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.
Source_Information:
Source_Citation:
Citation_Information:
Originator: Zachery W. Fehr, David G. Zawada, and Kimberley K. Yates
Publication_Date: 2021
Title:
Seafloor Elevation Change Analyses from 2016 to 2019 along the Florida Reef Tract, USA
Geospatial_Data_Presentation_Form: Shapefile
Publication_Information:
Publication_Place: St. Petersburg, FL
Publisher: U.S. Geological Survey
Online_Linkage: Unknown
Type_of_Source_Media: Elevation-change data
Source_Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 20160721
Ending_Date: 20190323
Source_Currentness_Reference: ground condition
Source_Citation_Abbreviation:
2016-2019 Florida Reef Tract Blocks 01-05 elevation-change points
Source_Contribution:
The original elevation-change points containing the calculated elevation change from 2016 to 2019 along the Florida Reef Tract.
Process_Step:
Process_Description:
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.
Process_Date: 2021
Process_Step:
Process_Description:
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.
Process_Date: 2021
Process_Step:
Process_Description:
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).
Process_Date: 2021
Process_Step:
Process_Description:
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.
Process_Date: 2021
Process_Step:
Process_Description:
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.
Process_Date: 2021
Process_Step:
Process_Description:
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.
Process_Date: 2021
Process_Step:
Process_Description:
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.
Process_Date: 2021
Process_Step:
Process_Description:
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.
Process_Date: 2021
Process_Step:
Process_Description:
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.
Process_Date: 2021
Process_Step:
Process_Description:
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.
Process_Date: 2021
Process_Step:
Process_Description:
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.
Process_Date: 2021
Process_Step:
Process_Description:
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.
Process_Step:
Process_Description:
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.
Process_Date: 2021
Process_Step:
Process_Description:
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.
Process_Date: 2021
Process_Step:
Process_Description:
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).
Process_Date: 2021
Process_Step:
Process_Description:
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.
Process_Date: 2021
