Landslide Hazards along River Corridors - Alpine fans more likely subject to debris flows

Metadata also available as - [Outline]

Frequently anticipated questions:


What does this data set describe?

Title:
Landslide Hazards along River Corridors - Alpine fans more likely subject to debris flows
Abstract:
Depositional fans are formed when sediment moving down a steep channel is deposited where the channel gradient abruptly decreases, for example where a steep valley-wall tributary reaches the valley floor. Sediment can be carried down such a steep channel in flow-type landslides (debris flows, debris floods) or as sediment can be carried by streamflow. Fans are subject to a range of hazards depending which of the preceding processes are active. Debris flows are a style of landslide movement that entail landslide debris moving in a fluid state down a channel, often travelling a long distance from the point of origin. This layer represents fans that are located in alpine areas and are more likely subject to debris flows.
Supplemental_Information:
Research in British Columbia has identified a simple landscape metric that identifies alpine drainage basins that are more likely to produce debris flows (Wilford et al. 2009). This metric is variously known as the Relative Relief Ratio (used here) or the Melton Ratio (see figure below). The ratio increases with the elevation range of the basin and decreases with the square root of the basin area. The ratio will therefore be greatest for small basins that span a large elevation change. Research in British Columbia has shown that basins with a Relative Relief Ratio of 0.6 or more are more likely to produce debris flows, and that fans with a Relative Relief Ratio less than 0.6 are more likely to produce debris floods or normal fluvial flooding (Wilford et al. 2009).
  1. How should this data set be cited?

    County, King, 20160816, Landslide Hazards along River Corridors - Alpine fans more likely subject to debris flows: King County, King County, WA.

    Online Links:

    Other_Citation_Details: None

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -122.039799
    East_Bounding_Coordinate: -121.162454
    North_Bounding_Coordinate: 47.779276
    South_Bounding_Coordinate: 47.147043

  3. What does it look like?

    <http://www5.kingcounty.gov/sdc/DataImages/lsr_f_alpinefanmorelikelydf.jpg> (JPG)
    JPG File of layer overlain on base of WA counties or local cities

  4. Does the data set describe conditions during a particular time period?

    Calendar_Date: 20-Jun-2016
    Currentness_Reference: publication date

  5. What is the general form of this data set?

    Geospatial_Data_Presentation_Form: vector digital data

  6. How does the data set represent geographic features?

    1. How are geographic features stored in the data set?

      This is a Vector data set. It contains the following vector data types (SDTS terminology):

      • GT-polygon composed of chains (269)

    2. What coordinate system is used to represent geographic features?

      The map projection used is NAD 1983 HARN StatePlane Washington North FIPS 4601 Feet.

      Projection parameters:
      Standard_Parallel: 47.5
      Standard_Parallel: 48.73333333333333
      Longitude_of_Central_Meridian: -120.8333333333333
      Latitude_of_Projection_Origin: 47.0
      False_Easting: 1640416.666666667
      False_Northing: 0.0

      Planar coordinates are encoded using coordinate pair
      Abscissae (x-coordinates) are specified to the nearest 0.00032808333333333333
      Ordinates (y-coordinates) are specified to the nearest 0.00032808333333333333
      Planar coordinates are specified in foot_us

      The horizontal datum used is D North American 1983 HARN.
      The ellipsoid used is GRS 1980.
      The semi-major axis of the ellipsoid used is 6378137.0.
      The flattening of the ellipsoid used is 1/298.257222101.

  7. How does the data set describe geographic features?

    Alpine fans more likely subject to debris flows
    area data table (Source: King County)

    OBJECTID
    Internal feature number. (Source: Esri)

    Sequential unique whole numbers that are automatically generated.

    Mapby
    Author of mapped shapes (Source: King County)

    ValueDefinition
    KC_DNRP 

    MapDate
    Date Author completed mapping (Source: King County)

    ValueDefinition
    2016-06 

    MapMethod
    Method used to identify more or less likely subject to debris flows (Source: King County)

    ValueDefinition
    Relative Relief Ratio 

    Likelihood
    Describes whether more or less likely subject to debris flows (Source: King County)

    ValueDefinition
    More likely 

    TypeofFan
    Description of fan (Source: King County)

    ValueDefinition
    Alpine fan 

    LiDARSourc
    Source LiDAR imagery and date imagery data sent to Author (Source: King County)

    ValueDefinition
    KC GIS 2016-06 

    Shape
    Feature geometry. (Source: Esri)

    Coordinates defining the features.

    Shape.area

    Shape.len

    Entity_and_Attribute_Detail_Citation: King County


Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)

  2. Who also contributed to the data set?

  3. To whom should users address questions about the data?

    King County King County Dept of Natural Resources and Parks, Water and Lands Resource Division
    Attn: Ken Rauscher
    GIS Analyst
    201 S Jackson St, Suite 706
    Seattle, WA 98104
    US

    206-477-4414 (voice)


Why was the data set created?

Suitable for general reference and analyses. Identifies only depositional fans that are located in alpine areas and are more likely subject to debris flows along the river corridor within the study limits in King County.


How was the data set created?

  1. From what previous works were the data drawn?

  2. How were the data generated, processed, and modified?

  3. What similar or related data should the user be aware of?


How reliable are the data; what problems remain in the data set?


How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?

Access_Constraints:
Access Constraint: Data is not available on GIS Data Portal, it may be available via a custom data request
Use_Constraints:
Use Constraint: King County data are made available with the understanding that they shall be used exclusively by the obtainer or his/her authorized agents. Digital products may not be reproduced or redistributed in any form or by any means without the express written authorization of King County.

  1. Who distributes the data set? (Distributor 1 of 1)

    KCGIS Center
    Attn: Cheryl Wilder
    Data Sales Coordinator
    201 S Jackson St, Suite 706
    Seattle, WA 98104
    US

    206-477-4421 (voice)

  2. What's the catalog number I need to order this data set?

    /plibrary2/enviro/shapes/polygon/lsr_f_alpinefanmorelikelydf.shp

  3. What legal disclaimers am I supposed to read?

    Distribution Liability: King County disclaims any warranty of use of any digital product or data beyond that for which it was designed.

  4. How can I download or order the data?


Who wrote the metadata?

Dates:
Last modified: 13-Oct-2016
Metadata author:
King County King County Dept of Natural Resources and Parks, Water and Lands Resource Division
Attn: Ken Rauscher
GIS Analyst
201 S Jackson St, Suite 706
Seattle, WA 98104
US

206-477-4414 (voice)
firstname.lastname@kingcounty.gov

Metadata standard:
FGDC Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)


Generated by mp version 2.9.12 on Sat Apr 06 04:31:33 2019