SIR2012_5290_ACAD_Saltmarshpolygons

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What does this data set describe?

Title: SIR2012_5290_ACAD_Saltmarshpolygons
Abstract:
High-quality aerial photography was used to identify candidate salt marshes for study and for delineation of marsh boundaries. Digital color aerial photography from Eastern Penobscot Bay to Schoodic Point consisting of high-resolution 24-bit color Ortho-rectified Digital Images (ODIs) with a pixel resolution of 0.5 meters was used. The photographs were collected by J. W. Sewall Co. during August 2008 at and near low-tide conditions. The digital 2008 Low Tide photos are geo-referenced and suitable for applications requiring a 1:2400 National Map Accuracy Standard (NMAS). The aerial photography was accessed via the Maine Geolibrary Web Mapping Services (<http://www.maine.gov/geolib/wms.htm>, accessed June 25, 2012) that serves the photography as a seamless mosaic. Digital color aerial photography was used to verify and update boundaries identified in the 1997 vegetation survey produced for the Acadia National Park Vegetation Mapping Project, USGS-NPS Vegetation Mapping Program for Mount Desert Island (MDI), Schoodic Peninsula, and Park holdings and easements on outlying islands (Lubinski and others, 2003), and to identify additional significant (> 1 hectare) salt marshes in all the coastal areas from eastern Penobscot Bay to Grand Marsh in Gouldsboro, Maine. Conservation partners, especially the Maine Coast Heritage Trust, were consulted to help identify additional salt marshes to include in the study using various sets of high-resolution aerial photos, taken at different seasons and in different years, provided by several online mapping services (Google MapsTM, BingTM) in addition to the 2008 Low Tide photos. A total of 114 salt marsh areas were identified, many of which exist within in larger groups of salt marsh areas.
Supplemental_Information:
Geodatabase product of a U.S. Geological Survey study funded by National Park Service Climate Change Response funding, NPS PMIS # 161531, "Inventory and Protection of Salt Marshes from Risks of Sea Level Rise at Acadia National Park, Maine", 2012.
The database layers are collectively termed "appendix 1" of the USGS SIR report. Database layers included in appendix 1 include: Surveyed benchmarks used in surveying exercise (SIR2012_5290_ACAD_SurveyedBMs); Surveyed marsh points used for quality control for LiDAR data (SIR2012_5290_ACAD_Surveyedmarshpoints); Surveyed elevation reference marks for each surveyed marsh (SIR2012_5290_ACAD_SurveyedERMs); Salt marshes inventoried for this study (SIR2012_5290_ACAD_Saltmarshpolys); Inundation lines for each marsh under 60 cm of sea level rise (SIR2012_5290_ACAD_Inundationlines); Potential barriers to migration of salt marshes (SIR2012_5290_ACAD_Potentialbarriers).
The inundation lines presented are in no way a prediction of whether marsh migration will actually occur, only indications of where land will be inundated and would therefore be available for migration under 60 cm. of sea level rise.
  1. How should this data set be cited?

    U.S. Geological Survey, Maine Water Science Center, Augusta, Maine, 2012, SIR2012_5290_ACAD_Saltmarshpolygons: U.S. Geological Survey, Augusta, Maine.

    Online Links:

    This is part of the following larger work.

    Nielsen, Martha G., and Dudley, Robert W., 2012, Estimates of Future Inundation of Salt Marshes in Response to Sea Level Rise in and Around Acadia National Park, Maine: U.S. Geological Survey Scientific Investigations Report SIR 2012-5290, U.S. Geological Survey, Reston, Virginia.

    Online Links:

    Other_Citation_Details: XX p.

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -68.786498
    East_Bounding_Coordinate: -68.002430
    North_Bounding_Coordinate: 44.574048
    South_Bounding_Coordinate: 44.147056

  3. What does it look like?

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

    Beginning_Date: 2010
    Ending_Date: 2012
    Currentness_Reference: Dates represent ground condition at the time of the study.

