National Assessment of Shoreline Change Part 3: Historical Shoreline Change and Associated Coastal Land Loss Along Sandy Shorelines of the California Coast Cheryl J. Hapke, David Reid, Bruce M. Richmond, Peter Ruggiero and Jeff List Open-File Report 2006-1219 U.S. Department of the Interior U.S. Geological Survey National Assessment of Shoreline Change Part 3: Historical Shoreline Change and Associated Coastal Land Loss Along Sandy Shorelines of the California Coast Cheryl J. Hapke1, David Reid2, Bruce M. Richmond2, Peter Ruggiero3, and Jeff List4 1U.S. Geological Survey, Coastal Field Station, Department of Geosciences, University of Rhode Island, Kingston, RI 02881 2U.S. Geological Survey, Pacific Science Center, Santa Cruz, CA 95060 3Dept. of Geosciences, Oregon State University, Corvallis, OR 97331 4U.S. Geological Survey, Woods Hole Science Center, Woods Hole, MA 02543 Open File Report 2006-1219 Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Hapke, C.J., Reid, D., Richmond, B.M., Ruggiero, P., and List, J., 2006, National assessment of shoreline change: Part 3: Historical shoreline changes and associated coastal land loss along the sandy shorelines of the California coast: U.S. Geological Survey Open-file Report 2006-1219. U.S. Department of the Interior U.S. Geological Survey Open-File Report 2006-1219 Contents EXECUTIVE SUMMARY ......................................................................................................................................................1 INTRODUCTION...................................................................................................................................................................1 U.S. Geological Survey National Assessment of Shoreline Change .................................................................1 Disclaimer ...................................................................................................................................................................2 Acknowledgments .....................................................................................................................................................2 THE ROLE OF STATE AND FEDERAL GOVERNMENTS ..................................................................................................4 PRIOR NATIONAL AND CALIFORNIA COAST SHORELINE ASSESSMENTS ............................................................4 METHODS OF ANALYZING SHORELINE CHANGE .........................................................................................................5 Compilation of Historical Shorelines ......................................................................................................................5 Delineation of a Modern (Lidar-derived) Shoreline .............................................................................................5 Geographic Information System (GIS) Procedures .............................................................................................6 Calculation and Presentation of Rates of Change ...............................................................................................7 Beach Alterations and Shoreline Definitions that Influence Rates of Change ...............................................8 Human Activities ............................................................................................................................................... 8 Shoreline Definitions ........................................................................................................................................ 9 Estimating the proxy-datum bias and the bias uncertainty ..................................................................... 10 Uncertainties and Errors.........................................................................................................................................11 End-point (short-term) shoreline change error ........................................................................................ 13 Linear regression (long-term) shoreline change error ............................................................................. 14 GEOLOGIC HISTORY AND SETTING ..............................................................................................................................15 General Geology of the California Coast ..............................................................................................................15 Climate .......................................................................................................................................................................19 Coastal Processes ...................................................................................................................................................20 Waves .............................................................................................................................................................. 20 Tides .............................................................................................................................................................. 21 Winds .............................................................................................................................................................. 22 Currents ............................................................................................................................................................ 22 Littoral cells and transport directions ......................................................................................................... 22 Sand Sources .................................................................................................................................................. 23 GEOMORPHOLOGY OF THE CALIFORNIA COAST .......................................................................................................24 Cliffs .......................................................................................................................................................................24 Beaches.....................................................................................................................................................................24 Coastal Dune Complexes ........................................................................................................................................26 Estuaries and Lagoons ............................................................................................................................................26 General Characteristics of the California Coast Sections .........................................................................................27 Northern Section: Oregon Border to Tomales Bay ...........................................................................................27 Central Section: Tomales Bay to Point Conception ............................................................................................30 Southern Section: Point Conception to the Mexican Border ...........................................................................30 Open-File Report 2006-1219 ii HISTORY OF INFRASTRUCTURE DEVELOPMENT .......................................................................................................30 HISTORICAL SHORELINE CHANGE ANALYSIS ............................................................................................................33 Northern California ..................................................................................................................................................33 Klamath Region ............................................................................................................................................... 33 Eureka Region.................................................................................................................................................. 34 Navarro Region ............................................................................................................................................... 36 Russian River Region ..................................................................................................................................... 40 Central California .....................................................................................................................................................42 San Francisco North Region ......................................................................................................................... 43 San Francisco South Region ......................................................................................................................... 43 Monterey Bay Region .................................................................................................................................... 47 Big Sur Region ................................................................................................................................................. 50 Morro Bay Region ........................................................................................................................................... 50 Santa Barbara North ...................................................................................................................................... 54 Southern California ..................................................................................................................................................56