The Effects of Landscape Transformation in a Changing Climate on Local Water Resources

Abstract

Integrated watershed studies can provide insight into the ways land-use change and climate change interact to transform regional and local hydrology. Most past work has treated baseflow and streamflow separately, and focused either on land-use change or climate change. To assess the relative role of climate change and land-cover change on baseflow, streamflow and peak runoff events for the rapidly urbanizing area surrounding Indianapolis, Indiana, we analyzed long-term records of streamflow, rainfall and land-use data, and performed modeling studies of water fluxes based on reconstructed land-cover change. Statistically significant increasing trends for streamflow and baseflow were present throughout the record, although precipitation did not show similar increases. This indicates that other factors, such as land-use change, had greater influence on watershed hydrology in this area than climate. However, large-scale modeling was not able to demonstrate that changes in hydrology were driven by land-cover change, suggesting that other aspects of land use, such as groundwater withdrawal might be significant. Although more detailed modeling work is required for this specific location, the general framework for integrating studies of streamflow, baseflow and land-cover change presented here is easily transferable to other watersheds and will be of use to communities and government agencies involved in water-resource planning.