November 08, 2003
After the Fire, the Deluge?
Last week Southern California was stalked by fires. This weekend, the forecast is for rain. And as I said last week, the area around Los Angeles is shaped by earthquakes, wind (the Santa Anas), fire, and water. Friday's California Report, aired on KQED (radio), has a segment covering the increased danger from rain that comes as a consequence of the fire.
There is rain in the forecast for Southern California this weekend. That could make it harder for people trying to recover from the massive wildfires that ravaged the mountains. The possibility of rain has many bracing for a different kind of natural disaster: mudslides and floods. Fires kill the vegetation that slows floods -- making the soil water repellant. So wildfires just before the rainy season are a kind of a one-two punch for people living there.
In Southern California, a team of geologists, hydrologists and governmental players, known as the Burned Area Rehabilitation Team (BARE team) are surveying every one of the more than 50 debris basins (those football field-sized catchment basins) to try to figure out which ones are most at risk because of the fires.
The segment reported that the burning of the Chapparal left a thin layer of wax on the dirt that causes the dirt to be "hydrophobic". (Aside: I just love this terminology -- such compelling and vivid verbage!) This means that the land (with its very steep slopes) acts like it has been paved with a very thin layer which sluffs off water with ease, but eventually with enough water can create enomous mudslides and debris flows. Today, even though the debris basins are very large, some of them are at least 4 times smaller than they should be to protect the schools, businesses and homes below.
In the area of Rancho Cucamonga, a debris flow could create a huge disaster because of the schools in the path of the potential mudslides. The areas affected by the fire will take at least a couple of years before this thin impermiable area is broken down and the threat from debris flows will return to normal.
Posted by Mary at November 8, 2003 11:52 AM | TrackBackI have been so busy between greeting people at Walmarts and cleaning glory holes at the porn parlor that I haven't had much time to blog anymore. Swing by the site and say hello. It's up and running again!
http://mwowatchwatchwatchwatch.blogspot.com/
Posted by: Barney Gumble on November 8, 2003 07:50 PMAnd see, Mary, the thing they rarely mention is that Chaparral biomes need fire to regenerate. Just like grasslands, everything is intended to get bone dry at a certain time of year and go up like a torch every so often. And then when you have as much fuel as you did this year, along with some determined arsonists...
California must have some seriously bad karma. In recent years they've been hit with bark beetles, corporate graft, drought, Republicans, fire, and now possibly floods. That's six, count them, six plagues. Don't be surprised by locusts, earthquakes, rains of fire, or the return from obscurity of glam rock. I recommend repentance, and possibly the purchase of a small goat suitable for sacrifice in case mad prophets should wander around suggesting that everyone put blood on their doorposts ;)
Posted by: natasha on November 8, 2003 09:33 PM...the purchase of a small goat suitable for sacrifice..
Hmmm. Never done that before. Would that be our first Eid?
Posted by: James R MacLean on November 13, 2003 03:53 PM