Fate of cohesive sediments in a marsh-dominated estuary

Zhang, Xiaohe, Leonardi, Nicoletta, Donatelli, Carmine and Fagherazzi, Sergio
(2019) Fate of cohesive sediments in a marsh-dominated estuary. ADVANCES IN WATER RESOURCES, 125. pp. 32-40.

[img] Text
ADWR 3265_Fate of cohesive sediments in a marsh-dominated estuary.docx - Author Accepted Manuscript

Download (3MB)


Deposition of fine sediments on a marsh platform favors accretion that counteracts Sea Level Rise. However, it is difficult to assess the sediment trapping capacity of a marsh given the heterogeneity of sediment sources and the geometric complexity of the system, with a network of dendritic and meandering creeks dissecting the intertidal area. Here we use a numerical model to study the sediment trapping capacity of a marsh-dominated estuary, Plum Island Sound, USA, and its variations across the landscape. The results highlight the importance of the timing between sediment inputs and tidal phase and show that sediment discharged from tidal rivers deposit within the rivers themselves or in adjacent marshes. Most sediment is deposited in shallow tidal flats and channels and is unable to penetrate farther inside the marshes because of the limited water depths and velocities on the marsh platform. Trapping capacity of sediment in different intertidal subdomains decreases logarithmically with the ratio between advection length and the typical length of channels and tidal flats. Moreover, sediment deposition on the marsh decreases exponentially with distance from the channels and marsh edge. This decay rate is a function of settling velocity and the maximum value of water depth and velocity on the marsh platform.

Item Type: Article
Uncontrolled Keywords: Salt marshes, Numerical modelling, Sediment exchange, Trapping capacity, Ponds expansion
Depositing User: Symplectic Admin
Date Deposited: 12 Jun 2019 08:39
Last Modified: 19 Jan 2023 00:40
DOI: 10.1016/j.advwatres.2019.01.003
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3045258