Abstract: To meet the requirements for waterlog forecast in the weather forecast,the waterlog occurrences at villages and towns level in Liaoning Province based on DEM were forecasted.The directions of water flow and convergence capacity grids were analyzed by using the basic topographic data of the 1:250000 scale DEM for Liaoning Province,based on geographic information system(GIS) platform.The Soil Conservation Service-Curve Number(SCS) hydrology model was debugged.The actual terrain runoff was obtained by coupling the runoff model with the converge ability.According to the corresponding relationship between converge and waterlog grade,the meteorological waterlog risk grade was gained.The waterlog occurrence was forecasted in a weather process.The forecasted results were consistent to the actual happening.

Key words: DEM, DEM, Flow direction, Converge ability, SCS hydrology model, Waterlog forecast