Submitted to: Journal of the American Water Resources Association
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/2/1999
Publication Date: N/A
Interpretive Summary: Water for irrigation in the Southest United States has increased in importance due to increased irrigated acreage as well as competition from municipal and environmental interest. Future increases in water demand from both agricultural and non-agricultural sectors will further burden our natural resource base. To address the potential for such changes, the potential effects of climate change on agricultural water use in the Southeast were analyzed. Climate prediction models generated climatological data for use in crop response models for prediction of crop output changes for Georgia in 2030 and 2090. The output changes were incorporated into a farm management model and mathematically optimized to address the impact of climate change on crop selection, farm income, and irrigated water usage. Changes in crop mix results indicating substantial decreases in corn acreage paralleled by increases in peanuts, cotton, and winter wheat.
Technical Abstract: Climate change has the potential to have dramatic effects on the agricultural sector, nationally and internationally, as documented in many research papers. This paper reports on research that was focused on a specific growing area to demonstrate how farm managers might respond to climate-induced yield changes and the implications of these responses for agricultural water use. The Hadley model was used to generate climate scenarios for important agricultural areas of Georgia in 2030 and 2090. Linked crop response models indicated generally positive yield changes, as increased temperatures were associated with increased precipitation and CO2. Using a farm management model, differences in climate-induced yield impacts among crops led to changes in crop mix and associated water use; non-irrigated cropland received greater benefit since irrigated land was already receiving adequate moisture. Model results suggest that farm managers will increase cropping intensity by decreasing fallowing and increasing double cropping. Corn decreased dramatically, peanuts moderatley and cotton and winter wheat increased. Water use on currently irrigated cropland fell. The potential for increased water use through conversion of agriculturally important, but currently non-irrigated, growing areas is substantial.