Predictive Analysis of Carpinteria Salt Marsh Reserve’s Coastal Geomorphology

Keywords: salt marshes, coastal geomorphology, physical geography, aerial imagery, drones, accretion rates, erosion rates, California coast, Sothern California
Abstract Type: Poster Abstract

Abstract

In the Southern California Bight, fewer than 30 salt marshes remain, with 62% of these losses in Santa Barbara County. Situated in the southern California Bight, the Carpinteria Salt Marsh Reserve (CSMR, one of the remaining salt marshes in the region) provides the unique opportunity to examine the erosion and deposition dynamics of these increasingly rare ecosystems. Short term erosion and deposition processes were examined in the Carpinteria Salt Marsh Reserve from 2022-2023. The survey consisted of six cross sections of two inlets proximal to the outlet using a Topcon RL-H5 laser level. Rates of accretion within the marsh were measured using feldspar horizon plots each located with an EOS Arrow Gold GPS. The plots were placed on the east and west sides of the marsh, with samples collected after higher-high tide. Aerial images acquired by a DJI Phantom 4 were used to document seasonal changes in the marsh. Ultimately, the research contributes to understanding rates of erosion and accretion in the short term with a view to predicting critical changes in light of sea level rise, continued anthropogenic pressure on the marsh hinterland, and impacts on this fragile ecosystem.