An automated overland flow model based upon remote sensing and GIS

This research uses remote sensing and raster-based GIS technology to establish an automated overland flow model in watershed hydrologic simulations. The basic framework is to construct watershed grid-based geographical feature data base. Based upon these raster watershed characteristics, the required hydrologic parameters for computer simulation can then be extracted automatically. Also, through watershed digital terrain model and simulated grid flow algorithms, a hydrologically ordered cell-to-cell flow sequence can thus be dictated. Finally, by combining the digital watershed flow algorithms with the kinematic-wave hydrologic modeling and using finite-difference method to solve the system equations, the output runoff hydrographs can thus be produced