Change in Surface Hydrology Due to Land Use Change in a Midwestern Watershed

Land use change and urbanization can have significant impacts on hydrologic processes within watershed systems. Monitoring data, however, are rarely sufficient to Fully understand the Spatial and temporal factors that contribute to the change in streamflows. This paper presents a modeling framework to evaluate changes in flow regimes at various spatial scales as a result of rapid urbanization in the Eagle Creek Watershed in the Midwestern United States. We also aim to determine which components of land use change and preexisting conditions (previous land use and hydrologic soil group) have greater impacts on changes in the flow regime. The Soil and Water Assessment Tool (SWAT) model was used to simulate 50 years of Streamflows for the 273 km² watershed under the land use conditions of the years 2000 and 2004, as defined by the National Agricultural Statistics Service (NASS) and National Land Cover Data (NLCD) geospatial datasets. Flow duration curves (FDCs) were constructed for 230 subbasins within the watershed under the 2000 and 2004 land use conditions. A two sample Kolmogorov-Smirnov test (KS test) was used to quantify the significance of the difference between the FDCs corresponding to the Year 2000 versus 2004 land use scenarios for each subbasin. A multivariate regression analysis indicated that change in urban area, change in forest area, and coverage by hydrologic soil group A have the greatest impact on the change in streamflows associated with land use change.