Rates and patterns of sediment deposition in the Salinas River basin, Central California
Abstract
Erosion rates in mountainous watersheds have increased during historic times due to land use changes such as logging, mining, road construction, agriculture, and urban/suburban development. This increase in erosion rates has resulted in (1) increased sediment accumulation in small and/or closed catchments, (2) rapid sediment infilling in reservoirs, and (3) shoreline progradation in large embayments such as Chesapeake Bay and San Francisco Bay. Conversely, land use changes and hydrological modifications in valleys and deltas, such as straightening and levee construction along river channels, favor sediment by- pass. The goal of the research described here is to better understand the composition and fate of sediment eroded from mountainous coastal watersheds, and to specifically put current and recent rates of sediment deposition into a longer-term context. Sediment cores collected from wetlands along the Salinas River, a mid-sized mountainous coastal watershed located in central California, have been analyzed for sediment composition, pollen, and rates of accumulation using radiocarbon, Cs-137, Pb-210, and pollen dating methods. The results of this study show current high rates of sediment accumulation in a high relief portion of the watershed, and lower than background rates of sediment accumulation in the deltaic portion of the watershed.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2008
- Bibcode:
- 2008AGUFM.H11F0844W
- Keywords:
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- 4217 Coastal processes;
- 4235 Estuarine processes (0442);
- 4800 OCEANOGRAPHY: BIOLOGICAL AND CHEMICAL (0460);
- 4952 Palynology