Distributed Hydrological Model Based on Topography Trend

In view of the characters of hydrologic and meteorological situation in the cold mountain areas, the paper dispersed the watershed into the minimum grids. Through analysis on the different effect of solar shortwave radiation flux on ground surfaces at the same elevation grid, the redistribution of surface cold and heat source due to topography variation and snowmelt runoff were studied. Then, topography trend factor was considered as an important input data to add into the model structure. Finally, the snowmelt Xinanjiang model and SCS confluence model were used for every grid to establish the distributed hydrological model for the entire watershed. The model was used in Mudanjiang watershed of Heilongjiang Province to show desirable runoff simulation results.