  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):

      • GT-polygon composed of chains (114)

    2. What coordinate system is used to represent geographic features?

      The map projection used is NAD_1983_UTM_Zone_19N.

      Projection parameters:
      Scale_Factor_at_Central_Meridian: 0.9996
      Longitude_of_Central_Meridian: -69.0
      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 0.0001
      Ordinates (y-coordinates) are specified to the nearest 0.0001
      Planar coordinates are specified in meters

      The horizontal datum used is D North American 1983.
      The ellipsoid used is GRS 1980.
      The semi-major axis of the ellipsoid used is 6378137.0.
      The flattening of the ellipsoid used is 1/298.257222101.

      Vertical_Coordinate_System_Definition:
      Altitude_System_Definition:
      Altitude_Datum_Name: North_American_Vertical_Datum_1988
      Altitude_Resolution: 1.0
      Altitude_Distance_Units: Meters
      Altitude_Encoding_Method: Attribute values

  7. How does the data set describe geographic features?

    SIR2012_5290_ACAD_Saltmarshpolygons
    Polygon feature class (Source: ESRI)

    OBJECTID
    Internal feature number (Source: ESRI)

    Sequential whole numbers that are automatically generated.

    Shape
    Feature geometry (Source: ESRI)

    Coordinates defining the features

    SHAPE_Length
    Length of features in internal units (meters) (Source: ESRI)

    Positive real numbers that are automatically generated

    SHAPE_Area
    Area of features in internal units (square meters) (Source: ESRI)

    Positive real numbers that are automatically generated

    Source
    Origin of saltmarsh polygon features (Source: U.S. Geological Survey)

    ValueDefinition
    Acad VegSaltmarsh was originally identified in the Acad Veg datalayer (see source citations)
    Digitized 2011Polygon was digitized from an aerial photo in 2011.
    Digitized 2012Polygon was digitized from an aerial photo in 2012.

    PhotoUsed
    Aerial photo that was used to digitize or edit the saltmarsh polygon boundary (See Source Citations) (Source: U.S. Geological Survey)

    ValueDefinition
    LT2008Low Tide 2008 orthophotos
    BingBing(TM) maps aerial photos
    LT central 2001Low Tide Central Coast 2001
    LT DE 2009Low Tide Down East 2009
    NAIP 2009USDA-FSA Aerial Photography NAIP 2009

    Usage_
    Attribute indicating how the saltmarsh polygon was used in the study. (Source: U.S. Geological Survey)

    ValueDefinition
    Inventory onlyThe saltmarsh polygon was included in the inventory, but was not surveyed, visited, or used to derive sea level rise lines. This value was reserved for a small number of very small (< 0.5 ha) salt marshes on private property.
    Inventory and SLRSaltmarsh was inventoried and inundation lines for estimated sea level rise were created. Was not surveyed or visited.
    SurveyedSaltmarsh was surveyed IN ADDITION to being included in the inventory and inundation lines for sea level rise analysis.
    visitedSaltmarsh was visited for consideration in the surveying phase, in addition to being included in the inventory and inundation lines for sea level rise analysis.

    Ownership
    Primary landowner and/or status as part of Acadia National Park (Source: U.S. Geological Survey)

    ValueDefinition
    PrivateSaltmarsh is privately owned and has no affiliation with Acadia National Park
    State of MaineOwned in part by the State of Maine (Holbrooke Island Sanctuary).
    The Nature ConservancyProperty is owned by The Nature Conservancy
    ANP - Conserv. easementProperty is under a conservation easement with Acadia National Park, as defined in the "ParkBoundary_Poly_CARTO_201201" shapefile.
    ANP - Fee owned landProperty is owned directly by Acadia National Park, as defined in the "ParkBoundary_Poly_CARTO_201201" shapefile.
    ANP - parcel to be acquiredProperty is targeted for future acquisition by Acadia National Park, as defined in the "ParkBoundary_Poly_CARTO_201201" shapefile.
    Maine Coast Heritage TrustParcel is under conservation easement or owned by the Maine Coast Heritage Trust.

