The Effect of Multi-Source DEM Accuracy on the Optimal Catchment Area Threshold

This study attempts to investigate the relationship between accuracy of different Digital Elevation Model (DEM) and fractal dimension D solve problem determining optimal catchment area threshold in plain watersheds. In this study, dimensions Shuttle Radar Topographic Survey (SRTM) V4.1 DEM, Hydrology 1K (HYDRO1K) Advanced Spaceborne Thermal Emission Reflection Radiometer Global (ASTER GDEM) with 90 m horizontal resolution 30 ASTER GDEM were calculated using box method, three data sources was studied. The determined. response river network similarity topographic features DEM explored, for verified. result shows that, increase threshold, stages rapid decline, gentle fluctuation, tend 1. Compared vertical has more influence on D. increases DEM. main order is SRTM > HYDRO1K digital extracted by 1.0245, same as actual network. 4.05 km2, which highest coincidence summary, source feasible determine