scholarly journals Effects of vegetation, sediment supply and sea level rise on the morphodynamic evolution of tidal channels

2021 ◽  
Author(s):  
Alessandro Sgarabotto ◽  
Andrea D’Alpaos ◽  
Stefano Lanzoni
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Sediment Supply ◽  
Tidal Channels ◽  
Morphodynamic Evolution ◽  
And Sea Level

Long-term morphodynamics of a large estuary subject to decreasing sediment supply and sea level rise

2020 ◽  
Vol 191 ◽  
pp. 103212 ◽  
Author(s):  
Bing Yuan ◽  
Jian Sun ◽  
Binliang Lin ◽  
Fanyi Zhang
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Sediment Supply ◽  
And Sea Level

Effect of decreasing sediment supply and sea level rise on the long-term morphodynamics of a large estuary

2021 ◽  
Author(s):  
Bing Yuan ◽  
Jian Sun ◽  
Binliang Lin ◽  
Fanyi Zhang
Keyword(s):  
Equilibrium State ◽  
Sea Level Rise ◽  
Sea Level ◽  
Yangtze Estuary ◽  
Sediment Supply ◽  
Bed Erosion ◽  
Adjustment Time ◽  
Riverine Sediment ◽  
And Sea Level

<p>Globally the riverine sediment supply to estuaries is decreasing and the mean sea level is rising, while the effects of these changes on the long-term estuarine morphodynamics have not been fully investigated. An idealized numerical model was used to explore the long-term morphodynamics of a large estuary subject to these changes. In the model, a funnel-shaped channel with fixed banks, constant riverine water and sediment fluxes, a single grain size and a semi-diurnal tide were used. A range of values of changes in the sediment supply (50-90% reduction) and sea level (1-5~mm/yr increase) were considered. Starting from an equilibrium state for an initial sediment supply, the estuary shifts to a new equilibrium for the considered changes on a timescale of millennia. Half of the bed level change occurs within several hundreds of years. A larger decrease in the sediment supply leads to a stronger bed erosion, while the corresponding adjustment time has minor changes in its range for the considered settings. When combined with sea level rise, the erosion is weakened and the adjustment time is shortened. The equilibrium state under sea level rise is characterized by a bed level keeping pace with the sea level and a significant amount of sediment being trapped in the estuary. Additional numerical experiments that use more realistic geometry and forcing of the Yangtze Estuary show that overall erosion of the estuary is expected for centuries.</p>

Rates of sediment supply and sea-level rise in a large coastal lagoon

2000 ◽  
Vol 167 (3-4) ◽  
pp. 261-284 ◽  
Author(s):  
R.A Morton ◽  
G.H Ward ◽  
W.A White
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Coastal Lagoon ◽  
Sediment Supply ◽  
And Sea Level

scholarly journals Contributions of Organic and Mineral Matter to Vertical Accretion in Tidal Wetlands across a Chesapeake Bay Subestuary

2021 ◽  
Vol 9 (7) ◽  
pp. 751
Author(s):  
Jenny R. Allen ◽  
Jeffrey C. Cornwell ◽  
Andrew H. Baldwin
Keyword(s):  
Organic Matter ◽  
Sea Level Rise ◽  
Chesapeake Bay ◽  
Sea Level ◽  
210Pb Dating ◽  
Sediment Supply ◽  
Mineral Matter ◽  
Tidal Wetlands ◽  
Vertical Accretion ◽  
Inorganic Matter

Persistence of tidal wetlands under conditions of sea level rise depends on vertical accretion of organic and inorganic matter, which vary in their relative abundance across estuarine gradients. We examined the relative contribution of organic and inorganic matter to vertical soil accretion using lead-210 (210Pb) dating of soil cores collected in tidal wetlands spanning a tidal freshwater to brackish gradient across a Chesapeake Bay subestuary. Only 8 out of the 15 subsites had accretion rates higher than relative sea level rise for the area, with the lowest rates of accretion found in oligohaline marshes in the middle of the subestuary. The mass accumulation of organic and inorganic matter was similar and related (R2 = 0.37). However, owing to its lower density, organic matter contributed 1.5–3 times more toward vertical accretion than inorganic matter. Furthermore, water/porespace associated with organic matter accounted for 82%–94% of the total vertical accretion. These findings demonstrate the key role of organic matter in the persistence of coastal wetlands with low mineral sediment supply, particularly mid-estuary oligohaline marshes.

Story mapping and sea level rise

2020 ◽  
Vol 8 (1) ◽  
pp. 5-18 ◽  
Author(s):  
Sonia H. Stephens ◽  
Daniel P. Richards
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Story Mapping ◽  
And Sea Level
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