Department of Civil and Environmental Engineering, Cornell University, Ithaca, NY, USA.
Department of Civil and Environmental Engineering, Washington State University, Pullman, WA, USA.
Nat Commun. 2020 Jul 10;11(1):3473. doi: 10.1038/s41467-020-17219-z.
Irrigated agriculture in snow-dependent regions contributes significantly to global food production. This study quantifies the impacts of climate change on irrigated agriculture in the snow-dependent Yakima River Basin (YRB) in the Pacific Northwest United States. Here we show that increasingly severe droughts and temperature driven reductions in growing season significantly reduces expected annual agricultural productivity. The overall reduction in mean annual productivity also dampens interannual yield variability, limiting yield-driven revenue fluctuations. Our findings show that farmers who adapt to climate change by planting improved crop varieties may potentially increase their expected mean annaul productivity in an altered climate, but remain strongly vulnerable to irrigation water shortages that substantially increase interannual yield variability (i.e., increasing revenue volatility). Our results underscore the importance for crop adaptation strategies to simultaneously capture the biophysical effects of warming as well as the institutional controls on water availability.
在依赖雪水的地区，灌溉农业对全球粮食生产有着重要的贡献。本研究量化了气候变化对美国太平洋西北地区依赖雪水的雅基马河流域（YRB）灌溉农业的影响。研究结果表明，日益严重的干旱和温度导致的生长季节缩短，极大地降低了预期的年度农业生产力。整体平均年度生产力的下降也抑制了年际产量的波动，限制了收益波动。我们发现，通过种植改良作物品种来适应气候变化的农民，在气候变化的情况下，他们的预期平均年度生产力可能会增加，但仍强烈面临灌溉水资源短缺的风险，这会大大增加年际产量的波动（即增加收入波动）。我们的研究结果强调了作物适应策略的重要性，既要捕捉变暖的生物物理效应，又要控制水资源的可得性。
