Florida Reef Tract 2016-2019 Seafloor Elevation Stability Models, Maps, and Tables

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Frequently anticipated questions:

What does this data set describe?

Title:
Florida Reef Tract 2016-2019 Seafloor Elevation Stability Models, Maps, and Tables
Abstract:
The U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center (SPCMSC) conducted research to identify areas of seafloor elevation stability and instability based on elevation changes between the years of 2016 and 2019 along the Florida Reef Tract (FRT) from Miami to Key West within a 939.4 square-kilometer area. USGS SPCMSC staff used seafloor elevation-change data from Fehr and others (2021) derived from an elevation-change analysis between two elevation datasets acquired in 2016/2017 and 2019 using the methods of Yates and others (2017). Most of the elevation data from the 2016/2017 time period were collected during 2016, so as an abbreviated naming convention, we refer to this time period as 2016. Due to file size limitations, the elevation-change data was divided into five blocks. A seafloor stability threshold was determined for the 2016-2019 FRT elevation-change datasets based on the vertical uncertainty of the 2016 and 2019 digital elevation models (DEMs). Five stability categories (which include, Stable: 0.0 meters (m) to ±0.24 m or 0.0 m to ±0.49 m; Moderately stable: ±0.25 m to ±0.49 m; Moderately unstable: ±0.50 m to ±0.74 m; Mostly unstable: ±0.75 m to ±0.99 m; and Unstable: ±1.00 m to Max/Min elevation change) were created and used to define levels of stability and instability for each elevation-change value (total of 235,153,117 data points at 2-m horizontal resolution) based on the amount of erosion and accretion during the 2016 to 2019 time period. Seafloor-stability point and triangulated irregular network (TIN) surface models were created for each block at five different elevation-change data resolutions (1st order through 5th order) with each resolution becoming increasingly more detailed. The stability models were used to determine the level of seafloor stability at potential areas of interest for coral restoration and 14 habitat types found along the FRT. Stability surface (TIN) models were used for areas defined by specific XY geographic points, while stability point models were used for areas defined by bounding box coordinate locations. This data release includes ArcGIS Pro map packages containing the binned and color-coded stability point and surface (TIN) models, potential coral restoration locations, and habitat files for each block; maps of each stability model; and data tables containing stability and elevation-change data for the potential coral restoration locations and habitat types. Data were collected under Florida Keys National Marine Sanctuary permit FKNMS-2016-068. Coral restoration locations were provided by Mote Marine Laboratory under Special Activity License SAL-18-1724-SCRP.
  1. How might this data set be cited?
    Murphy, Kelly A., and Yates, Kimberly K., 20210709, Florida Reef Tract 2016-2019 Seafloor Elevation Stability Models, Maps, and Tables:.

    This is part of the following larger work.

