Tropical Storm Gordon Assessment of Potential Coastal Change Impacts: NHC Advisory 8, 0700 AM CDT TUE SEP 04 2018

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?
   Birchler, Justin J., Doran, Kara S., Long, Joseph W., Schreppel, Heather A., and Stockdon, Hilary F., 20190619, Tropical Storm Gordon Assessment of Potential Coastal Change Impacts: NHC Advisory 8, 0700 AM CDT TUE SEP 04 2018: U.S. Geological Survey Data Release doi:10.5066/P9Z362BC, U.S. Geological Survey, St. Petersburg, FL.

   Online Links:

   • https://doi.org/10.5066/P9Z362BC

   This is part of the following larger work.
   U.S. Geological Survey, 2019, USGS Coastal Change Hazards Portal.

   Online Links:

   • https://marine.usgs.gov/coastalchangehazardsportal

2. What geographic area does the data set cover?

   West_Bounding_Coordinate: -90.962989
   East_Bounding_Coordinate: -85.001346
   North_Bounding_Coordinate: 30.397309
   South_Bounding_Coordinate: 29.045053
   

3. What does it look like?
4. Does the data set describe conditions during a particular time period?

   Calendar_Date: 04-Sep-2018

   Currentness_Reference:

   Ground condition

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

   Geospatial_Data_Presentation_Form: vector digital data
   

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 (768)
   2. What coordinate system is used to represent geographic features?
      Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest 8.9831528411952133e-009. Longitudes are given to the nearest 8.9831528411952133e-009. Latitude and longitude values are specified in Decimal Degrees. The horizontal datum used is D_WGS_1984.
      The ellipsoid used is WGS_1984.
      The semi-major axis of the ellipsoid used is 6378137.0.
      The flattening of the ellipsoid used is 1/298.257223563.
      
7. How does the data set describe geographic features?

   Gordon_PCOI_line

   Probabilities of hurricane-induced coastal erosion, dune morphology, and hurricane hydrodynamic data (Source: USGS)

   FID

   Internal feature number. (Source: Esri) Sequential unique whole numbers that are automatically generated.

   Shape

   Feature geometry. (Source: Esri) Coordinates defining the features.

   DHIGH

   Elevation of dune crest, in meters, using the North American Vertical Datum of 1988 (NAVD88). Extracted from lidar surveys collected January 2010 to October 2016. (Source: USGS)

   Value	Definition
   -999	Null value

   Range of values
   Minimum:	0.777625
   Maximum:	9.085712
   Units:	meters NAVD88

   DLOW

   Elevation of the dune toe, in meters NAVD88. Extracted from lidar surveys collected January 2010 to October 2016. (Source: USGS)

   Value	Definition
   -999	Null value

   Range of values
   Minimum:	0.673951
   Maximum:	4.331845
   Units:	meters NAVD88

   DHIrms

   Root mean squared error of dune crest elevation measurements (square meters). (Source: USGS)

   Value	Definition
   -999	Null value

   Range of values
   Minimum:	0.109187
   Maximum:	1.685519
   Units:	square meters

   DLOrms

   Root mean square error of dune toe elevation measurements (square meters). (Source: USGS)

   Value	Definition
   -999	Null value

   Range of values
   Minimum:	0
   Maximum:	1.126975
   Units:	square meters

   SURGE

   Storm surge water level (Source: NOAA)

   Range of values
   Minimum:	0
   Maximum:	1.44236
   Units:	meters NAVD88

   RUNUP

   Wave runup water level (Source: USGS)

   Value	Definition
   -999	Null value

   Range of values
   Minimum:	0.167996
   Maximum:	2.2713
   Units:	meters NAVD88

   SETUP

   Wave setup water level (Source: USGS)

   Value	Definition
   -999	Null value

   Range of values
   Minimum:	0.007475
   Maximum:	0.900522
   Units:	meters NAVD88

   PCOL

   Probability of collision (Source: USGS)

