SWAT2009_LUC: A Tool to Activate the Land Use Change Module in SWAT 2009

Abstract

In watersheds where land use and land cover changes take place over the modeling period, using a single land use geospatial dataset is not a true representation of the watershed condition. This article describes development of SWAT2009_LUC, a computer-based, geospatial tool that ingests multiple land use/land cover geospatial datasets and other associated information interactively and activates the land use change (LUC) module in the latest release of the Soil and Water Assessment Tool (SWAT 2009). The geospatial tool was tested in an urbanizing watershed in northwest Arkansas by using three temporal land use geospatial data layers acquired during 1999, 2004, and 2006. The results show that the land use distribution generated by the tool was consistent with the input land use layer for each year and was updated correctly during the model run. Model simulations with and without the activation of the LUC module showed that groundwater was underpredicted by up to 15%, while surface runoff was overpredicted by up to 13% at the subwatershed scale when a single post-development land use layer was used. Overall, the results showed that activating the LUC module using the SWAT2009_LUC tool improves the spatial and temporal hydrological responses from the SWAT 2009 model.