Influence of Natural and Anthropogenic Processes on Coastal Swash Geomorphology, Land-Ocean Exchange and Water Quality
Abstract
Coastal swashes are broad sandy fields on sandy beaches formed by estuarine tidal-creek water discharges, tidal pumping, waves and coastal currents. Where they are numerous and heavily modified, as is the case in Long Bay, South Carolina, they can be an important conduit of land-derived materials, both natural and anthropogenic, to the coastal ocean. Modification takes the form of significant land-use change in the surrounding areas but also realignment and redirection of the constantly migrating creek outlet to maintain lower water levels and high flushing rates inland, and to limit impingement on coastal infrastructure on the shorefront. We present our findings from a time-series study of two swashes using web cameras and tidal creek water level, temperature, salinity and oxygen using sensors and continuous data loggers. We concentrate on changes in primary channel properties, such as water level, tidally induced flushing, and oxygen concentrations, in response to seasonal variations, natural disturbances such as storms and hurricanes, and anthropogenic interventions such dredging and realignment of the channel outlet on the beach face. We evaluate the role of these changes on erosion prevention, flood mitigation and removal of land-derived chemicals. Finally, we elaborate on the implications of our findings on coastal water quality and the management of swashes in urbanized areas, given their serious repercussions for environmental and human health.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2022
- Bibcode:
- 2022AGUFMGC42J0837H