Digital Shoreline Analysis System version 4.3 transects and long-term linear regression shoreline change statistics for all data available within the Outer Cape Cod coastal region from Long Point in Provincetown to Monomoy Island (OuterCapeCod_transects_rates_LTw.shp)

Transect Features Generated using DSAS v.4.2 in ArcGIS 9.3. Parameters Used: baseline layer=OuterCapeCod_baseline, baseline group field=NULL, transect spacing=50 meters, transect length=400 meters, cast direction=AUTO-DETECT, baseline location=on/off shore, cast method=smoothed baseline, smoothing distance=250 meters, flip baselines=not selected. For additional details on these parameters, please see the DSAS help file distributed with the DSAS software, or visit the USGS website at: https://pubs.usgs.gov/of/2008/1278/.
This process step and all subsequent process steps were performed by Theresa Smith.

After transects were generated, it was sometimes necessary to modify their length using standard editing tools in ArcMap v9.3 so that they intersected the shoreline data needed for analysis. In some cases sections of the baseline were modified using the dynamic topology in DSAS that allows edits to the baseline in a standard ArcMap (v9.3) editing session to update the position of transects if the transect field is enabled as the target layer in the DSAS (v4.2) toolbar.

After transects were generated, the entire geodatabase was upgraded to v.10 by right-clicking on the geodatabase and choosing Properties from the pop-up window in ArcCatalog v.10. The Upgrade Geodatabase button was clicked at the bottom of the General tab in the Database Properties window.

The southern end of the Outer Cape Cod region from Nauset Beach in Chatham to Monomoy Island is a highly dynamic barrier system. Because of the complexity of the associated vector shorelines in this area, it was necessary to calculate shoreline change statistics for the Chatham-Monomoy section in batches, separating the backshore shorelines (sheltered coast) from Atlantic-facing (open ocean) shorelines. Therefore, shoreline change statistics were calculated three times to compute a complete set of rates for the Outer Cape Cod region. The attribute field Calc_run represents the extent of each section used to calculate rates for the Outer Cape Cod region, where:
1- Includes the ocean-facing coast from Long Point in Provincetown to Nauset Beach in Orleans, including the backshore (sheltered) region within Pleasant Bay; 2- Includes the Atlantic ocean-facing coast (open ocean), southeast of Toms Neck in Chatham to Monomoy Island. 3- Includes the backshore (sheltered) coast, southeast of Toms Neck in Chatham to Monomoy Island;
Rate Calculations Performed using DSAS v.4.3 for ArcMap 10 for section 1, (the ocean-facing coast from Long Point in Provincetown to Nauset Beach in Orleans including the backshore (sheltered) region within Pleasant Bay). Parameters Used: shoreline layer=OuterCapeCod_shorelines, shoreline date field=Date_, shoreline uncertainty field name=Uncy (additional shoreline data stored in OuterCapeCod_shorelines_uncertainty.dbf), the default accuracy=10.8 meters, shoreline intersection parameters=nearest, stats calculations=[Shoreline Change Envelope (SCE), Net Shoreline Movement (NSM), Linear Regression Rate (LRR)], shoreline threshold=3, confidence interval=90%, Output rate table name=OuterCapeCod_transects_rates_20121212_095458.dbf.

The shoreline rates output table (OuterCapeCod_transects_rates_20121212_095458.dbf) was joined to the transect feature class in ArcMap v.10 by right-clicking on the transect layer > joins and relates > join > join attributes from a table. Parameters: join field - ObjectID; table to join - OuterCapeCod_transects_rates_20121212_095458; field in table: TransectID; join options - keep only matching records.

The joined data were exported to a shapefile in ArcMap v.10 by right-clicking the transect file, choosing data > export data, permanently linking the joined rate fields to the transect attribute table. The new shapefile was named OuterCapeCod_transects_rates_LTw.shp. Transects 1384-2328, and 2336-2345 were deleted from the file, as they extend outside section 1.

Due to the lack of continuous long-term shoreline position data, some transects intersected shorelines from 1970-2009, but did not intersect shorelines prior to 1970, which resulted in long-term linear regression rates that were identical to short-term linear regression rates. A filter was applied to the transect/rates data in ArcMap v10: 1) Select by Attributes > create new selection: SELECT FROM MA_shorelines.shp WHERE [Year] >=1970; and 2) Select by Location, Target layer: OuterCapeCod_transects_rates_LTw.shp, Source layer: MA_shorelines.shp, parameters: use selected features spatial selection method: Target layer(s) features intersect the source layer feature). Transects that did not intersect long-term shoreline data (1844-1960) were deleted in a standard editing session (ArcMAP v10).