    Murphy, Kelly A., and Yates, Kimberly K., 20210709, Florida Reef Tract 2016-2019 Seafloor Elevation Stability Models, Maps, and Tables: U.S. Geological Survey data release doi:10.5066/P9KSJ2GI, U.S. Geological Survey, St. Petersburg, FL.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -81.958437
    East_Bounding_Coordinate: -80.086515
    North_Bounding_Coordinate: 25.799166
    South_Bounding_Coordinate: 24.442791
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 21-Jul-2016
    Ending_Date: 23-Mar-2019
    Currentness_Reference:
    ground condition
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: vector, tabular and 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 Point 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: 17
      Transverse_Mercator:
      Scale_Factor_at_Central_Meridian: 0.9996
      Longitude_of_Central_Meridian: -81.0
      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 0.6096
      Ordinates (y-coordinates) are specified to the nearest 0.6096
      Planar coordinates are specified in METERS
      The horizontal datum used is North American Datum of 1983 National Spatial Reference System (2011).
      The ellipsoid used is GRS_1980.
      The semi-major axis of the ellipsoid used is 6378137.0.
      The flattening of the ellipsoid used is 1/298.257222.
      Vertical_Coordinate_System_Definition:
      Altitude_System_Definition:
      Altitude_Datum_Name: North American Vertical Datum of 1988 (NAVD88) GEOID12B
      Altitude_Resolution: 0.2
      Altitude_Distance_Units: meters
      Altitude_Encoding_Method:
      Explicit elevation coordinate included with horizontal coordinates
  7. How does the data set describe geographic features?
    Entity_and_Attribute_Overview:
    The detailed attribute descriptions for the stability data tables and maps are provided in the included data dictionaries (StabilityCategories_DataDictionary.pdf, StabilityTables_DataDictionary.pdf, and HabitatTypes_DataDictionary.pdf). These metadata are not complete without these files.
    Entity_and_Attribute_Detail_Citation:
    The entity and attribute information were generated by the individual and/or agency identified as the originator of the dataset. 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)
    • Kelly A. Murphy
    • Kimberly K. Yates
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
    Kimberly K. Yates
    Southeast Region: St. Petersburg Coastal and Marine Science Center
    Research Oceanographer
    600 4th Street South
    St. Petersburg, Florida
    United States

    727-502-8059 (voice)
    kyates@usgs.gov

Why was the data set created?

These data were used to identify areas of seafloor elevation stability and instability, from 2016 to 2019, along the Florida Reef Tract.

How was the data set created?

  1. From what previous works were the data drawn?
    2016-2019 Florida Reef Tract Blocks 01-05 elevation-change points (source 1 of 1)
    Zachery W. Fehr, David G. Zawada, and Kimberley K. Yates, 2021, Seafloor Elevation Change Analyses from 2016 to 2019 along the Florida Reef Tract, USA: U.S. Geological Survey, St. Petersburg, FL.

    Online Links:

