Comparison of DEMs for Analysis of Catchment Hydrology

摘要

Grid-based Digital Elevation Models (DEMs) are commonly used to define topographic characteristics and flow paths for hydrological modelling. DEMs at 10 m and 50 m resolution were compared for an agricultural catchment. For each DEM, derived hydrological characteristics were compared with a digital dataset and a manually derived catchment boundary based on a topographic map. The results show differences in catchment area and in the geographic location of the boundaries and stream pathways derived from each source. However, the classification of flow pathway length and slope is highly correlated between DEMs. The potential significance of these results for modelling runoff in agricultural catchments is discussed.