Evaluating DEM conditioning techniques, elevation source data, and grid resolution for field-scale hydrological parameter extraction

摘要: Abstract Although digital elevation models (DEMs) prove useful for a number of hydrological applications, they are often the end result numerous processing steps that each contains uncertainty. These uncertainties have potential to greatly influence DEM quality and further propagate DEM-derived attributes including derived surface near-surface drainage patterns. This research examines impacts grid resolution, source data, conditioning techniques on spatial statistical distribution field-scale 12,000 ha watershed an agricultural area within southwestern Ontario, Canada. Three techniques, depression filling (DF), breaching (DB), stream burning (SB), were examined. The catchments draining boundary 7933 fields delineated using patterns modeled from LiDAR interpolated 1 m, 5 m, 10 m resolution DEMs, photogrammetric DEM. results showed variation in resulted significant differences distributions contributing areas downslope flowpath length. Degrading data 1 m disagreement mapped between 29.4% 37.3% study area, depending technique. disagreements among large, with nearly half alternate field boundaries. Differences flowpaths various increased substantially at finer resolutions, largest occurring DB SB (37% disagreement) DB-DF comparison (36.5% areas). demonstrate decision use one technique over another, constraints available source, can impact scale individual fields. work has significance applications attempt optimize best-management practices (BMPs) reducing soil erosion runoff contamination watersheds.