Wolkeba Fitsume T, Mekonnen Mesfin M, Brauman Kate A, Kumar Mukesh
Department of Civil, Construction, and Environmental Engineering, University of Alabama, Tuscaloosa, AL, USA.
Global Water Security Center, Alabama Water Institute, University of Alabama, Tuscaloosa, AL, USA.
Sci Rep. 2024 Jul 2;14(1):15182. doi: 10.1038/s41598-024-65155-5.
Water scarcity is a global challenge affecting billions of people worldwide. This study systematically assesses differences in the estimation of the global population exposed to water scarcity based on 7 water scarcity indicators and 11 Environmental Flow Requirements (EFR) evaluated at various spatial and temporal resolutions. All indicators show an increase in water scarcity since 1901. However, considering monthly average water scarcity estimates spatially aggregated at the basin scale found 35% less population exposed than estimates based on a distributed grid over the landscape. Estimates temporally disaggregated to consider water scarcity for at least one month a year found 50% (tenfold) larger population exposed compared to average monthly (annual) estimates. The study illustrates that estimates of the impacts of water scarcity are an artifact of how water scarcity is defined and calculated. This suggests caution is needed when relying on a single method and emphasizes the importance of considering the diversity of factors that can influence estimates of impact when assessing water scarcity.
水资源短缺是一项影响全球数十亿人的全球性挑战。本研究基于7个水资源短缺指标和11个在不同空间和时间分辨率下评估的环境流量需求（EFR），系统地评估了全球面临水资源短缺人口估计数的差异。所有指标均显示自1901年以来水资源短缺情况有所增加。然而，考虑流域尺度空间汇总的月平均水资源短缺估计数时，发现受影响人口比基于景观分布式网格的估计数少35%。按时间分解以考虑每年至少一个月的水资源短缺情况时，发现受影响人口比月平均（年度）估计数多50%（增加了九倍）。该研究表明，水资源短缺影响的估计数是水资源短缺定义和计算方式的产物。这表明在依赖单一方法时需要谨慎，并强调在评估水资源短缺时考虑可能影响影响估计数的各种因素的多样性的重要性。
