Jiayao Zhu, Beibei Ding, Yong Chen, Puyu Feng, Jianing Ge, De Li Liu, Raghavan Srinivasan, Lili Yu, Xueliang Zhang
Abstract
Groundwater overexploitation threatens agricultural sustainability in the U.S. Ogallala Aquifer, while climate change adds uncertainty to the Crop–Water–Economy relationship. This study employs an integrated SWAT-GW-MAD-CO₂ model, coupled with an economic analysis, to assess future irrigation demand, groundwater dynamics, and economic outcomes under two emission scenarios. The groundwater module was well calibrated and validated (P-factor > 0.9, R-factor < 0.2, R² > 0.7, PBIRS < 5 %). Projections for 2070–2089 reveal that irrigated wheat yields increase by 33.2 % under high-emission scenarios (SSP5–8.5), generating $152 million, while irrigated sorghum yields and revenues decline. Corn yields remain stable, but groundwater extraction cost savings exceed $180 million. Dryland wheat shows moderate yet consistent gains in revenue and cost savings. Summer crops exhibit faster groundwater declines (>0.85 m/year) than winter crops, due to higher water demand, yet exhibit greater resilience to climate variability. Irrigated systems demonstrate higher yield stability and economic returns than dryland systems. Net economic benefits are projected to increase by $51–220 million for irrigated wheat, $22–66 million for dryland wheat, and $30–180 million for irrigated corn, but decrease by $6.6–21 million for irrigated sorghum. This study highlights the differential impacts of climate change on crop types, with winter crop benefits primarily driven by yield increases, and summer crop benefits more reliant on groundwater cost savings. By integrating hydrological and economic dynamics across 27 GCMs, the findings underscore the importance of adaptive management and emissions mitigation to support groundwater sustainability, agricultural productivity, and regional economic resilience.
1-s2.0-S0378377425004317-main.pdf