   Value	Definition
   -999	Null value

   Range of values
   Minimum:	0.025969
   Maximum:	98.267459
   Units:	percent

   POVW

   Probability of overwash (Source: USGS)

   Value	Definition
   -999	Null value

   Range of values
   Minimum:	0
   Maximum:	99.948112
   Units:	percent

   PIND

   Probability of inundation (Source: USGS)

   Value	Definition
   -999	Null value

   Range of values
   Minimum:	0
   Maximum:	94.045064
   Units:	percent

   MEAN

   Mean water level (surge + setup) (Source: USGS)

   Value	Definition
   -999	Null value

   Range of values
   Minimum:	0.439621
   Maximum:	2.026811
   Units:	meters NAVD88

   EXTREME

   Extreme water level (surge + runup). (Source: USGS)

   Value	Definition
   -999	Null value

   Range of values
   Minimum:	0.843427
   Maximum:	3.160719
   Units:	meters NAVD88

   TIDE

   Predicted tide water level (Source: USGS)

   Range of values
   Minimum:	0
   Maximum:	0
   Units:	meters NAVD88

Who produced the data set?

1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
   • Justin J. Birchler
   • Kara S. Doran
   • Joseph W. Long
   • Heather A. Schreppel
   • Hilary F. Stockdon
2. Who also contributed to the data set?

   The predicted elevations of storm surge were extracted from the National Oceanic and Atmospheric Administration's (NOAA) Sea, Lake, and Overland Surges from Hurricanes (SLOSH) model, which has been employed by NOAA in inundation risk studies and operational storm surge forecasting. Wave runup and setup conditions were generated using NOAA's WaveWatch III model.

3. To whom should users address questions about the data?
   U.S. Geological Survey

   Attn: Hilary Stockdon

   600 4th Street South

   Saint Petersburg, FL
   

   UNITED STATES

   727-502-8074 (voice)

   727-502-8182 (FAX)

   hstockdon@usgs.gov

Why was the data set created?

To provide data on the probability of storm-induced coastal erosion hazards for the Louisiana, Mississippi, Alabama and Florida coast post-Tropical Storm Gordon.

How was the data set created?

1. From what previous works were the data drawn?

   Psurge (source 1 of 7)

   National Hurricane Center, National Oceanic and Atmospheric Administration, 20180904, Probabilistic Hurricane Storm Surge.

   Online Links:

   • https://slosh.nws.noaa.gov/psurge2.0/index.php

   Type_of_Source_Media: Online digital data
   Source_Contribution:

   Data provides water levels that have a 1 in 10 chance of being exceeded during the next 3 days.

   WW3 (source 2 of 7)

   NOAA National Weather Service Environmental Modeling Center, 20180904, NOAA Wavewatch III.

   Online Links:

   • https://polar.ncep.noaa.gov/waves

   Type_of_Source_Media: Online digital data
   Source_Contribution:

   Model that was used to estimate wave setup and runup conditions for Tropical Storm Gordon.

   DS 839 LA 2012 (source 3 of 7)

   Guy, K.K., 20140602, Topographic Lidar Survey of the Alabama, Mississippi, and Southeast Louisiana Barrier Islands, from September 5 to October 11, 2012: Data Series 839.

   Online Links:

   • https://doi.org/10.3133/ds839

   Other_Citation_Details: Geographic Coverage: LA, MS
   

   Type_of_Source_Media: Online digital data
   Source_Contribution:

   A lidar survey that was used to estimate dune morphology variables.

   DS 838 LA 2013 (source 4 of 7)

   Guy, K.K., 20140602, Topographic Lidar Survey of Dauphin Island, Alabama and Chandeleur, Stake, Grand Gosier and Breton Islands, Louisiana, July 12-14, 2013: U.S. Geological Survey Data Series 838.

   Online Links:

   • https://doi.org/10.3133/ds838

   Other_Citation_Details: Geographic Coverage: Chandeleur Islands, LA
   

   Type_of_Source_Media: Online digital data
   Source_Contribution:

   A lidar survey that was used to estimate dune morphology variables.

