Bushfire burn scars can intensify and even trigger thunderstorms, leading to catastrophic flooding – here’s how
08 September 2021
Published by https://www.9news.com.au/
USA – Wildfires and bushfires burn millions of acres of land every year, leaving changed landscapes that are prone to flooding.
Wildfire burn scars are often left with little vegetation and with a darker soil surface that tends to repel rather than absorb water.
These changes in vegetation and soil properties leave the land more susceptible to flooding and erosion, so less rainfall is necessary to produce a devastating flood and debris flow than in an undisturbed environment.
Factors contributing to thunderstorms
When that rising warm air draws in more humid air from surrounding areas, it can produce cumulonimbus clouds and even thunderstorms that can trigger rain and flooding.
Riding the thermals
A wildfire in one of these locations would burn more intensely because of the swift air currents, leaving a dark, water-repelling surface with little vegetation behind.
Many of the record-breaking 2020 wildfires in Colorado and Arizona occurred in mountainous terrain where flash flooding on burn scars has been deadly in the past. These areas will continue to be of particular concern over the next few years.
The effects can linger
This article by William R Cotton from Colorado State University is republished from The Conversation under a Creative Commons license. Read the original article here.