The effect of climate uncertainty on water management for long-run aquifer abundance.

The adaptation of agriculture to climate change depends on the ability to integrate irrigation practices into water management applications. This requires robust water use estimates and the evaluation of management practices as a tool to conserve water. We combine a landscape level agricultural management model that accounts for risk and uncertainty through climate change with an aquifer model. The modelling system produces estimates of the long run aquifer abundance for management scenarios for a study area in the Lower Mississippi River Basin, United States. Except in the driest climate outcome, the aquifer abundance rises over time. We find that the increase in the aquifer for most climate outcomes occurs through judicious crop choice and aquifer recharge followed by a use of on-farm reservoirs later in the study period. Our modelling points to the greatest sensitivity of the long run aquifer abundance to fluctuations in crop prices and production costs followed by the cost of surface water for aquifer recharge.