Cooperative Agreement # 02WRAG0057
by
Northwest Research Associates (NWRA)
Bellevue, WA for
United States Geological Survey (USGS)
Coastal and Marine Geology Program
Submitted to Drs. Peter Ruggiero and Guy Gelfenbaum: 24 July 2003
US Geological Survey
345 Middlefield Rd MS-999
Menlo Park, CA 94025
650-329-5433 – Voice (Ruggiero)
650-329-5483 – Voice (Gelfenbaum)
650-329-5190 - Fax pruggiero@usgs.gov
- email (Ruggiero) ggelfenbaum@usgs.gov
- email (Gelfenbaum)
First Year Completed
Contact Information:
NorthWest Research Associates
14508 NE 20 th Street
Bellevue, WA 98005
For Technical Questions: Dr. Joan Oltman-Shay, 425.644.9660 x314, 425.644.8422 (fax) joan@nwra.com
For Contract Questions: Ms. Yvonne Pipkin, 425.644.9660 x220, yvonne@nwra.com
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Cooperative Agreement # 02WRAG0057
TABLE OF CONTENTS
Table of Contents .......................................................................................................................... ii
1.
Background ............................................................................................................................1
1.1 Statement of Problem ..................................................................................................... 1
2.
Goals and objectives ..............................................................................................................2
2.1 Long-Term Goal............................................................................................................. 2
2.2 Scientific Objectives ...................................................................................................... 2
2.3 Technical Objectives for year one.................................................................................. 2
2.3.1 Task1: Preparations and Installation ....................................................................... 2
2.3.2 Task 2: Routine Operations .................................................................................... 3
2.3.3 Task 3: Data Products ............................................................................................. 4
3.
Results from the First-Year Effort .......................................................................................5
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Cooperative Agreement # 02WRAG0057
1.
BACKGROUND
1.1
STATEMENT OF PROBLEM
Distinguishing features of Kachemak Bay are a 4-mile long spit of sand (Homer Spit) that extends into the bay from the north shore ( Figure 3 ) and an 8-m tide range. This spit is morphodynamically connected to eroding bluffs northwest of the spit. From the perspective of the State and the Kachemak Bay Research Reserve there are two primary objectives for studying the coastal processes along the spit and adjacent bluffs:
1.
Coastal Erosion : Understand and quantify both the short- and long-term morphodynamics in the nearshore as a function of both wave energy and sand supply.
The sand supply at this location was greatly increased following the 1964 earthquake that caused massive land subsidence on the east side of Cook Inlet. The subsequent introduction of sand from bluff toe erosion provided the bulk of the sand supply to the system. It is hypothesized that construction of newly proposed shore protection structures may cause localized sand starvation and increased shore erosion within the town of
Homer, both along the spit and the bluffs to the northwest.
2.
Nearshore Habitat : Whereas the sand volume appears to have recently decreased in the nearshore, the deeper water benthos still has considerable sediment. In fact a kelp bed was destroyed recently following a massive movement of sand during a winter storm.
The kelp bed habitat was found to be buried by over 1 meter of sand this past summer.
The kelp beds provide habitat for many other organisms and are the basis for the nearshore ecosystem.
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Cooperative Agreement # 02WRAG0057
2.
GOALS AND OBJECTIVES
2.1
LONG-TERM GOAL
Improve our understanding of the large-scale coastal fluid and sediment processes of the nation’s coastlines for the purpose of developing predictive capabilities and monitoring methods that will contribute to the foundation upon which informed coastal management decisions can be made.
2.2
SCIENTIFIC OBJECTIVES
This proposal is part of a collaborative research effort with Drs. Guy Gelfenbaum and
Peter Ruggiero. The following represents the objectives of this joint effort.
The Kachemak Bay study site is unusual in its macro-tidal, high-wave energy, large-scale features (surf zone, tidal flats, and morphology). These extreme parameters set this site apart from the other sites studied by nearshore oceanographers. A study of this extreme beach genre is likely to reveal aspects that are only subtle on other beaches, and may reveal processes unique to this type of beach.
Objective 1: Monitor shoreline and morphology changes frequently enough to observe episodic changes, before and after extreme tides and high waves, and long enough to determine statistical trends in sediment movement.
Objective 2: Integrate the shoreline and morphology observations with information on waves, tides, currents, presence or absence of hard structures, size and health of the ecosystem for the purpose of developing an understanding of the interplay between fluids, sediments, and the ecosystem.
2.3
TECHNICAL OBJECTIVES FOR YEAR ONE
2.3.1
Task1: Preparations and Installation

Design: NWRA will work with USGS staff to design the desired sampling strategy and the site infrastructure requirements. It is expected that USGS will provide the site layout specifics (e.g. camera location, desired resolution as a function of position, etc.) for determination of number of cameras and camera lens focal-length requirements.

