Interactions of Estuarine Shoreline Infrastructure With Multiscale Sea Level Variability. Issue 12 (15th December 2017)

• Record Type: Journal Article
• Authors: Wang, Ruo‐Qian; Herdman, Liv M.; Erikson, Li; Barnard, Patrick; Hummel, Michelle; Stacey, Mark T.
• Is Part Of: Journal of geophysical research. Volume 122:Issue 12(2017)
• Page Start: 9962
• Page End: 9979
• Publication Date: 2017-12-15
• Subjects: infrastructure -- dynamic mode decomposition -- inverse method -- sea level rise -- coastal flooding -- shoreline protection; Oceanography -- Periodicals; 551.4605
• DOI: 10.1002/2017JC012730
• Languages: English
• ISSNs: 2169-9275

Abstract

Abstract: Sea level rise increases the risk of storms and other short‐term water‐rise events, because it sets a higher water level such that coastal surges become more likely to overtop protections and cause floods. To protect coastal communities, it is necessary to understand the interaction among multiday and tidal sea level variabilities, coastal infrastructure, and sea level rise. We performed a series of numerical simulations for San Francisco Bay to examine two shoreline scenarios and a series of short‐term and long‐term sea level variations. The two shoreline configurations include the existing topography and a coherent full‐bay containment that follows the existing land boundary with an impermeable wall. The sea level variability consists of a half‐meter perturbation, with duration ranging from 2 days to permanent (i.e., sea level rise). The extent of coastal flooding was found to increase with the duration of the high‐water‐level event. The nonlinear interaction between these intermediate scale events and astronomical tidal forcing only contributes ∼1% of the tidal heights; at the same time, the tides are found to be a dominant factor in establishing the evolution and diffusion of multiday high water events. Establishing containment at existing shorelines can change the tidal height spectrum up to 5%, and the impact of this shoreline structure appears stronger in the low‐frequency range. To interpret the spatial and temporal variability at a wide range of frequencies, Optimal Dynamic Mode Decomposition is introduced to analyze the coastal processes and an inverse method is applied to determine the coefficients of a 1‐D diffusion wave model that quantify the impact of bottom roughness, tidal basin geometry, and shoreline configuration on the high water events. Key Points: The diffusion of multiday water level events is studied with tidal motions and the interaction with shoreline accommodation schemes Multiday high water events do not significantly alter the tidal dynamics, but the tides are important to the evolution of multiday events The effect of coastal protection can be estimated by calculating the equivalent local diffusion coefficient with inverse modeling