News > Flash floods: why are more of them devastating the world’s driest regions?

Flash floods: why are more of them devastating the world’s driest regions?

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 mm in one hour. Floods in wetter regions typically follow more prolonged bouts of rainfall.