Site Infrastructure: USGS will arrange with locals entities for the building and deployment of both a camera mounting platform and a computer shelter. NWRA will provide engineering design support for this. The camera-mounting platform will necessarily need to minimize movement in wind. The computer shelter will need to minimize exposure of the computers to salt air, and protect against ocean waves, snow, and rain. In addition, the shelter must be kept in a temperature range required of desk-top computers.
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Cooperative Agreement # 02WRAG0057

Local Support Services: USGS will arrange for, and pay for, or have locals pay for, electrical power and telephone services. NWRA will arrange for, and pay for, internet communications. Note: if a local internet provider is not available, long distance charges to Seattle may be substantial (i.e., $2,000/year).

ABM-Station Fabrication, Calibration, and Testing: NWRA will define the ABMS requirements, purchase necessary components, and assemble and calibrate the ABMS.
Based on information provided by our cooperators, the costing assumes that the station will consist of six Sony digital color video cameras, lenses and filters, with environmental enclosures, an SGI

Unix workstation with a right-to-use license for the
ABMS system software, power unit and switch controller, uninterruptible power supply, cables, connectors, surge suppressors, and mounting supplies. Spares of some equipment (e.g., video cameras) that can be shipped to the field within 72-hours if a problem occurs also will be available, but are not included in the costing.

Installation: NWRA will pack all equipment and ship it to the field. NWRA will travel to the field and install the ABMS with assistance from USGS and Homer personnel.
NWRA will arrange for, and pay for, surveying services and be directly responsible for the ABMS assembly, on-site calibration, and the definition and surveying of ground control points (GCP); the latter are used to routinely calibrate each camera’s geometry solution. In addition, NWRA will configure the station to collect the following data each hour: a snapshot image, a time-exposure (“timex”) image, and a variance image
(variance of the pixel intensity,

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), and send these data to the NWRA computer facilities either hourly (if a local internet provider can be obtained and data stream requires less than 20 minutes to send) or daily.

On-site maintenance (cleaning of lenses, rebooting computer): NWRA will train local site technicians from the Homer area in routine maintenance and trouble-shooting operations.
2.3.2
Task 2: Routine Operations

Data Collection: NWRA will, on a daily, if not hourly basis, automatically poll the
ABMS and transfer the most recent data to NWRA’s offices for immediate placement on the project web site (see Task 3 below). NWRA will review the data (a minimum of
3X/week) and verify that the station is operating properly, and arrange for Homer personnel to visit the site and trouble-shoot any problems as needed. Data collection will be dependent on all communication systems functioning. However, no data will be lost in transfer because it is also stored locally on the SGI and is therefore retrievable when communications are re-established.

Data QC: NWRA will, on a weekly basis, perform data quality control and calibrate the video image data. The digital imagery from the station’s cameras will be reviewed for problems with image quality (e.g., images obscured by fog), and image geometry will be examined; new geometry solutions will be calculated as need.

System Rental: NWRA will rent the ABMS system to the project for the duration of the installation. This rental includes replacement costs due to system malfunction, theft, and
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Cooperative Agreement # 02WRAG0057 vandalism. In the case of weather related damage, NWRA will replace damaged equipment up to a maximum total cost of $5,000.

Routine On-site Maintenance: NWRA will oversee the on-site maintenance by Homer personnel. These efforts include- general inspection of the station, cleaning of the camera lenses and housings, checking of all mounting hardware, inspection and repair of cables as needed, servicing of the SGI

workstation (as needed, with phone guidance from NWRA), and entry into an on-site maintenance log.

