Aligning water supply with demand is a challenge, particularly in areas with large seasonal variation in precipitation and those dominated by winter precipitation. Climate change is expected to exacerbate this challenge, increasing the need for long-term planning. Long-term projections of water supply and demand that can aid planning are mostly published as agency reports, which are directly relevant to decision-making but less likely to inform future research. We present 20-year water supply and demand projections for the Columbia River, produced in partnership with the Washington State Dept. of Ecology. This effort includes integrated modeling of future surface water supply and agricultural demand by 2040 and analyses of future groundwater trends, residential demand, instream flow deficits, and curtailment. We found that shifting timing in water supply could leave many eastern Washington watersheds unable to meet late-season out-of-stream demands. Increasing agricultural or residential demands in watersheds could exacerbate these late-season vulnerabilities, and curtailments could become more common for rivers with federal or state instream flow rules. Groundwater trends are mostly declining, leaving watersheds more vulnerable to surface water supply or demand changes. Both our modeling framework and agency partnership can serve as an example for other long-term efforts that aim to provide insights for water management in a changing climate elsewhere around the world.

中文翻译：

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同时评估供水和需求对于评估气候变化的脆弱性至关重要

使供水与需求保持一致是一项挑战，特别是在降水季节性变化较大的地区以及以冬季降水为主的地区。气候变化预计将加剧这一挑战，增加长期规划的必要性。有助于规划的长期供水和需求预测大多以机构报告的形式发布，这些报告与决策直接相关，但不太可能为未来的研究提供信息。我们与华盛顿州生态部合作制定了哥伦比亚河 20 年供水和需求预测。这项工作包括到 2040 年对未来地表水供应和农业需求进行综合建模，并对未来地下水趋势、住宅需求、河内流量赤字和限水进行分析。我们发现，供水时间的改变可能导致华盛顿东部的许多流域无法满足季末停水需求。流域农业或住宅需求的增加可能会加剧这些晚季的脆弱性，对于具有联邦或州内河流量规则的河流来说，限水可能会变得更加普遍。地下水趋势大多呈下降趋势，使流域更容易受到地表水供应或需求变化的影响。我们的建模框架和机构合作伙伴关系都可以作为其他长期努力的典范，这些努力旨在为世界其他地方不断变化的气候中的水管理提供见解。