Climate Science and Policy

Sea level rise resulting from human-induced global warming poses a grave threat to our planet, particularly endangering low-lying coastal areas susceptible to flooding. Effective beach monitoring can help vulnerable coastal communities anticipate the adverse impacts of sea level rise. CoastSnap, a worldwide beach monitoring program, collects and analyses coastline photos contributed by smartphone users. The primary objective is to study how beaches change over time while engaging and educating communities about the dynamic nature of their coastlines. CoastSnap employs community science, which empowers communities to actively participate in the scientific data collection and inquiry process, catering to the unique needs of each community. This capstone project focuses on establishing CoastSnap stations in and around the City of Imperial Beach, an exceptionally vulnerable coastal region within San Diego County. Three locations, including two on Imperial Beach Pier and one at Border Field State Park, have been identified as suitable sites for new stations. Additionally, an analysis of CoastSnap data from the Torrey Pines station explored the accuracy of image-derived beach width measurements in comparison to data obtained through physical beach surveying (in-situ), to demonstrate CoastSnap’s suitability for monitoring coastlines in Southern California. The comparison of CoastSnap measurements with in-situ measurements revealed an overall mean deviation of 1.35 meters, with CoastSnap measurements tending slightly more seaward. When considering tide levels, low tide events resulted in a lower mean deviation (mean = 0.94 meters) compared to high tides (mean = 1.78 meters). The analysis also found that CoastSnap-derived shorelines from Winter showed the strongest seaward deviation (mean = 4.30 meters), while Fall measurements tended to deviate slightly landward on average (mean = -0.61 meters).