Both creep and earthflow processes control hillslope erosion over large parts of the Redwood Creek basin. The type of process and displacement rates are largely dependent on underlying bedrock type and precipitation input. Progressive creep with rates ranging from 1.0 to 2.5 mm/a dominates on slopes west of the Grogen fault underlain by sheared and foliated schists. Movement appears to respond primarily to annual increments of precipitation. Complex earthflows occur predominantly on slopes east of the Grogen fault underlain by sheared graywacke and mudstone. Movement rates range from 3.0 to 131.0 mm/a and characteristically display dominant rainy season movement.

The fact that landslides constitute more than a local hazard is now well recognized and has been responsible for numerous major investigations by the U.S. Geological Survey and other organizations. This volume, approached from the engineering geology standpoint, has two goals: (1) to update significant information about landslides and present some case histories and (2) to refocus earlier works into new syntheses and insights. Includes contributions not only from the authors but also from government agencies, universities, and consulting firms. Presented in 5 parts: 1. Overview; 2. Regional Studies; 3. Specific and Local Studies; 4. Engineering Geology and Highway Engineering; and 5. Environmental Planning. A valuable resource book if you are involved with studies of landslides.

The conceptual framework of an erosion model has been designed to link processes of mass wasting, surface erosion, and channel storage and transport. A program to stimulate mass wasting will be based on a variation of the factor of safety approach which balances forces tending to drive mass movement against those resisting it. Surface erosion will be treated by using a form of the universal soil loss equation adapted to account for dry ravel processes as well as precipitation generated surface erosion. These processes move material eroded from hillslope landscape areas into the stream channel. Channel erosion may occur either as bedload and suspension load transport or in episodic debris torrents, triggered by debris dam failure or by mass movement from a hillslope. The model will be driven primarily by hydrologic processes and will also receive key inputs from vegetation components of the general ecosystem model. Model development will aim at producing a computer model which will have sufficient realism and predictive capability to be useful to land managers.