Patrick L. Barnard
Schuyler A. Smith
Amy C. Foxgrover
20201231
Mean high water (MHW) shorelines along the coast of California used to calculated shoreline change from 1998 to 2016
polyline shapefiles
data release
DOI:10.5066/P91QSGXF
Pacific Coastal and Marine Science Center, Santa Cruz, California
U.S. Geological Survey
https://doi.org/10.5066/P91QSGXF
https://www.sciencebase.gov/catalog/item/5f9317ac82ce720ee2d59707
Patrick L. Barnard
Schuyler A. Smith
Amy C. Foxgrover
2020
California shorelines and shoreline change data, 1998-2016
point and polyline shapefiles
data release
DOI:10.5066/P91QSGXF
Pacific Coastal and Marine Science Center, Santa Cruz, California
U.S. Geological Survey
https://doi.org/10.5066/P91QSGXF
This dataset contains mean high water (MHW) shorelines for sandy beaches along the coast of California for the years 1998/2002, 2015, and 2016. The MHW elevation in each analysis region (Northern, Central, and Southern California) maintained consistency with that of the National Assessment of Shoreline Change. The operational MHW line was extracted from Light Detection and Ranging (LiDAR) digital elevation models (DEMs) using the ArcGIS smoothed contour method. The smoothed contour line was then quality controlled to remove artifacts, as well as remove any contour tool interpretation of human-made infrastructure (such as jetties, piers, and sea walls), using satellite imagery from ArcGIS.
This work is one portion of ongoing coastal monitoring efforts for California and the western United States. These data provide an estimate of past shoreline positions and shoreline change throughout California, with the goal of understanding how shorelines change over time and in response to El Nino events. The data are intended for policy makers, resource managers, science researchers, students, and the general public. These data can be used with geographic information systems or other software to identify and assess possible areas of vulnerability. These data are not intended to be used for navigation.
Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
19980418
20160501
Dates of datasets used in the analysis
None planned
-114.14
-124.42
42.00
32.53
Data Categories for Marine Planning
Physical Habitats and Geomorphology
USGS Thesaurus
Climate Change
Storms
Sea-level Change
El Nino-Southern Oscillation
ISO 19115 Topic Category
Oceans
ClimatologyMeteorologyAtmosphere
Marine Realms Information Bank (MRIB) keywords
sea level change
waves
coastal erosion
El Nino events
None
U.S. Geological Survey
USGS
Coastal and Marine Hazards and Resources Program
CMHRP
Pacific Coastal and Marine Science Center
PCMSC
USGS Metadata Identifier
USGS:5f9317ac82ce720ee2d59707
Geographic Names Information System
State of California
None
Northern California
Central California
Southern California
NorCal
CenCal
SoCal
none
USGS-authored or produced data and information are in the public domain from the U.S. Government and are freely redistributable with proper metadata and source attribution. Please recognize and acknowledge the U.S. Geological Survey as the originator(s) of the dataset and in products derived from these data.
U.S. Geological Survey, Pacific Coastal and Marine Science Center
PCMSC Science Data Coordinator
mailing and physical
2885 Mission Street
Santa Cruz
California
95060-5792
USA
831-427-4747
pcmsc_data@usgs.gov
Schuyler A. Smith
Patrick L. Barnard
2020
The impacts of the 2015/2016 El Nino on Californias sandy beaches
Smith, S.A., and Barnard, P.L., 2020, The impacts of the 2015/2016 El Nino on Californias sandy beaches: Geomorphology
https://doi.org/10.1016/j.geomorph.2020.107583
Estimates of shoreline position accuracy using mean high water lines derived from LiDAR DEMS have been cross checked with satellite-derived shorelines, shorelines derived by the national assessment of shoreline change, and in-situ data collected by GPS surveys. However, lack of alternate data collection methods during this time limits the amount of validation possible for this dataset.
Data have undergone QA/QC and fall within expected/reasonable ranges. The MHW elevation in each analysis region (Northern, Central, and Southern California) maintained consistency with that of the National Assessment of Shoreline Change.
These geospatial projections are complete. Any gaps in these data, if applicable, are a consequence of nonexisting data or existing data that did not meet quality assurance standards. Users are advised to read the rest of the metadata record and references carefully for additional details.
A formal accuracy assessment of the shorelines was conducted for each region. The uncertainty associated with each LiDAR-derived shoreline is comprised of the vertical and horizontal uncertainty of the source DEM. Average beach slopes for North, Central, and Southern California were calculated and used to convert the reported vertical uncertainty of the DEM to a horizontal uncertainty. The derived horizontal uncertainty and vertical uncertainty were summed in quadrature to calculate a final uncertainty value associated with each shoreline. The horizontal accuracy (or uncertainty) for each shoreline is included within this geospatial dataset and was determined at the 95 percent confidence level.
