Coastal Base Flood Elevations, Ott Water Study

Frequently-anticipated questions:

What does this data set describe?

Title: Coastal Base Flood Elevations, Ott Water Study
Abstract:
The points depicted are attributed the flood elevations for the 10, 50, 100, and 500 year coastal flood events for various coastal communities in Northern California.
Supplemental_Information:
Data was derived from the Ott Water Engineers, Inc. (1984) Northern California Coastal Flood Studies, prepared for the Federal Emergency Management Agency.
  1. How should this data set be cited?

    Heberger, Matthew, and Herrera, Pablo, 2009, Coastal Base Flood Elevations, Ott Water Study: 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: -124.219987
    East_Bounding_Coordinate: -121.787860
    North_Bounding_Coordinate: 41.750949
    South_Bounding_Coordinate: 36.602254

  3. What does it look like?

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

    Calendar_Date: 1984
    Currentness_Reference: Study has not been updated

  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 (59)

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

      Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest 0.000000. Longitudes are given to the nearest 0.000000. Latitude and longitude values are specified in Decimal degrees.

      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?

    Ott_water_flood_elev

    NGVD_500yr
    500 year flood elevation NGVD29 (feet)

    LOCATION

    NGVD_10YR

    NGVD_50YR

    NGVD_100YR

    NGVD_500YR

    FID
    Internal feature number. (Source: ESRI)

    Sequential unique whole numbers that are automatically generated.

    Location
    Location of transect

    NGVD_100yr
    100 year flood elevation NGVD29 (feet)

    NGVD_10_M

    NGVD_50_M

    Shape
    Feature geometry. (Source: ESRI)

    Coordinates defining the features.

    NGVD_100_M

    NGVD_500_M

    NAVD_10YR

    NAVD_50YR

    NAVD_100YR

    NAVD_500YR

    NAVD_100_F

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?

Depict the estimated coastal flood elevations for coastal communities in Northern California.

How was the data set created?

  1. From what previous works were the data drawn?

    (source 1 of 1)
    Ott Water Engineers, Inc., 1984, Northern California Coastal Flood Studies, prepared for the Federal Emergency Management Agency.:.

    Type_of_Source_Media: ESRI shapefile

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

    Date: 1906 (process 1 of 5)
    Using the USGS 7.5 minute topo maps, provided in the report, which had the study areas and transects drawn in, we used the heads-up-digitizing technique to draw the transect lines in a new shapefile over a DRG of the USGS 7.5 minute maps.

    Date: 1906 (process 2 of 5)
    The polyline to point tool in ETGeoWizards was then used to extract the midpoint of the transect lines.

    Date: 1906 (process 3 of 5)
    Point ID and NGVD 29 elevations were input into an excel spreadsheet. Elevation values were converted to meters.

    Date: 1906 (process 4 of 5)
    The shapefile and Excel spreadsheet were joined based on point ID and exported to a new shapefile.

    Date: 1906 (process 5 of 5)
    Elevation values were then converted from NGVD 29 to NAVD 88 using the Vertcon program.

  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?

    Elevations for the 100-yr flood are based on results from 1984 Ott Water Engineers study. See report for accuracy of elevations. Data was converted from NGVD29 feet to NGVD meters, then to NAVD88 using the Vertcon tool.

  2. How accurate are the geographic locations?

    Locations of points are approximate. Locations were digitized based on paper versions of USGS 1:24,000 7.5 minute topo maps and located on DRG versions of the USGS topo maps at the same resolution.

  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: 26-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