi-arid Chinese loess plateau. In this research, remote sensing method was used to calculate the LAI and solve the problem of vegetation interception better.