Effects of spatial detail of soil data on distributed hydrological modeling

Effects of different soil data resolutions on distributed hydrological modeling and total water yield were investigated using a modeling approach.The semi-distributed SWAT(Soil and Water Assessment Tool) model and the fully distributed WetSpa(Water and Energy Transfer between Soil,Plant and Atmosphere) Extension were used in this study.Both the US SSURGO(Soil Survey Geographic) soil data and the detailed SoLIM(Soil-land Inference Model) soil data were utilized in the modeling investigation.Results show that different soil data resolutions will lead to a large discrepancy in modeling water yield at simulation points distributed over a watershed.However,the difference in simulation of total water yield decreases with increasing the area of watersheds.Based on the modeling experiment,it is recommended that detailed spatial data will be required where the simulation primarily focuses on the spatial distribution of water fluxes,while the data condition could be relaxed for the simulation of total water yield especially for large-sized watersheds.