Advanced Techniques for Watershed Visualization

Analytical shaded relief is commonly used for visualization of digital elevation models (DEMs). Sometimes, the quality of unaltered analytical shaded relief can be lacking for identification of streams and water divides. Hydroshading is a technique that provides enhanced capabilities of visualization of hydrologically-meaningful topographical features. In this research, hydroshading algorithms are applied to NASA´s Shuttle Radar Topography Mission (SRTM) DEM datasets. The visualization technique is applied to coastal and inland watersheds in Mississippi (Saint Louis Bay and Luxapallila, respectively). The testing of hydroshading in these two areas shows that the technique is more effective in areas with moderate topographical relief than in low relief terrain. Combining hydroshading with standard three- dimensional visualization identification of water Hydroshaded DEMs were used to manually delineate Luxapallila and Saint Louis Bay´s Wolf River catchments. Delineation results are comparable to output of standard automated delineation produced by GIS software (BASINS).