GC066-06
Peak grain forecasts in the U.S. High Plains amid withering waters
Thursday, 10 December 2020: 20:50
Virtual
Assaad Mrad1, Gabriel George Katul2, Delphis F Levia Jr3, Andrew J Guswa4, Elizabeth W Boyer5, Michael P Bruen6, Darryl E Carlyle-Moses7, Rachel Coyte2, Irena F Creed8, Nick Van De Giesen9, Domenico Grasso10, David M Hannah11, Janice Elaine Hudson12, Vincent Humphrey13, Shin'ichi Iida14, Robert B Jackson15, Tomo'omi Kumagai16, Pilar Llorens17, Beate Michalzik18, Kazuki Nanko19, Catherine A Peters20, John S Selker21, Doerthe Tetzlaff22,23, Maciej Zalewski24 and Bridget R Scanlon25, (1)Duke University, Nicholas School of the Environment, Durham, NC, United States, (2)Nicholas School of the Environment, Duke University, Durham, NC, United States, (3)University of Delaware, Departments of Geography and Spatial Sciences & Plant and Soil Sciences, Newark, DE, United States, (4)Smith College, Picker Engineering Program, Northampton, MA, United States, (5)Penn State University, University Park, PA, United States, (6)Univ College Dublin, Dublin, Ireland, (7)Thompson Rivers University, Geography and Environmental Studies, Kamloops, BC, Canada, (8)Univ Western Ontario, London, ON, Canada, (9)Delft University of Technology, Faculty of Civil Engineering and Geosciences, Delft, Netherlands, (10)University of Michigan- Dearborn, Dearborn, MI, United States, (11)University of Birmingham, School of Geography, Earth and Environmental Sciences, Birmingham, B15, United Kingdom, (12)University of Delaware, Newark, DE, United States, (13)California Institute of Technology, Environmental Science and Engineering, Pasadena, CA, United States, (14)Forestry & Forest Products Research Institute, Department of Disaster Prevention, Meteorology and Hydrology, Ibaraki, Japan, (15)Stanford University, Stanford, CA, United States, (16)Nagoya University, Institute for Space-Earth Environmental Research, Nagoya, Japan, (17)Institute of Environmental Assessment and Water Research (IDAEA-CSIC), Barcelona, Spain, (18)Friedrich Schiller University of Jena, Jena, Germany, (19)FFPRI, Ibaraki, Japan, (20)Princeton University, Princeton, NJ, United States, (21)Oregon State University, Biological and Ecological Engineering, Corvallis, OR, United States, (22)Leibniz Institute of Freshwater Ecology and Inland Fisheries, Berlin, Germany, (23)Humboldt University of Berlin, Berlin, Germany, (24)University of Lodz, Department of Applied Ecology, Lodz, Poland, (25)University of Texas at Austin, Bureau of Economic Geology, Jackson School of Geosciences, Austin, TX, United States
Abstract:
Groundwater-based crop irrigation is driven by the inter-dependent dynamics of economics, climate, policy, resource availability, and technological innovation. An analysis that includes these dependent dynamics is required to project groundwater lifespan and crop production thereby evaluating food security. However, recent research on aquifer lifespan has utilized analyses based on Hubbert’s approach to projecting crude oil production in the United States. This approach consists of fitting water level changes to a logistic curve and extrapolating into the future. It lacks an account of how changes in crop production, market demand, and climate might affect future groundwater withdrawals. We propose a predator-prey type dynamical system wherein crop production ‘preys’ on groundwater resources. It accounts for groundwater recharge and crop yield improvements. We apply this model to the northern, central, and southern U.S. High Plains. In the southern and central High Plains, withdrawals have exceeded recharge for so long that surface water and groundwater resources have become disconnected. In these regions, groundwater withdrawals have peaked driving a subsequent peak in crop production, called peak grain. It was found that lags between these peaks increased with the adoption of improved irrigation practices and higher recharge rates. Results indicate that in Texas, withdrawals peaked in 1966, followed by a peak in grain production nine years later. After better irrigation technologies were adopted, the lag increased to 15 years from 1997 to 2012. In Kansas, where these technologies were employed concurrently with the rise of irrigated grain production, this lag was predicted to be 24 years starting in 1994. In contrast, Nebraska enjoys such high recharge rates and abundant surface water resources that irrigated crop production is expected to rise through 2050. We explore how climate change and groundwater quality are accommodated in the proposed framework.
