Variations of water quality in the Scheldt estuary
Van Damme, S.; Struyf, E.; Wartel, S.; Van Nieuwenhuize, J.; Meire, P. (2002). Variations of water quality in the Scheldt estuary, in: ECSA Local Meeting: ecological structures and functions in the Scheldt Estuary: from past to future, Antwerp, Belgium October 7-10, 2002: abstract book. pp. 20
In: (2002). ECSA Local Meeting: Ecological structures and functions in the Scheldt Estuary: from past to future, Antwerp, Belgium October 7-10, 2002: abstract book. University of Antwerp: Antwerp. 73 + 1 cd-rom pp., meer
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Documenttype: Congresbijdrage
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| Trefwoorden |
Chemical compounds > Nitrogen compounds > Nitrates
Chemical compounds > Silicon compounds > Silica
Eutrophication
Gradients
Monitoring
Properties > Chemical properties > Salinity
Water bodies > Coastal waters
Water quality
België, Schelde R. [Marine Regions]
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| Auteurs | | Top |
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- Van Nieuwenhuize, J.
- Meire, P., meer
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| Abstract |
Since December 1995 the monitoring of the Scheldt estuary is integrated in a coordinated border-crossing campaign from river mouth to the upper tidal reach. Concentration profiles showed an improvement of the water quality. Is monthly monitoring of surface water sufficient? The monitoring results are situated in a frame of estuarine variations. Nitrogen concentrations changed within a vertical salinity gradient in the brackish zone. Tidal cycles can show peculiar patterns. The water quality picture changes when discharge is taken into account. A five-year period of continuously increasing discharge was used to study possible impact of global change on estuarine nutrient fluxes. In the upper freshwater parts of the estuary, higher discharges resulted in lower N and P concentrations due to dilution. Silica concentrations strongly increased at higher discharges due to flushing of diatoms. Lower residence times in the freshwater zone resulted in a negative effect on water quality further downstream. Nitrate and silica concentrations in the coastal waters, two major actors in coastal eutrophication, were significantly correlated to total yearly discharges observed upstream. |
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