Author(s): Maryam Roostaee; Zhiqiang Deng
Linked Author(s): Zhiqiang Deng
Keywords: DEM sources; HSPF model; Uncertainty analysis; Watershed modeling
Abstract: DEMs are important data required in watershed-based hydrological and water quality modeling since they are employed to derive critical characteristics of watershed through a watershed delineation process. This study aims to analyze the uncertainties associated with DEM sources in watershed modeling and compare them to DEM resolution-originated uncertainties. Toward this end, six different scenarios, involving 3 DEMs of 30-m resolution and 3 DEMs of 90-m resolution from NED, ASTER and SRTM sources, were developed using HSPF model for an agricultural watershed in Iowa, USA. The HSPF model was run for each scenario to produce simulated flow and loads of sediment, nitrate, and phosphorus. Results suggested that the level of uncertainty involved in the DEM sources was considerably (up to twofold) greater than those originated from decreasing DEM resolution. The finding is important to the proper selection of DEM data source and thereby to the reduction of uncertainties involved in watershed-based hydrological and water quality modelling.
Year: 2018