High Risk Erosion Hazard Zone for Dune-Backed Beaches, Tillamook County, DOGAMI, 2001

Citation:

Citation Information:

Originator: Oregon Department of Geology and Mineral Industries
Publication Date: 2001
Title: High Risk Erosion Hazard Zone for Dune-Backed Beaches, Tillamook County, DOGAMI, 2001
Edition: Preliminary
Geospatial Data Presentation Form: vector digital data
Series Information:

Series Name: Open File Report
Issue Identification: O-01-03

Publication Information:

Publication Place: Portland, Oregon
Publisher: Oregon Department of Geology and Mineral Industries

Other Citation Details: A text report accompanies the vector digital data
Online Linkage: http://www.oregongeology.com
Larger Work Citation:

Citation Information:

Originator: Oregon Department of Geology and Mineral Industries
Publication Date: 20011231
Title: Evaluation of coastal erosion hazard zones along dune and bluff backed shorelines in Tillamook County, Oregon: Cascade Head to Cape Falcon
Other Citation Details:
Other Digital map data files associated with this Open-file Report include: Historical shorelines - 1927, 1953, 1955, 1986, 1994, 1997, 1998; Dune hazard data - Neskowin cell beach data, Netarts cell beach data, Rockaway cell beach data, Sand Lake cell beach data; Erosion data - Spot erosion rates; Hazard zones - Active hazard zone, Bluff hazard zones, high dune hazard zone, low dune hazard zone, moderate dune hazard zone; Landslides - Tillamook coastal landslides; Misc. geology -Basalt, Slide block widths Tillamook.
Online Linkage: http://www.oregongeology.com

Description:

Abstract:
Polygon data capturing High Risk Hazard Zones for Dune-backed beaches on the Tillamook County coast. The High Risk Hazard Zone is analogous to the 2-3 March 1999 La Niña winter storm. This scenario is based on the storm waves occurring over the cycle of an above average high tide, coincident with a 3.3 ft storm surge. Under this scenario, the designated HIGH-risk hazard zone was found to range from 250 to 280 ft, and varies between the four littoral cells due to subtle differences in the beach morphologies between the littoral cells. This data set is one portion of a larger study of the entire Tillamook County Coastline. For full details on study results and methods please consult DOGAMI Open-file Report O-01-03, and associated digital files.
Purpose:
To assess existing and potential coastal erosion hazards along the Tillamook County shoreline, extending from Cascade Head in the south to Cape Falcon in the north. Further, to assist County planners in effective decisionmaking adjacent to the shoreline.
Supplemental Information:
This report describes and documents a range of coastal hazards zones distinguished for the Tillamook County coastline. In particular, the report focuses on identifying maximum potential erosion distances for bluffs and for dune backed shorelines using two quite different but complementary approaches for these two different shore types.
Hazard zones on dune-backed beaches were determined from a geometric model, whereby property erosion occurs when the total water level produced by the combined effect of extreme wave runup (R) plus the tidal elevation (ET), exceeds some critical elevation of the fronting
beach, typically the elevation of the beach-dune junction (EJ).

The range of shoreline retreat predicted for dune backed beaches is clearly quite large for Tillamook County, and reflects the uncertainty in predicting future shoreline behavior based purely on extreme wave erosion events. Shoreline retreat estimated for Tillamook County ranged from ~120-1,400 feet, depending on the water level scenario chosen and the local beach conditions. Despite the low probabilities of some of the extreme water level scenarios adopted for Tillamook County, the width of the resulting average hazard zones is still justified since it can accommodate in a gross sense such changes as migrating rip current embayments, the wholesale
transport of sand by longshore drift, and the on-offshore transport of sand. For example, recent erosion at places like Cape Lookout State Park has already approached close to the shoreline retreat predicted by some of the worst-case scenarios.

Time Period of Content:

Time Period Information:

Single Date/Time:

Calendar Date: 2001
Time of Day: Unknown

Currentness Reference: 20010625

Status:

Progress: Complete
Maintenance and Update Frequency: None planned

Spatial Domain:

Bounding Coordinates:

West Bounding Coordinate: -124.026532
East Bounding Coordinate: -123.902652
North Bounding Coordinate: 45.731217
South Bounding Coordinate: 45.094804

Keywords:

Theme:

Theme Keyword Thesaurus: NA
Theme Keyword: Beach Morphology
Theme Keyword: Coastal Erosion
Theme Keyword: Geology
Theme Keyword: Hazard Zone

Place:

Place Keyword Thesaurus: NA
Place Keyword: Tillamook County
Place Keyword: Oregon Coast

