PDF of REPORT # 4: THE ARGUS BEACH MONITORING STATION AT THE MOUTH OF THE COLUMBIA RIVER - NORTH HEAD, WA.

This report covers the maintenance and data collection from 1 April 2006 – 30 September 2006 and analysis from February 2004 through September 2006.

Warning: This pdf is 2 Mbytes.

The table of contents for this report is shown below:

Table of Contents ii
List of Figures iv
1. Introduction 1
2. Data Collection, Availability, and Presentation 2
2.1 Hour Image and Pixel Time series Collection 2
2.1.1 Data Collection Interruptions 2
2.2 Web-Accessible Images and Data Products 3
2.3 Archival Storage of Argus Images and Pixel Collection 3
2.4 Meetings and Presentations 3
3. System Maintenance and Improvements 4
3.1 System Repair And Maintenance Logs 4
3.1.1 2-6 June 2006 4
3.1.2 18-21 August 2006 4
3.2 Maintenance of Video Capture Equipment for PIV Analysis 4
4. System Metadata 5
4.1 Geometry Solutions 5
4.1.1 Data Quality Control using the Geometry Solutions 5
4.2 Field Data 6
4.2.1 Tide and Barometric Pressure Data 6
4.2.2 Ocean Wave Data 6
5. Analysis 7
5.1 Argus Intertidal Bathymetry: Comparisons with GPS (Buggy) Data 7
5.1.1 Argus shoreline contour elevation mapping 7
5.1.1.1 Calculating Argus contour elevations 7
5.1.1.1.1 Barometrically-corrected tidal elevation 8
5.1.1.1.2 Wave setup and swash 8
5.1.1.1.3 Image bias of the average swash location 9
5.1.1.1.4 Equation for the Waterline Elevation 9
5.1.1.2 Argus waterline contour data preparation – estimating foreshore beach slope 9
5.1.2 WA DOE intertidal bathymetry maps 10
5.1.3 Comparison of Argus shoreline contours with GPS buggy bathymetry 10
5.1.3.1 Comparisons: Argus Data Acquired for Flood versus Flood and Ebb Tides 10
5.1.3.2 Comparisons: Argus Estimates Using Measured versus Fixed Beach Slope 13
5.1.3.3 Comparisons: Argus and GPS-Buggy 2.0m NAVD88 Contours 13
5.1.4 Summary: Argus and GPS-Buggy Bathymetry Comparison 14
5.2 Basic Data Products 17
5.2.1 Hourly images 17
5.2.2 Panoramic and plan-view images 17
5.2.3 Tide and wave field data 17
5.2.4 Coordinate reference map 17
5.2.5 Intertidal contour maps 17
5.2.6 Intertidal bathymetry data 18
5.2.7 MHW (2.0m NAVD88) contour locations - a statistical summary 18
5.2.8 MHW shoreline shape changes 23
6. Data Analysis Toward a Conceptual Sediment Process Model 29
6.1 Summary of Findings to Date 29
6.2 Finding #1: The dominant seasonal signal of dry-beach acreage and intertidal volume changes on Benson Beach is associated with sand bar movement 29
6.2.1 On the importance of sand bars in sediment transport 30
6.2.2 Sand bars and the concomitant changes in shoreline contour shape 30
6.2.3 Intertidal sand volume changes as a proxy for intertidal beach profile changes 30
6.2.4 The role of sand bars on the north section of Benson Beach 35
6.2.5 The role of sand bars on the middle section of Benson Beach 35
6.2.6 The role of sand bars on the south section of Benson Beach 35
6.3 Finding #2: The summer time disposal of dredge material on the SWS is not only optimal for safety but may also be optimal for sediment transport away from the MCR and onto Benson Beach. 35
6.4 Finding #3: Potential long-term loss (35,000 sq meters) of dry beach acreage (i.e., net shoreward movement of the 2.0m NAVD88, MHW position) is evident following the harsh 2005/2006 winter. 36
6.4.1 2005/2006 winter affect on the north section of Benson Beach 36
6.4.2 2005/2006 winter affect on the middle section of Benson Beach 37
6.4.3 2005/2006 winter affect on the south section of Benson Beach 37
7. References 38