Appendix 1.  Geospatial data of salt marshes, inundation contours, and surveying data in and near Acadia National Park, Maine.

This section describes the geospatial data produced for this report. These GIS layers were developed along with the final report (USGS SIR 2012-5290, Estimates of future inundation of salt marshes in response to sea level rise in and around Acadia National Park, Maine, by Martha Nielsen and Robert Dudley) for the identification of areas adjacent to salt marshes that are expected to be inundated after 60 cm of sea level rise occurs. The layers document the location and extent of the salt marshes, the extent of inundation expected around each marsh (with 95-percent confidence interval lines), potential manmade barriers to marsh migration, and all the surveying data collected as part of the project.

The layers are delivered in ESRI File Geodatabase format in the Universal Transverse Mercator, Zone 19, projection (meters). Metadata are Federal  Geographic Data Committee (FGDC) compliant, and provided in in Extensible Markup  Language (*.xml) format.

The layers may be viewed and manipulated in ArcGIS 9.x or ArcView 3.x or higher.  If you do not have any GIS software, you may view the data via ArcReader, a free mapping  application distributed by ESRI for Windows, Linux, and Unix operating systems.  Download ArcReader and install it. Go to the ESRI website at http://www.esri.com/software/arcgis/arcreader/download.html and follow the directions for downloading and installing the free software.

In addition to using the links below to access the data, they may be accessed through the National Park Service’s IRMA web portal at https://irma.nps.gov/App/Portal/Home. Search for data at ACAD (Acadia National Park) to find these data.

Layer	Description	Thumbnail	Metadata
	Overview of SIR2012_5290 Saltmarsh Spatial Data		http://pubs.usgs.gov/sir/2012/5290/ Appendix1/Metadata/SIR2012_5290_ACAD _ SaltmarshSLR_overview.xml
Saltmarsh polygons	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.		http://pubs.usgs.gov/sir/2012/5290/ Appendix1/Metadata/SIR2012_5290_ACAD _Saltmarshpolygons.xml
Inundation lines	The purpose of this datalayer is to show lowland areas surrounding salt marshes in the study area that would be inundated after 60 cm of sea level rise, and would therefore provide potential areas for salt marshes to migrate into, if accretionary processes accompanying sea level rise permit. The 95-percent confidence intervals on the elevation data are also shown, to illustrate how the uncertainty in the LiDAR data translate into uncertainty in the land area that would be inundated.		http://pubs.usgs.gov/sir/2012/5290/ Appendix1/Metadata/SIR2012_5290_ACAD _Inundationlines.html
Potential barriers to migration	Landforms that are potential barriers to the horizontal migration of salt marshes in and around Acadia National Park are potentially important in the analysis of the future viability of saltmarshes. Roads and railroad grades both may act as potential barriers. The potential barriers to migration of salt marshes in and around ANP were developed using the inundation lines for salt marshes with 60 cm of sea level rise, and a shaded-relief image of the LiDAR data on which the inundation lines were based.		http://pubs.usgs.gov/sir/2012/5290/ Appendix1/Metadata/SIR2012_5290_ACAD _Potentialbarriers.html
Surveyed benchmarks	Published benchmarks and other base stations used for differential Global Positioning System (GPS) surveying of ERMs and marsh points.		http://pubs.usgs.gov/sir/2012/5290/ Appendix1/Metadata/SIR2012_5290_ACAD _SurveyedBMs.xml
Surveyed ERMs	Vertical control was established using previously-published benchmarks and one base station that was not previously published. ERM points were used as datum to survey elevations of marsh points.		http://pubs.usgs.gov/sir/2012/5290/ Appendix1/Metadata/SIR2012_5290_ACAD _SurveyedERMs.xml
Surveyed marsh points	Marsh Points were used as part of independent accuracy assessment of LiDAR data at salt marsh surfaces. Five surveyed points at each of the 20 marshes were used for LiDAR elevation accuracy assessment. Each of these points is located at a wooden stake pounded into the marsh surface and flush with the marsh surface. These points were used to determine the root mean squared error (RMSE) of the LiDAR data in this study area, and the 95 percent confidence intervals.		http://pubs.usgs.gov/sir/2012/5290/ Appendix1/Metadata/SIR2012_5290_ACAD _Surveyedmarshpoints.xml

First posted April 29, 2013