1. Introduction. Scope and importance of problem. Initial concepts and definitions. Conclusion. 2. Basic Geologic Concepts. Introduction. Competing geologic doctrines. Alluvial fan systems: general. Conditions favoring the development and modification of alluvial fans. Fanhead entrenchment. Conditions favorable to the formation of debris and mud-flows. Characteristics of flows in ephemeral streams. 3. Basic Principles of Open Channel Hydraulics. Introduction. Specific energy. Uniform/normal flow. Alluvial channel stability. Debris flow mechanics. Hydraulic/physical models. Conclusion. 4. Models of Hydraulic Processes on Alluvial Fans. Introduction. Numerical model, geologic time scale: Price (1972, 1974). Physical model, geologic time scale: Hooke (1965, 1967, 1968). Numerical/physical model, engineering time scale: Anon.(1981a). Numerical models of debris flows in channels: DeLeon and Jeppson (1982) and Jeppson and Rodriguez (1983). Conclusion. 5. Methods of Flood Hazard Assessment on Alluvial Fans. Introduction. FEMA methodology for alluvial fan studies. Alternative methodology for alluvial fan studies. Proposed modification of the FEMA methodology. Conclusion. 6. Conclusion. Introduction. Socio-economic and institutional problems. Research needs. Glossary. Author Index. Index.