Climate change is driving an increase in the frequency and intensity of extreme weather events, with alterations to the functioning of the water cycle. Global-scale assessments of shifts in the hydrologic response to climatic perturbations (i.e. hydrologic sensitivity) are needed to identify regions where mitigation efforts will be necessary to avert detrimental changes on terrestrial water resources. In this work, we quantified the hydrologic sensitivity of the terrestrial planet by assessing year to year changes in hydrologic response to the interannual variability in climate forcing during the 2001–2016 period, while evaluating the role of major topoclimatic factors in modulating these responses. Using a metric derived from the inverse of the elasticity concept in Budyko’s space, we produce a Hydrologic Sensitivity Index (HSi) evaluating the hydrologic behavior of a location under variable climatic conditions by examining the extent of the changes in Evaporative Index (AET/P) against the interannual variation in the Dryness Index (PET/P) for consecutive years. This approach produces HSi > 1 for hydrologic sensitive regions and HSi ≤ 1 for hydrologically resilient locations while also allowing the detection of changes in water yields as well as wetting or drying conditions. Globally, the results indicate that hydrologic sensitive areas are clustered at high and low latitudes; at high latitudes, boreal and arctic zones show heightened hydrologic sensitivity accompanied by increasing water yields, while at low latitudes, tropical rainforests show the largest hydrologic sensitivity with the majority of their sensitive area leaning towards decreasing water yields. We found that hydrologic sensitivity is amplified at high elevations and steep-sloped terrain, outlining the importance of topography in modulating the impacts of varying climatic forcing on hydrologic response. We direct the attention towards climate warming resulting in rapid snowmelt and increasing precipitation in Arctic tundra and boreal forests and reduced tree cover in tropical forests, as probable mechanisms driving the observed patterns. Our study highlights the regions with greatest hydrologic sensitivity to interannual climatic variability, motivating further regional and basin-scale investigations on their cascading effects on ecosystems and water resources and their attribution.

随着水循环功能的改变，气候变化正在推动极端天气事件的频率和强度增加。需要对气候扰动的水文响应变化（即水文敏感性）进行全球规模的评估，以确定需要采取缓解措施以避免陆地水资源发生不利变化的区域。在这项工作中，我们通过评估 2001-2016 年期间水文响应对气候强迫年际变化的逐年变化来量化类地行星的水文敏感性，同时评估主要气候因素在调节这些响应中的作用。使用从 Budyko 空间中弹性概念的逆推导出的度量，我们通过检查蒸发指数 (AET/P) 相对于干燥指数 (PET/P) 的年际变化的变化程度，生成水文敏感性指数 (HSi)，评估不同气候条件下某个地点的水文行为。年。这种方法对于水文敏感区域产生 HSi > 1，对于水文弹性位置产生 HSi ≤ 1，同时还允许检测水产量以及润湿或干燥条件的变化。在全球范围内，结果表明水文敏感区集中在高低纬度；在高纬度地区，北方和北极地区显示出水文敏感性增强，同时水产量增加，而在低纬度地区，热带雨林表现出最大的水文敏感性，其大部分敏感区域倾向于减少水量。我们发现水文敏感性在高海拔和陡坡地形被放大，概述了地形在调节不同气候强迫对水文响应的影响方面的重要性。我们将注意力集中在导致北极苔原和北方森林快速融雪和降水增加以及热带森林树木覆盖减少的气候变暖上，这是推动观察到的模式的可能机制。我们的研究突出了对年际气候变化具有最大水文敏感性的区域，推动了对它们对生态系统和水资源的级联效应及其归因的进一步区域和流域尺度调查。