CoSMoS Southern California v3.0 Phase 2 projections of coastal cliff retreat due to 21st century sea-level rise

Metadata also available as - [Outline] - [Parseable text] - [XML]

Frequently anticipated questions:


What does this data set describe?

Title:
CoSMoS Southern California v3.0 Phase 2 projections of coastal cliff retreat due to 21st century sea-level rise
Abstract:
This dataset contains projections of coastal cliff-retreat rates and positions for future scenarios of sea-level rise (SLR). Present-day cliff-edge positions used as the baseline for projections are also included. Projections were made using numerical and statistical models based on field observations such as historical cliff retreat rate, nearshore slope, coastal cliff height, and mean annual wave power, as part of Coastal Storm Modeling System (CoSMoS) v.3.0 Phase 2 in Southern California. Details: Cliff-retreat position projections and associated uncertainties are for scenarios of 0.25, 0.5, 0.75, 1, 1.25, 1.5, 1.75, 2, and 5 meters of SLR. Projections were made at CoSMoS cross-shore transects (CST) spaced 100 m alongshore using a baseline sea-cliff edge from 2010 (included in the dataset). Within each zip file, there are two separate datasets available: one that ignores coastal armoring, such as seawalls and revetments, and allows the cliff to retreat unimpeded (“Do Not Hold the Line”); and another that assumes that current coastal armoring will be maintained and 100% effective at stopping future cliff erosion ("Hold the Line"). Eight numerical models synthesized from literature (Trenhaile, 2000; Walkden and Hall, 2005; Trenhaile, 2009; Trenhaile, 2011; Ruggiero and others, 2011; Hackney and others, 2013) were used to make projections. All models relate breaking-wave height and period to cliff rock or unconsolidated sediment erosion. Models range in complexity from 2-D models in which the entire profile evolves, from below water to the cliff edge, to simple 1-D empirical or statistical models in which only the cliff edge evolves as a function of wave impact intensity and frequency. The projections are a robust average of all models, and the uncertainties are proportional to 1) underlying uncertainties in the model input data, such as historical cliff retreat rates, and 2) the differences between individual model forecasts at each CST so that uncertainty is larger when the models do not agree. As sea level rises, waves break closer to the sea cliff, more wave energy impacts the cliffs, cliff erosion rates accelerate. Model behavior also includes wave run-up (Stockdon and others, 2006), wave set-up that raises the water level during big-wave events, and tidal levels. The more complex 2-D models were run on idealized cliff profiles extending from about 10 m water depth to 1 kilometer inland from the cliff edge. Profiles were extracted by overlaying the cross-shore transects on a high-resolution digital elevation model (DEM) covering the Southern California study area. For all models, the presence of a beach was recorded (yes or no) for all transects using aerial photography, and the cliff toe elevation (or beach/cliff junction) was digitized from the DEM profiles. Using historic cliff edge retreat rates by Hapke and Reid (2007), unknown coefficients within the cliff-profile models were calibrated using a Monte Carlo simulation (in other words, coefficients were tuned until the modeled mean retreat rate equaled the observed mean retreat rate for a given transect). Uncertainty was tallied using a root mean squared error (RMSE) approach. The RMSE represents cumulative uncertainty from multiple sources and assumes that different sources of error will, at times, cancel each other out. It is therefore not a 'worst-case uncertainty' (in other words, a straight sum of errors) but instead an average uncertainty. Total RMSE increased with SLR rate and varied between +/- 2-3 m to a maximum of +/- 50 m for the extreme 5 m SLR scenario. For more information on model details, data sources, and integration with other parts of the CoSMoS framework, see CoSMoS_3.0_Phase_2_Southern_California_Bight:_Summary_of_data_and_methods (available at https://www.sciencebase.gov/catalog/file/get/57f1d4f3e4b0bc0bebfee139?name=CoSMoS_SoCalv3_Phase2_summary_of_methods.pdf).
Supplemental_Information:
This work is one portion of ongoing modeling efforts for California and the western United States. For information on data sources and details on methodology, see https://www.sciencebase.gov/catalog/file/get/57f1d4f3e4b0bc0bebfee139?name=CoSMoS_SoCalv3_Phase2_summary_of_methods.pdf. For more information on CoSMoS implementation, see https://walrus.wr.usgs.gov/coastal_processes/cosmos/
  1. How might this data set be cited?
    Limber, Patrick W., and Barnard, Patrick L., 2017, CoSMoS Southern California v3.0 Phase 2 projections of coastal cliff retreat due to 21st century sea-level rise: data release DOI:10.5066/F7T151Q4, U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, California.

