Development and application of a grid-based distributed hydrological model

A grid-based distributed hydrological model is proposed,which can simulate the physical processes of hydrological cycle,including precipitation,interception,infiltration,evaptranspiration,runoff generation and flow concentration in each grid and flow routing in river networks.To obtain rainfall values for each grid,the co-Kriging method integrating the altitude influences is applied.To compute evaptranspiration and interception,the land use-cover change information in study site is derived from remote sensing data.To compute the runoff generation in each grid,a relationship between topography index,which can be generated from the digitat elevation model(DEM),and the maximal soil moisture deficit is established.The flow routing paths of effective rainfall in each grid are derived from DEM.The model structure is simple and most parameters can be determined directly from DEM.The model is calibrated and applied to the Yanduhe Basin of Three Gorges flow reach of the Yangtse River.The simulation results are satisfactory.