Access Constraints: None
Use Constraints: This regional investigation is not intended for use as a site-specific analysis tool. It can be used to identify areas in need of more detailed site-specific geotechnical studies.
Point of Contact:

Contact Information:

Contact Person Primary:

Contact Person: Jonathan C. Allan
Contact Organization: Oregon Department of Geology and Mineral Industries

Contact Position: Coastal geomorphologist
Contact Address:

Address Type: mailing and physical address
Address: 313 SW 2nd, Suite D
City: Newport
State or Province: Oregon
Postal Code: 97365

Contact Voice Telephone: 541 574-6642
Contact Facsimile Telephone: 541 265-5241

Data Set Credit:
This investigation was supported by a professional services agreement with Tillamook County and from resources of the State of Oregon Department of Geology and Mineral Industries (DOGAMI). County funds were derived from the Project Impact program of the Federal Emergency Management Agency. The project was greatly facilitated by the Netarts Littoral Cell Management Planning Project supported by the Oregon Department of Land Conservation and Development, Oregon Parks and Recreation Division, and Tillamook County. We are especially grateful to John Beaulieu (Director of DOGAMI), Dennis Olmstead (Deputy State Geologist), Zhenming Wang (acting Earthquake Program Director for DOGAMI), Paul Komar (Oregon State University), John Marra (Department of Land Conservation and Development), Richard Rinne (Hart Crowser, Inc), and Doug Gless (H.G. Schlicker & Associates, Inc), for their insightful comments on this report. Thanks must also be extended to Randy Dana, Department of Land Conservation and Development, for his help in collating the NOS T-sheets, Chris Chickadel, Oregon State University, for helping out with the ARGUS photographic data, and James Good, Oregon State University, who offered helpful advice early on in the project. We are also extremely grateful to Stuart Albright of Hart Crowser, Inc. for sending invaluable geotechnical data from The Capes project. Eileen Hemphill-Halley of the US Geological Survey and University of Oregon kindly provided data analyses of diatoms present in Quaternary deposits of The Capes landslide.
Native Data Set Environment: Microsoft Windows Vista Version 6.1 (Build 7601) Service Pack 1; ESRI ArcCatalog 9.3.1.4000

Positional Accuracy:

Vertical Positional Accuracy:

Vertical Positional Accuracy Report: Elevations in this data set are relative to the North American Vertical Datum of 1988 (NAVD’ 88)

Lineage:

Source Information:

Source Citation:

Citation Information:

Title: Preliminary report for Tillamook County shoreline

Source Scale Denominator: 12000
Type of Source Media: CD-ROM
Source Time Period of Content:

Time Period Information:

Range of Dates/Times:

Beginning Date: 1999
Beginning Time: Unknown
Ending Date: 2001
Ending Time: Unknown

Source Citation Abbreviation: DOGAMI OFR O-01-03
Source Contribution: Original DOGAMI files were in MapInfo format, and in UTM Zone 10N NAD27 projection.

Process Step:

Process Description:
For the entire project, the process steps included the following: 1. Work with local advisory groups to guide the investigation. 2. Obtain appropriate historical aerial photography. 3. Search the literature for hazard data. 4. Map existing open coastal shoreline landslides, classifying them as prehistoric, potentially active, or active. 6. Collect shoreline topographic profiles and other data necessary to estimate the width of a zone of shoreline variability on dune-backed open coastal shorelines. 7. In collaboration with County and technical advisers, establish a methodology for mapping erosion hazard areas. 8. Map the erosion hazard areas. 9. Digitize all line data. 10. Transmit all digital data to County. 11. Provide follow-up advice on use of the maps in policy development.
Process Date: 1999

Process Step:

Process Description:
Hazard zones on dune-backed beaches were determined from a geometric model, whereby property erosion occurs when the total water level produced by the combined effect of extreme wave runup (R) plus the tidal elevation (ET), exceeds some critical elevation of the fronting beach, typically the elevation of the beach-dune junction (EJ).
Process Contact:

Contact Information:

Contact Person Primary:

Contact Person: Jonathan C. Allan
Contact Organization: Oregon Department of Geology and Mineral Industries

Contact Position: Coastal geomorphologist
Contact Address:

Address Type: mailing and physical address
Address: 313 SW 2nd, Suite D
City: Newport
State or Province: Oregon
Postal Code: 97365

Contact Voice Telephone: 541 574-6642
Contact Facsimile Telephone: 541 265-5241

Process Step:

Process Description:
The original MapInfo Interchage Format files were exported from CD-ROM and converted to ESRI Shapefile format. The data was reprojected during this transformation in to the Oregon statewide Lambert projection.
Process Contact:

Contact Information:

Contact Person Primary:

