|STEWARD, DAVID - Kansas State University|
|BRUSS, PAUL - Kansas State University|
|YANG, XIAOYING - Fudan University|
|STAGGENBORG, SCOTT - Kansas State University|
|WELCH, STEPHEN - Kansas State University|
|APLEY, MICHAEL - Kansas State University|
Submitted to: Proceedings of the National Academy of Sciences (PNAS)
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/16/2013
Publication Date: 9/10/2013
Citation: Steward, D.R., Bruss, P.J., Yang, X., Staggenborg, S.A., Welch, S.M., Apley, M.D. 2013. Tapping unsustainable groundwater stores for agricultural production in the High Plains Aquifer of Kansas, projections to 2110. Proceedings of the National Academy of Sciences. 110(37):E3477-E3486.
Technical Abstract: Groundwater provides a reliable tap to sustain agricultural production, yet persistent aquifer depletion threatens future sustainability. The High Plains Aquifer supplies 30% of the nation’s irrigated groundwater, and the Kansas portion supports the congressional district with the highest market value for agriculture in the nation. We project groundwater declines to assess when the study area might run out of water, and comprehensively forecast the impacts of reduced pumping on corn and cattle production. So far, 30% of the groundwater has been pumped and another 39% will be depleted over the next 50 years given existing trends. Recharge supplies 15% of current pumping and would take an average of 500–1,300 years to completely refill a depleted aquifer. Significant declines in the region’s pumping rates will occur over the next 15–20 years given current trends, yet irrigated agricultural production might increase through 2040 because of projected increases in water use efficiencies in corn production. Water use reductions of 20% today would cut agricultural production to the levels of 15–20 years ago, the time of peak agricultural production would extend to 2070's, and production beyond 2070 would significantly exceed that projected without reduced pumping. Scenarios evaluate incremental reductions of current pumping by 20–80%, the latter rate approaching natural recharge. Findings substantiate that saving more water today would result in increased net production due to projected future increases in crop water use efficiencies. Society has an opportunity now to make changes with tremendous implications for future sustainability and livability.