    Online Links:

    This is part of the following larger work.

    Barnard, Patrick L, Erikson, Li H, Foxgrover, Amy C, Limber, Patrick W, O'Neill, Andrea C, and Vitousek, Sean, 2018, Coastal Storm Modeling System (CoSMoS) for Southern California, v3.0, Phase 2: data release doi:10.5066/F7T151Q4, U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, California.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -120.48706054569
    East_Bounding_Coordinate: -117.01538085833
    North_Bounding_Coordinate: 34.51524902452
    South_Bounding_Coordinate: 32.472325899539
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 10-Dec-2015
    Ending_Date: 10-Aug-2017
    Currentness_Reference:
    oldest dataset used through publication date
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form:
    Cliff retreat projections in Google Earth KMZ and ESRI shapefile (SHP) formats
  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.
    2. What coordinate system is used to represent geographic features?
      Grid_Coordinate_System_Name: Universal Transverse Mercator
      Universal_Transverse_Mercator:
      UTM_Zone_Number: 11
      Transverse_Mercator:
      Scale_Factor_at_Central_Meridian: 0.999600
      Longitude_of_Central_Meridian: -100.000000
      Latitude_of_Projection_Origin: 0.000000
      False_Easting: 500000.000000
      False_Northing: 0.000000
      Planar coordinates are encoded using row and column
      Abscissae (x-coordinates) are specified to the nearest 2.000000
      Ordinates (y-coordinates) are specified to the nearest 2.000000
      Planar coordinates are specified in meters
      The horizontal datum used is North American Datum 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:
      Depth_System_Definition:
      Depth_Datum_Name: NAVD88
      Depth_Resolution: 2.0
      Depth_Distance_Units: meters
      Depth_Encoding_Method: Implicit coordinate
  7. How does the data set describe geographic features?
    CoSMoS_v3Phase2_coastal_cliff_projections_KMZ
    Coastal cliff erosion rates and positions due to erosion caused by wave impacts in different sea-level rise scenarios and management conditions (Source: originators at United States Geolgical Survey, Pacific Coastal and Marine Science Center)
    Transect ID
    ID number assigned by producer and initial position (Source: producer defined) sequential whole numbers
    Historical cliff retreat rate (m/yr)
    Historical cliff retreat rates, in meters per year (Source: producer defined)
    ValueDefinition
    Historical cliff retreat rate (m/yr)Historical cliff retreat rates, in meters per year
    Historical cliff retreat rate uncertainty (m/yr)
    Uncertainty in historical cliff retreat rates, in meters per year (Source: producer defined)
    ValueDefinition
    Historical cliff retreat rate uncertainty (m/yr)Uncertainty in historical cliff retreat rates, in meters per year
    Cliff retreat rate (m/yr), X.XX m SLR
    Projected cliff retreat rates, in meters per year, in different sea-level-rise scenarios (X.XX m SLR) (Source: producer defined)
    ValueDefinition
    Cliff retreat rate (m/yr), X.XX m SLRProjected cliff retreat rate, in meters per year, in different sea-level-rise scenarios (X.XX m SLR) and "Hold the line" or "No Hold the line" conditions as named
    Cliff position projections
    Projected long-term coastal cliff positions in different sea-level-rise scenarios (Source: producer defined)
    ValueDefinition
    NameCoastal cliff position at X meters of sea-level rise and "Hold the line" or "No Hold the line" conditions as named
    Cliff position projection uncertainty
    Uncertainty in projected long-term coastal cliff positions in different sea-level-rise scenarios (Source: producer defined)
    ValueDefinition
    NameUncertainty in projected coastal cliff position at X meters of sea-level rise and "Hold the line" or "No Hold the line" conditions as named
    CoSMoS_v3Phase2_coastal_cliff_projections_SHP
    Coastal cliff erosion rates and positions due to erosion caused by wave impacts in different sea-level rise scenarios (Source: originators at United States Geolgical Survey, Pacific Coastal and Marine Science Center)
    CliffEdge_projections_(NO)HoldTheLine
    Projected long-term coastal cliff positions in different sea-level-rise scenarios (Source: producer defined)
    ValueDefinition
    ScenarioCoastal cliff position at X.XX meters of sea-level rise for "Hold the line" or "No Hold the line" conditions as named
    CliffEdge_projection_uncertainty_(NO)HoldTheLine
    Uncertainty in projected long-term coastal cliff positions in different sea-level-rise scenarios (Source: producer defined)
    ValueDefinition
    ScenarioUncertainty in projected coastal cliff position at X.XX meters of sea-level rise for "Hold the line" or "No Hold the line" conditions as named

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • Patrick W. Limber
    • Patrick L. Barnard
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
    Patrick W. Limber
    U.S. Geological Survey, Pacific Coastal and Marine Science Center
    2885 Mission Street
    Santa Cruz, California
    USA

    831-460-7548 (voice)
    831-427-4748 (FAX)
    plimber@usgs.gov

Why was the data set created?

