Shoreline data for Ocean Beach, San Francisco, California, 2004 to 2021

Frequently anticipated questions:

• What does this data set describe?
  1. How might this data set be cited?
  2. What geographic area does the data set cover?
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
  5. What is the general form of this data set?
  6. How does the data set represent geographic features?
  7. How does the data set describe geographic features?
• Who produced the data set?
  1. Who are the originators of the data set?
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
• Why was the data set created?
• 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?
  1. How well have the observations been checked?
  2. How accurate are the geographic locations?
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
  5. How consistent are the relationships among the data, including topology?
• How can someone get a copy of the data set?
  1. Are there legal restrictions on access or use of the data?
  2. Who distributes the data?
  3. What's the catalog number I need to order this data set?
  4. What legal disclaimers am I supposed to read?
  5. How can I download or order the data?
• Who wrote the metadata?

What does this data set describe?

1. How might this data set be cited?
   Hoover, Daniel J., Snyder, Alex G., Barnard, Patrick L., Hansen, Jeff E., and Warrick, Jonathan A., 20241108, Shoreline data for Ocean Beach, San Francisco, California, 2004 to 2021: data release 10.5066/P13CAWLM, U.S. Geological Survey, Coastal and Marine Geology Program, U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz.

   Online Links:

   • https://doi.org/10.5066/P13CAWLM

   Other_Citation_Details:

   Suggested Citation: Hoover, D.J., Snyder, A.G., Barnard, P.L., Hansen, J.E. and J.A. Warrick, 2024, Shoreline data for Ocean Beach, San Francisco, California, 2004 to 2021: U.S. Geological Survey data release, https://doi.org/10.5066/P13CAWLM.

2. What geographic area does the data set cover?

   West_Bounding_Coordinate: -122.515054
   East_Bounding_Coordinate: -122.495797
   North_Bounding_Coordinate: 37.780722
   South_Bounding_Coordinate: 37.672023
   

3. What does it look like?

   OB MSL 2004 thru 2021.jpg (JPEG)

   Map view of all MSL shorelines for the period 2004 through 2021

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

   Beginning_Date: 07-Apr-2004

   Ending_Date: 06-Dec-2021

   Currentness_Reference:

   ground condition at time data were collected

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

   Geospatial_Data_Presentation_Form: vector digital data (polyline)
   

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):
      • String (4960)
   2. What coordinate system is used to represent geographic features?
      

      Grid_Coordinate_System_Name: Universal Transverse Mercator
      Universal_Transverse_Mercator:

      UTM_Zone_Number: 10
      Transverse_Mercator:

      Scale_Factor_at_Central_Meridian: 0.99960000
      Longitude_of_Central_Meridian: -123.00000000
      Latitude_of_Projection_Origin: 0.0
      False_Easting: 500000.0
      False_Northing: 0.0
      

      Planar coordinates are encoded using coordinate pair
      Abscissae (x-coordinates) are specified to the nearest 0.0001
      Ordinates (y-coordinates) are specified to the nearest 0.0001
      Planar coordinates are specified in Meter
      The horizontal datum used is North American Datum 1983.
      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?

   Attribute Table

   Table containing attribute information associated with the data set. (Source: U.S. Geological Survey)

   FID

   Index number unique to each record in the attribute table (Source: Esri) Sequentially unique whole numbers that are automatically generated for each shapefile

   Shape

   Feature geometry (Source: Esri) Coordinates defining the feature

   ID

   Shoreline segment number (Source: Esri) Sequentially unique whole numbers that are automatically generated for each shapefile

   CONTOUR

   Contour elevation relative to the NAVD88 vertical datum (Source: Producer defined)

   Range of values
   Minimum:	0.9749999
   Maximum:	1.6190000
   Units:	m
   Resolution:	0.0000001

   Date_

   date of data collection (Source: Producer defined)

   Range of values
   Minimum:	04/07/2004
   Maximum:	12/06/2021
   Units:	MM/DD/YYYY
   Resolution:	1

   Accuracy

   Entity accuracy placeholder (Source: Esri) Accuracy placeholders that are automatically generated as zero for each shapefile. Field retained to facilitate data use by external programs that require an Accuracy field.

   Entity_and_Attribute_Overview:

   The entity and attribute information provided here describes the tabular data associated with the data set. Please review the detailed descriptions that are provided (the individual attribute descriptions) for information on the values that appear as fields/table entries of the data set. Note that attribute values listed above are for data visualization using geospatial software; attribute values may read differently in other platforms. Note also that the Date attribute format of MM/DD/YYYY is based on shapefiles generated in ArcGIS and is different from the folder data convention (YYYYMMDD) which was used to facilitate folder sorting by date

   Entity_and_Attribute_Detail_Citation:

   The entity and attribute information were generated by the individual and/or agency identified as the originator of the data set. Please review the rest of the metadata record for additional details and information.

Who produced the data set?

