The faults and fractures that are present are such that, while influencing local topography and stream locations, their density, type, and orientation do not create significant weaknesses that lead to large zones of mass movement and instability. Map S-3 . Potential for Soil Movement following Wildfire. The hazard rating is displayed on Map S-3 . The term hydrophobicity refers to the water-repellent layers that are formed when polarized organic molecules are formed as they diffuse down into the soil, then cool and condense forming a compound that coats soil particles, and fills pore spaces.
Hydrophobicity interferes with and reduces the soils infiltration characteristics.
The specific mechanism is not fully understood, however, it is accepted that soil physical properties such as texture, moisture content and soil temperature play a role in this process. In a qualitative sense hydrophobic soils probably increase the net surface erosion of soils by retarding infiltration and thereby increasing sheet wash. It may be that once the organic carbon deposits are eroded away the rate of infiltration will increase and sheet wash and erosion will be reduced.