| Title |
Evaluation of DEM-based Channel Network Delineation Methods on Watershed Drainage System |
| Keywords |
Area-threshold;channel network;DEM;watershed drainage system;geomophological laws;slope-area threshold;면적한계기준;수로망;유역 배수구조;지형법칙;경사-면적 한계기준 |
| Abstract |
Channel network delineation from DEM (Digital Elevation Model) is a fundamental pre-process for hydrologic model application since it determines the drainage system in a watershed. This study aims to propose an effective and efficient channel network delineation process and assess the effects of DEM-based channel networks on the watershed drainage system. For these objectives, we applied two methods to generate the channel networks of the Jinan-cheon catchment with 18.28 ㎢ from the 20 m resolution DEM: a widely-used area-threshold method and a slope-area threshold method based on the relationship between contributing areas and local slopes. The results showed that the area-threshold method led to unreliable drainage system, which did not satisfy geomorphological laws with respect to drainage density and source area representation whereas the slope-area threshold method provided acceptable results under the geomorphological laws. Our suggestions in this study can give valuable pre-processing information in DEM-based hydrologic modeling. |