These 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.

How was the data set created?

  1. From what previous works were the data drawn?
    Summary of methods (source 1 of 1)
    Barnard, Patrick, Erikson, Li, Foxgrover, Amy, O'Neill, Andrea, Vitousek, Sean, Herdman, Liv, and Warrick, Jonathan, 2017, CoSMoS_3.0_Phase_2_Southern_California_Bight:_Summary_of_data_and_methods: U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, California.

    Online Links:

    Type_of_Source_Media: online
    Source_Contribution:
    Complete explanation of data and methodology used in model framework
  2. How were the data generated, processed, and modified?
    Date: 15-Oct-2014 (process 1 of 7)
    Built numerical models of sea-cliff erosion and retreat rates due to wave impacts and sea-level rise
    Date: 01-Feb-2015 (process 2 of 7)
    Overlaid transects on digital elevation model (DEM) to find sea-cliff height, mean shore-platform slope, mean cliff-face slope, cliff-toe elevation, and mean intertidal slope for each cross-shore transect; accessed oblique photographs from the California Coastal Records Project (http://www.californiacoastline.org/) to record the presence of a beach for each transect; used the USGS National Shoreline Assessment database to assign a long-term (about 70 years) sea-cliff retreat rate to each transect.
    Date: 01-Jun-2015 (process 3 of 7)
    Ran 2-D numerical models of cliff behavior on each idealized transect; performed >50,000 model runs to calibrate unknown model coefficients; estimated model coefficients by matching modeled long-term cliff retreat to observed long-term cliff retreat and/or predicting them using an Artificial Neural Network (ANN) trained using physical, oceanographic, and geomorphic characteristics from each transect.
    Date: 01-Aug-2015 (process 4 of 7)
    Ran calibrated 2-D cliff behavior models on idealized transects for different sea-level rise (SLR) scenarios and used an ANN to parse model results and draw statistical relationships between the physical properties of each transect (for example, sea cliff height, shore platform slope), historical cliff behavior, and the predicted cliff behavior for each SLR scenario; ran simpler 1-D models at each transect as a Monte Carlo ensemble to include uncertainty.
    Date: 14-Aug-2018 (process 5 of 7)
    Metadata was modified to add or correct the Larger_Work section, and to correct the link(s) to the Methods Summary pdf so that it points to the new location of the file. No data information was changed. Person who carried out this activity:
    Susan A Cochran
    U.S. Geological Survey, Pacific Coastal and Marine Science Center
    Geologist
    2885 Mission Street
    Santa Cruz, CA
    USA

    (831) 460-7545 (voice)
    scochran@usgs.gov
    Date: 19-Oct-2020 (process 6 of 7)
    Edited metadata to add keywords section with USGS persistent identifier as theme keyword. No data were changed. Person who carried out this activity:
    U.S. Geological Survey
    Attn: VeeAnn A. Cross
    Marine Geologist
    384 Woods Hole Road
    Woods Hole, MA

    508-548-8700 x2251 (voice)
    508-457-2310 (FAX)
    vatnipp@usgs.gov
    Date: 14-Oct-2021 (process 7 of 7)
    Performed minor edits to the metadata to correct typos. No data were changed Person who carried out this activity:
    U.S. Geological Survey
    Attn: Susan A. Cochran
    Geologist
    2885 Mission Street
    Santa Cruz, CA

    831-460-7545 (voice)
    scochran@usgs.gov
  3. What similar or related data should the user be aware of?
    Hackney, C., Darby, S. E., and Leyland, J., 2013, Modelling the response of soft cliffs to climate change: A statistical, process-response model using accumulated excess energy.

    Other_Citation_Details:
    Hackney, C., Darby, S. E., and Leyland, J., 2013, Modelling the response of soft cliffs to climate change: A statistical, process-response model using accumulated excess energy, Geomorphology, 187, 108-121.
    Hapke, C., and Reid, D., 2007, National Assessment of Shoreline Change, Part 4: Historical Coastal Cliff Retreat along the California Coast.

    Other_Citation_Details:
    Hapke, C.J., and Reid, D., 2007, National Assessment of Shoreline Change, Part 4: Historical Coastal Cliff Retreat along the California Coast: U.S. Geological Survey Open-file Report 2007-1133. http://pubs.usgs.gov/of/2007/1133/
    Ruggiero, P., Komar, P. D., McDougal, W. G., Marra, J. J., and Beach, R. A., 2001, Wave runup, extreme water levels and the erosion of properties backing beaches.

