New development in regions with rapidly changing climates may experience unforeseen hazards. Thermokarst lakes (bodies of freshwater that collect in depressions formed by thawing permafrost) cover 20% of Arctic lowlands and are naturally prone to causing catastrophic flooding. Cumulative lake drainage over time has resulted in up to 60% landscape coverage by drained thermokarst lake basins (DTLBs). Although the impacts of lake drainage on ecosystems and infrastructure have long been considered a potential hazard, these occurrences are usually viewed as one‐time events. However, recent observations in northern Alaska highlight a previously unrecognized threat: annually recurring snow‐dam outburst floods from DTLBs. Each winter, blowing snow fills DTLB drainage gullies, impounding meltwater in the spring and – upon snow‐dam failure – releasing downstream floods. Data collected from 14 DTLBs in Alaska reveal a wide range in flood peaks, many of which exceed river flood events, providing a missing link in Arctic ecosystem hydrology. Projected snowier winters may result in even larger snow‐dam outbursts from DTLBs, adding uncertainty to future risk assessments. If climate change also drives enhanced lake drainage, we predict even more sporadic and higher magnitude floods, with implications for downstream ecosystems and human infrastructure as development pushes into the Arctic lowlands.

中文翻译：

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排水湖反复爆发的洪水：新出现的北极灾害

气候变化迅速的地区的新发展可能会遇到无法预料的危害。喀斯特地区的喀斯特湖（淡水聚集在因永久冻土融化而形成的洼地中）覆盖了20％的北极低地，自然容易造成灾难性的洪灾。随着时间的流逝，累积的湖泊排水导致热喀斯特湖盆地（DTLB）排水的景观覆盖率高达60％。尽管长期以来人们一直认为湖泊排水对生态系统和基础设施的影响是潜在的危害，但这些事件通常被视为一次性事件。但是，最近在阿拉斯加北部的观测结果突显了以前无法识别的威胁：每年由DTLB引发的雪坝暴发洪水。每年冬天，DTLB排水沟都积雪，在春季蓄积融化水，并在雪坝失灵时释放下游洪水。从阿拉斯加的14个DTLB收集的数据显示，洪峰范围很广，其中许多洪峰超过了河流洪灾事件，为北极生态系统水文学提供了一个缺失的环节。预计下雪的冬天可能导致DTLB爆发更大的雪坝爆发，为未来的风险评估增加不确定性。如果气候变化也能促进湖泊排水的增加，我们预测洪水会更加零星发生，洪水数量也会更大，这将对下游生态系统和人类基础设施产生影响，因为发展将进入北极低地。预计下雪的冬天可能导致DTLB爆发更大的雪坝爆发，为未来的风险评估增加不确定性。如果气候变化也能促进湖泊排水的增加，我们预测洪水会更加零星发生，洪水数量也会更大，这将对下游生态系统和人类基础设施产生影响，因为发展将进入北极低地。预计下雪的冬天可能导致DTLB爆发更大的雪坝爆发，为未来的风险评估增加不确定性。如果气候变化也能促进湖泊排水的增加，我们预测洪水会更加零星发生，洪水数量也会更大，这将对下游生态系统和人类基础设施产生影响，因为发展将进入北极低地。