中山大学戴永久等在调和全球气候变暖背景下河流洪水变化的分歧的研究中取得重要进展。相关论文于2022年11月28日发表在《自然—气候变化》杂志上。

该团队证明了先前报道的河流泄洪量(定义为年最大泄洪量)对极端降水增加的不明显甚至负响应，在很大程度上是由不同产生机制的洪水信号混合引起的。按洪水类型分层，暴雨引发的洪水对极端降水增加有积极的响应。

然而，这一响应几乎完全被同时发生的与雪灾相关的洪水减少所抵消，导致在历史观测和未来气候预测中，全球洪水总量的总体变化并不明显。研究强调，气候变暖导致暴雨引发洪水的风险增加，以及在评估洪水变化和相关的社会经济和环境风险时区分洪水产生机制的重要性。

据悉，全球变暖加剧了水文循环，预计将会增加极端降水事件的强度和频率。然而，极端降水的增加是否以及在多大程度上转化为河流洪水的变化仍然存在争议。

附：英文原文

Title: Reconciling disagreement on global river flood changes in a warming climate

Author: Zhang, Shulei, Zhou, Liming, Zhang, Lu, Yang, Yuting, Wei, Zhongwang, Zhou, Sha, Yang, Dawen, Yang, Xiaofan, Wu, Xiuchen, Zhang, Yongqiang, Li, Xiaoyan, Dai, Yongjiu

Issue&Volume: 2022-11-28

Abstract: An intensified hydrological cycle with global warming is expected to increase the intensity and frequency of extreme precipitation events. However, whether and to what extent the enhanced extreme precipitation translates into changes in river floods remains controversial. Here we demonstrate that previously reported unapparent or even negative responses of river flood discharge (defined as annual maximum discharge) to extreme precipitation increases are largely caused by mixing the signals of floods with different generating mechanisms. Stratifying by flood type, we show a positive response of rainstorm-induced floods to extreme precipitation increases. However, this response is almost entirely offset by concurrent decreases in snow-related floods, leading to an overall unapparent change in total global floods in both historical observations and future climate projections. Our findings highlight an increasing rainstorm-induced flood risk under warming and the importance of distinguishing flood-generating mechanisms in assessing flood changes and associated social-economic and environmental risks.

DOI: 10.1038/s41558-022-01539-7

Source: https://www.nature.com/articles/s41558-022-01539-7