Facing the Coastal Challenge: Modeling Coastal Erosion in Southern California

Abstract

Erosion due to natural and human activities poses a challenge to the future of California’s coast. A process-based coastal evolution model is being developed to evaluate the past, present, and future rates of erosion of the southern California coast and present this dynamic environment in a visual format. The model consists of a mobile sediment transport component and a bedrock cutting component, both coupled and operating in varying time and space domains determined by sea level and boundaries of the littoral cell. We will utilize retrospective data from geomorphology, tectonics, sea level, climate, and paleoecology to investigate erosional and depositional processes and rates of change. Correlating the earlier shorelines with past climate conditions and time-stepping the ancient coastlines forward to the modern coastline will serve to validate the model. The model then will project the future evolution of the coastline using three scenarios: a most likely change, a minimum change, and a maximum change based on climate projections and possible human interventions. Our goals are to make this modeling technology and 3D visualization accessible to coastal planners and to advance public understanding of coastal evolution.