    HighMarshEl
    Elevation that best describes the highest part of the saltmarsh, as it transitions into the adjacent upland or freshwater marsh. Elevations were picked off the LiDAR 2-m digital elevation model data. Data are considered accurate to within +/- 26 cm. (Source: U.S. Geological Survey)

    Range of values
    Minimum:1.6
    Maximum:3.0
    Units:Meters above NAVD88.

    SLR_est
    Estimated level of the top of the marsh surface plus 60 centimeters, which was used as the estimated amount of sea level rise for this study. Data are considered accurate to within +/- 26 cm at a 95-percent confidence interval. (Source: U.S. Geological Survey)

    Range of values
    Minimum:2.2
    Maximum:3.6
    Units:Meters above NAVD88.

    SLR_conf_upper
    Upper 95-percent confidence interval on the SLR_est value, based on the independent accuracy assessment of the LiDAR data. (SLR_est + 26 cm) (Source: U.S. Geological Survey)

    Range of values
    Minimum:2.46
    Maximum:3.86
    Units:Meters above NAVD88.

    SLR_conf_lower
    Lower 95-percent confidence interval on the SLR_est value, based on the independent accuracy assessment of the LiDAR data. (SLR_est - 26 cm) (Source: U.S. Geological Survey)

    Range of values
    Minimum:1.94
    Maximum:3.34
    Units:Meters above NAVD88.

    Area_ha
    Area of saltmarsh, in hectares. (Source: U.S. Geological Survey)

    Range of values
    Minimum:0.145
    Maximum:52.1
    Units:hectares

    Ownership2
    Secondary ownership of land covered by saltmarsh, if the saltmarsh crosses property boundaries. (Source: U.S. Geological Survey)

    ValueDefinition
    PrivateSaltmarsh is privately owned and has no affiliation with Acadia National Park
    ANP - Fee owned landProperty is owned directly by Acadia National Park, as defined in the "ParkBoundary_Poly_CARTO_201201" shapefile.
    ANP - parcel to be acquiredProperty is targeted for future acquisition by Acadia National Park, as defined in the "ParkBoundary_Poly_CARTO_201201" shapefile.

    Marsh_ID
    Sequential identification number of the marsh, assigned during the ditigization and inventory exercise. Some marshes include more than one polygon, if they are physically proximal to one another, are located in the same embayment, and are separated by a channel. (Source: U.S. Geological Survey)

    Range of values
    Minimum:2
    Maximum:126

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?

    Produced in cooperation with the National Park Service. Funding provided by the National Park Service. LiDAR data for the Northeast funded largely by USGS American Reinvestment and Recovery Act funds, and provided by the Maine Office of GIS. Acknowledgment of the U.S. Geological Survey and the National Park Service would be appreciated in products derived from these data.

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

    Martha G. Nielsen
    U.S. Geological Survey, Maine Water Science Office
    Hydrogist
    196 Whitten Rd.
    Augusta, Maine 04330

    207-622-8201 x116 (voice)
    207-622-8204 (FAX)
    mnielsen@usgs.gov

Why was the data set created?

These polygons of salt marshes in the study area, in and around Acadia National Park (ANP), Maine, were used as an inventory of the population of salt marshes that are at risk because of expected sea level rise in the coming decades. Each marsh is represented by one or more polygons, and contours representing sea level rise are mapped for each marsh in this inventory > 0.5 ha, unless it was on ANP property (saltmarshes as small as 0.2 ha were analyzed on ANP property.

How was the data set created?

