Reproducible, Automated and Objective Stream Threshold Selection and Upstream Riparian Corridor Delineation from Digital Elevation Models

Selection of accumulation thresholds for automated stream network extraction from digital elevation models (DEM) and delineation of upstream riparian corridors for given stream sampling points are important in water resources research. Accumulation threshold selection is often done by subjective comparison to a surveyed stream network and upstream riparian corridors are delineated manually. In this paper, we present "ATRIC", a combination of two algorithms developed by integrating the open source software packages R and GRASS GIS. ATRIC extracts DEM stream sources based on lateral displacements from surveyed stream network. The lateral displacement is selected by optimizing the number of DEM streams compared to the number of surveyed streams. Then an accumulation threshold is selected by optimizing the percentage of overlapped DEM stream cells with surveyed stream cells buffered with the selected lateral displacement. ATRIC extracts upstream riparian corridors from upstream catchments delineated by snapping stream sampling points to DEM extracted stream network. ATRIC showed better goodness of fit when compared to available algorithms and thus will improve topographic mapping and hydrological information extraction.