The current ‘Deployable Output’ approach for assessing water resources system performance in England and Wales is a practical, communicable means for assessing the adequacy of a water supply system and determining the relative benefits of proposed system enhancements. A recognised flaw with this approach is that it fails to characterise the severity of potential supply shortfalls, leading to mischaracterisation of risks and benefits associated with alternative candidate investments. Here, we propose a Monte Carlo procedure that could supplement the existing process by exposing the magnitude (% water demand unserved) and duration (number of days) of supply curtailments under a range of drought scenarios. The method is demonstrated using a realistic, stylised water resources system and a discrete number of infrastructure investments. Results demonstrate that vulnerability assessments can expose previously unidentified risks that might radically alter a planner’s estimate of the cost‐effectiveness of a particular investment.

中文翻译：

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一个简单的干旱风险分析程序，可补充英格兰和威尔士的水资源管理计划

当前在英格兰和威尔士评估水资源系统性能的“可部署产出”方法是一种实用的，可交流的手段，用于评估供水系统的充足性并确定拟议中的系统改进的相对利益。这种方法的一个公认缺陷是，它无法描述潜在供应短缺的严重性，从而导致与替代性候选投资相关的风险和收益的误判。在这里，我们提出了一种蒙特卡洛程序，该程序可以通过暴露一系列干旱情景下的供应削减幅度（未满足的水需求百分比）和持续时间（天数）来补充现有过程。使用现实的，程式化的水资源系统和大量基础设施投资来演示该方法。