Read the summary project proposal
2018 Progress Update:
Results assess the impact of extreme storm and wave events in different types of Southern California estuaries. The study has maintained long term measurements of water level, current velocity, stratification, dissolved oxygen, stream flow, waves, and drone footage, and researchers have drafted a paper comparing results from multiple estuaries. Analysis so far suggests that estuaries that have structures (jetties, groins, etc.) tended to remain open and experience less sediment accretion and less exacerbated high water levels than estuaries without structures (which also tend to have more marsh habitat). However, structures enhanced erosion of the adjacent beaches. Analysis also shows that a single storm event lasting 1-2 days can result in large-scale sediment changes and alter lagoon circulation for weeks. Further analysis and collaboration with coastal mangers will occur in the final year of this study and will help managers better predict the response of estuaries to climate change impacts and adopt coastal resiliency programs to reduce damage in the future.
2017 Progress Update:
Analysis is underway. Our intensive measurements during the winter 2015-2016 El Niño season clearly document the importance of both wave-current interactions and morphology (sill height) on sediment transport during high water level events. In particular we find that infragravity waves dominate incoming wave energy in the lagoon and are modulated by the water height relative to the sill and the strength of the currents at the mouth. When water levels are above the sill and the tide is flowing into the estuary, infragravity waves can propagate significantly far into the inlet and move sediment. This is an important contribution to the field as it narrows in the physical processes that can drive sediment transport and thus morphodynamic responses in these types of estuaries. The goal of making predictions about the response of these estuaries to future conditions is ongoing.
Project photos courtesy of Sarah Giddings Lab
Los Peñasquitos Lagoon -