Integrated hydrologic modeling and GIS in water resources management

The integration of a physically-based distributed model with a geographic information system (GLS) in watershed-based water resources management is presented, and an example watershed is chosen to demonstrate the spatial database and modeling system developed in this study. The spatial data is first processed by GIS. The model is then used to simulate runoff hydrographs. It operates at a daily time step on 1 x 1 km grid squares and simulates important hydrologic processes including evapotranspiration, snowmelt, infiltration, aquifer recharge, ground-water flow, and overland and channel runoff. Finally, the model result is displayed by using GIS. This study demonstrates that the integration of a physically based distributed model and GIS may successfully and efficiently implement the watershed-based water resources management. Not only does this process facilitate examination of a wider range of alternatives that would be impossible by using conventional methods, but it also provides a living management that could be modified and updated by water managers once the watershed condition is changed.