Contact Person: Tanya C. Haddad
Contact Organization: Oregon Coastal Management Program

Contact Position: Coastal Atlas Coordinator
Contact Address:

Address Type: mailing and physical address
Address: 800 NE Oregon St, #1145
City: Portland
State or Province: OR
Postal Code: 97232
Country: USA

Contact Voice Telephone: 971-673-0962
Contact Facsimile Telephone: 971-673-0911
Contact Electronic Mail Address: tanya.haddad@state.or.us

Cloud Cover: 0

Direct Spatial Reference Method: Vector
Point and Vector Object Information:

SDTS Terms Description:

SDTS Point and Vector Object Type: G-polygon
Point and Vector Object Count: 9

Horizontal Coordinate System Definition:

Planar:

Map Projection:

Map Projection Name: Lambert Conformal Conic
Lambert Conformal Conic:

Standard Parallel: 43
Standard Parallel: 45.5
Longitude of Central Meridian: -120.5
Latitude of Projection Origin: 41.75
False Easting: 1312335.958
False Northing: 0

Planar Coordinate Information:

Planar Coordinate Encoding Method: Coordinate Pair
Coordinate Representation:

Abscissa Resolution: 0
Ordinate Resolution: 0

Planar Distance Units: international feet

Geodetic Model:

Horizontal Datum Name: North American Datum of 1983
Ellipsoid Name: Geodetic Reference System 80
Semi-major Axis: 6378137
Denominator of Flattening Ratio: 298.257

Detailed Description:

Entity Type:

Entity Type Label: tillamook_cnty_high_hazard_zone_DOGAMI_2001

Attribute:

Attribute Label: FID
Attribute Definition: Internal feature number.
Attribute Definition Source: ESRI
Attribute Domain Values:

Unrepresentable Domain: Sequential unique whole numbers that are automatically generated.

Attribute:

Attribute Label: High_hazar

Attribute:

Attribute Label: ID

Attribute:

Attribute Label: Shape
Attribute Definition: Feature geometry.
Attribute Definition Source: ESRI
Attribute Domain Values:

Unrepresentable Domain: Coordinates defining the features.

Overview Description:

Entity and Attribute Overview: See accompanying Open-File Report text for a discussion and explanation of digital map data attributes.
Entity and Attribute Detail Citation: Oregon Department of Geology and Mineral Industries Open File Report O-01-03

Distributor:

Contact Information:

Contact Person Primary:

Contact Person: Donald Haines
Contact Organization: Nature of the Northwest Info Center

Contact Position: Manager
Contact Address:

Address Type: physical address
Address: 800 NE Oregon Street
City: Portland
State or Province: OR
Postal Code: 97232
Country: USA

Resource Description: High Risk Erosion Hazard Zone for Tillamook County, DOGAMI, 2001, from OFR O-01-03
Distribution Liability:
Although these data have been processed successfully on a computer system at the Oregon Department of Geology and Mineral Industries (DOGAMI), no warranty expressed or implied is made regarding the accuracy or utility of the data on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. This disclaimer applies both to individual use of the data and aggregate use with other data. It is strongly recommended that these data are directly acquired from DOGAMI, and not indirectly through other sources which may have changed the data in some way. It is also strongly recommended that careful attention be paid to the contents of the metadata file associated with these data. The Oregon Department of Geology and Mineral Industries shall not be held liable for improper or incorrect use of the data described and/or contained herein.
Standard Order Process:

Digital Form:

Digital Transfer Information:

Transfer Size: 0.041

Custom Order Process: For the original OFR files in MapInfo format please contact the Oregon Department of Geology and Mineral Industries
Available Time Period:

Time Period Information:

Single Date/Time:

Calendar Date: 1/1/1895
Time of Day: Unknown

Metadata Date: 2/21/2013
Metadata Review Date:
Metadata Future Review Date:
Metadata Contact:

Contact Information:

Contact Person Primary:

Contact Person: Tanya C. Haddad
Contact Organization: Oregon Coastal Management Program

Contact Position: Coastal Atlas Coordinator
Contact Address:

Address Type: mailing and physical address
Address: 800 NE Oregon St, #1145
City: Portland
State or Province: OR
Postal Code: 97232
Country: USA

Contact Voice Telephone: 971-673-0962
Contact Facsimile Telephone: 971-673-0911
Contact Electronic Mail Address: tanya.haddad@state.or.us

Metadata Standard Name: FGDC Content Standards for Digital Geospatial Metadata
Metadata Standard Version: FGDC-STD-001-1998
Metadata Time Convention: local time
Metadata Extensions:

Online Linkage: http://www.esri.com/metadata/esriprof80.html
Profile Name: ESRI Metadata Profile