Simulating the impacts of future climate change on water footprints and crop production allows for selecting alternative crops for mitigating climate change effects. In this study, climate change impacts on irrigated grain corn, grain sorghum, winter wheat, and dryland (rainfed) winter wheat in the Palo Duro watershed of the Texas High Plains were assessed using an improved Soil and Water Assessment Tool (SWAT) model with an enhanced irrigation representation of management allowed depletion (MAD) irrigation scheduling. Climate change analyses in this study used the Coupled Model Intercomparison Project Phase 5 (CMIP5) climate projections of 11 General Circulation Models (GCMs) under four Representative Concentration Pathway (RCP) emission scenarios of RCP2.6, 4.5, 6.0, and 8.5 during two 30-year periods of the middle (2040-2069) and end (2070-2099) of the 21^st century to compare to a baseline period of 1970-1999. For the irrigated summer crops of corn and sorghum, all 11 GCMs predicted the reductions of future irrigation, crop evapotranspiration (ET_c), and yields compared to the baseline period. According to an ensemble of 11 GCMs, the simulated reductions in average annual irrigation, ET_c, and yield for the irrigated corn were 63%, 34%, and 13%, respectively, at the end of the 21^st century under the severe emission scenario of RCP8.5. Those values were 80%, 34%, and 34% under the irrigated sorghum land use. As for the irrigated winter wheat, the decreases in future irrigation and ET_c were also identified in all GCMs relative to the baseline period. However, irrigated wheat yields were increased in the future climate. The changes in dryland wheat ET_c were consistent with the rainfall variation under all climate change scenarios. Generally, the future climate could benefit the dryland wheat yields. A large uncertainty was found for the surface runoff simulations under both irrigated and dryland wheat according to various GCMs.

模拟未来气候变化对水足迹和作物生产的影响可以选择替代作物来减轻气候变化的影响。在这项研究中，使用改进的土壤和水评估工具 (SWAT) 模型评估了气候变化对德克萨斯高原帕洛杜罗流域的灌溉谷物玉米、谷物高粱、冬小麦和旱地（雨养）冬小麦的影响。管理允许消耗 (MAD) 灌溉调度的增强灌溉表示。本研究中的气候变化分析在 RCP2.6、4.5、6.0 和 8 的四个代表性浓度路径 (RCP) 排放情景下使用了 11 个一般环流模型 (GCM) 的耦合模型比对项目第 5 阶段 (CMIP5) 气候预测。^ST世纪来比较的1970-1999基准期。对于夏季灌溉的玉米和高粱作物，与基线期相比，所有 11 个 GCM 都预测了未来灌溉、作物蒸散量 (ET _c ) 和产量的减少。据的11个环流模型的集成，在平均每年灌溉，ET模拟的削减_Ç和产量是灌溉玉米分别为63％，34％，13％，在21的端部^ST世纪严重发射下RCP8.5 的场景。在灌溉高粱土地利用下，这些值分别为 80%、34% 和 34%。对于灌溉冬小麦，未来灌溉和 ET _c的减少在与基线期相关的所有 GCM 中也被识别出来。然而，灌溉小麦产量在未来气候中有所增加。旱地小麦ET _c的变化与所有气候变化情景下的降雨变化一致。一般来说，未来的气候可能有利于旱地小麦的产量。根据各种 GCM，灌溉和旱地小麦下的地表径流模拟存在很大的不确定性。