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newportdem

Metadata Updated: June 15, 2024

To assess the current topography of the tidal marshes we conducted survey-grade elevation surveys at all sites between 2009 and 2013 using a Leica RX1200 Real Time Kinematic (RTK)Global Positioning System (GPS) rover (±1 cm horizontal, ±2 cm vertical accuracy; Leica Geosystems Inc., Norcross, GA; Figure 4). At sites with RTK network coverage (San Pablo, Petaluma, Pt. Mugu, and Newport), rover positions were received in real time from the Leica Smartnet system via a CDMA modem (www.lecia-geosystems.com). At sites without network coverage (Humboldt, Bolinas, Morro and Tijuana), rover positions were received in real time from a Leica GS10 antenna base station via radio link. When using the base station, we adjusted all elevation measurements using an OPUS correction (www.ngs.noaa.gov/OPUS). We used the WGS84 ellipsoid model for vertical and horizontal positioning. We verified rover accuracy and precision by measuring positions at local National Geodetic Survey (NGS) benchmarks and temporary benchmarks established at each site (Table 1). Average measured vertical errors at benchmarks were 1-2 cm throughout the study, comparable to the stated error of the GPS. At each site, we surveyed marsh surface elevation along transects oriented perpendicular to the major tidal sediment source, with a survey point taken every 12.5 m; 50 m separated transect lines. We used the Geoid09 model to calculate orthometric heights from ellipsoid values (m, NAVD88; North American Vertical Datum of 1988) and projected all points to NAD83 UTM zone 10 or zone 11 using Leica GeoOffice (Leica Geosystems Inc, Norcross, GA, v. 7.0.1).We synthesized the elevation survey data to create a digital elevation model (DEM) at each site in ArcGIS 10.2.1 Spatial Analyst (ESRI 2013; Redlands, CA) with exponential ordinary kriging methods (5 x 5 mcell size) after adjusting model parameters to minimize the root-mean-square error (RMS). We used elevation models as the baseline conditions for subsequent analyses in this study including tidal inundation patterns, SLR response modeling, and mapping of sites by specific elevation (flooding) zones.

Access & Use Information

Public: This dataset is intended for public access and use. License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

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Dates

Metadata Created Date June 1, 2023
Metadata Updated Date June 15, 2024

Metadata Source

Harvested from DOI EDI

Additional Metadata

Resource Type Dataset
Metadata Created Date June 1, 2023
Metadata Updated Date June 15, 2024
Publisher Climate Adaptation Science Centers
Maintainer
@Id http://datainventory.doi.gov/id/dataset/64121f43d1763ce191cf0f92c48593a6
Identifier 86a52e0a-07a8-459c-b7f6-911d4500407d
Data Last Modified 2016-03-11
Category geospatial
Public Access Level public
Bureau Code 010:00
Metadata Context https://project-open-data.cio.gov/v1.1/schema/catalog.jsonld
Metadata Catalog ID https://datainventory.doi.gov/data.json
Schema Version https://project-open-data.cio.gov/v1.1/schema
Catalog Describedby https://project-open-data.cio.gov/v1.1/schema/catalog.json
Harvest Object Id 068501b5-d5c4-4a86-9170-90a539c377c5
Harvest Source Id 52bfcc16-6e15-478f-809a-b1bc76f1aeda
Harvest Source Title DOI EDI
Metadata Type geospatial
Old Spatial -117.888821,33.645112,-117.868853,33.652469
Source Datajson Identifier True
Source Hash c33a2f2ce72652c7ad8acf315dcad657d008d72a8a7f43a4f28ae5f35364e002
Source Schema Version 1.1
Spatial {"type": "Polygon", "coordinates": -117.888821, 33.645112, -117.888821, 33.652469, -117.868853, 33.652469, -117.868853, 33.645112, -117.888821, 33.645112}

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