    • Unknown

    Type_of_Source_Media: Elevation-change data
    Source_Contribution:
    The original elevation-change points containing the calculated elevation change from 2016 to 2019 along the Florida Reef Tract.
  2. How were the data generated, processed, and modified?
    Date: 2021 (process 1 of 16)
    Step 1: The original 2016-2019 Florida Reef Tract (FRT) blocks 01-05 elevation-change points were processed and published by Fehr and others (2021). Also, elevation-change surface models (TINs) were created for each block using the calculated elevation-change points. Please note the very large files and ensure you have the adequate computing compacity to access these files. The TIN files were generated and can be viewed using ArcGIS Pro version 2.1.3 or later to accommodate the large file sizes. They may not be accessible in other geoprocessing software with file size limits. Smaller TIN files can be generated for viewing in other programs using the following methods: generate a polygon shapefile covering a data extent that does not exceed available computing capabilities and clip the relevant elevation-change point shapefile (blocks 01-05 elevation-change points) to the extent of the polygon shapefile using the “Clip (Analysis)” tool. Follow the remaining process steps in Fehr and others (2021) to generate a TIN from the clipped point shapefile to represent this smaller data extent. For more information on the elevation-change data processing steps, source elevation data, and elevation-change points and TINs, see Fehr and others (2021). Horizontal coordinates are referenced to the Universal Transverse Mercator (UTM) North American Horizontal Datum of 1983 (NAD83) National Spatial Reference System of 2011 (NSRS2011) National Readjustment and vertical coordinates are referenced to the North American Vertical Datum of 1988 (NAVD88), GEOID12B geoid model.
    Date: 2021 (process 2 of 16)
    Step 2: The 2016-2019 FRT blocks 01-05 TIN files were classified into five stability categories using a defined stability threshold to identify areas of stability and instability. The stability threshold is the total root mean square error (RMSE) calculated for the 2016-2019 FRT elevation-change points using the vertical uncertainty of the 2016 and 2019 DEMs. A total RMSE of 0.19 m was calculated and rounded up to create a conservative stability threshold of 0.25 m that was applied to the TINs. See Yates and others (2017) for methods on calculating the RMSE. Based on the specified stability threshold of 0.25 m, the following five stability categories were identified: Stable: 0.0 m to ±0.24 m or 0.0 m to ±0.49 m; Moderately stable: ±0.25 m to ±0.49 m; Moderately unstable: ±0.50 m to ±0.74 m; Mostly unstable: ±0.75 m to ±0.99 m; and Unstable: ±1.00 m to Max/Min elevation change. Category boundaries use the pattern of “lower bound < or = x < upper bound” to avoid inclusion of individual elevation-change values in multiple categories. The categories were assigned based on the absolute value of the elevation-change values. For example, values within ±0.24 m of change were classified as Stable.
    Date: 2021 (process 3 of 16)
    Step 3: Due to the large file size of the TIN files, Esri ArcGIS Desktop Advanced version 10.6 (ArcMap) couldn’t render or run geoprocessing tools on the TIN, and therefore, ArcGIS Pro version 2.1.3 was used. The 2016_2019_FRT_Block01_SeafloorStability_TIN file was opened in ArcGIS Pro and the “Symbology” window was opened by double clicking the TIN in the “Table of Contents” and selecting “Symbology”. Within the “Symbology” tab, “Surface” was set to Elevation, and “Classes” was set to 10. The following “Class Breaks” were used to classify and bin the elevation-change values into ten classes: -0.994999 (class1); -0.744999 (class 2); -0.494999 (class 3); -0.244999 (class 4); 0 (class 5); 0.244999 (class 6); 0.494999 (class 7); 0.744999 (class 8); 0.994999 (class 9); and maximum positive elevation-change value (class 10). The “Class Breaks” were based on the 0.25 m stability threshold, with each class increasing in increments of 0.24 m up to ±1 m of change. Classes 4, 5 and 6 represent the stable elevation-change values with no change detected (Stable), classes 1 and 10 represent the unstable elevation-change values with change greater than ±1 m (Unstable), and the remaining classes represent the elevation-change values in between (Moderately stable through Mostly unstable).
    Date: 2021 (process 4 of 16)
    Step 4: The color symbology of the classes listed in the “Class Breaks” were changed to represent each stability category. A color gradient of red, gray, and blue shades was applied to the binned TIN to distinguish the stability level of each elevation-change value and distinguish areas of erosion and accretion. Both positive and negative elevation-change values that fell within the Stable category were colored gray. However, red and blue shades were applied to elevation-change values that fell within categories Moderately stable through Unstable to distinguish areas of erosion and accretion. Blue shades were applied to elevation-change values with positive elevation change (accretion) and red shades were applied to elevation-change values with negative elevation change (erosion). Lighter shades indicate the smallest amount of change while darker shades indicate the largest amount of change.
