Comparison of Three GIS-Based Hydrological Models

Three geographic information system GIS -based distributed hydrological models were developed for flood simulation and forecasting in a subbasin of the Yellow River. A grid-and-topography-based distributed hydrological physical model, i.e., the GTOPMODEL model, is described that includes vegetation and root interception, evapotranspiration, and runoff generation via the saturation excess mechanism, as well as subsurface via the Darcian approach used by TOPMODEL, runoff concentration, and flow routing. The downslope redistribution of soil moisture is explicitly calculated on a grid by grid basis. Using the isochrone curve method based on GIS, another two models are developed on the basis of the Xinanjiang and TOPMODEL models. The three developed models were applied to the Upper Lushi basin in Luohe River, one tributary of the Yellow River, with an area of 4,716 km2 for flood simulation. The results show that all of these models perform well in the simulation and can be used for flood forecasting in the Yellow River basin and that GTOPMODEL performed the best among the three models. DOI: 10.1061/ ASCE 1084-0699 2008 13:5 364 CE Database subject headings: Hydrologic models; Hydrology; Hydrologic properties; Hydraulic networks; Geographic information systems; Comparative studies.