Impacts of Proposed Sediment Borrow Pits on the Neashore Wave Climate and Longshore Transport Rate along Breton Island, LA: G1_grid

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Frequently anticipated questions:


What does this data set describe?

Title:
Impacts of Proposed Sediment Borrow Pits on the Neashore Wave Climate and Longshore Transport Rate along Breton Island, LA: G1_grid
Abstract:
As part of a plan to preserve Breton Island, the southernmost extent of the Chandeleur Islands and part of the Breton Island National Wildlife Refuge, the National Fish and Wildlife Service (FWS) plans to nourish the island with sand supplied from offshore sand resources. The planned sand extraction sites are offshore of the island to the east and south in 5-10 m of water. Because borrow pits are perturbations to shallow-water bathymetry, they can impact the wave field in a variety of ways, and may result in alterations in sediment transport and new erosional or accretional patterns along the beach. For the present study, a scenario-based numerical modeling strategy was used to assess the impacts of the proposed borrow pits on the nearshore wave field. Impacts were assessed over a range of wave conditions, and were gauged by changes in significant wave height and wave direction inshore of the borrow sites.
Supplemental_Information:
This data layer is a subset of USGS Open-File Report 2015-1055, Impacts of Proposed Sediment Borrow Pits on the Neashore Wave Climate and Longshore Transport Rate along Breton Island, LA. It presents the model grid G1 over which hydrodynamic scenario calculations were conducted.
  1. How should this data set be cited?

    Dalyander, P. Soupy , Mickey, Rangley C. , Long, Joseph W. , and Flocks, James G. , 2015, Impacts of Proposed Sediment Borrow Pits on the Neashore Wave Climate and Longshore Transport Rate along Breton Island, LA: G1_grid: U.S. Geological Survey, Coastal and Marine Geology Program, St. Petersburg Coastal and Marine Science Center, St. Petersburg, FL.

    Online Links:

    This is part of the following larger work.

    Dalyander, P. Soupy , Mickey, Rangley C. , Long, Joseph W. , and Flocks, James G. , 2015, Impacts of Proposed Sediment Borrow Pits on the Neashore Wave Climate and Longshore Transport Rate along Breton Island, LA: Open-File Report (OFR) 2015-1055, U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center.

    Online Links:

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -90.0520316261
    East_Bounding_Coordinate: -84.9689800936
    North_Bounding_Coordinate: 30.5997898873
    South_Bounding_Coordinate: 29.1581003773

  3. What does it look like?

    <http://pubs.usgs.gov/of/2015/1055/datadirectory/G1_bathymetry.jpg> (JPEG)
    Graphic showing the numerical model domain over which analysis was conducted.

  4. Does the data set describe conditions during a particular time period?

    Calendar_Date: 10-Jul-2014
    Currentness_Reference: ground condition

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

    Geospatial_Data_Presentation_Form: Vector Digital Data Set (Polygon)

  6. How does the data set represent geographic features?

    1. How are geographic features stored in the data set?

      Indirect_Spatial_Reference: Gulf of Mexico
      This is a Vector data set. It contains the following vector data types (SDTS terminology):
      • G-Polygon

    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 0.0197890822. Longitudes are given to the nearest 0.0226960591. Latitude and longitude values are specified in Decimal seconds.

      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.

      Vertical_Coordinate_System_Definition:
      Altitude_System_Definition:
      Altitude_Datum_Name: North American Vertical Datum of 1988
      Altitude_Resolution: 0.01 m
      Altitude_Distance_Units: meters
      Altitude_Encoding_Method:
      Explicit elevation coordinate included with horizontal coordinates.

  7. How does the data set describe geographic features?

    G1_grid
    Model grid used in hydrodynamic calculations of wave scenarios. (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.

    ModelGrid
    Model grid domain (in this case, the model grid used for wave scenario calculations). (Source: USGS)

    Keyword indicating which model grid this layer contains.


Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)

  2. Who also contributed to the data set?

    U.S. Geological Survey

  3. To whom should users address questions about the data?

    U.S. Geological Survey, USGS Southeast Area
    Attn: P. Soupy Dalyander
    Research Oceanographer
    600 4th Street South
    St. Petersburg, FL 33701
    US

    727-502-8124 (voice)
    727-502-8001 (FAX)
    sdalyander@usgs.gov


Why was the data set created?

