Eelgrass distributions and bathymetry derived from an acoustic survey of the Nisqually River delta, Washington, 2012

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Metadata:

Identification_Information:
Citation:
Citation_Information:
Originator: Andrew W. Stevens
Originator: Renee K. Takesue
Originator: Eric E. Grossman
Publication_Date: 20200721
Title:
Eelgrass distributions and bathymetry derived from an acoustic survey of the Nisqually River delta, Washington, 2012
Geospatial_Data_Presentation_Form: comma-delimited text
Series_Information:
Series_Name: data release
Issue_Identification: DOI:10.5066/P9N9K2I1
Publication_Information:
Publication_Place:
Pacific Coastal and Marine Science Center, Santa Cruz, California
Publisher: U.S. Geological Survey
Online_Linkage: https://doi.org/10.5066/P9N9K2I1
Online_Linkage: Larger_Work_Citation:
Citation_Information:
Originator: Andrew W. Stevens
Originator: Renee K. Takesue
Originator: Eric E. Grossman
Publication_Date: 2020
Title:
Eelgrass distributions and bathymetry of the Nisqually River delta, Washington
Series_Information:
Series_Name: data release
Issue_Identification: DOI:10.5066/P9N9K2I1
Publication_Information:
Publication_Place:
Pacific Coastal and Marine Science Center, Santa Cruz, California
Publisher: U.S. Geological Survey
Online_Linkage: https://doi.org/10.5066/P9N9K2I1
Description:
Abstract:
This portion of the USGS data release presents eelgrass distribution and bathymetry data derived from acoustic surveys of the Nisqually River delta, Washington in 2012 (USGS Field Activity Number D-01-12-PS). Eelgrass and bathymetry data were collected from the R/V George Davidson equipped with a single-beam sonar system and global navigation satellite system (GNSS) receiver. The sonar system consisted of a Biosonics DT-X single-beam echosounder and 420 kHz transducer with a 6-degree beam angle. Depths from the echosounder were computed using sound velocity assuming a salinity of 30 psu and temperature of 10 degrees Celsius. Positioning of the survey vessel was determined at 5 to 10 Hz using a Trimble R7 GNSS receiver and Trimble Zephyr Model 2 antenna operating in real time kinematic (RTK) mode. Differential corrections were transmitted by a VHF radio to the GNSS receiver on the survey vessel at 1-Hz from a GNSS base station placed on a nearby benchmark with known horizontal and vertical coordinates relative to the North American Datum of 1983 (CORS96 realization). Output from the GNSS and sonar systems were combined in real time by the Biosonics DT-X deck unit and output to a computer running HYPACK hydrographic survey software. Navigation information was displayed on a video monitor, allowing the vessel operator to navigate along predefined survey lines spaced at 25-50 m intervals alongshore at speeds of 2 to 3 m/s. Acoustic backscatter data were analyzed using a custom graphical user interface that implements a signal processing algorithm applied to each sonar sounding that differentiates and extracts the location of the seafloor apart from the presence of vegetation (Stevens and others, 2008). Individual acoustic returns along a survey line were grouped into packets of ten, and eelgrass percent cover was calculated as the fractional percent of acoustic returns that were classified as vegetated within each group, resulting in an estimate of percent cover every 4 to 5 m (depending on the vessel speed). Orthometric elevations relative to the NAVD88 vertical datum were computed using National Geodetic Survey Geoid12a offsets. The average estimated vertical uncertainty of the bathymetric measurements is 12 cm. The point data are provided in a comma-separated text file and are projected in Cartesian coordinates using the Universal Transverse Mercator (UTM), Zone 10 north, meters coordinate system.
Purpose:
Data were obtained to document interannual changes in eelgrass distributions and coastal morphology following the removal of a dike that restored tidal processes to over 300 ha of former freshwater wetlands on the Nisqually River delta in 2009. These data are intended for science researchers, students, policy makers, and the general public. These data can be used with geographic information systems or other software to identify the distributions of eelgrass and shallow-water bathymetric features.
