Short Citation:
Office for Coastal Management, 2021: Inundation Mapping Tidal Surface - Mean Higher High Water, https://www.fisheries.noaa.gov/inport/item/48104.

Item Identification

Title: Inundation Mapping Tidal Surface - Mean Higher High Water
Short Name: NOAA_OCM_MHHW_Metadata
Status: Completed
Publication Date: 2019
Abstract:

These data are a derived product of the NOAA VDatum tool and they extend the tool's Mean Higher High Water (MHHW) tidal datum conversion inland beyond its original extent.

VDatum was designed to vertically transform geospatial data among a variety of tidal, orthometric and ellipsoidal vertical datums - allowing users to convert their data from different horizontal/vertical references into a common system and enabling the fusion of diverse geospatial data in desired reference levels (http://vdatum.noaa.gov/). However, VDatum's conversion extent does not completely cover tidally-influenced areas along the coast. For more information on why VDatum does not provide tidal datums inland, see http://vdatum.noaa.gov/docs/faqs.html.

Because of the extent limitation and since most inundation mapping activities use a tidal datum as the reference zero (i.e., 1 meter of sea level rise on top of Mean Higher High Water), the NOAA Office for Coastal Management created this dataset for the purpose of extending the MHHW tidal datum beyond the areas covered by VDatum. The data do not replace VDatum, nor do they supersede the valid datum transformations VDatum provides. However, the data are based on VDatum's underlying transformation data and do provide an approximation of MHHW where VDatum does not provide one. In addition, the data are in a GIS-friendly format and represent MHHW in NAVD88, which is the vertical datum by which most topographic data are referenced.

Data are in the UTM NAD83 projection. Horizontal resolution varies by VDatum region, but is either 50m or 100m. Data are vertically referenced to NAVD88 meters.

Purpose:

These data were created to support the mapping of tidally-based inundation scenarios on high resolution digital elevation models. The data represent the MHHW tidal datum referenced to NAVD88, which is the official civilian orthometric datum by which most topographic data are referenced.

Notes:

10961

Supplemental Information:

These data do not replace valid VDatum transformations. They do not incorporate VDatum's bounding polygons (or valid transformation areas) - the data extend beyond these areas.

Keywords

Theme Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Science Keywords Earth Science > Land Surface > Geomorphic Landforms/Processes > Coastal Processes > Flooding
Global Change Master Directory (GCMD) Science Keywords Earth Science > Land Surface > Geomorphic Landforms/Processes > Coastal Processes > Sea Level Changes
Global Change Master Directory (GCMD) Science Keywords Earth Science > Land Surface > Topography > Terrain Elevation > Digital Elevation/Terrain Model (Dem)
ISO 19115 Topic Category elevation
None DEM
None Digital Elevation Model
None elevation
None flooding
None inundation
None mean higher high water
None MHHW
None sea level rise
None tidal datum
None topography

Spatial Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Location Keywords Continent > North America > United States Of America
Global Change Master Directory (GCMD) Location Keywords Ocean > Atlantic Ocean > North Atlantic Ocean > Caribbean Sea > Puerto Rico
Global Change Master Directory (GCMD) Location Keywords Ocean > Atlantic Ocean > North Atlantic Ocean > Caribbean Sea > Virgin Islands
None coastal states
None Conterminous US
None Puerto Rico
None US Virgin Islands

Physical Location

Organization: Office for Coastal Management
City: Charleston
State/Province: SC

Data Set Information

Data Set Scope Code: Data Set
Maintenance Frequency: As Needed
Distribution Liability:

Any conclusions drawn from the analysis of this information are not the responsibility of the Office for Coastal Management or its partners.

Data Set Credit: Acknowledgment of the NOAA Office for Coastal Management as a data source would be appreciated in products developed from these data, and such acknowledgment as is standard for citation and legal practices for data source is expected.

Support Roles

Data Steward

CC ID: 620566
Date Effective From: 2019
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address: coastal.info@noaa.gov
Phone: (843) 740-1202
URL: https://coast.noaa.gov

Distributor

CC ID: 620568
Date Effective From: 2019
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address: coastal.info@noaa.gov
Phone: (843) 740-1202
URL: https://coast.noaa.gov

Metadata Contact

CC ID: 620569
Date Effective From: 2019
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address: coastal.info@noaa.gov
Phone: (843) 740-1202
URL: https://coast.noaa.gov

Point of Contact

CC ID: 620567
Date Effective From: 2019
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address: coastal.info@noaa.gov
Phone: (843) 740-1202
URL: https://coast.noaa.gov

Extents

Currentness Reference: Publication Date

Extent Group 1

Extent Group 1 / Geographic Area 1

CC ID: 620572
W° Bound: -124.851
E° Bound: -64.51
N° Bound: 49.005
S° Bound: 17.619

Extent Group 1 / Time Frame 1

CC ID: 620571
Time Frame Type: Range
Start: 2007-10-01
End: 2019-10-24

Spatial Information

Spatial Representation

Representations Used

Grid: Yes

Access Information

Security Class: Unclassified
Data Access Constraints:

None

Data Use Constraints:

The dataset is provided as is, without warranty to its performance, merchantable state, or fitness for any particular purpose. The entire risk associated with the results and performance of this dataset is assumed by the user. This dataset should be used strictly as a planning reference and not for navigation, permitting, or other legal purposes.

