Runoff generation and soil erosion after forest fires from the slopes to the rivers at a basin scale

Abstract

In many parts of the world, forest fires are very common. Fires burn more or less severely the vegetation and even the most organic parts of the forest soil. Fire can modify the physical properties of soil; due to the combustion of vegetation and organic matter, some chemical substances appear and ashes are deposited in the soil surface in various quantities. During the combustion, there is a production of gases, which go to the atmosphere but some of them go deep into the soil and condensate around the soil particles. Due to these important changes resulting from fires, the rainfall arrives at the soil surface in a different way, the infiltration capacity changes due to hydrophobicity, the runoff generation can increase and also the movement of fine and coarse soil particles takes place. All these changes are important for the water and sediment production at the slopes and the consequences can remain during months or years at a basin scale.