Although no formal vertical position accuracy assessment was conducted, the uncertainty associated with each LiDAR-derived shoreline is comprised of the vertical (and horizontal) uncertainty of the source DEM. It is assumed that uncertainty associated with the extraction of the MHW line from a DEM is negligible.
National Oceanic and Atmospheric Administration (NOAA)
2016
NOAA LiDAR surveys of the Central California region 1998-2016
online
NOAA Digital Coast
https://coast.noaa.gov/dataviewer
online
19980101
20160528
data collection dates
NOAA LiDAR
MHW shoreline positions were digitized from multiple LiDAR data sets within the full geographic extent of the study area from 1998 - 2016.
Data from Southern California Coastal Response to 2015-2016 El Nino
2018
Data from Southern California Coastal Response to the 2015-2016 El Nino
online
University of California San Diego Library Digital Collection
https://library.ucsd.edu/dc/collection/bb80931629
online
20151006
20160322
data collection dates
SoCal LiDAR
Using ArcGIS, MHW shorelines were extracted from these airborne LiDAR datasets collected on 6-October-2015 and 22-March-2016.
High-accuracy LiDAR data were downloaded from NOAA Digital Coast in the form of digital elevation models (DEMs) for both pre-El Nino (2015) and post-El Nino (2016), as well as 1998/2002 for perspective. Due to sparse LiDAR data coverage in southern California, SoCal LiDAR from UC San Diego Library Collections was used in this region.
NOAA LiDAR
SoCal LiDAR
20170701
The operational MHW line was extracted using the ArcGIS smoothed contour method with the smoothing tolerance parameter set to 30 m alongshore. The NAVD88 datum was used for the MHW elevation. The mean high water (MHW) shoreline elevation in each analysis region (Northern, Central, and Southern California) maintained consistency with that of the National Assessment of Shoreline Change.
20170815
The smoothed contour line was then quality controlled to remove artifacts, as well as remove any contour tool interpretation of human-made infrastructure (such as jetties, piers, and sea walls), using satellite imagery available in ArcGIS.
20180401
Using the uncertainty values reported in the DEM metadata, the DEM vertical uncertainty was converted to horizontal uncertainty using the slope of the beach at 50-meter points along the MHW line, using the following steps: Slope maps were created from the DEMS within ArcMap using the 3D Analyst Raster Surface Slope tool. Next, the MHW lines were converted to 50-meter-spaced points, at which the slope value of the DEM was extracted. The average of these values for North, Central, and Southern California was used to convert the vertical uncertainty of the DEM to a horizontal uncertainty. Finally, the horizontal uncertainty and converted vertical uncertainty were summed in quadrature to calculate a final uncertainty value associated with each shoreline.
20180615
Vector
Universal Transverse Mercator
10
0.999600
-123.000000
0.000000
500000.000000
0.000000
row and column
2.000000
2.000000
meters
North American Datum of 1983
Geodetic Reference System 80
6378137.000000
298.257222
California shorelines for the years 1998/2002, 2015, and 2016
Shapefiles consisting of shoreline position, defined by MHW, for discrete years and regions of the state: Northern California (NorCal), Central California (CenCal), and Southern California (SoCal).
originators at United States Geological Survey, Pacific Coastal and Marine Science Center
Date
Effective date of MHW shoreline location from all contributing data
producer defined
4/18/98
5/1/16
month/day/year
Uncert
Horizontal uncertainty of shoreline location
producer defined
0.28
4.35
meters
U.S. Geological Survey - ScienceBase
mailing and physical
Denver Federal Center, Building 810, Mail Stop 302
Denver
CO
80225
USA
1-888-275-8747
sciencebase@usgs.gov
These data are available in shapefile format. Each shoreline year (1998/2002, 2015, and 2016) and region (Northern, Central, and Southern California) is available as a separate shapefile. CSDGM FGDC-compliant metadata is zipped with the dataset.
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. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
shapefile
ArcGIS 10.6
Features are in shapefile format and are projected in NAD 1983 UTM zone 10 coordinates with a geographic coordinate system of GCS North American 1983.
The .zip file includes shapefiles of shorelines and the XML (.xml) version of the metadata
WinZip
19.7
https://www.sciencebase.gov/catalog/file/get/5f9317ac82ce720ee2d59707
https://www.sciencebase.gov/catalog/item/5f9317ac82ce720ee2d59707
https://doi.org/10.5066/P91QSGXF
Data can be downloaded using the Network_Resource_Name links. The first link is a direct link to download the zipped file of shoreline data and metadata. The second link points to the page from which the shapefiles for individual regions or dates can be downloaded individually. The third link points to the landing page for the entire data release.
none
20201231
U.S. Geological Survey, Pacific Coastal and Marine Science Center
PCMSC Science Data Coordinator
mailing and physical
2885 Mission Street
Santa Cruz
California
95060-5792
USA
831-427-4747
pcmsc_data@usgs.gov
Content Standard for Digital Geospatial Metadata
FGDC-STD-001-1998