   USGS MS 2015 (source 5 of 7)

   U.S. Geological Survey, 20161018, USGS Lidar Point Cloud LA SoTerrebonne-GI 2015.

   Online Links:

   • https://nationalmap.gov/viewer.html

   Other_Citation_Details: Geographic Coverage: Mississippi Barrier Islands
   

   Type_of_Source_Media: Online digital data
   Source_Contribution:

   A lidar survey that was used to estimate dune morphology variables.

   USACE AL 2016 (source 6 of 7)

   United States Army Corps of Engineers (USACE), 20180514, 2016 USACE NCMP Topobathy Lidar: Gulf Coast (AL, FL, MS, TX).

   Online Links:

   • https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=5186

   Other_Citation_Details: Geographic Coverage: Alabama
   

   Type_of_Source_Media: Online digital data
   Source_Contribution:

   A lidar survey that was used to estimate dune morphology variables.

   USACE FL 2010 (source 7 of 7)

   United States Army Corps of Engineers (USACE), 20150508, 2010 US Army Corps of Engineers (USACE) Joint Airborne Lidar Bathymetry Technical Center of Expertise (JALBTCX) Topobathy Lidar: Alabama Coast and Florida Gulf Coast.

   Online Links:

   • ftp://coast.noaa.gov/pub/DigitalCoast/lidar1_z/geoid12a/data/1064
   • https://coast.noaa.gov/dataviewer/index.html?action=advsearch&qType=in&qFld=ID&qVal=1064

   Other_Citation_Details:

   Geographic Coverage: AL (Fort Morgan to AL/FL border), FL (AL/FL border to Bald Point State Park)

   Type_of_Source_Media: Online digital data
   Source_Contribution:

   A lidar survey that was used to estimate dune morphology variables.

2. How were the data generated, processed, and modified?

   Date: 2018 (process 1 of 4)

   Process_Description: For dune morphology data: Elevation data from lidar surveys were interpolated in MATLAB (version 2017a) to a gridded domain that was rotated parallel to the shoreline and had a resolution of 10 m in the longshore direction and 2.5 m in the cross-shore direction. The interpolation method applied spatial filtering with a Hanning window that was twice as wide as the grid resolution. Dune morphology data were extracted from the elevation grid in MATLAB. Dune morphology data were then summarized to 1 km sections. Sections with greater than 75 percent of data missing were flagged with the invalid number of -999. The 1-km smoothed dune crest (DHIGH), toe (DLOW) and root mean square (RMS) error for each (DHIrms and DLOrms) were written to line shapefiles using MATLAB's shapewrite.m script. Person who carried out this activity:
   

   U.S. Geological Survey

   Attn: Justin J. Birchler

   600 4th Street South

   Saint Petersburg, FL
   

   UNITED STATES

   727-502-8019 (voice)

   727-502-8182 (FAX)

   jbirchler@usgs.gov

   Data sources used in this process:

   • DS 839 LA 2012
   • DS 838 LA 2013
   • USGS MS 2015
   • USACE AL 2016
   • USACE FL PH 2010

   Data sources produced in this process:

   • Dune morphology (DHIGH, DLOW, DHIrms, DLOrms)

   Date: 04-Sep-2018 (process 2 of 4)

   For hydrodynamic data: Water level was computed in MATLAB by adding storm surge from NOAA's Probabilistic Tropical Storm Surge (P- Surge) model (https://slosh.nws.noaa.gov/psurge2.0/) to wave setup and runup. The wave height and period used for calculating wave runup and setup came from the Wavewatch III model. Hydrodynamic parameters were calculated in MATLAB and exported into ArcGIS shapefile format. For details on modeling parameterization, see: Stockdon, H.F., Doran, K.J., Thompson, D.M., Sopkin, K.L., Plant, N.G., and Sallenger, A.H., 2012, National assessment of hurricane-induced coastal erosion hazards: Gulf of Mexico: U.S. Geological Survey Open-File Report 2012-1084, 51 p. https://doi.org/10.3133/ofr20121084 Person who carried out this activity:
   

