Modelling of water and sediment quality in the Scheldt estuary

Gils, J.A.G. van; Ouboter, Maarten; Rooij, N. M. de

doi:10.1007/bf02334789

Cited by 25 publications

(1 citation statement)

References 4 publications

(4 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The period in which the simulations were carried out was from 1 January 2012 to 1 March 2013. In this work, the Delft3D-FLOW hydrodynamic module [59,60] and the water quality module Delft3D-WAQ [61] were applied. The hydrodynamic module, Delft3D-FLOW, allows working in 2 or 3 dimensions, and it solves shallow water equations based on Navier-Stokes three-dimensional and continuity equations using the finite difference method.…”

Section: Model Implementationmentioning

confidence: 99%

Modeling the Impact of Extreme River Discharge on the Nutrient Dynamics and Dissolved Oxygen in Two Adjacent Estuaries (Portugal)

Oliveira

Sousa

Morgado

et al. 2019

JMSE

View full text Add to dashboard Cite

The Minho and Lima are adjacent estuaries located in the north of Portugal, with high ecological and economic importance. To address gaps in knowledge about changes in nutrient patterns in adjacent estuaries subject to different freshwater inflows, a numerical model, Delft3D, was implemented and developed, using a single domain, which allowed physical communication between estuaries. Calibration and validation of the model was successfully performed. Three numerical simulations were carried out, in which only river flows were varied (1st corresponds to a baseline numerical run, the 2nd a flood scenario, and the 3rd a drought scenario). Under flooding conditions, similar patterns were verified in both estuaries, with high fluvial discharges showing to have a reduced impact on both estuarine dynamics. In this case the nutrients were not a limiting factor for the biota, both for summer and winter seasons, since there was no significant decrease in dissolved oxygen concentration. For the drought scenario, it was observed that the estuary with the lower inflow of freshwater (Lima) was the most affected, with a significant decrease in the concentration of nutrients and oxygen dissolved in the winter season (decrease of 2 mg O2/L). In conclusion, this work reveals that it is essential to continuously monitor dam-controlled estuarine systems, as a significant decrease in river discharge will cause significant changes in the variables analysed (O2, PO4, and NO3) and may cause loss of biodiversity.

show abstract

Section: Model Implementationmentioning

confidence: 99%

Modeling the Impact of Extreme River Discharge on the Nutrient Dynamics and Dissolved Oxygen in Two Adjacent Estuaries (Portugal)

Oliveira

Sousa

Morgado

et al. 2019

JMSE

View full text Add to dashboard Cite

show abstract

Potential chemical time bombs in the schelde estuary

Eck

Rooij

1993

Land Degrad Dev

View full text Add to dashboard Cite

The Schelde estuary is heavily polluted with many different (micro)pollutants. This results in high concentrations in the abiotic and biotic compartments of the Schelde estuary and in various effects. The present day suboxic and anoxic conditions in the upper estuary are probably responsible for the high distribution coefficients for some trace metals in the lower Schelde estuary (Western Schelde). A future reduction in discharges with a high biological oxygen demand will therefore not only result in higher oxygen concentrations, but probably also in lower distribution coefficients for trace metals in the Western Schelde. Simulations show that lower trace metal distribution coefficients will probably result in higher concentrations of dissolved (bioavailable) trace metals, even with substantially reduced discharge rates, due to the desorption of trace metals from resuspended bottom sediments. KEY WORDS Schelde estuary Sediment pollution modelling Trace metals Organic pollutants SCHELDE ESTUARY: THE NEED FOR POLLUTION MODELLINGThe Schelde estuary, which drains a densely populated and industrialized area in northern France, west Belgium and the southwest Netherlands, is faced with two major problems: (1) extensive dredging and dumping of (contaminated) sediments to keep the port of Antwerp accessible; and (2) large domestic and industrial waste water discharges, a significant proportion of which is discharged without treatment.The Schelde estuary (Figure 1; Wollast, 1988;Zwolsman and Van Eck, 1993) is a macrotidal coastal plain estuary with a tidal range of 4-5 m and an average water depth of 10 m. The river Schelde and its tributaries drain about 21600 km2 and the river discharge ranges from 20 m3 s-' in summer to 400 m3 s-' during winter, averaging 104 m3 s-' over the period 1949-86. The length of the estuarine mixing zone is 60-120 km and the residence time of the water in the estuary ranges from one to three months. The water column generally shows a well mixed circulation pattern, except during extreme river discharges in winter. The estuary can be divided into two zones with different hydrographical characteristics.The upper estuary or Zeeschelde, located in northwest Belgium, is heavily polluted by organic wastes, trace metals and organic contaminants. One of the most striking features of this area is the presence of an anoxic water column during most of the year . Previous studies in the Schelde estuary have suggested that this anoxic zone plays an important part in the behaviour of trace metals (Salomons and Eysink, 1981;Duinker, et al., 1982). The bottom sediments consist of sands, sandy muds and clayey muds. The origin of the sediments is predominantly fluvial, but the marine component of the sediments increases in a seaward direction. The finest sediments are found in the so-called high turbidity zone (HTZ) between the city of Antwerp and the Dutch-Belgian border (Wartel, 1977). The HTZ is an important sedimentation zone.The lower estuary or Western Schelde, situated between the Dutch-Belgian bo...

show abstract

Modeling Our Past, Present, and Future

Glibert

2024

Phytoplankton Whispering: An Introduction to the Physiology and Ecology of Microalgae

View full text Add to dashboard Cite

Modelling of water and sediment quality in the Scheldt estuary

Cited by 25 publications

References 4 publications

Modeling the Impact of Extreme River Discharge on the Nutrient Dynamics and Dissolved Oxygen in Two Adjacent Estuaries (Portugal)

Modeling the Impact of Extreme River Discharge on the Nutrient Dynamics and Dissolved Oxygen in Two Adjacent Estuaries (Portugal)

Potential chemical time bombs in the schelde estuary

Modeling Our Past, Present, and Future

Contact Info

Product

Resources

About