Modeling Riparian Zones Utilizing DEMS and Flood Height Data

Riparian ecotones are unique, diverse networks of vegetation and soils in close proximity to streams, rivers, and lakes. Previous approaches to riparian boundary delineation utilized fixed width buffers, but using a fixed width riparian buffer only takes the watercourse into consideration; it does not consider the surrounding landscape. By hydrologically defining a riparian ecotone to occur at the 50-year flood height and incorporating digital elevation data, the spatial modeling capabilities of ArcMap (R) GIS are utilized to map riparian zones accurately. This approach better characterizes the watercourse and its associated floodplain. Riparian zones delineated using 10 versus 30 meter DEMs and stream course information from the National Hydrography Dataset differ significantly. Within our study areas, 30 meter DEMS are not adequate to map elevation changes for accurate riparian area delineation. The result is a robust GIS based model in an ArcMap (R) Toolbox format to delineate a variable-width riparian boundary.