Optimizing Hydrological Research: Comparative Analysis of DEMs for Enhanced Catchment Area Delineation

Catchment area delineation is fundamental for hydrological modeling and research pursuits. Traditionally, delineating catchment areas entailed manual demarcation on topographical maps, a laborious task requiring skilled personnel. However, with the advent of Geographical Information System (GIS)-based software, this process has evolved, leveraging Digital Elevation Model (DEM) data for enhanced efficiency. Despite this advancement, selecting an optimal DEM remains pivotal, balancing quality with cost, given the substantial resources and approvals often necessary for high-quality DEM acquisition. This study, utilizing ArcGIS software, aimed to compare catchment area delineations derived from three distinct DEMs: Contour-based DEM, SRTM DEM, and IFSAR DEM across multiple locations. Using IFSAR DEM as the benchmark, this study demonstrate that both Contour-based DEM and SRTM DEM offer viable alternatives, exhibiting less than a 3.5% variance in delineated catchment area across all locations. Notably, SRTM DEM outperformed Contour-based DEM, boasting higher accuracy as evidenced by lower Root Mean Square Error (RMSE) values. Furthermore, this study elucidated the influence of geological and topographical factors on DEM accuracy in catchment area determination. This comprehensive understanding underscores the significance of selecting the most suitable DEM, considering factors such as cost, accuracy, and availability for future research. This study serves as a valuable resource for researchers, aiding in the judicious selection of DEMs tailored to specific research requirements, thereby enhancing the precision and efficiency of hydrological investigations.