  1. From what previous works were the data drawn?

    LiDAR data for the Northeast (source 1 of 8)
    Photo Science, Inc., Unpublished Material, State of Maine (Raster DEM): LIDAR for the North East ARRA and LiDAR for the North East Part II. (USGS Contract: G10PC00026, ARRA LIDAR Task Order Numbers) USGS Contract: G10PC00026 Task Order Number: G10PD02143 Task Order Numbers: G10PD01027 (ARRA) and G10PD02143 (non-ARRA).

    Other_Citation_Details:
    The LiDAR data were the primary outside source information for the study. The LiDAR data have a grid cell size of 2 m. Individual data tiles are 751x751 grid cells (1.5 km x 1.5 km) in size. As of October 2012, the LiDAR data are still availably only from state GIS offices. Final publication for public download has not been announced.
    The project area required LiDAR to be collected on 2.0 meter GSD or better and processed to meet a bare earth vertical accuracy of 15.0 centimeters RMSEz or better. Raster DEMs were tested by Photo Science for both vertical and horizontal accuracy. All data is seamless from one tile to the next, no gaps or no data areas. The vertical unit of the data file is in decimal meters with 2-decimal point precision. The reported RMSEz was 0.113 m. USGS independently developed a RMSEz for saltmarsh landcover types to be 0.133 m.
    Type_of_Source_Media: External hard drive
    Source_Scale_Denominator: 2400
    Source_Contribution:
    The LiDAR data were the primary outside data used in the study. The main use was to create accurate contours showing areas of upland that would be inundated with 60 cm of sea level rise (SLR) adjacent to saltmarshes in and around Acadia National Park. The USGS conducted an independent accuracy assessment of the elevation data to create 95-percent confidence interval contours on the SLR inundation contours. The data tiles were joined together into larger mosaics, and shaded relief images were created to for visualization of the land surface and to identify location/shape of potential barriers to migration of salt marshes.

    LT 2008 (source 2 of 8)
    of, Maine Office GIS, 2009, Low Tide orthophotos 2008..

    Online Links:

    Type_of_Source_Media: unknown
    Source_Scale_Denominator: 2400
    Source_Contribution:
    Low-tide orthophotos from 2008 were used to delineate the polygon boundaries of most of the saltmarsh polygons used in the study, by looking at the visible changes in vegetation. They also were used to help identify the potential barriers to migration and to identify the type of barrier (road or railroad grade).

    LT central 2001 (source 3 of 8)
    of, Maine Office GIS, 20090326, Low Tide Central Coast 2001.

    Online Links:

    Type_of_Source_Media: unknown
    Source_Scale_Denominator: 2400
    Source_Contribution:
    The LT central coast 2001 aerial photos were used to help delineate some of the saltmarsh polygon boundaries, particularly on the western-most edge of the study area.

    NAIP 2009 (source 4 of 8)
    USDA-FSA Aerial Photography Field Office, 20091009, NAIP 2009: Maine Office of Geographic Information Systems (MEGIS), Augusta ME.

    Online Links:

    Other_Citation_Details:
    USDA-FSA Aerial Photography Field Office collected the aerial photography data.
    Type_of_Source_Media: unknown
    Source_Scale_Denominator: 40000
    Source_Contribution:
    The NAIP 2009 data were used to help inventory saltmarshes to use in the study and to initially map polgon boundaries for a few of the saltmarshes.

    LT DE 2009 (source 5 of 8)
    of, Maine Office GIS, 20091019, Low Tide Down East 2009.

    Online Links:

    Type_of_Source_Media: unknown
    Source_Scale_Denominator: 3600
    Source_Contribution:
    The LT DE 2009 aerial photos were used to help delineate polygon boundaries for a small number of the saltmarsh polygons used in the study.

    ACAD_Park_Boundary_2012 (source 6 of 8)
    Acadia National Park, US National Park Service, 201201, ParkBoundary_Poly_CARTO_201201: U.S. National Park Service, Bar Harbor, ME.