    Date: 2021 (process 5 of 16)
    Step 5: Additionally, the 2016-2019 FRT blocks 01-05 elevation-change points were classified into the five stability categories. The process was similar to the methods described in steps 3-5; however, the “Class Breaks” were defined differently because the method for binning points is different than delineating break points for a TIN in ArcGIS Pro. The 2016_2019_FRT_Block01_SeafloorStability_Points shapefile was opened in ArcGIS Pro and the “Symbology” window was opened by double clicking the TIN in the “Table of Contents” and selecting “Symbology”. Within the “Symbology” tab, “Symbology” was set to Graduated Colors, “Field” was set to the attribute containing the elevation-change values (Diff_m) and “Classes” was set to 10. The following “Class Breaks” were used to classify and bin the Diff_m values into ten classes: -0.995 (class 1); -0.745 (class 2); -0.495 (class 3); -0.245 (class 4); 0 (class 5); 0.244999 (class 6); 0.494999 (class 7); 0.744999 (class 8); 0.994999 (class 9); and max positive Diff_m value (class 10). The remaining steps to change the color symbology are the same as described in step 5.
    Date: 2021 (process 6 of 16)
    Step 6: The above process steps were repeated four times using different stability categories to represent a total of five different resolutions of elevation-change stability maps for each block. The same color scheme was used for each resolution map. The above stability categories and “Class Breaks” described in Steps 3-6 represent the highest resolution map, 5th order. The remaining four resolutions of maps (1st through 4th order) required different “Class Breaks” and stability category ranges. The specific parameters for each resolution map are described in steps 7 through 10.
    Date: 2021 (process 7 of 16)
    Step 7: The 4th order resolution map was generated for each elevation-change TIN file using the following eight “Class Breaks”: -0.744999, -0.494999, -0.244999, 0, 0.244999, 0.494999, 0.744999, and max positive elevation-change value. The following eight “Class Breaks” were used for each elevation-change point shapefile: -0.745, -0.495, -0.245, 0, 0.244999, 0.494999, 0.744999, and max Diff_m value. The four associated stability categories for both are as follows: Stable: 0.0 m to ±0.24 m, Moderately stable: ±0.25 m to ±0.49 m, Moderately unstable: ±0.50 m to ±0.74 m, Unstable: ±0.75 m to Max/Min elevation change. The 4th order resolution maps combine the Mostly unstable values into the Unstable category.
    Date: 2021 (process 8 of 16)
    Step 8: The 3rd order resolution map was generated for each elevation-change TIN file using the following six “Class Breaks”: -0.494999, -0.244999, 0, 0.244999, 0.494999, and max positive elevation-change value. The following six “Class Breaks” were used for each elevation-change point shapefile: -0.495, -0.245, 0, 0.244999, 0.494999, and max positive Diff_m value. The three associated stability categories for both are as follows: Stable: 0.0 m to ±0.24 m, Moderately stable: ±0.25 m to ±0.49 m, Unstable: ±0.50 m to Max/Min elevation change. The 3rd order resolution maps combine the Moderately unstable and Mostly unstable values into the Unstable category.
    Date: 2021 (process 9 of 16)
    Step 9: The 2nd order resolution map was generated for each elevation-change TIN file using the following three “Class Breaks”: -0.494999, 0.494999, and max positive elevation-change value. The following three “Class Breaks” were used for each elevation-change point shapefile: -0.495, 0.494999, and max positive Diff_m value. The two associated stability categories for both are as follows: Stable: 0.0 m to ±0.49 m and Unstable: ±0.50 m to Max/Min elevation change. The 2nd order resolution maps combine the Moderately stable values into the Stable category, and the Moderately unstable and Mostly unstable values into the Unstable category.
    Date: 2021 (process 10 of 16)
    Step 10: The 1st order resolution map was generated using the same “Class Breaks” and stability category ranges as the 2nd order resolution map. However, both positive and negative values that fell within the Unstable category were colored dark red regardless of being negative or positive to depict only stable and unstable areas regardless of gain or loss in elevation.
    Date: 2021 (process 11 of 16)
    Step 11: The USGS SPCMSC analyzed seafloor elevation change and stability throughout the Florida Reef Tract (FRT) at potential coral reef restoration locations provided by partnering stakeholders. Ten reef locations of interest throughout the FRT were identified by the National Oceanic and Atmospheric Administration (NOAA) Florida Keys National Marine Sanctuary, 10 reefs of which (Western Dry Rocks reef, Eastern Dry Rocks reef, Western Sambos reef, Eastern Sambos reef, Looe Key reef and research only area, Sombrero Key reef, Cheeca Rocks reef, Horseshoe reef, and Carysfort reef) fall within the bounds of the 2016-2019 FRT full data extent. Additionally, seafloor stability data were requested from Mote Marine Laboratory for 50 authorized coral outplant sites (Special Activity License: SAL-18-1724-SCRP) and five potential coral outplant sites along the FRT. Thirty-seven of the 50 authorized outplant sites and all of the potential outplant sites fell within the bounds of the 2016-2019 FRT full data extent.
