Effect of land surface elevation data availability on river hydraulic model output

River hydraulic models are useful tools in watershed management. They are critical components of flood planning studies, and are prerequisites for pollution transport modeling. One of the critical parameters in modeling river hydraulics is the river channel slope. When the river system of a large watershed is of concern, the land surface elevation data can be used to create the river network and to determine the slopes of the river channels. Digital elevation maps (DEMs) created by using remote observations, together with GIS tools provide an easy way to delineate the river network and to determine the river channel slopes. However, the validity of the resultant model parameterization is very much dependent on the resolution and the accuracy of the DEM data. The alternative to using DEM data based on remote sensing is to use actual site elevation measurements throughout the river network. Although this alternative has the potential to provide more accurate results, collecting and compiling measurement data in the adequate resolution may not be economically feasible if the data is not already available, especially in case of developing countries