Effects of Soil Data Resolution on the Simulated Stream Flow and Water Quality: Application of Watershed-Based SWAT Model

Document Type

Conference Proceeding

Publication Date


Publication Title

World Environmental and Water Resources Congress 2018

Publisher Location

Minneapolis, Minnesota


The hydrologic response of a watershed mostly depends on factors such as land use, soil type, and climatic inputs. Watershed modeling requires information on several soil properties, such as, texture, taxonomy, soil moisture, number of layers, and hydraulic conductivity. Several models are available that allow users to simulate the streamflow for a particular watershed using land use, topography, soil properties, and weather data. Better understanding of the future streamflows and waterquality is essential for the long-term planning and management of waterresources. The prediction of future flows and other hydrological parameters can be performed using different available modeling tools. Over the years, modeling of a watershed has significantly developed with the introduction of different sets of soildata such as Soil Survey Geographic (SSURGO) and State Soil Geographic (STATSGO). Both SSURGO and STATSGO data are compatible with GIS-enabled interfaces and can be used in both distributed and lumped hydrologic models. Soiland water assessment tool (SWAT) is one such tool that allow the use of soilproperties data to estimate the runoff process of a watershed. The predictability of hydrological models vary significantly with the variation in input data resolution. The primary objective of this study was to compare the SWAT-simulated outputs: stream flow; and water quality parameters, for SSURGO and STASTGO data. The study was performed in the watershed of Lower Cumberland-Sycamore in Tennessee. The simulation results has demonstrated that the effectiveness of the model prediction depends mostly on the type and quality of input soil data, and suggested that the higher resolution data yields better model results when compared with observed data.


Hydrology | Soil Science



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