    Date: 2021 (process 12 of 16)
    Step 12: Boundaries for the coral reefs of interest were downloaded as a Keyhole Markup Language Zipped file (KMZ) from the NOAA Florida Keys National Marine Sanctuary webpage (https://floridakeys.noaa.gov/fknms_map/welcome.html; last accessed: 27 November 2019). Using ArcMap, the KMZ file was converted to a single merged polygon shapefile, creating the NOAA_CoralReef_LocationsOfInterest shapefile. The polygons encompassing the 10 reefs of interest were included in this file. Point shapefiles containing the 37 authorized outplant sites (MotesAuthorized_OutplantSites shapefile) and five potential outplant sites (MotesPotential_OutplantSites shapefile) were created using the coordinate locations from Mote Marine Laboratory. Mote Marine Laboratory provided the USGS SPCMSC with the latitude, longitude, and site description of each outplant site. Horizontal coordinates are referenced to the UTM NAD83 (NSRS2011) National Readjustment and vertical coordinates are referenced to the NAVD88, GEOID12B geoid model.
    Date: 2021 (process 13 of 16)
    Step 13: Elevation-change information was extracted from the 2016_2019_FRT_Block04_SeafloorStability_TIN and 2016_2019_FRT_Block05_SeafloorStability_TIN files at the location of the MotesAuthorized_OutplantSites shapefile using the “Add Surface Information (3D Analyst)” tool by specifying the MotesAuthorized_OutplantSites shapefile as the “Input Feature Class”, the 2016_2019_FRT_Block04_SeafloorStability_TIN or 2016_2019_FRT_Block05_SeafloorStability_TIN file as the “Input Surface”, Z as the “Output Property”, LINEAR as the “Method”, and “Sampling Distance” and “Z Factor” left blank. A single elevation-change value was extracted from the TINs at the location of each point that fell within the bounds of the 2016_2019_FRT_Block04_SeafloorStability_TIN and 2016_2019_FRT_Block05_SeafloorStability_TIN files. Elevation-change information was also extracted from the 2016_2019_FRT_Block01_SeafloorStability_TIN and 2016_2019_FRT_Block02_SeafloorStability_TIN files at the location of the MotesPotential_OutplantSites shapefile following the same steps.
    Date: 2021 (process 14 of 16)
    Step 14: The average elevation change and standard deviation was calculated from the 2016_2019_FRT_Block02_SeafloorStability_Points, 2016_2019_FRT_Block03_SeafloorStability_Points, 2016_2019_FRT_Block04_SeafloorStability_Points, and 2016_2019_FRT_Block05_SeafloorStability_Points shapefiles at the location of each reef of interest using the “Statistics” tool in ArcGIS Pro. When calculating average elevation change and standard deviation for locations defined by bounding box coordinates, the elevation-change points were used.
    Date: 2021 (process 15 of 16)
    Step 15: Using Microsoft Excel 2016, all statistics were entered into a table and color coded based on the defined stability colors for each map resolution. Additionally, average elevation changes and standard deviations calculated by the USGS SPCMSC for each habitat found within the 2016-2019 FRT elevation-change points full data extent were included in the table. No-data values are indicated by -99. For information on how to calculate elevation-change statistics by habitat type, see Yates and others (2017) and Fehr and others (2021).
    Date: 2021 (process 16 of 16)
    Step 16: Map packages (.mpkx) containing a map document and the data it contains were created for each resolution map of each block. Each map document contains the MotesAuthorized_OutplantSites shapefile, MotesPotential_OutplantSites shapefile, NOAA_CoralReef_LocationsOfInterest shapefile, habitat map, and the binned and color coded elevation-change points shapefile and elevation-change TIN file for each block. For users that have access to ArcGIS Pro, the map packages can be downloaded and opened to display the coral restoration locations, habitat types, and binned points and TIN for each resolution of each block. The individual contents of the map packages are also provided in this data release, including layer files that store the symbology information for each resolution of the seafloor stability points and TIN. The layer files can be applied to the stability points or TINs in ArcGIS Pro using the “Apply Symbology From Layer (Data Management)” tool.
  3. What similar or related data should the user be aware of?
    Fehr, Zachery W., Zawada, David G., and Yates, Kimberly K., 20210825, Seafloor Elevation Change Analyses from 2016 to 2019 along the Florida Reef Tract, USA: U.S. Geological Survey data release doi:10.5066/P9CHC95D, U.S. Geological Survey, St. Petersburg, FL.

