Alluvial fan flooding definition

Alluvial fan flooding means flooding occurring on the surface of an alluvial fan or similar landform which originates at the apex and is characterized by high-velocity flows; active processes of erosion, sediment transport, and deposition; and unpredictable flow paths.
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Alluvial fan flooding means a fan-shaped sediment deposit formed by a stream that flows from a steep mountain valley or gorge onto a plain or the junction of a tributary stream with the main stream. Alluvial fans contain active stream channels and boulder bars, and recently abandoned channels. Alluvial fans are predominantly formed by alluvial deposits and are modified by infrequent sheet flood, channel avulsions and other stream processes.
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Alluvial fan flooding means a fan-shaped sediment deposit formed by a stream that flows from a steep mountain valley or gorge onto a plain or the junction of a tributary
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Examples of Alluvial fan flooding in a sentence

  • Alluvial Fan Flooding means flooding occurring on the surface of an alluvial fan or similar landform that originates at the apex.

  • Section A: Three-Stage Analysis The three-stage analysis of alluvial fans is described in the Federal Emergency Management Agency’s (FEMA's) Consolidated Guidelines and Specifications for Flood Hazard Mapping Partners, Appendix G: Guidance for Alluvial Fan Flooding Analyses and Mapping, which can be obtained from the Federal Emergency Management Agency’s (FEMA’s) Internet site at http://www.fema.gov/fhm/dl_cgs.shtm.

  • Section A: Three-Stage Analysis The three-stage analysis of alluvial fans is described in the Federal Emergency Management Agency’s (DHS- FEMA's) Consolidated Guidelines and Specifications for Flood Hazard Mapping Partners, Appendix G: Guidance for Alluvial Fan Flooding Analyses and Mapping, which can be obtained from the Federal Emergency Management Agency’s (DHS-FEMA’s) Internet site at http://www.fema.gov/plan/prevent/fhm/dl_cgs.shtm.

  • Until this new guidance document is final, please continue to use Guidelines and Specifications for Flood Hazard Mapping Partners, Appendix G: Guidance for Alluvial Fan Flooding Analyses and Mapping.

  • SECTION A: THREE-STAGE ANALYSIS The three-stage analysis of alluvial fans is described in the Federal Emergency Management Agency’s (DHS- FEMA's) Guidelines and Specifications for Flood Hazard Mapping Partners, Appendix G: Guidance for Alluvial Fan Flooding Analyses and Mapping, which can be obtained from the Federal Emergency Management Agency’s (DHS-FEMA’s) Internet site at http://www.fema.gov/media-library/assets/documents/13948.

  • The approach, detailed in the Guidelines for Determining Flood Hazards on Alluvial Fans (February 2000), addresses recommendations in a 1996 report by the National Research Council’s (NRC’s) Committee on Alluvial Fan Flooding.

  • The administrator shall describe the course and give their reason(s).

  • However, it will be required after construction is complete and a revision to the Flood Insurance rate Map (FIRM) is requested.Section C: Mapping RequirementsWith the revision request, submit a certified topographic map showing the information indicated in the Mapping Requirements section of the Alluvial Fan Flooding Form.

  • Additional information also can be found in the National Research Council report entitled Alluvial Fan Flooding (National Research Council, 1996).

  • Determine the Boundaries of the Area Subject A5-6 to Alluvial Fan Flooding C.


More Definitions of Alluvial fan flooding

Alluvial fan flooding means flooding occurring on the surface of an alluvial fan or similar
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Alluvial fan flooding means flooding occurring on the surface of an alluvial fan or similar landform which originates at t he apex and i s c haracterized b y hi gh-velocity f lows, active pr ocesses of erosion, sediment transport, and deposition, and unpredictable flow paths.
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Alluvial fan flooding means flooding occurring on the surface of an alluvial fan or similar landform which originates at the apex and is characterized by
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Alluvial fan flooding means flooding occurring on the surface of an alluvial fan or similar landform which originates at the apex and is characterized by high- velocity flows; active processes of erosion, sediment
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Alluvial fan flooding means flooding occurring on the surface of an alluvial fan or similar landform which originates at the apex and is characterized by high-velocity flows; active processes of erosion, sediment transport, and deposition; and, unpredictable flow paths. “Apex” means a point on an alluvial fan or similar landform below which the flow path of the major stream that formed the fan becomes unpredictable and alluvial fan flooding can occur.
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Alluvial fan flooding means flooding occurring on the surface of an alluvial fan or similar landform, which originates at the apex and is characterized by high-velocity flows; active processes of erosion, sediment transport, and deposition; and unpredictable flow paths. For the purposes of the NFIP, "apex" means a point on an alluvial fan or similar landform below which the flowpath of the major stream that formed the fan becomes unpredictable and alluvial fan flooding can occur. The degree to which the processes that charac­terize alluvial fan flooding are present can vary greatly. For example, the fact that active deposition has not recently occurred on some portion of the fan surface does not necessarily preclude the use of FEMA's methodology for determining hazards from alluvial fan flooding.
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Related to Alluvial fan flooding

  • Flooding means a volume of water that is too great to be confined within the banks or walls of the stream, water body, or conveyance system and that overflows onto adjacent lands, thereby causing or threatening damage.

  • Special Fare means any fare other than a Normal Fare.

  • Area of shallow flooding means a designated AO or AH Zone on a community's Flood Insurance Rate Map (FIRM) with one percent or greater annual chance of flooding to an average depth of one to three feet where a clearly defined channel does not exist, where the path of flooding is unpredictable and indeterminate; and where velocity flow may be evident. Such flooding is characterized by ponding or sheet flow.

  • Floodplain or flood-prone area means any land area susceptible to being inundated by water from any source. See "Flood or flooding."

  • 100-year floodplain means any area of land that:

  • Floodplain or "Flood-prone area" means any land area susceptible to being inundated by water from any source (see definition of "Flooding").

  • Habitat means the physical and biological environment in which

  • Erosion means the detachment and movement of soil or rock fragments by water, wind, ice, or gravity.