Supplemental_Information:
Additional information about the field activities from which these data were derived are available online at:
https://cmgds.marine.usgs.gov/fan_info.php?fan=D0112PS
Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 20120215
Ending_Date: 20120219
Currentness_Reference: ground condition at time data were collected
Status:
Progress: Complete
Maintenance_and_Update_Frequency: Not planned
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -122.7582570
East_Bounding_Coordinate: -122.6743017
North_Bounding_Coordinate: 47.1236026
South_Bounding_Coordinate: 47.0861282
Keywords:
Theme:
Theme_Keyword_Thesaurus: USGS Metadata Identifier
Theme_Keyword: USGS:5eb9823682ce25b5135d2618
Theme:
Theme_Keyword_Thesaurus: USGS Thesaurus
Theme_Keyword: bathymetry
Theme_Keyword: bathymetry measurement
Theme_Keyword: aquatic vegetation
Theme_Keyword: GPS measurement
Theme_Keyword: sea-floor characteristics
Theme_Keyword: marine geophysics
Theme_Keyword: single-beam echo sounder
Theme:
Theme_Keyword_Thesaurus: ISO 19115 Topic Category
Theme_Keyword: elevation
Theme:
Theme_Keyword_Thesaurus: Data Categories for Marine Planning
Theme_Keyword: Bathymetry and Elevation
Theme:
Theme_Keyword_Thesaurus: Marine Realms Information Bank (MRIB) keywords
Theme_Keyword: Global Positioning System (GPS) observations
Theme:
Theme_Keyword_Thesaurus: Global Change Master Directory (GCMD)
Theme_Keyword: Water Depth
Theme_Keyword: GPS (Global Positioning System)
Theme_Keyword: Echo Sounders
Theme:
Theme_Keyword_Thesaurus: None
Theme_Keyword: U.S. Geological Survey
Theme_Keyword: USGS
Theme_Keyword: Coastal and Marine Hazards and Resources Program
Theme_Keyword: CMHRP
Theme_Keyword: Pacific Coastal and Marine Science Center
Theme_Keyword: PCMSC
Theme_Keyword: USGS Coastal Habitats in Puget Sound Project (CHIPS)
Place:
Place_Keyword_Thesaurus: Geographic Names Information System (GNIS)
Place_Keyword: Salish Sea
Place_Keyword: Puget Sound
Place_Keyword: Pierce County
Place_Keyword: Thurston County
Place_Keyword: Nisqually River
Place_Keyword: Billy Frank Jr Nisqually National Wildlife Refuge
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. This information is not intended for navigational purposes.
Point_of_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: PCMSC Science Data Coordinator
Contact_Organization:
U.S. Geological Survey, Pacific Coastal and Marine Science Center
Contact_Address:
Address_Type: mailing and physical
Address: 2885 Mission Street
City: Santa Cruz
State_or_Province: CA
Postal_Code: 95060
Contact_Voice_Telephone: 831-427-4747
Contact_Electronic_Mail_Address: pcmsc_data@usgs.gov
Browse_Graphic:
Browse_Graphic_File_Name: Browse_Graphic_File_Description:
Top: map showing bathymetry data along 2012 survey tracklines; Bottom: map showing eelgrass distribution and percent coverage along 2012 survey tracklines.
Browse_Graphic_File_Type: PNG
Native_Data_Set_Environment: MATLAB Version: 9.6.0.1214997 (R2019a)
Cross_Reference:
Citation_Information:
Originator: Andrew W. Stevens
Originator: Jessica R. Lacy
Originator: David P. Finlayson
Originator: Guy Gelfenbaum
Publication_Date: 2008
Title:
Evaluation of a single-beam sonar system to map seagrass at two sites in northern Puget Sound, Washington
Geospatial_Data_Presentation_Form: comma-delimited text
Publication_Information:
Publication_Place: Reston, VA
Publisher: U.S. Geological Survey
Online_Linkage: https://pubs.usgs.gov/sir/2008/5009/
Cross_Reference:
Citation_Information:
Originator: International Hydrographic Organization (IHO)
Publication_Date: 2008
Title: IHO standards for hydrographic surveys (5th ed.)
