Land use legacy and watershed management

We couple two spatial-temporal models, a backcast land use change model and a groundwater flow model, to develop what we call “land use legacy maps”. We quantify how a land use legacy map, created from maps of past land use and groundwater travel times, differs from a current land use map. We show how these map differences can impact land use planning and watershed management decisions at a variety of spatial and temporal scales. Our approach demonstrates that land use legacy maps provide a better accurate representation of the linkage between land use/cover and current water quality compared to the current land use map. We believe that the historical signatures of land use impacts on current water quality should be considered in land use planning and watershed management.