Alluvial Fan Flooding


Book Description

Alluvial fans are gently sloping, fan-shaped landforms common at the base of mountain ranges in arid and semiarid regions such as the American West. Floods on alluvial fans, although characterized by relatively shallow depths, strike with little if any warning, can travel at extremely high velocities, and can carry a tremendous amount of sediment and debris. Such flooding presents unique problems to federal and state planners in terms of quantifying flood hazards, predicting the magnitude at which those hazards can be expected at a particular location, and devising reliable mitigation strategies. Alluvial Fan Flooding attempts to improve our capability to determine whether areas are subject to alluvial fan flooding and provides a practical perspective on how to make such a determination. The book presents criteria for determining whether an area is subject to flooding and provides examples of applying the definition and criteria to real situations in Arizona, California, New Mexico, Utah, and elsewhere. The volume also contains recommendations for the Federal Emergency Management Agency, which is primarily responsible for floodplain mapping, and for state and local decisionmakers involved in flood hazard reduction.




Guidelines for the Geologic Evaluation of Debris-flow Hazards on Alluvial Fans in Utah


Book Description

The Utah Geological Survey (UGS) developed these guidelines to help geologists evaluate debris-flow hazards on alluvial fans to ensure safe development. Debris-flow hazard evaluations are particularly important because alluvial fans are the primary sites of debris-flow deposition and are also favored sites for development. The purpose of a debris-flow-hazard evaluation is to characterize the hazard and provide design parameters for risk reduction. The UGS recommends critical facilities and structures for human occupancy not be placed in active debris flow travel and deposition areas unless the risk is reduced to an acceptable level. These guidelines use the characteristics of alluvial fan deposits as well as drainage-basin and feeder-channel sediment-supply conditions to evaluate debris-flow hazards. The hazard evaluation relies on the geomorphology, sedimentology, and stratigraphy of existing alluvial fan deposits. Analysis of alluvial-fan deposits provides the geologic basis for estimating frequency and potential volume of debris flows and describing debris-flow behavior. Drainage-basin and feeder-channel characteristics determine potential debris-flow susceptibility and the volume of stored channel sediment available for sediment bulking in future flows.




Principles of Alluvial Fan Morphology


Book Description

This book offers a comprehensive overview of the alluvial fan phenomena, including all terminology, morphology, sedimentology, controlling factors, processes and the human impact. It combines the knowledge dispersed widely in existing literature with regional case studies, color figures and photographs. The chapters provide a useful basis to understand alluvial fans and a selection of papers attached to each chapter offers additional, more focused reading. This volume is aimed at engineers, planners and especially students in earth sciences.




Inland Flood Hazards


Book Description

This edited volume was originally published in 2000 and presents a comprehensive, interdisciplinary review of issues related to inland flood hazards. It addresses physical controls on flooding, flood processes and effects, and responses to flooding, from the perspective of human, aquatic, and riparian communities. Individual chapter authors are recognized experts in their fields who draw on examples and case studies of inland flood hazards from around the world. This volume is unusual among treatments of flood hazards in that it addresses how the non-occurrence of floods, in association with flow regulation and other human manipulation of river systems, may create hazards for aquatic and riparian communities. This book will be a valuable resource for everyone associated with inland flood hazards: professionals in government and industry, and researchers and graduate students in civil engineering, geography, geology, hydrology, hydraulics, and ecology.







Subdivision Design and Flood Hazard Areas


Book Description

Sustainability, resilience, and climate change are top of mind for planners and floodplain managers. For subdivision design, those ideas haven't hit home. The results? Catastrophic flood damage in communities across the country. This PAS Report is out to end the cycle of build-damage-rebuild and bring subdivision design into line with the best of floodplain planning. Readers will get the tools they need to save lives, protect property, and lay the foundation for a better future.




Alluvial Fan Flooding


Book Description

Alluvial fans are gently sloping, fan-shaped landforms common at the base of mountain ranges in arid and semiarid regions such as the American West. Floods on alluvial fans, although characterized by relatively shallow depths, strike with little if any warning, can travel at extremely high velocities, and can carry a tremendous amount of sediment and debris. Such flooding presents unique problems to federal and state planners in terms of quantifying flood hazards, predicting the magnitude at which those hazards can be expected at a particular location, and devising reliable mitigation strategies. Alluvial Fan Flooding attempts to improve our capability to determine whether areas are subject to alluvial fan flooding and provides a practical perspective on how to make such a determination. The book presents criteria for determining whether an area is subject to flooding and provides examples of applying the definition and criteria to real situations in Arizona, California, New Mexico, Utah, and elsewhere. The volume also contains recommendations for the Federal Emergency Management Agency, which is primarily responsible for floodplain mapping, and for state and local decisionmakers involved in flood hazard reduction.