Coastal Base Flood Elevations, Flood Insurance Studies

Frequently-anticipated questions:

What does this data set describe?

Title: Coastal Base Flood Elevations, Flood Insurance Studies
Abstract:
This data layer is a compilation of all of the coastal flood elevation data available from the published Flood Insurance Studies for the California coast.
Supplemental_Information:
The data was assembled by county and community for all California coastal communities where Flood Insurance Studies (FIS) are published. For counties where updated DFIRM's were available, the FIS was not examined and no data was added. The points were digitized over USGS 7.5-minute Topo Maps based on the descriptions of the transects given in the FIS.
  1. How should this data set be cited?

    Heberger, Matthew, and Herrera, Pablo, 2009, Coastal Base Flood Elevations, Flood Insurance Studies: The Impacts of Sea-Level Rise on the California Coast, Pacific Institute, Oakland CA.

    Online Links:

    This is part of the following larger work.

    Heberger, Matthew, Cooley, Heather, Gleick, Peter, and Herrera, Pablo, 2009, The Impacts of Sea-Level Rise on the California Coast: Pacific Institute, Oakland CA.

    Online Links:

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -120.907315
    East_Bounding_Coordinate: -117.004756
    North_Bounding_Coordinate: 35.453362
    South_Bounding_Coordinate: 32.630151

  3. What does it look like?

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

    Beginning_Date: 1983
    Ending_Date: 2008
    Currentness_Reference: Dependent on source data

  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):

      • Entity point (167)

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

      The map projection used is Albers Conical Equal Area.

      Projection parameters:
      Standard_Parallel: 34.000000
      Standard_Parallel: 40.500000
      Longitude_of_Central_Meridian: -120.000000
      Latitude_of_Projection_Origin: 0.000000
      False_Easting: 0.000000
      False_Northing: -4000000.000000

      Planar coordinates are encoded using coordinate pair
      Abscissae (x-coordinates) are specified to the nearest 0.000000
      Ordinates (y-coordinates) are specified to the nearest 0.000000
      Planar coordinates are specified in meters

      The horizontal datum used is North American Datum of 1983.
      The ellipsoid used is Geodetic Reference System 80.
      The semi-major axis of the ellipsoid used is 6378137.000000.
      The flattening of the ellipsoid used is 1/298.257222.

      Vertical_Coordinate_System_Definition:
      Altitude_System_Definition:
      Altitude_Datum_Name: North American Vertical Datum of 1988
      Altitude_Distance_Units: meters
      Altitude_Encoding_Method: Attribute values

  7. How does the data set describe geographic features?

    FIS_flood_elev

    FID
    Internal feature number. (Source: ESRI)

    Sequential unique whole numbers that are automatically generated.

    Shape
    Feature geometry. (Source: ESRI)

    Coordinates defining the features.

    Feat_ID
    Feature ID reference for each point from FIS

    Location
    Verbatim text description of location from FIS

    WR_10yr
    Wave runup for 10 year flood event in feet

    WR_100yr
    Wave runup for 100 year flood event in feet

    WR_500yr
    Wave runup for 500 year flood event in feet

    WS_10yr
    Wave setup for 10 year flood event in feet

    WS_100yr
    Wave setup for 100 year flood event in feet

    WS_500yr
    Wave setup for 500 year flood event in feet

    County
    County of FIS

    Community
    Community of FIS

    Eff_date
    Date that FIS was last updated

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?

    Pacific Institute
    c/o Matthew Heberger
    Research Associate/GIS Manager
    654 13th Street
    Oakland, CA 94612
    USA

    (510) 251-1600 (voice)
    (510) 251-2203 (FAX)
    mheberger@pacinst.org

    Hours_of_Service: 9:00 AM to 5:00 PM

Why was the data set created?

To develop a digital layer showing the Base Flood Elevation for coastal flooding for the entire California coast.

How was the data set created?

  1. From what previous works were the data drawn?

    (source 1 of 1)
    Federal Emergency Management Agency, FEMA FIS reports.

