Climate change impact on flood and extreme precipitation increases with water availability

TLDR

The hydrological cycle is expected to intensify with global warming, likely increasing extreme precipitation and flood risk, but observed changes often deviate from the theoretical increase in atmospheric water‑holding capacity, especially where water availability is limited. The study quantifies how projected changes in extreme precipitation and flood intensities by the end of the twenty‑first century relate to spatial and seasonal water availability. The authors analyze climate model outputs to link projected extreme precipitation and flood intensities to spatial and seasonal water‑availability patterns. Results show that extreme precipitation and flood intensification rises with higher water availability across climate regions and seasons, and the relationship becomes stronger for less extreme events.

Abstract

Abstract The hydrological cycle is expected to intensify with global warming, which likely increases the intensity of extreme precipitation events and the risk of flooding. The changes, however, often differ from the theorized expectation of increases in water‐holding capacity of the atmosphere in the warmer conditions, especially when water availability is limited. Here, the relationships of changes in extreme precipitation and flood intensities for the end of the twenty-first century with spatial and seasonal water availability are quantified. Results show an intensification of extreme precipitation and flood events over all climate regions which increases as water availability increases from dry to wet regions. Similarly, there is an increase in the intensification of extreme precipitation and flood with the seasonal cycle of water availability. The connection between extreme precipitation and flood intensity changes and spatial and seasonal water availability becomes stronger as events become less extreme.