Flash floods in dry areas discussed

From a commentary piece at Nature:

Last year, around two-thirds of Pakistan was affected by widespread flash flooding, with more than 1,500 people killed and around 33 million made homeless. Almost 2,000 people died in flash floods across Africa, and parts of the United Arab Emirates, Iran, Saudi Arabia, Qatar, Oman and Yemen were inundated with water.

Flash floods are a growing threat in some of the world’s driest regions. Deluges can trigger sudden and rapid torrents of run-off that flow down dry river beds and rocky channels.

Because parched soils repel water rather than allowing it to soak in, flash floods can be more devastating in drylands than in wetter areas. Surges can result from relatively small amounts of rain, as little as 10 millimetres in one hour. By comparison, floods in wetter regions typically follow more prolonged bouts of rainfall.

Look at this:

A slew of other factors will put many more people at risk from flash floods in future (see ‘Drylands: flash-flood risks’). Climate change is making such events more intense and frequent^1–3. In parts of Pakistan, for example, the 5-day maximum level of rainfall is 75% greater today than it was before 1900 (see go.nature.com/41awzzj). Our analysis shows that globally, the rate of dryland flash flooding was 20 times higher between 2000 and 2022 than it was between 1900 and 1999 (numbering 278 and 64 floods, respectively).