    Online Links:

    Type_of_Source_Media: ESRI shapefile

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

    (process 1 of 3)
    Locations of points were digitized from paper maps and/or brief text descriptions to shapefiles using heads-up-digitizing over DRG versions of USGS 1:24,000 7.5 minute topo maps.

    Date: 1906 (process 2 of 3)
    Point ID, location descriptions, wave-runup and wave-setup elevations (feet), for the 10, 100 and 500 year flood events, were input into an excel spreadsheet.

    (process 3 of 3)
    The shapefile and Excel spreadsheet were joined based on point ID and exported to a new shapefile.

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

    .

    This is part of the following larger work.

    ,.

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

  1. How well have the observations been checked?

    The attributes are transcribed verbatim from the FIS reports. See FIS reports for statements on accuracy of flood elevations. Data was converted from NGVD29 feet to NGVD29 meters, then to NAVD88 using the Vertcon tool.

  2. How accurate are the geographic locations?

    The location of the points is described approximate through brief text decriptions in the FIS reports, therefore the locations of the points are approximates only. The text descriptions of the locations are included in the "Location" attribute field, if a cross reference is needed. Where paper maps were provided in addition to text descrtiptions, approximate locations were digitized over DRG versions of USGS 1:24,000 7.5 minute topo maps.

  3. How accurate are the heights or depths?

  4. Where are the gaps in the data? What is missing?

    Data set has been visually inspected.

  5. How consistent are the relationships among the observations, including topology?

    The dataset is topologically correct.

How can someone get a copy of the data set?

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

Access_Constraints:
None. Data are freely downloadable and available for use in GIS and mapping subject the use constraints below.
Use_Constraints:
The data are freely redistributable with proper metadata and source attribution. Please reference the Pacific Institute as the originator of the dataset in any future products or research derived from these data. This information is being made available for informational purposes only. Users of this information agree by their use to hold blameless the State of California, and its respective officers, employees, agents, contractors, and subcontractors for any liability associated with its use in any form. This work shall not be used to assess actual coastal hazards, insurance requirements, or property values and specifically shall not be used in lieu of Flood Insurance Studies and Flood Insurance Rate Maps issued by the Federal Emergency Management Agency (FEMA).

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

    Pacific Institute
    c/o Matthew Heberger
    Research Associate/GIS Manager
    654 13th Street,
    Preservation Park
    Oakland, CA 94612
    USA

    (510) 251-1600 (voice)
    (510) 251-2203 (FAX)
    mheberger@pacinst.org

    Hours_of_Service: 9:00 AM to 5:00 PM
  2. What's the catalog number I need to order this data set?

    Downloadable Data

  3. What legal disclaimers am I supposed to read?

    The data are freely redistributable with proper metadata and source attribution. Please reference the Pacific Institute as the originator of the dataset in any future products or research derived from these data.
    This information is being made available for informational purposes only. Users of this information agree by their use to hold blameless the State of California, and its respective officers, employees, agents, contractors, and subcontractors for any liability associated with its use in any form. This work shall not be used to assess actual coastal hazards, insurance requirements, or property values and specifically shall not be used in lieu of Flood Insurance Studies and Flood Insurance Rate Maps issued by the Federal Emergency Management Agency (FEMA).

  4. How can I download or order the data?

  5. What hardware or software do I need in order to use the data set?

    These data are available in Environmental Systems Research Institute (ESRI) shapefile format. The user must have ArcGIS or ArcView 3.0 or greater software to read and process the data file. In lieu of ArcView or ArcGIS, the user may utilize another GIS application package capable of importing the data. A free data viewer, ArcExplorer, capable of displaying the data is available from ESRI at www.esri.com.

Who wrote the metadata?

Dates:
Last modified: 24-Feb-2009
Metadata author:
Pacific Institute
c/o Matthew Heberger
Research Associate/GIS Manager
654 13th Street,
Preservation Park
Oakland, CA 94612
USA

(510) 251-1600 (voice)
(510) 251-2203 (FAX)
mheberger@pacinst.org

Hours_of_Service: 9:00 AM to 5:00 PM
Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)
Metadata extensions used:

Generated by mp version 2.9.6 on Thu Feb 26 11:55:07 2009