Special On-Site Maintenance: NWRA will send a technician/engineer to the field for repairs that cannot be accomplished by Homer personnel.
2.3.3
Task 3: Data Products

On-line Image Archive Site: For each camera, NWRA will build an on-line image archive, accessible over the internet, that includes the hourly calibrated snap-shot, timex, and variance images.

Data Collection Modifications: NWRA will, at the request of USGS, remotely adjust the station’s operating configuration to accommodate changes needed in the sampling strategy (e.g., run-up time series collection) using the ABMS system software and remote-control capabilities.

QC Database: NWRA will build a database, in a standard format (e.g., Microsoft

Excel), that describes the contents of the image archives and documents site activities, sampling protocols, problem resolution, quality control information, etc.

Geometry Solution Database: NWRA will build a MSQL database of camera geometries for image analysis with ABMS Matlab algorithms. This database will be available to
USGS scientists on-line.

Web Site: NWRA will develop and maintain a project web site that provides USGS,
Homer, and NWRA easy access to the data products.

Image Rectification and Merging: NWRA will rectify and merge a to-be-determined number of camera images and enter them into the on-line image archive. The merged images will provide maps of the study area from which features can be identified and studied. Typically, a timex images are rectified and merged to reveal submerged sand bar location, size, and orientation, and to map the shoreline location at a pre-determined tidal stanza. However, on this macro-tidal, low-sloping beach, the variance images may better serve shoreline analysis.

Data Archives: NWRA will provide regular (2-3 month interval), data archives of the on-line image archives and the qc database. In addition, NWRA will keep offsite copies of these archives.
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Cooperative Agreement # 02WRAG0057
3.
RESULTS FROM THE FIRST-YEAR EFFORT
The focus of the first year effort was on 1) system design, equipment calibration and preparation, and installation of the ABMS, 2) routine daily acquisition and quality control operations, and 3) data preparation, logging, and project web site development and maintenance for dissemination of data.
All first-year technical objectives were met.
The first year was very successful. We were most fortunate to be able to place the ABM-
Station on a headland east of the Beluga Slough. Our cameras and the camera platform are on private property, in the backyard of a homeowner; our communication system is in their greenhouse. This remarkable location provides the opportunity to watch fluid and sediment processes around the headland. The original ABM-Station design was expanded to eight cameras to allow for full coverage around the headland ( Figure 3 ).
Figure 3 . Aerial view of the Homer ABMS Site. The cameras are located at the point on the headland from which the black lines are radiating. The black lines demark the field-of-views of
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Cooperative Agreement # 02WRAG0057 each of the eight cameras. The power of the camera lens used for each view is also shown in mm. The distance from the cameras are indicated by the circles labeled 500 and 1000m.
The station was installed in February 2003 on an elevated platform designed by NWRA and built by the City of Homer ( Figure 4 ). The difficulty of obtaining ground-control-points
(GCPs) in the field-of-view of each of the cameras, especially those pointing directly offshore, was successfully overcome by using a combination of painted rocks and night lights on the distant Homer Spit as GCPs. There was some movement of the cameras in the first few weeks, including concerns about eagles landing on the cameras, but camera movement has since quieted. The geometries of all field-of-views have been proven to be tractable so that good rectifications and merges of images are expected.
Figure 4 . View of the camera tower looking south across the Kachemak Bay.
An example rectified- and merged-image composite is shown in Figure 5 . A close-up of one of the sand slugs of interest, believed to migrate from the Beluga Slough, can be seen in
Figure 6 .
The web site developed for these data can be found at www.planetargus.com
by clicking on ABMS sites to bring up a map of the world and clicking near the town of Homer, Alaska to bring up the Argus Homer site. The site provides both a background explanation of the effort as well as access to the last hourly image acquired and the archive of images.
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Cooperative Agreement # 02WRAG0057
Figure 5.
Example rectified- and merged-image composite of the nearshore around the headland at a moderately low tide. The black denotes the area not in the field-of-view of the cameras. The image picks up1) the shoreline location (dark line at bottom of image against the near-solid white, 2) the streams from the Beluga Spit (white branches on the left of image), 3) the finegrain, sorted sand against the coarse, darker sediment (sand slugs on the right side, near the water edge), and other geomorphic features.
Figure 6.
Example rectified- and merged-image composite zooming in on an interest area, in this case the location of a sand slug.
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