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

This study explores the long spatio-temporal evolution of global annual maximum flood extent (AMFE) and impervious area, as proxy of urbanization, using high-resolution observational global data over the last 30 years. Understanding the influence of increasing global urbanization trends on AMFE is of pivotal importance for preserving inland water ecosystems and guaranteeing freshwater sources for agriculture, water supply, and electricity production. Changes in the availability of seasonal surface water can also lead to different impacts on society and ecosystems at different scales.

The study finds out 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.