近日，美国达特茅斯学院Corey S. Lesk团队报道了更集中的降水减少了陆地的储水量。2026年5月13日出版的《自然》杂志发表了这项成果。

陆地水资源的可用性是决定人类和生态系统福祉的关键因素。除了平均降水和蒸发的变化之外，日尺度降水集中为更少但更强的降水事件如何影响水文分配和陆地水分平衡，目前尚不清楚。研究组通过观测数据表明，在全球所有气候区，降水越集中，陆地水可用性越低；这种干燥效应的强度，与总降水量增加所带来的湿润效应相当。

简单和复杂的地表模型均能重现这一观测效应，而理想化模拟表明，该效应源于陆地表面水文分配变化所导致的蒸发增强。在全球变暖约2°C的情景下，由升温驱动的降水集中对陆地水储量的预估影响将导致全球27%的人口所在陆地表面转向异常干燥状况（≥0.5个标准差），且这一变化独立于总降水量或灌溉的任何变化。该研究结果揭示了陆地水分平衡新的关键决定因素，强调了其对降水时间分布的敏感性，对未来水资源可用性具有广泛启示。

附：英文原文

Title: More concentrated precipitation decreases terrestrial water storage

Author: Lesk, Corey S., Mankin, Justin S.

Issue&Volume: 2026-05-13

Abstract: Terrestrial water availability is a key determinant of human and ecosystem well-being1,2. Apart from mean precipitation and evaporation changes3,4, it is unknown how daily-scale precipitation concentration into fewer, heavier events affects hydrologic partitioning and the land water balance5,6,7,8,9. Here we show observationally that more concentrated precipitation decreases land water availability across all climates globally, a drying effect as strong in magnitude as the wetting effect of increased total precipitation. Simple and complex land-surface models recover the observed effect, whereas idealized simulations show that it arises from enhanced evaporation caused by hydrologic partitioning changes at the land surface. Projected terrestrial water storage impacts of warming-driven precipitation concentration at about 2°C of warming shift the land surface to abnormally dry conditions (≥0.5 standard deviation10) for 27% of the global population, independent of any total precipitation or irrigation changes. Our results show new key determinants of the land water balance, highlighting its sensitivity to the temporal distribution of precipitation, with broad implications for future water availability.

DOI: 10.1038/s41586-026-10487-7

Source: https://www.nature.com/articles/s41586-026-10487-7