   U.S. Geological Survey

   Attn: Justin J. Birchler

   600 4th Street South

   Saint Petersburg, FL
   

   UNITED STATES

   727-502-8019 (voice)

   727-502-8182 (FAX)

   jbirchler@usgs.gov

   Data sources used in this process:

   • Psurge
   • WW3

   Data sources produced in this process:

   • Hydrodynamics (SURGE, SETUP, RUNUP)

   Date: 04-Sep-2018 (process 3 of 4)

   Probabilities of coastal erosion hazards were based on estimating the likelihood that the beach system would experience erosion and deposition patterns consistent with collision (PCOL), overwash (POVW), or inundation (PIND) regimes. The regimes were calculated by using values of dune morphology and mean and extreme water levels for each 1 km section, such that the probability of collision (PCOL) occurs when extreme water levels reach the dune toe; overwash (POVW) when extreme water levels reach the dune crest; and inundation (PIND) when mean water levels reach the dune crest. Probabilities were calculated in MATLAB and exported using MATLAB's shapewrite.m script. For details on modeling parameterization, see: Stockdon, H.F., Doran, K.J., Thompson, D.M., Sopkin, K.L., Plant, N.G., and Sallenger, A.H., 2012, National assessment of hurricane-induced coastal erosion hazards: Gulf of Mexico: U.S. Geological Survey Open-File Report 2012-1084, 51 p. https://pubs.usgs.gov/of/2012/1084/ Person who carried out this activity:
   

   U.S. Geological Survey

   Attn: Justin J. Birchler

   600 4th Street South

   Saint Petersburg, FL
   

   UNITED STATES

   727-502-8019 (voice)

   727-502-8182 (FAX)

   jbirchler@usgs.gov

   Data sources used in this process:

   • Dune morphology
   • Hydrodynamics

   Data sources produced in this process:

   • Probabilities (PCOL, POVW, PIND)

   Date: 13-Oct-2020 (process 4 of 4)

   Added keywords section with USGS persistent identifier as theme keyword. 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

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?
   Horizontal accuracy was not estimated.
3. How accurate are the heights or depths?
   Vertical accuracy for hydrodynamic measurements (surge, setup, and runup) is dependent on input data. SLOSH model accuracy is estimated to be +/- 20 percent of the calculated value. No other accuracy checks were performed. Vertical accuracy for dune morphology (dune crest and toe elevation) data is dependent on the positional accuracy of the lidar data. Estimated accuracy of lidar surveys are +/- 15 centimeters. However, vertical accuracies may vary based on the type of terrain (for example, inaccuracies may increase as slope increases or with the presence of extremely dense vegetation), the accuracy of the global positioning system (GPS), and aircraft-attitude measurements.
4. Where are the gaps in the data? What is missing?
   This dataset includes dune morphology and hurricane hydrodynamic data used to generate probabilities of hurricane-induced erosion, elevation data from lidar surveys are not included. Measurements were collected approximately every 10 meters (m) and summarized to 1-kilometer (km) segments.
5. How consistent are the relationships among the observations, including topology?
   No additional checks for consistency were performed on this data.

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:

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 originators of the data in future products or derivative research.

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

   Attn: Justin J. Birchler

   600 4th Street South

   Saint Petersburg, FL
   

   727-502-8019 (voice)

   727-502-8182 (FAX)

   jbirchler@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 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 and/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?
   • Availability in digital form:

     Data format:	shapefile
     Network links:	https://coastal.er.usgs.gov/data-release/doi-P9Z362BC/data/Gordon_2018.zip

   • Cost to order the data: None, if obtained online.

Who wrote the metadata?

Dates:

Last modified: 13-Oct-2020

Metadata author:

U.S. Geological Survey

Attn: Justin J. Birchler

600 4th Street South

Saint Petersburg, FL

UNITED STATES

727-502-8019 (voice)

727-502-8182 (FAX)

jbirchler@usgs.gov

Metadata standard:

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