Stages of sedimentary infilling in a hypertidal bay using a combination of sedimentological, morphological and dynamic criteria (Bay of Somme, France)

Abstract

In the context of rising sea level, many estuaries and bays show an overall trend to sedimentary infilling. Among these coastal environments, the Bay of Somme is a hypertidal tide and wave-dominated estuary, filled in by marine sands, with a superficy of 70 km2. This study proposes a spatial zonation of the intertidal area of the bay based on the combination of information on sediments, seabed morphology and dynamics. Data come from a surficial sediment sampling campaign and six airborne LiDAR topographic surveys, acquired over the period 2011–2013, providing information on grain size, carbonate content, bedform occurrence and seabed dynamics. The Main Map shows the morpho-sedimentary and -dynamic zonation used as a basis to describe infilling stages in the bay.

Keywords

• Sedimentary infilling
• sediment dynamics
• sediment grain-size
• hydraulic dunes
• hypertidal estuary
• intertidal
• LiDAR
• Bay of Somme