Mean Higher High Water Surface, 2100

Frequently-anticipated questions:

What does this data set describe?

Title: Mean Higher High Water Surface, 2100
Abstract:
This raster file represents an interpolated surface of the Mean Higher High Water (MHHW), after a 1.4 meter sea-level rise (scenario for year 2100), for the entire California coastline (excluding the San Francisco Bay). The base raster (mhhw_2000) is interpolated from data for 12 NOAA tide stations along the coast. This raster added 140 centimeters to the mhhw_2000 raster.
Supplemental_Information:
The station locations and tide data for all NOAA operated tide stations is available from NOAA in non-spatial format from the website: <http://tidesandcurrents.noaa.gov/station_retrieve.shtml?type=Tide+Data>
  1. How should this data set be cited?

    Heberger, Matthew, and Herrera, Pablo, 2009, Mean Higher High Water, 2100: 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: -124.830192
    East_Bounding_Coordinate: -115.912902
    North_Bounding_Coordinate: 42.198953
    South_Bounding_Coordinate: 32.315324

  3. What does it look like?

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

    Calendar_Date: 2008
    Currentness_Reference:
    Time span of tidal measurements varies by station, elevations are for a future scenario (year 2100)

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

    Geospatial_Data_Presentation_Form: raster digital data

  6. How does the data set represent geographic features?

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

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

      • Entity point (52)
      It contains the following raster data types:
      • Dimensions 2199 x 1984 x 1, type Grid Cell

    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?

    mhhw_2100.vat

    Rowid
    Internal feature number. (Source: ESRI)

    Sequential unique whole numbers that are automatically generated.

    VALUE
    Elevation of year 2100 MHHW in centimeters

    COUNT

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 generate a coastline that shows the MHHW line, after a 1.4 meter sea-level rise, to view the extent of land that could be inundated on a near daily basis but not permananently inundated.

How was the data set created?

  1. From what previous works were the data drawn?

    (source 1 of 1)
    NOAA, NOAA Tide Stations.

    Online Links:

    Type_of_Source_Media: ESRI shapefile

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

    (process 1 of 4)
    A buffer was created around the California coastline of 10 kilometers

    (process 2 of 4)
    Elevation data (attributes as Z-values) for the CA_Tide_Stations.shp were converted from floating point (meters) to integer (centimeters) to speed processing time and minimize storage space.

    (process 3 of 4)
    Using the buffered coastline polygon as a mask (limiting extent of raster), the "surface" of MHHW elevation was interpolated between the tide stations (CA_Tide_Stations.shp) using the Inverse Distance Weighting tool, with a power of 1. The elevation value was derived from the attribute of MHHW as a Z-value (NAVD88 centimeters)

    (process 4 of 4)
    Using raster math, a value of 140 centimeters was added uniformely to all cells in the mhhw_2000 raster.

  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 tide station data is derived directly from the NOAA tide information available online at: <http://tidesandcurrents.noaa.gov/station_retrieve.shtml?type=Tide+Data>. For attribute accuracy refer to the website.
    The interpolated surface is derived from computer automated processes and tidal elevations may vary depending on location. No ground-truth was carried out nor were oceanographers or coastal engineers consulted.
    The future sea-level rise is considered a possible scenario, but not a prediction. 1.4 meters is an estimate for a given scenario.

  2. How accurate are the geographic locations?

    Locations of tide stations are provided in Decimal Degrees, which we projected into WGS 1984 using ArcGIS. These stations were used to interpolate the surface elevation of MHHW between stations

  3. How accurate are the heights or depths?

    The tide station data is derived directly from the NOAA tide information available online at: <http://tidesandcurrents.noaa.gov/station_retrieve.shtml?type=Tide+Data>. For vertical accuracy refer to the website.
    The interpolated surface is derived from computer automated processes and tidal elevations may vary depending on location. No ground-truth was carried out nor were oceanographers or coastal engineers consulted.
    The future sea-level rise is considered a possible scenario, but not a prediction. 1.4 meters is an estimate for a given scenario.

  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 11:55:10 2009