A Dynamic Simulation Model of Beach Sand Replenishment: a Case Study of Santa Barbara, California

Sediment deprivation from dam installments contributes to beach erosion yet the underlying physical and economic factors linking them together have traditionally been isolated during regional planning. In order to gain a better understanding of the behavior of a managed beach system, a dynamic simulation model was developed incorporating physical and monetary factors influencing the amount of available beach sand. The Santa Barbara littoral cell was chosen as a case study to evaluate the feasibility of beach preservation goals under scenarios in which annual sand replenishment funding, sand prices, or sediment recovery from behind dams were limiting factors to available beach sand. Sources of model uncertainty included limited information on historical sand replenishment costs and true residence time of sand in the littoral cell. Results indicate that with ample sand replenishment funding and moderate annual sand loss assumed, a beach could be maintained at a desired width for several decades.