Products from El Nino studies in southern California

Geologic mapping and El Niño in southern California:

How to get maps describing debris-flows susceptibility

The U.S. Geological Survey's Southern California project is making maps that describe areas prone to possible future damage. The maps are constructed at a scale of 1:100,000 and are suitable for general planning purposes but not for site-specific applications such as determining the hazard for a single building.

The maps show in bright yellow the areas that are prone to possible debris flows. The areas are plotted on a background of shaded relief showing mountains, canyons, and plains. Try an example from Palos Verdes to see what the maps are like and how to interpret them.

Index of areas for debris-flow hazard maps: View the index map.

Getting the maps: Click on the 1:100,000 scale quadrangle (either its name or on the map) you want to download. Files are in PDF format (except Santa Ana which are JPG) and require Adobe Acrobat Reader (Acrobat Reader is available free from Adobe Systems Inc. ). Note that the files are large! Files too big? Data release site for smaller, low resolution files.