Hydrologic and Economic Implications of Climate Change for Typical River Basins of the Agricultural Midwestern United States

Abstract

The Midwest is the largest agricultural area of the United States. Historically, the climate there has been suitable for unirrigated farming. However, the specter of climate change has created concerns about the future of Midwestern agriculture, regional fresh water resources and the relationship between the two. Implications of climate change for the agricultural Midwest are revealed in a recent study on two typical agricultural Midwestern watersheds, the Mackinaw River Basin and the upper Sangamon River Basin of central Illinois. Generally in this study a future climate with more frequent droughts is envisioned based on the outcome of one of the major general circulation models, the Canadian Climate Centre model. The climate change impacts on agricultural productivity, low flow frequencies of streams, and the profitability of irrigation, which could be triggered by the climate change, are evaluated. This study shows that the changes in climatic factors of temperature and precipitation tend to reduce crop yields, induce irrigation, and increase low flow frequencies. However, such adverse effects may well be counteracted by the effects of elevated