How the fires that occur in California participate in the Erosion?

Answer 1

A couple of ways: they remove vegetation which holds soil in place, so there will be increased erosion when it rains (or even when the wind blows); also, fire causes spalling of rock from granite outcrops (large flakes of rock break off due to the fire).

Answer 2

Soils are less prone to erosion when vegetated because roots will hold the soil together as well as use some of the moisture by uptaking it into their roots. When the vegetation is removed (whether it be fire or any other form of clearing the land), the soil no longer has the structural system to hold it together. This is especially true when the land is on a hill side or mountain. The California fires that occurred recently are largely in hilly terrain. The Grass Valley Valley fire and Slide Fires both occurred in the San Bernardino Mountains. The Rice Fire occurred in Fallbrook, which is a hilly/slightly mountainous area and primarily burned ridges and hill sides. Same with some of the other fires. These fires left tens of thousands of acres in hilly and mountainous areas void of vegetation. Also, Southern California gets the majority of its rain in the winter months, especially January and February. With major wildfires occurring in October (2003 and 2007 wildfires) and the rainy season shortly behind it, leaves no time for growth to establish and protect those hillsides (not to mention things don't grow much in the fall and winter). You can research the effects of the 2003 fires in Southern California for an idea of what is to come.