Runoff simulated from Goodwin Creek Watershed using SWAT

Goodwin Creek Watershed (GCW), located in northern Mississippi, was simulated for 10 years using a deterministic simulation model, SWAT (Soil and Water Assessment Tool). GCW contains 14 instream measuring stations for runoff Each measuring station represented an outlet of one or more nested subbasins, which were each simulated separately and routed to each outlet using SWAT. Each subbasin was described using the GRASS geographic information system, integrated with SWAT, to determine input parameters. Storm event rainfall was measured individually from one raingage for each subbasin. Results show that simulations using SWAT predicted the relative trends of runoff on a daily and annual basis from multiple subbasins, except for a completely wooded subbasin. Using GCW, this study has shown that SWAT has the capability of adequately simulating the effects on runoff from the temporal and spatial variability of watershed characteristics. Accurately simulating runoff improves the prediction of the movement of chemicals, nutrients, and sediment.