Document of bibliographic reference 222302

BibliographicReference record

Type

Bibliographic resource

Type of document

Book chapters

Type of document

Conference paper

BibLvlCode

AM

Title

A dredging and disposal strategy for managing the Western Scheldt's morphology and ecology

Abstract

In 1999, Flanders and The Netherlands agreed to set up a common strategy for managing the Scheldt river in its estuarine reach. In 2002, both parties signed a memorandum of understanding in which was defined a "Long Term Vision" strategy and its objectives. One of these is the preservation in the Western Scheldt of a dynamic and complex flood and ebb channel network Scheldt, the so-called "multi-channel system". The present trend, a continuation of past natural morphological evolutions combined with human interference (poldering, dredging and other river works) may jeopardise this objective.

An expert team appointed by the Port of Antwerp proposed the idea of morphological dredging for curbing this negative trend, aiming at steering the estuarine morphology. In a first phase, sediment from dredging works could be used to reshape sandbars where needed. One case study is discussed in this paper, the aim being to reconstruct the eroded tip of a sandbar at a bifurcation so that the flood and ebb flows would be persevered, a condition to maintain the multi-channel system in the reach. The strategy would not only cut back on the ongoing degradation of the ecological and morphological values of the estuary, but it would could also possibly help reducing the quantity of material to be dredged on the crossings by increasing the scouring or self-dredging capacity of the flow. A diffuser-type device will be used to disperse the dredged material in a controlled way in shallow water along the sandbar edges.

Since 2002, the new dumping strategy is being investigated as a pilot project (Plaat van Walsoorden). The research programme combines three tools: field measurements, physical scale models and 3D numerical models. The results of the research work completed so far confirm the feasibility of the idea. Further research work will be needed to investigate the use of morphological dredging on other locations of the Western Scheldt estuary.

Bibliographic citation

Meersschaut, Y.; Parker, W.R.; Peters, J.J.; Plancke, Y. (2004). A dredging and disposal strategy for managing the Western Scheldt's morphology and ecology, in: Csiti, A. (Ed.) Dredging in a Sensitive Environment: Proceedings of the World Dredging Congress XVII, Hamburg, Germany, 27 September–1 October 2004. pp. [1-11]

Topic

Marine