SWAT Literature Database for Peer-Reviewed Journal Articles

Title:Use of SWAT to scale sediment delivery from field to watershed in an agricultural landscape with topographic depressions 
Authors:Almendinger, J.E., M.S. Murphy and J.S. Ulrich 
Journal:Journal of Environmental Quality 
Volume (Issue):43(1) 
Article ID: 
URL (non-DOI journals): 
Broad Application Category:hydrologic & pollutant 
Primary Application Category:sediment loss and transport 
Secondary Application Category:depressional (pothole, wetland or pond) effects and/or processes 
Watershed Description:717 km^2 (to stream gauge) Willow River and 991 km^2 Sunrise River, located respectively in western Wisconsin and eastern Minnesota, U.S. 
Calibration Summary: 
Validation Summary: 
General Comments:This article is part of a special SWAT section published in JEQ volume 43(1). This study was actually focused on the effects of depressional areas (potholes) but utilized the SWAT pond and wetland routines due to deficiencies in the pothole algorithms at the time of the study. 
Abstract:For two watersheds in the northern Midwest USA, we show that landscape depressions have a significant impact on watershed hydrology and sediment yields, and that the Soil and Water Assessment Tool (SWAT) has appropriate features to simulate these depressions. In our SWAT models of the Willow River in Wisconsin and the Sunrise River in Minnesota, we used Pond and Wetland features to capture runoff from about 40% of the area in each watershed. These depressions trapped considerable sediment, yet further reductions in sediment yield were required for calibration and achieved by reducing the Universal Soil Loss Equation (USLE) cropping-practice (P) factor to 0.40-0.45. We suggest terminology to describe annual sediment yields at different conceptual spatial scales and show how SWAT output can be partitioned to extract data at each of these scales. These scales range from plot-scale yields calculated with the USLE to watershed-scale yields measured at the outlet. Intermediate scales include field, upland, pre-riverine and riverine scales, in descending order along the conceptual flow path from plot to outlet. Sediment delivery ratios (SDRs), when defined as watershed-scale yields as a percentage of plot-scale yields, ranged from 1% for the Willow watershed (717 km^2) to 7% for the Sunrise watershed (991 km^2). SDRs calculated from published relations based on watershed area alone were about 5-6%, closer to pre-riverine-scale yields in our watersheds.