Geospatial_Data_Presentation_Form: comma-delimited text
Publication_Information:
Publication_Place: Monaco
Publisher: International Hydrographic Bureau Special Publication 44, 28p.
Online_Linkage: https://www.iho.int/iho_pubs/standard/S-44_5E.pdf
Data_Quality_Information:
Attribute_Accuracy:
Attribute_Accuracy_Report: No formal attribute accuracy tests were conducted.
Logical_Consistency_Report: All data falls within expected ranges.
Completeness_Report:
Dataset is considered complete for the information presented, as described in the abstract. Users are advised to read the rest of the metadata record carefully for additional details.
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report:
Survey-grade positions of the survey vessel were achieved with a global navigation satellite system (GNSS) differentially corrected with data from a single GNSS base station placed on a benchmark with horizontal coordinates relative to the North American Datum of 1983 (CORS96 realization). The position of the GNSS base station was derived from a static GNSS occupation on February 21, 2012 with a duration of approximately 4 hours. The static observations were processed using the National Geodetic Survey Online Positioning User Service (OPUS) to derive the final base station coordinates. The estimated uncertainty derived from the static occupation was 2 cm and 3.5 cm for the latitude and longitude of the benchmark, respectively. Additional uncertainty in the horizontal positions of the survey vessel was estimated based on the distance between survey vessel and GNSS base station. Manufacturer reported accuracy for the differentially corrected horizontal positions for the GNSS rover trajectories is 0.8 cm + 0.5 ppm. Baselines from the GNSS base station varied between 50 m and 4.5 km with a mean of 1.75 km, suggesting the average horizontal accuracy of survey vessel positions to be about 1 cm. Combining the uncertainty in the benchmark and survey vessel yields a total uncertainty of 5 cm. Uncertainty in the horizontal positions associated with pitch and roll of the survey vessel is unknown.
Vertical_Positional_Accuracy:
Vertical_Positional_Accuracy_Report:
Uncertainty in the final elevations is derived from the combination of uncertainty in the GNSS positioning and bathymetric sounding measurements. The vertical position of the benchmark was derived from a static GNSS occupation with an estimated uncertainty of 3.9 cm. The manufacturer-reported accuracy for the differentially corrected vertical positions for the GNSS rover trajectories is 1.5 cm + 1 ppm relative to the benchmark elevation. Baselines from the GNSS base station varied between 50 m and 4.5 km with a mean of 1.75 km, suggesting the average vertical accuracy of survey vessel positions to be about 1.7 cm. The manufacturer of the single-beam echosounder used in this study reports a vertical accuracy of 1 cm. Most of the vertical uncertainty in the final computed elevations data is related to the unmeasured speed of sound used to compute depths from bathymetric soundings and, thus, is depth-dependent. Based on analysis of nearby buoys, we estimate uncertainties in the final depth soundings to be no greater than 3 percent of the water depth. The total vertical uncertainty is calculated using the constant- and depth-dependent factors summed in quadrature (International Hydrographic Organization, 2008). The vertical uncertainty in final elevations varied between 4 cm and 60 cm with a mean estimated vertical uncertainty of 12 cm. Uncertainty in the vertical positions associated with pitch and roll of the survey vessel is unknown.
Lineage:
Process_Step:
Process_Description:
Eelgrass and bathymetry data were collected from the R/V George Davidson equipped with a single-beam sonar system and global navigation satellite system (GNSS) receiver. The sonar system consisted of a Biosonics DT-X single-beam echosounder and 420 kHz transducer with a 6-degree beam angle. Depths from the echosounder were computed using sound velocity data measured using a YSI CastAway CTD during the survey. Positioning of the survey vessel was determined at 5 to 10 Hz using a Trimble R7 GNSS receiver and Trimble Zephyr Model 2 antenna operating in real time kinematic (RTK) mode. Differential corrections were transmitted by a VHF radio to the GNSS receiver on the survey vessel at 1-Hz from a GNSS base station placed on a nearby benchmark with known horizontal and vertical coordinates relative to the North American Datum of 1983 (CORS96 realization). Output from the GNSS and sonar systems were combined in real time by the Biosonics DT-X deck unit and output to a computer running HYPACK hydrographic survey software. Navigation information was displayed on a video monitor, allowing the vessel operator to navigate along predefined survey lines spaced at 25-50 m intervals alongshore at speeds of 2-3 m/s.