    Online Links:

    Other_Citation_Details:
    NOTE: for official land status information, please contact the NPS Lands Office. This layer is produced, maintained, and used by Acadia National Park for cartographic purposes because it fits well with other local data. It does not represent an official or surveyed boundary and should not be used for land transaction purposes.
    Type_of_Source_Media: vector digital data
    Source_Scale_Denominator: 24000
    Source_Contribution:
    The Acadia National Park Boundary polygons were used to determine ownership or association of the salt marsh polygons and the upland inundated areas.

    Acad Veg (source 7 of 8)
    NPS Vegetation Mapping Program Coordinator, 20031001, Vegetation Spatial Database Coverage for the Acadia National Park Vegetation Mapping Project: U. S. Geological Survey Upper Midwest Environmental Sciences Center, La Crosse, Wisconsin.

    Online Links:

    • https://irma.nps.gov/App/Reference/Profile/1045111

    Other_Citation_Details: Geospatial Dataset-1045111
    Type_of_Source_Media: unknown
    Source_Scale_Denominator: 15840
    Source_Contribution:
    Acadia NP vegetation mapping database was used as the first cut for the location of ACAD salt marshes for inclusion in this project. All the salt marshes identified in the Acad Veg shapefile were checked on higher-resolution aerial photos, and a few were not used because they looked unlikely to be actual salt marshes or were mis-coded on the original source.

    Bing maps imagery (source 8 of 8)
    USGS, 2010, Bing Bird's eye imagery: Microsoft Corporation, Redmond, WA.

    Online Links:

    Other_Citation_Details:
    Copyright 2010 DigitalGlobe, Image courtesy of USGS Copyright 2012 Microsoft Corporation
    Type_of_Source_Media: online digital image
    Source_Scale_Denominator: 1200
    Source_Contribution:
    The Bing map server was used to fill in detailed aerial photo information in locations where the 2008 Low Tide photos were not available and other Maine aerial photos were not detailed enough to map the boundaries of salt marshes in the study area. Two salt marshes were digitized using the Bing maps imagery.

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

    Date: 2010 (process 1 of 8)
    Polygons in the ACAD_Veg datalayer that were identified as salt marshes were copied to a new datalayer. These polygons are tagged as "Acad Veg" in the "Source" attribute.

    Data sources used in this process:

    • ACAD_Veg

    Date: 21-Jun-2010 (process 2 of 8)
    Met with Acadia National Park resource managers and GIS staff to help identify salt marshes that were not in the ACAD_Veg datalayer but were in the larger study area. Included in this meeting were representative from the Maine Coast Heritage Trust who also assisted in locating saltmarshes for the inventory and surveying, and in identifying which salt marshes were protected by MCHT conservation easements.

    Date: 2010 (process 3 of 8)
    Investigated available high-resolution aerial photos (Low Tide 2008, NAIP 2009, LT Central 2001, LT DE 2009, and Bing using ArcGIS to digitize boundaries of salt marshes visible on these photos. Also edited the boundaries of the salt marshes identified in the Acad Veg datalayer, making them more precise. Numbered the salt marsh polygons with sequential numbers as identification as they were digitized (attribute "Marsh_ID" . This process was conducted over several months during the summer of 2010. The attribute "Photo Used" was assigned based on which aerial photo was used for the digitizing.

    Date: 2010 (process 4 of 8)
    Selected salt marshes to use for the high-accuracy surveying to check the elevations of the LiDAR data. Some of the salt marshes were visited but not used for the surveying. The marshes that were surveyed are tagged "Surveyed" in the Usage attribute. Marshes that were visited but not surveyed are tagged "visited" in the Usage attribute. This process occurred over several weeks in July, 2010.

    Date: 2011 (process 5 of 8)
    Used the LiDAR data to identify the High Marsh Elevation for each of the salt marshes. This was an iterative process. The 2-m DEM was queried at the upper edge of the saltmarsh as visible on the high-resoultion aerial photos. A contour at this elevation was created using the Contour tool in Spatial Analyst. If this contour appeared to correctly circumscribe or outline the edge of the marsh, the "HighMarshEL" attribute was populated with this number (contours were not saved during this step). This process was repeated until a value for HighMarshEl was determined to be the best representation of the upper marsh surface. This process was conducted during 2011.

