Climate More Important for Chinese Flood Changes Than Reservoirs and Land Use. Issue 11 (2nd June 2021)

• Record Type: Journal Article
• Authors: Yang, Long; Yang, Yixin; Villarini, Gabriele; Li, Xiang; Hu, Hongchang; Wang, Lachun; Blöschl, Günter; Tian, Fuqiang
• Is Part Of: Geophysical research letters. Volume 48:Issue 11(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-06-02
• Subjects: Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1029/2021GL093061
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: River regulations and changing land management practices are generally perceived to be the dominant drivers of river flood changes in countries with rapid economic growth, such as China. Here, we demonstrate based on the most comprehensive flood database to date, that climate variations dominate the spatial pattern of changes in annual flood peak discharge in China, despite intense human alterations of the river and land systems over the past four decades. Regional flood increases are mainly associated with increasing precipitation due to changes in the East Asian Summer Monsoon, tropical cyclones and the subtropical westerly jet. Regional flood decreases are due to decreased soil moisture in the North China plain. Our results highlight the need for flood management policies to go beyond local measures and adapt to the effects of climate change. Plain Language Summary: Changes in river floods are of worldwide concern due to their massive socio‐economic impacts. Understanding the reasons of changes in this hazard is a prerequisite for managing the associated risks efficiently. Potential reasons include climate change, river regulations and changing land management practices. In some countries, such as China, the recent rapid socio‐economic development has led to dramatic modifications of the river and land system. Existing studies suggest that flood changes in China are mainly a result of land use change and the construction of reservoirs. Here, we demonstrate based on the most comprehensive flood database to date, that climate variations dominate the spatial pattern of changes in annual flood peak discharge in China, despite the intense human alterations over the past four decades. Flood trends of human‐modified and neighboring near‐natural watersheds are generally similar. Regional flood increases are mainly associated with increasing precipitation due to changes in the East Asian Summer Monsoon, tropical cyclones and the subtropical westerly jet. Regional flood decreases are due to decreased soil moisture in the North China Plain. Our results highlight the need for flood management policies to go beyond local measures and adapt to the effects of climate change. Key Points: Near‐natural watersheds exhibit very similar flood trends compared to their human‐modified neighbors The variations of three key climate drivers, precipitation, soil moisture and snow depth, explain these flood changes well We highlight the necessity of evaluating the existing flood management practices in order to climate‐proof them