Final Report to the Beach Erosion Authority for Clean Oceans and Nourishment (BEACON) Coastal Processes Study of Santa Barbara and Ventura Counties, California By Patrick L. Barnard, David L. Revell, Dan Hoover, Jon Warrick, John Brocatus, Amy E. Draut, Pete Dartnell, Edwin Elias, Neomi Mustain, Pat E. Hart, and Holly F. Ryan Open File Report 2009–1029 U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior KEN SALAZAR, Secretary U.S. Geological Survey Suzette M. Kimball, Acting Director U.S. Geological Survey, Reston, Virginia: 2009 For product and ordering information: World Wide Web: http://www.usgs.gov/pubprod Telephone: 1-888-ASK-USGS For more information on the USGS—the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment: World Wide Web: http://www.usgs.gov Telephone: 1-888-ASK-USGS Suggested citation: Barnard, P.L., Revell, D.L., Hoover, D., Warrick, J., Brocatus, J., Draut, A.E., Dartnell, P., Elias, E., Mustain, N., Hart, P.E., and Ryan, H.F., 2009, Coastal processes study of Santa Barbara and Ventura Counties, California: U.S. Geological Survey Open-File Report 2009-1029, 904 p. [http://pubs.usgs.gov/of/2009/1029/]. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this report is in the public domain, permission must be secured from the individual copyright owners to reproduce any copyrighted material contained within this report. ii Contents Executive Summary of Major Findings .......................................................................................................................... 1 Chapter 2—Historical Changes.................................................................................................................................. 2 Chapter 3—BEACON Surveys................................................................................................................................... 4 Chapter 4—Recent Morphological Changes.............................................................................................................. 4 Chapter 5—Grain-Size Analysis ................................................................................................................................ 6 Chapter 6—The Impacts of Debris Basins on Sediment Delivery to the Santa Barbara Littoral Cell, California ........ 7 Chapter 7—Multibeam Bathymetry............................................................................................................................ 7 Chapter 8—Seismic-Reflection Images of Shallow Sedimentary Deposits................................................................ 8 Chapter 9—Numerical Modeling ................................................................................................................................ 8 Chapter 1—Introduction................................................................................................................................................. 9 Project Summary ....................................................................................................................................................... 9 Project Objectives.....................................................................................................................................................10 Project Approach ......................................................................................................................................................10 Future Work ..............................................................................................................................................................11 Report Outline...........................................................................................................................................................11 Project Support and Collaboration ............................................................................................................................12 Acknowledgments.....................................................................................................................................................13 References................................................................................................................................................................13 Chapter 2—Historical Changes ....................................................................................................................................15 Summary...................................................................................................................................................................15 Introduction ...............................................................................................................................................................16 Methods ....................................................................................................................................................................20 iii Historical Air Photos and Topographic Sheets ......................................................................................................20 Lidar and GPS Surveys.........................................................................................................................................22 Uncertainties and Errors........................................................................................................................................23 Correlation of Dredge Volumes and Beach Volumes ............................................................................................25 Results......................................................................................................................................................................26 Beach Widths ........................................................................................................................................................26 Beach Widths and Shoreline Orientations.............................................................................................................28 Shoreline Changes................................................................................................................................................29 Case Study: Carpinteria Erosion ...........................................................................................................................31 Case Study: Hope Ranch......................................................................................................................................33 Sand Transport and Lag Correlation Analyses......................................................................................................33 Discussion.................................................................................................................................................................36 Beach Width..........................................................................................................................................................36 Shoreline Changes................................................................................................................................................38 Human Alterations.................................................................................................................................................38 Storm Event Responses........................................................................................................................................40 Sediment Transport and Lag Correlations.............................................................................................................40 Conclusions ..............................................................................................................................................................42 References................................................................................................................................................................45 Chapter 3—BEACON Surveys .....................................................................................................................................63 Introduction ...............................................................................................................................................................63 Methods ....................................................................................................................................................................63 Results......................................................................................................................................................................65 Recent Changes (2003-2007) ...............................................................................................................................65 iv Recent Decadal Changes (1987-2007) .................................................................................................................67 Other Observations ...............................................................................................................................................68 Shoreline-Change Rates .......................................................................................................................................68 Conclusions ..............................................................................................................................................................69