Process_Date: 20120219
Process_Step:
Process_Description:
Acoustic-backscatter data were analyzed using a custom graphical user interface that implements a signal processing algorithm applied to each sonar sounding to extract the location of the bottom and presence of vegetation (Stevens and others, 2008). Individual acoustic returns along a survey line were grouped into packets of ten, and eelgrass percent cover was calculated as the fractional percent of acoustic returns that were classified as vegetated within each group, resulting in an estimate of percent cover every 4 to 5 m (depending on the vessel speed). Orthometric elevations relative to the NAVD88 vertical datum were computed using National Geodetic Survey Geoid12a offsets. The final point data are provided in a comma-separated text file and are projected in Cartesian coordinates using the Universal Transverse Mercator (UTM), Zone 10 north, meters coordinate system.
Process_Date: 20130204
Process_Step:
Process_Description:
All available eelgrass distribution and bathymetry data from the survey were compiled into a comma-delimited text file for distribution.
Process_Date: 20200511
Process_Step:
Process_Description:
Edited metadata to add keywords section with USGS persistent identifier as theme keyword. No data were changed.
Process_Date: 20201019
Process_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: U.S. Geological Survey
Contact_Person: VeeAnn A. Cross
Contact_Position: Marine Geologist
Contact_Address:
Address_Type: Mailing and Physical
Address: 384 Woods Hole Road
City: Woods Hole
State_or_Province: MA
Postal_Code: 02543-1598
Contact_Voice_Telephone: 508-548-8700 x2251
Contact_Facsimile_Telephone: 508-457-2310
Contact_Electronic_Mail_Address: vatnipp@usgs.gov
Spatial_Data_Organization_Information:
Direct_Spatial_Reference_Method: Point
Point_and_Vector_Object_Information:
SDTS_Terms_Description:
SDTS_Point_and_Vector_Object_Type: Point
Point_and_Vector_Object_Count: 593447
Spatial_Reference_Information:
Horizontal_Coordinate_System_Definition:
Geographic:
Latitude_Resolution: 0.0000001
Longitude_Resolution: 0.0000001
Geographic_Coordinate_Units: Decimal degrees
Geodetic_Model:
Horizontal_Datum_Name: North American Datum of 1983
Ellipsoid_Name: GRS_1980
Semi-major_Axis: 6378137.0
Denominator_of_Flattening_Ratio: 298.257222101
Vertical_Coordinate_System_Definition:
Altitude_System_Definition:
Altitude_Datum_Name: North American Vertical Datum of 1988
Altitude_Resolution: 0.01
Altitude_Distance_Units: meters
Altitude_Encoding_Method:
Explicit elevation coordinate included with horizontal coordinates
Entity_and_Attribute_Information:
Detailed_Description:
Entity_Type:
Entity_Type_Label: Attribute Table
Entity_Type_Definition:
Table containing attribute information associated with the dataset
Entity_Type_Definition_Source: Producer defined
Attribute:
Attribute_Label: datetime_utc
Attribute_Definition:
The date and time of data collection in Coordinated Universal Time (UTC).
