Effects of Beach Nourishment Project on Coastal Geomorphology and Mangrove Dynamics in Southern Louisiana, USA

Relative sea-level (RSL) rise associated with decreased fluvial sediment discharge and increased hurricane activity have contributed to the high rate of shoreline retreat threatened coastal ecosystems in Port Fourchon, Louisiana, USA. This study, based on QuickBird/drone images (2004–2019) LIDAR data (1998–2013), analyzed impacts dynamics mangroves (Avicennia germinans) marshes before after initiation a beach nourishment project 2013. The barrier dune crest migrated landward between 1998 Meanwhile, height 2001, then 2013, probably due impacts. total volume along this sandy presented an overall trend decline 1998–2013 period, resulting wetlands loss ~15.6 ha 4 km coastline. has led sand migration onto muddy tidal flats occupied by Avicennia germinans (1.08 ha) Spartina (14.52 ha). However, resulted advancement from Nov/2012 Jan/2015, followed relatively stable period Jan/2015 Mar/2019. Additionally, both 2013 2019. set factors favored establishment expansion (3.2 saltmarshes (25.4 backbarrier environments allowing keep pace RSL rise. waves currents caused erosion following Oct/2017 Nov/2019, threatening resuming long-term process retreat.