Hydrologic risk from consecutive dry and wet extremes at the global scale
Hydrologic risk from consecutive dry and wet extremes at the global scale
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全球范围内连续干湿极端天气的水文风险
DOI：
10.1088/2515-7620/ac77de
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发表时间：
2022-06
影响因子：
2.9
通讯作者：
M. Rashid;T. Wahl
中科院分区：
文献类型：
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作者：
M. Rashid;T. Wahl
极端干旱和潮湿(即干旱和洪水)是对基础设施和社会环境系统造成的最昂贵的水文危害。由于它们是同一水文循环中相互紧密联系和相互依赖的极端，它们经常紧密相继发生，有可能加剧水文风险。然而，传统上，这一点被忽视，在水文风险评估中将这两种危险分开考虑；这可能导致低估关键基础设施风险(例如，大坝、堤坝、堤坝和水库)。在这里，我们使用标准化的降水蒸散指数识别和表征连续的干湿极端(CDW)事件，使用Copula模型评估它们的多危害水文风险，并调查与大尺度气候变率的遥相关。我们确定了北美、欧洲和澳大利亚的CDW事件热点，这些地区的CDW事件总数从1901年到2015年的20到30个不等。恢复时间(即结束干极端和开始湿极端之间的时间)的减少趋势和干极端和湿极端严重程度的增加趋势表明，CDW事件随着时间的推移而加剧。我们量化了相当于50年和100年单变量重现期的干湿极端严重度的联合超越概率(对于50年和100年重现期，分别高达20%和54%)，当考虑CDW事件及其相关相关性时，与独立和孤立的事件相比，干湿极端严重度的联合超越概率增加了数倍。我们发现了CDW和Niño3.4之间的遥相关；至少80%的CDW事件与热点地区50%的网格位置上的Niño3.4有因果联系。这项研究促进了对CDW事件的多危害水文风险的理解，所提出的结果可以帮助更稳健的规划和决策。
Dry and wet extremes (i.e., droughts and floods) are the costliest hydrologic hazards for infrastructure and socio-environmental systems. Being closely interconnected and interdependent extremes of the same hydrological cycle, they often occur in close succession with the potential to exacerbate hydrologic risks. However, traditionally this is ignored and both hazards are considered separately in hydrologic risk assessments; this can lead to an underestimation of critical infrastructure risks (e.g., dams, levees, dikes, and reservoirs). Here, we identify and characterize consecutive dry and wet extreme (CDW) events using the Standardized Precipitation Evapotranspiration Index, assess their multi-hazard hydrologic risks employing copula models, and investigate teleconnections with large-scale climate variability. We identify hotspots of CDW events in North America, Europe, and Australia where the total numbers of CDW events range from 20 to 30 from 1901 to 2015. Decreasing trends in recovery time (i.e., time between termination of dry extreme and onset of wet extreme) and increasing trends in dry and wet extreme severities reveal the intensification of CDW events over time. We quantify that the joint exceedance probabilities of dry and wet extreme severities equivalent to 50-year and 100-year univariate return periods increase by several folds (up to 20 and 54 for 50-year and 100-year return periods, respectively) when CDW events and their associated dependence are considered compared to their independent and isolated counterparts. We find teleconnections between CDW and Niño3.4; at least 80% of the CDW events are causally linked to Niño3.4 at 50% of the grid locations across the hotspot regions. This study advances the understanding of multi-hazard hydrologic risks from CDW events and the presented results can aid more robust planning and decision-making.