Rate Calculations Performed using DSAS 4.3 for ArcMap 10 for section 2 (Atlantic ocean-facing coast (open ocean), southeast of Toms Neck in Chatham to Monomoy Island) on Selected Shoreline Features Only (shoreline location= open ocean). Parameters Used: shoreline layer=OuterCapeCod_shorelines, shoreline date field=Date_, shoreline uncertainty field name=Uncy, the default accuracy=10.8 meters, shoreline intersection parameters=nearest, stats calculations=[Shoreline Change Envelope (SCE), Net Shoreline Movement (NSM), Linear Regression Rate (LRR)], shoreline threshold=3, confidence interval=90%, Output rate table name=OuterCapeCod_transects_rates_20130422_122024.

The shoreline rates output table (OuterCapeCod_transects_rates_20121212_095458.dbf) was joined to the transect feature class in ArcMap v.10 by right-clicking on the transect layer > joins and relates > join > join attributes from a table. Parameters: join field - ObjectID; table to join - OuterCapeCod_transects_rates_20130422_122024; field in table: TransectID; join options - keep only matching records.

The joined data were exported to a shapefile in ArcMap v.10 by right-clicking the transect file, choosing data > export data, permanently linking the joined rate fields to the transect attribute table. The new shapefile was named OuterCapeCod_transects_rates_LTw_sect2.shp. Transects 1-1383, 1781-2328, and 2336-2345 were deleted from the file as they extend outside section 2.

Rate Calculations Performed using DSAS 4.3 for ArcMap 10 for section 3 (backshore (sheltered) coast, southeast of Toms Neck in Chatham to Monomoy Island) on Selected Shoreline Features Only (shoreline location= sheltered coasts). Parameters Used: shoreline layer=OuterCapeCod_shorelines, shoreline date field=Date_, shoreline uncertainty field name=Uncy, the default accuracy=10.8 meters, shoreline intersection parameters=nearest, stats calculations=[Shoreline Change Envelope (SCE), Net Shoreline Movement (NSM), Linear Regression Rate (LRR)], shoreline threshold=3, confidence interval=90%, Output rate table name=OuterCapeCod_transects_rates_20130422_111818.

The shoreline rates output table (OuterCapeCod_transects_rates_20130422_111818.dbf) was joined to the transect feature class in ArcMap v.10 by right-clicking on the transect layer > joins and relates > join > join attributes from a table. Parameters: join field - ObjectID; table to join - OuterCapeCod_transects_rates_20130422_111818; field in table: TransectID; join options - keep only matching records.

The joined data were exported to a shapefile in ArcMap v.10 by right-clicking the transect file, choosing data > export data, permanently linking the joined rate fields to the transect attribute table. The new shapefile was named OuterCapeCod_transects_rates_LTw_sect3.shp. Transects 1-1763, 1781-1967, and 1968-2093 were deleted from the file as they extend outside section 3.

The shapefiles OuterCapeCod_transects_rates_LTw_sect2.shp, and OuterCapeCod_transects_rates_LTw_sect3.shp (sections 2 and 3) were merged in Esri's ArcToolbox (v.10), Data Management Tools > General > Merge. The merged shapefile was appended to OuterCapeCod_transects_rates_LTw.shp (section 1), ArcToolbox >Data Management Tools>General>Append to produce one set of results for display and publication purposes encompassing the whole extent of the Outer Cape Cod region.

The appended transect shapefile was projected in Esri's ArcToolbox (v.10) > Data Management Tools > Projections and Transformations > Feature > Project. Parameters: input projection - NAD_1983_StatePlane_Massachusetts_Mainland_FIPS_2001; output projection - geographic coordinates (NAD83); transformation - none.

Edits to the metadata were made to fix any errors that MP v 2.9.36 flagged. This is necessary to enable the metadata to be successfully harvested for various data catalogs. In some cases, this meant adding text "Information unavailable" or "Information unavailable from original metadata" for those required fields that were left blank. Other minor edits were probably performed (title, publisher, publication place, etc.). Attempted to modify http to https where appropriate. Added a landing page link as the first link in the identification section. Fixed online link to DSAS cross-reference. The distribution format name was modified in an attempt to be more consistent with other metadata files of the same data format. The metadata date (but not the metadata creator) was edited to reflect the date of these changes. The metadata available from a harvester may supersede metadata bundled within a download file. Compare the metadata dates to determine which metadata file is most recent.

Added keywords section with USGS persistent identifier as theme keyword.