    Person who carried out this activity:

    Luke P. Sturtevant
    U.S. Geological Survey, Maine Water Science Center, Augusta, ME
    Student intern
    196 Whitten Rd.
    Augusta, ME 04330
    USA

    207-622-8201 x101 (voice)

    Date: 2011 (process 6 of 8)
    The attributes "SLR_est", "SLR_conf_upper" and "SLR_conf_lower" were added. In ArcMap, they were calculated as follows: SLR_est = HighMarshEl + 0.60 m; SLR_conf_upper = SLR_est + .26 m; SLR_conf_lower = SLR_est - 0.26 m.

    Person who carried out this activity:

    Luke P. Sturtevant
    U.S. Geological Survey, Maine Water Science Center, Augusta, ME
    Student intern
    196 Whitten Rd.
    Augusta, ME 04330
    USA

    207-622-8201 x101 (voice)

    Date: 2012 (process 7 of 8)
    Calculated area of each salt marsh, in hectares, using ArcGIS Calcualte geometry command (attribute "Area_ha").

    Date: 2012 (process 8 of 8)
    Populated "Ownership" and "Ownership2" attributes (second used if the salt marsh polyon crossed ownership boundaries). Used the Acadia NP boundary datalayer of 2012 to assign ownership of salt marshes that fall within the boundary of ANP. The ANP salt marsh polyons were either on fee owned land, and ANP conservation easement, or a parcel to be acquired. The Maine Coast Heritage Trust polygons were checked. The remained of the saltmarsh polygons were assumed to be privately held.

    Data sources used in this process:

    • ACAD_Park_Boundary_2012

  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?

    All attributes in the accompanying data layers were checked.

  2. How accurate are the geographic locations?

    The locations are based on very-high resolution aerial photographs and topographic data. Most positions are accurate to within 2 meters.

  3. How accurate are the heights or depths?

    Where elevations are included in the datasets, the data are accurate to within +/- 26 cm at a 95-percent confidence level.

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

    The saltmarsh polygons in this layer represent the most complete inventory of salt marshes in the study area that is currently (2012) available. The study area encompases the eastern portion of Penobscot Bay, Maine, eastward to Grand Marsh in Gouldsboro, Maine. Small (<0.5 ha) fringing saltmarshes are not well represented, as they are difficult to identify even on highly-accurate digital orthophotos, such as are currently availble from online sources such as Bing(TM).

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

    Data are internally consistent.

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:
No legal use constraints. Users must assume responsibility in determining the usability of these data for their purposes.

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

    U.S. Geological Survey
    Ask USGS -- Water Webserver Team
    445 National Center
    Reston, VA 20192
    USA

    1-888-275-8747 (1-888-ASK-USGS) (voice)
    <http://water.usgs.gov/user_feedback_form.html>

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

    Downloadable Data

  3. What legal disclaimers am I supposed to read?

    Although these data have been used by the U.S. Geological Survey, U.S. Department of the Interior, no warranty expressed or implied is made by the U.S. Geological Survey as to the accuracy of the data. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the U.S. Geological Survey in the use of these data, software, or related materials. The use of firm, trade, or brand names in this report is for identification purposes only and does not constitute endorsement by the U.S. Geological Survey. The names mentioned in this document may be trademarks or registered trademarks of their respective trademark owners.

  4. How can I download or order the data?

Who wrote the metadata?

Dates:
Last modified: 20-Dec-2012
Metadata author:
U.S. Geological Survey, New England Water Science Center, Maine Office
Hydrologist
196 Whitten Rd.
Augusta, ME 04330
USA

207-622-8201 (voice)
mnielsen@usgs.gov

Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)

Generated by mp version 2.9.20 on Wed Mar 13 14:01:57 2013