    Online Links:

    Yates, Kimberly K., Zawada, David G., Smiley, Nathan A., and Tiling-Range, Ginger, 20170420, Divergence of seafloor elevation and sea level rise in coral reef ecosystems: Biogeosciences, Munich, Germany.

    Online Links:

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

  1. How well have the observations been checked?
    Datasets were visually inspected by USGS staff in Esri ArcGIS Pro version 2.1.3 for identification of data inconsistencies.
  2. How accurate are the geographic locations?
    For the 2016 and 2019 lidar DEMs used to produce the point dataset, the data positions were obtained using post-processed kinematic global positioning system (KGPS) methods. The horizontal accuracy of the 2016 data is better than plus or minus 1.0 m; Quantitative Value: 1.0 m. The horizontal accuracy of the 2019 data is better than plus or minus 0.12 m; Quantitative Value: 0.12 m.
  3. How accurate are the heights or depths?
    For the 2016 and 2019 lidar DEMs used to produce the point dataset, the data positions were obtained using post-processed KGPS methods. Data used to validate the lidar were collected with static GPS observational equipment and compared against the published data. The vertical accuracy of the 2016 data is better than plus or minus 0.15 m; Quantitative Value: 0.15 m. The vertical accuracy of the 2019 data is better than plus or minus 0.11 m; Quantitative Value: 0.11 m.
  4. Where are the gaps in the data? What is missing?
    This dataset is considered complete for the information presented, as described in the abstract section. Users are advised to read the rest of the metadata record and Fehr and others (2021) carefully for additional details.
  5. How consistent are the relationships among the observations, including topology?
    Data cover the area specified for this project, without any known issues.

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?
Access_Constraints:
Please note the very large files and ensure you have the adequate computing compacity to access these files. See process step 1 for more information.
Use_Constraints:
Public domain data from the U.S. Government are freely redistributable with proper metadata and source attribution. The U.S. Geological Survey requests to be acknowledged as originator of these data in future products or derivative research.
  1. Who distributes the data set? (Distributor 1 of 1)
    Kimberly K. Yates
    Southeast Region: St. Petersburg Coastal and Marine Science Center
    Research Oceanographer
    600 4th Street South
    St. Petersburg, FL
    United States

    727-502-8059 (voice)
    kyates@usgs.gov
  2. What's the catalog number I need to order this data set?
  3. What legal disclaimers am I supposed to read?
    Although these data have been processed successfully on a computer system at 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. The USGS shall not be held liable for improper or incorrect use of the data described or contained herein. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
  4. How can I download or order the data?
  5. What hardware or software do I need in order to use the data set?
    Users must have access to Esri ArcGIS Pro version 2.1.3 or later to open the map packages provided in this data release.

Who wrote the metadata?

Dates:
Last modified: 27-Aug-2021
Metadata author:
Kimberly K. Yates
Southeast Region: St. Petersburg Coastal and Marine Science Center
Research Oceanographer
600 4th Street South
St. Petersburg, Florida
United States

727-502-8059 (voice)
kyates@usgs.gov
Metadata standard:
Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)
This page is <https://cmgds.marine.usgs.gov/catalog/spcmsc/2016_2019_FRT_stability_metadata.faq.html>
Generated by mp version 2.9.50 on Tue Sep 21 18:18:31 2021