Logon
Translate

User login

GTranslate

French German Italian Portuguese Russian Spanish

Eco-Community with Spirit

WHEN YOU’VE SEEN FIRE AND YOU’VE SEEN RAIN, EXPECT MUDSLIDES...

Submitted by yathed on

Fires raged across Southern California, leaving a charred landscape vulnerable to erosion after heavy rains.CrClockwise from top left, Noah Berger/Associated Press; Hilary Swift for The New York Times; Mike Eliason/Santa Barbara County Fire, via European Pressphoto Agency; Eric Risberg/Associated Press

 

This week, we’re looking at the causes behind California’s mudslides; why coal and nuclear power are fighting for survival; and the Trump administration’s effort to delete “climate change.”

If, as some scientists think, climate change may make for more frequent severe wildfire seasons in California, it may lead to more deadly mudslides as well.

That’s because in California, as in other fire-prone regions, fires and mudslides are inextricably linked.

The connection was demonstrated again this week, when, following recent devastating fires, California was hit by torrential rainfall.

                             Related: Deadly California mudslide 'like Niagara falls' as hills turn to rivers of debris...

The rains, as much as an inch an hour in some places, caused mudslides on steep denuded slopes that destroyed homes and killed more than a dozen people.

Burned slopes are susceptible to mudslides, also known as debris flows, because of what fire does to soil. Especially hot fires change the soil’s structure, making it repel water more easily. That means less rainfall is absorbed and more runs off.

In a heavy rain, the extra runoff can be overwhelming, picking up loose soil, dead vegetation and rocks of all sizes as it heads downhill.

A typical debris flow begins with several of these smaller flows at various points on a slope, said Jonathan W. Godt, a landslide expert with the United States Geological Survey. The separate flows eventually converge at a streambed, and the resulting sludge of water, mud, rocks and vegetation, flowing rapidly downstream, can cause destruction and loss of life.

Related: Southern California mudslides: At least 17 dead, 100 homes destroyed...

I had the chance to see the effects of fire on soil back in 2009 in the rugged hills above Santa Barbara. I spent a day with two scientists with the geological survey who lugged their gear down a steep hillside that was still covered in ash from a wildfire four months before.

Their goal was to set up instruments to measure runoff when the rains inevitably came, part of a program to improve understanding of mudslide hazards.

The work was fascinating, and backbreaking, and I learned a lot that day. But for me the most intriguing thing was the quick demonstration that one of the researchers did to show me how the soil had changed. You can read about it in the first few paragraphs of this story.

Jan. 11, 2018

By Henry Fountain

source: https://www.nytimes.com/

original story HERE

Sign Up for Our Free Global Warming Blog RSS feed by clicking here. About once a week you will automatically get all the best blog stories of the week. (The blog now has thousands of articles.)

 

Share This Blog Post: If you would like to share this blog post, go to the original shorter version of this post and look to lower right for the large green Share button. Ask them to sign up too for the Global Warming Blog.

 

Click here for information on the groundbreaking and disruptive new Climageddon book. It is about the global warming emergency and what you can do to help end it!
To View Our: current positions, opinions, agreement or disagreement with this blog article or its facts, click here.

Tags: