Deciphering human influence on annual maximum flood extent at the global level

Abstract

Human actions are increasingly altering most river basins worldwide, resulting in changes in hydrological processes and extreme events. Yet, global patterns of changes between seasonal surface water and urbanization remain largely unknown. Here we perform a worldwide analysis of 106 large river basins and uncover global trends of annual maximum flood extent and artificial impervious area, as proxy of urbanization, over the past three decades. We explore their relationships with hydroclimatic variability, expressed as rainfall and snowmelt, and find that hydroclimatic variability alone cannot explain changes in annual maximum flood extent in 75% of the analyzed major river basins worldwide. Considering rainfall and urban area together can explain changes in the annual maximum flood extent in 57% of the basins. Our study emphasizes the importance of understanding the global impacts of human presence on changes in seasonal water dynamics.

Recent Advances and New Frontiers in Riverine and Coastal Flood Modeling

“…Zhang et al, 2018). Mazzoleni et al (2022) recently conducted a global analysis of the relationship between annual maximum flood extent (AMFE) and impervious artificial areas as a proxy for urban areas. The study revealed that hydroclimatic variability alone cannot account for changes in AMFE, and urbanization plays a critical role in explaining flood generation in most basins.…”

Historical information sheds new light on the intensification of flooding in the Central Mediterranean

“…However, approaches to detect flood variability from historical climatology are scarce, although they are critical for understanding landscape sensitivity to past environmental changes. Here we can recall events studied in some detail by reconstructing multi-decadal and multi-centennial flood time-series at global 6 , continental 7 , 8 , regional 9 , 10 and local 11 geographical scales. Floods have thus been widely used by climate historians as a possible indicator of long-term climate change 12 , 13 .…”

A Probabilistic Approach for Off-Stream Reservoir Failure Flood Hazard Assessment

“…Floods are natural phenomena that cause serious economic, environmental and social damage [1,2]. However, in certain situations, floods can be induced by anthropic actions [3][4][5][6][7]. In such cases, the flood risk become greater not only due to the increase in vulnerability and exposure [8][9][10][11], but also when a wrong operation or malfunctioning of flood protection structures may occur [12][13][14][15][16][17][18].…”