1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
   • Daniel J. Hoover
   • Alex G. Snyder
   • Patrick L. Barnard
   • Jeff E. Hansen
   • Jonathan A. Warrick
2. Who also contributed to the data set?
3. To whom should users address questions about the data?
   U.S. Geological Survey, Pacific Coastal and Marine Science Center

   Attn: PCMSC Science Data Coordinator

   2885 Mission Street

   Santa Cruz, CA
   

   831-427-4747 (voice)

   pcmsc_data@usgs.gov

Why was the data set created?

How was the data set created?

1. From what previous works were the data drawn?
2. How were the data generated, processed, and modified?

   Date: 06-Dec-2021 (process 1 of 5)

   Global navigation satellite system (GNSS) point data were collected along the beach face using a GNSS receiver with an antenna mounted a fixed height above the beach surface.

   Date: 08-Dec-2021 (process 2 of 5)

   Point data elevations were adjusted in ArcGIS for the antenna offset to obtain beach surface elevations and reviewed for overall data quality.

   Date: 08-Dec-2021 (process 3 of 5)

   Quality-controlled point data were processed in ArcGIS to obtain a triangular interpolated network (TIN) which then was converted to a 2m grid of the 3-D beach surface.

   Date: 08-Dec-2021 (process 4 of 5)

   Local MHW (1.619m NAVD88) and MSL (0.975m NAVD88) shoreline contours were extracted from the 2m grid. Note that the alongshore extent of contours depends on the availability of survey data in the appropriate elevation range for some surveys contours are not continuous along the entire study area, and for four surveys (12/10/06, 1/16/07, 5/7/13, and 1/25/16) no MSL contour is available at all.

   Date: 25-Sep-2024 (process 5 of 5)

   Contours were cleaned to remove portions extrapolated outside the point coverage or through non-beach features, or to interpolate across short gaps.

3. What similar or related data should the user be aware of?
   Barnard, Patrick L., Hansen, Jeff E., and Erikson, Li H., 2012, Synthesis Study of an Erosion Hot Spot, Ocean Beach, California.

   Online Links:

   • https://doi.org/10.2112/JCOASTRES-D-11-00212.1

   Other_Citation_Details:

   Barnard, P.L.; Hansen, J.E., and Erikson, L.H., 2012. Synthesis study of an erosion hot spot, Ocean Beach, California (USA). Journal of Coastal Research, 28(4), 903?922. West Palm Beach (Florida), ISSN 0749-0208

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

1. How well have the observations been checked?
   The data provided here are a compilation of all available shorelines from 17 years of beach topographic surveys. Accuracy estimates reflect positional and measurement uncertainties calculated during the process of extracting the MHW and MSL contours from the topographic survey data as described in the process steps, including quality assurance procedures.
2. How accurate are the geographic locations?
   The horizontal accuracy of shoreline positions is affected by both the measurement uncertainty of the underlying point data and topographic survey methodology. For Ocean Beach MHW shorelines the mean positional uncertainty is about 0.75m (Barnard and others, 2012). The mean positional uncertainty for MSL shorelines has not been calculated but should be comparable to that calculated for MHW shorelines.
3. How accurate are the heights or depths?
   
4. Where are the gaps in the data? What is missing?
   Dataset is considered complete for the information presented. Users are advised to read the rest of the metadata record carefully for additional details.
5. How consistent are the relationships among the observations, including topology?
   Individual shoreline positions were quality checked for reasonableness (position relative to prior and subsequent shorelines) during data processing and shoreline extraction.

How can someone get a copy of the data set?

1. Who distributes the data set? (Distributor 1 of 1)
   
   U.S. Geological Survey - CMGDS

   2885 Mission Street

   Santa Cruz, CA
   

   831-427-4747 (voice)

   pcmsc_data@usgs.gov
2. What's the catalog number I need to order this data set? These data are available in shapefile format contained in a single zip file, which also includes CSDGM FGDC- compliant metadata.
3. What legal disclaimers am I supposed to read?
   Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty.
4. How can I download or order the data?
   • Availability in digital form:

     Data format:	These files (.cpg, .dbf, .prj,.sbn, .sbx, .shp, and .shx) are a collection of files with a common filename prefix and must be downloaded and stored in the same directory. Together they are the components of the shapefile and include FGDC CSDGM-compliant metadata. in format Shapefile (version ArcGIS Desktop 10.8.1) Esri polyline shapefile Size: 25.6
     Network links:	https://doi.org/10.5066/P13CAWLM

   • Cost to order the data: None.

5. What hardware or software do I need in order to use the data set?
   These data are available in a polyline shapefile format. The user must have software to read and process the data components of a shapefile.

Who wrote the metadata?

Dates:

Last modified: 08-Nov-2024

Metadata author:

U.S. Geological Survey, Pacific Coastal and Marine Science Center

Attn: PCMSC Science Data Coordinator

2885 Mission Street

Santa Cruz, CA

831-427-4747 (voice)

pcmsc_data@usgs.gov

Metadata standard:

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