Attribute_Definition_Source: Producer Defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 2012-02-15 17:44:49.103
Range_Domain_Maximum: 2012-02-19 23:35:02.300
Attribute_Units_of_Measure: date and time in yyyy-mmm-dd HH:MM:SS.FFF format
Attribute:
Attribute_Label: longitude
Attribute_Definition:
Longitude coordinate of data point relative to the North American Datum of 1983
Attribute_Definition_Source: Producer defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: -122.7582570
Range_Domain_Maximum: -122.6743017
Attribute_Units_of_Measure: Decimal degrees
Attribute:
Attribute_Label: latitude
Attribute_Definition:
Latitude coordinate of data point relative to the North American Datum of 1983
Attribute_Definition_Source: Producer defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 47.0861282
Range_Domain_Maximum: 47.1236026
Attribute_Units_of_Measure: Decimal degrees
Attribute:
Attribute_Label: easting_m
Attribute_Definition:
East coordinate of data point relative to the North American Datum of 1983, projected in the Universal Transverse Mercator (UTM) Zone 10 North, meters, coordinate system
Attribute_Definition_Source: Producer defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 518338.26
Range_Domain_Maximum: 524709.03
Attribute_Units_of_Measure: meters
Attribute:
Attribute_Label: northing_m
Attribute_Definition:
North coordinate of data point relative to the North American Datum of 1983,projected in the Universal Transverse Mercator (UTM) Zone 10 North, meters, coordinate system
Attribute_Definition_Source: Producer defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 5214771.17
Range_Domain_Maximum: 5218929.10
Attribute_Units_of_Measure: meters
Attribute:
Attribute_Label: elev_m_navd88
Attribute_Definition:
Height in meters of data point with reference to the North American Vertical Datum of 1988
Attribute_Definition_Source: Producer defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: -20.16
Range_Domain_Maximum: 0.42
Attribute_Units_of_Measure: meters
Attribute:
Attribute_Label: veg_flag
Attribute_Definition:
Flag that indicates the presence or absence of eelgrass at each location along the survey track
Attribute_Definition_Source: producer defined
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: 0
Enumerated_Domain_Value_Definition: eelgrass absent
Enumerated_Domain_Value_Definition_Source: producer defined
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: 1
Enumerated_Domain_Value_Definition: eelgrass present
Enumerated_Domain_Value_Definition_Source: producer defined
Attribute:
Attribute_Label: veg_cover
Attribute_Definition:
Fractional percent of points classified as vegetated grouped into packets of 10 sequential points
Attribute_Definition_Source: Producer defined
Attribute_Domain_Values:
Range_Domain:
Range_Domain_Minimum: 0.00
Range_Domain_Maximum: 1.00
Attribute_Units_of_Measure: fractional percent
Distribution_Information:
Distributor:
Contact_Information:
Contact_Person_Primary:
Contact_Person: U.S. Geological Survey - Science Base
Contact_Organization: U.S. Geological Survey
Contact_Address:
Address_Type: mailing and physical
Address: Denver Federal Center, Building 810, Mail Stop 302
City: Denver
State_or_Province: CO
Postal_Code: 80225
Country: USA
Contact_Voice_Telephone: 1-888-275-8747
Contact_Electronic_Mail_Address: sciencebase@usgs.gov
Resource_Description:
Eelgrass distribution and bathymetry data are available as a comma-delimited text file, along with associated FGDC-compliant metadata and a browse graphic.
Distribution_Liability:
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.
Standard_Order_Process:
Digital_Form:
Digital_Transfer_Information:
Format_Name: comma-delimited text
Format_Version_Number: Matlab 9.6.0.1214997
Format_Specification: text
Format_Information_Content: comma-delimited text file
Transfer_Size: 47
Digital_Transfer_Option:
Online_Option:
Computer_Contact_Information: Access_Instructions:
Data can be downloaded using the Network_Resource_Name links. The first link is a direct link to download the eelgrass distribution and bathymetry data. The second link points to a landing page with the eelgrass distribution and bathymetry data, metadata, and a browse graphic. The third link points to a landing page for the annual survey. The fourth link points to a landing page for the entire data release.
Fees: None
Metadata_Reference_Information:
Metadata_Date: 20201019
Metadata_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: PCMSC Science Data Coordinator
Contact_Organization:
U.S. Geological Survey, Pacific Coastal and Marine Science Center
Contact_Address:
Address_Type: mailing and physical
Address: 2885 Mission St.
City: Santa Cruz
State_or_Province: CA
Postal_Code: 95060
Contact_Voice_Telephone: 831-427-4747
Contact_Electronic_Mail_Address: pcmsc_data@usgs.gov
Metadata_Standard_Name: Content Standard for Digital Geospatial Metadata
Metadata_Standard_Version: FGDC-STD-001-1998

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