Sediment Yields in Coastal Southern California

In southern California the delivery of inland sediments to the coast is important for shoreline stability and the preservation of natural beach areas. During the past several decades, changes in land use and the construction of water conservation and flood control structures have materially affected natural sediment movements and coastal deliveries. To provide a basis for regional sediment management, a study has been undertaken at the California Institute of Technology to quantify natural sediment movements and man's effect on these processes. As a first step in this study, sediment yields from inland areas have been estimated. Results indicate that an annual average of 12 million $m^3$ of sedimentary material are yielded from geologically erosional areas. Of this, 6 million $m^3$ are fine sediments, 5 million $m^3$ are sand, and 0.8 million $m^3$ are coarser than 2 mm.