URLs

URL 2

CC ID: 620564
URL: http://vdatum.noaa.gov/
URL Type:
Online Resource

URL 3

CC ID: 620565
URL: https://coast.noaa.gov/digitalcoast/tools/slr
URL Type:
Online Resource

Activity Log

Activity Log 1

CC ID: 620595
Activity Date/Time: 2017-10-31
Description:

Date that the source FGDC record was last modified.

Activity Log 2

CC ID: 620594
Activity Date/Time: 2017-11-14
Description:

Converted from FGDC Content Standards for Digital Geospatial Metadata (version FGDC-STD-001-1998) using 'fgdc_to_inport_xml.pl' script. Contact Tyler Christensen (NOS) for details.

Data Quality

Completeness Report:

Data are complete and cover all areas defined by the source data.

Conceptual Consistency:

Standard mapping methods were used to develop the data, which are described in the Process Steps section. Outputs were inspected for errors and inconsistencies, which were addressed and remedied.

Lineage

Sources

Census County Boundaries

CC ID: 620559
Contact Name: Census Bureau
Publish Date: 2014-01-01
Extent Type: Discrete
Extent Start Date/Time: 2014
Source Contribution:

Census County Boundaries, https://www.census.gov/geo/maps-data/data/cbf/cbf_counties.html | Type of Source Media: online

NOAA VDatum Version 4.0.1

CC ID: 620557
Contact Role Type: Originator
Contact Type: Organization
Contact Name: NOAA
Publish Date: 2019-10-24
Extent Type: Range
Extent Start Date/Time: 2007-10-01
Extent End Date/Time: 2019-10-24
Citation URL: https://vdatum.noaa.gov/
Source Contribution:

NOAA VDatum transformation grids for each VDatum region, https://vdatum.noaa.gov/docs/gtx_info.html. | Type of Source Media: online

USGS 10 and 12-digit hydrologic unit code (HUC) watershed boundaries

CC ID: 620558
Contact Role Type: Originator
Contact Type: Organization
Contact Name: USGS
Publish Date: 2016-01-06
Extent Type: Discrete
Extent Start Date/Time: 2019-09-04
Source Contribution:

USGS 10 and 12-digit hydrologic unit code (HUC) watershed boundaries from the Watershed Boundary Dataset, http://nhd.usgs.gov/wbd.html | Type of Source Media: online

Process Steps

Process Step 1

CC ID: 620560
Description:

Buffered Census Counties offshore by 6km. Source VDatum .gtx files were shifted from positive east longitude values to negative west values. The tss grid was subtracted from the MHHW tidal grid. This step resulted in the MHHW tidal datum referenced to an orthometric datum, specifically NAVD88. Each region's orthometric-referenced tidal grid was converted to a point file, where each cell's centroid is a point containing the value of the cell. The point data were then clipped to county boundaries that extend ~6 km offshore to limit the number of points in the interpolation below. 10 and 12-digit hydrologic unit code (HUC) watershed boundaries that intersect the point data were selected. Where VDatum regions overlapped for an area, the VDatum bounding polygons were used to remove points outside of these areas. Where there was still overlap, points from either the higher resolution region or regions covering bays and estuaries were used. Using the Inverse Distance Weighted interpolation method, the point data were used to interpolate the NAVD88-based tidal surface inland, using the selected HUC boundaries as barriers to interpolation. This approach uses only points within the watershed and limits the interpolation to areas only within the watershed. This process was done for both 10 and 12-digit HUC watersheds. The resulting interpolated surfaces were then nested or mosaicked, where the HUC 12 interpolated surface was the primary raster and the HUC 10 surface the secondary. A Euclidean Allocation approach was then used to extend the conversion further inland to areas where the HUC 10 watersheds did not cover the study area. County boundaries were used as the inland limit instead of watersheds since most topographic data are collected and/or available on a county basis.

Process Date/Time: 2016-01-01 00:00:00

Catalog Details

Catalog Item ID: 48104
Metadata Record Created By: Anne Ball
Metadata Record Created: 2017-11-14 14:15+0000
Metadata Record Last Modified By: William Brooks
Metadata Record Last Modified: 2019-11-07 13:38+0000
Metadata Record Published: 2017-11-16
Owner Org: OCM
Metadata Publication Status: Published Externally
Do Not Publish?: N
Metadata Next Review Date: 2018-11-17