    Other_Citation_Details:
    Ruggiero, P., Komar, P. D., McDougal, W. G., Marra, J. J., and Beach, R. A. (2001), Wave runup, extreme water levels and the erosion of properties backing beaches. Journal of Coastal Research, 407-419.
    Stockdon, H., Holman, R. A., Howd, P.A., and Sallenger Jr., J. A., 2006, Empirical parameterization of setup, swash, and runup.

    Other_Citation_Details:
    Stockdon, H.F., Holman, R. A., Howd, P. A., and Sallenger Jr., A. J., 2006, Empirical parameterization of setup, swash, and runup, Coastal Engineering, Volume 53, Issue 7, Pages 573-588, ISSN 0378-3839. http://dx.doi.org/10.1016/j.coastaleng.2005.12.005.
    Trenhaile, A. S., 2000, Modeling the development of wave-cut shore platforms.

    Other_Citation_Details:
    Trenhaile, A. S., 2000, Modeling the development of wave-cut shore platforms, Marine Geology, Volume 166, Issues 1-4, Pages 163-178, ISSN 0025-3227. http://dx.doi.org/10.1016/S0025-3227(00)00013-X.
    Trenhaile, A. S., 2009, Modeling the erosion of cohesive clay coasts.

    Other_Citation_Details:
    Trenhaile, A. S., 2009, Modeling the erosion of cohesive clay coasts, Coastal Engineering, Volume 56, Issue 1, Pages 59-72, ISSN 0378-3839. http://dx.doi.org/10.1016/j.coastaleng.2008.07.001.
    Trenhaile, A. S., 2011, Predicting the response of hard and soft rock coasts to changes in sea level and wave height.

    Other_Citation_Details:
    Trenhaile, A. S., 2011, Predicting the response of hard and soft rock coasts to changes in sea level and wave height, Climatic Change, Volume 109, Issues 3-4, Pages 599-615, ISSN 0165-0009. http://dx.doi.org/10.1007/s10584-011-0035-7.
    Walkden, M. J. A., and Hall, J. W., 2005, A predictive Mesoscale model of the erosion and profile development of soft rock shores.

    Other_Citation_Details:
    Walkden, M. J. A., and Hall, J.W., 2005, A predictive Mesoscale model of the erosion and profile development of soft rock shores, Coastal Engineering, Volume 52, Issue 6, Pages 535-563, ISSN 0378-3839. http://dx.doi.org/10.1016/j.coastaleng.2005.02.005.

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

  1. How well have the observations been checked?
    Attribute values are estimates of sea-cliff retreat rate due to plausible future sea-level rise scenarios and therefore cannot be cross-checked with observations, because observations do not exist. The projections were generated using up-to-date statistical and numerical methods and are in line with projections made by previous researchers. Uncertainty bands are included that take into account the positional accuracy of the geospatial data used to calibrate the numerical models, statistical agreement between different models used to generate the projections, and variations of the projections caused by varying assumptions (in other words, a sensitivity analysis).
  2. How accurate are the geographic locations?
    Data are concurrent with specified transect locations.
  3. How accurate are the heights or depths?
    N/A
  4. Where are the gaps in the data? What is missing?
    Data set is considered complete. 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?
    Data have undergone QA/QC and fall within expected/reasonable ranges.

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?
Access_Constraints: none
Use_Constraints:
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.
  1. Who distributes the data set? (Distributor 1 of 1)
    U.S. Geological Survey - ScienceBase
    Denver Federal Center, Building 810, Mail Stop 302
    Denver, CO
    USA

    1-888-275-8747 (voice)
    sciencebase@usgs.gov
  2. What's the catalog number I need to order this data set?
  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?

Who wrote the metadata?

Dates:
Last modified: 14-Oct-2021
Metadata author:
Patrick W. Limber
U.S. Geological Survey, Pacific Coastal and Marine Science Center
Research Geologist
2885 Mission Street
Santa Cruz, California
USA

831-460-7548 (voice)
831-427-4748 (FAX)
plimber@usgs.gov
Metadata standard:
Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)

This page is <https://cmgds.marine.usgs.gov/catalog/pcmsc/DataReleases/ScienceBase/DR_F7T151Q4/CoSMoS_v3_Phase2_coastal_cliff_retreat_projections_metadata.faq.html>
Generated by mp version 2.9.50 on Fri Oct 15 19:10:26 2021