This GIS layer contains the model grid used for calculation of waves in the wave climate scenarios used to investigate hydrodynamic variability in the northern Gulf of Mexico. This data layer is intended to illustrate the nested model grid G1 over which calculations were performed. The analysis results, which are contained in other data layers, are only presented at those locations where model outputs exist (e.g., "wet" grid cells, as opposed to "dry" grid cells in the model representing land).


How was the data set created?

  1. From what previous works were the data drawn?

    NGDC NGC (source 1 of 1)
    NOAA National Geophysical Data Center (NGDC), 2012, Northern Gulf Coast, LA/MS/FL/AL 1 arc-second NAVD 88 DEM: NOAA National Geophysical Data Center (NGDC), Boulder, CO.

    Online Links:

    Type_of_Source_Media: online
    Source_Contribution:
    Bathymetric data contained in the Northern Gulf Coast DEM were interpolated to grid cell locations to generate model bathymetry for grid G1. Love, M.R., C.J. Amante, B.W. Eakins, and L.A. Taylor, 2012. Digital Elevations Models of the Northern Gulf Coast: Procedures, Data Sources and Analysis, NOAA Technical Memorandum NESDIS NGDC-59, U.S. Dept. of Commerce, Boulder, CO, 43 pp.

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

    Date: 2014 (process 1 of 1)
    Mathworks MATLAB (v2014) was used to interpolate Northern Gulf Coast DEM data onto the model grid.

    Person who carried out this activity:

    P. Soupy Dalyander
    U.S. Geological Survey
    Oceanographer
    600 4th Street S
    St. Petersburg, FL 33701
    USA

    (727)-502-8124 (voice)
    (727)-502-8001 (FAX)
    sdalyander@usgs.gov

    Data sources used in this process:
    • NGDC NGC

    Data sources produced in this process:

    • G1BATHY

  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?

    This data layer contains the grid over which hydrodynamic wave scenario results were calculated. Within the SWAN model, these coordinates are in latitude and longitude for this data layer.

  2. How accurate are the geographic locations?

    This layer contains the model grid over which hydrodynamic wave scenario results were calculated. Within the SWAN model, these coordinates are in UTM, which have been converted into latitude and longitude for this data layer.

  3. How accurate are the heights or depths?

    Vertical datum is in North American Vertical Datum of 1988 (NAVD88) with an estimated resolution of 0.01 m.

  4. Where are the gaps in the data? What is missing?

    This layer contains the complete model grid (including wet and dry, e.g., land, grid cells) used for calculation of wave scenario hydrodynamic results.

  5. How consistent are the relationships among the observations, including topology?

    No duplicate features are present. All polygons are closed, and all lines intersect where intended. No undershoots (lines falling short of the line they should intersect to form the polygon) or overshoots (lines crossing over the line they should intersect to form the polygon) are present.


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. Please recognize the U.S. Geological Survey as the originator of the dataset.

  1. Who distributes the data set? (Distributor 1 of 1)

    U.S. Geological Survey, USGS Southeast Area
    Attn: P. Soupy Dalyander
    Research Oceanographer
    600 4th Street South
    St. Petersburg, FL 33701
    US

    727-502-8124 (voice)
    727-502-8001 (FAX)
    sdalyander@usgs.gov

  2. What's the catalog number I need to order this data set?

  3. What legal disclaimers am I supposed to read?

    Distributor assumes no liability for misuse of data.

  4. How can I download or order the data?

  5. What hardware or software do I need in order to use the data set?

    These data are available in Environmental Systems Research Institute (ESRI) shapefile format. The user must have ArcGIS or ArcView 3.0 or greater software to read and process the data file. In lieu of ArcView or ArcGIS, the user may utilize another GIS application package capable of importing the data. A free data viewer, ArcExplorer, capable of displaying the data is available from ESRI at www.esri.com.


Who wrote the metadata?

Dates:
Last modified: 10-Jul-2014
Metadata author:
P. Soupy Dalyander
U.S. Geological Survey, USGS Southeast Area
Research Oceanographer
600 4th Street South
St. Petersburg, FL 33701
US

727-502-8124 (voice)
727-502-8001 (FAX)
sdalyander@usgs.gov

Metadata standard:
FGDC Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)
Metadata extensions used:


Generated by mp version 2.9.12 on Tue Mar 24 15:08:02 2015