WP3 Deliverables

Task 3.1 Summary of status of current pressures and trends, and analysis of current measures effectiveness

This report is part of the different actions foreseen in Work Package 3. ‘Measures: Defining pressures and solutions’ and presents the results of activity 3.1 - Summary of status of current pressures and trends, and analysis of current measure effectiveness. The aim of this work package is to analyse the estuary pressures to improve collective understanding of anticipated pressures and trends, as well as evaluate existing measure effectiveness. Specifically, measures will be evaluated for their delivery of expected benefits and transferability - including similarities among measures to address common problems. Based on the results from this activity, partners will work on designing solutions for their estuaries. Partners already have an indication of themes that require solutions, e.g. using dredged material for flood risk management. The goal of this activity is to form the foundation for others to tackle the issues in other projects or in their strategies or processes. However, it should be kept in mind that not all common trends and pressures identified can be addressed during the project. For activity 3.1, national and regional organizations relevant for estuary management are the key target group. Sometimes these are the partners themselves, sometimes project supporters. Surveys and interviews will primarily involve the target groups in these activities. This report presents the results of this task. It consists of 2 major topics:

• Overview of existing and anticipated/future pressures and trends, based on EU projects and current research.

• Analysis of existing measures’ ability to deliver identified benefits

 

Task 3.7 Description of the mouth of the Scheldt estuary and overview of data availability (in Dutch).

Rijkswaterstaat aims to construct a pilot nourishment in the mouth of the Scheldt Estuary in order to 1) increase the knowledge of nourishing ebb-tidal deltas, 2) develop knowledge of the nourishment effect on local hydrodynamics, morphodynamics and ecology and 3) to use this knowledge to improve large-scale numerical models to improve our capabilities to answer questions such as the impact of sea-level rise. This report contains a general area description and an overview of relevant data that is available about this area.

 

Task 3.7 Morphology and ecology of the mouth of the Scheldt estuary (in Dutch, with English summary)

Rijkswaterstaat aims to construct a pilot nourishment in the mouth of the Scheldt Estuary in order to 1) increase the knowledge of nourishing ebb-tidal deltas, 2) develop knowledge of the nourishment effect on local hydrodynamics, morphodynamics and ecology and 3) to use this knowledge to improve large-scale numerical models to improve our capabilities to answer questions such as the impact of sea-level rise. In order to identify gaps in understanding and data, this report is an addition to the overview of the existing knowledge and available data on the morphology and the ecology of the mouth of the Scheldt Estuary that was already described in report [1].

 

Task 3.7 Pilot nourishment: assessment framework and alternative locations for the nourishment (in Dutch, with English summary)

Rijkswaterstaat aims to construct a pilot nourishment in the mouth of the Scheldt Estuary in order to 1) increase the knowledge of nourishing ebb-tidal deltas, 2) develop knowledge of the nourishment effect on local hydrodynamics, morphodynamics and ecology and 3) to use this knowledge to improve large-scale numerical models to improve our capabilities to answer questions such as the impact of sea-level rise. This report describes the boundary conditions and evaluation framework for the pilot nourishment. These were derived from the nourishment objectives and the knowledge base of the mouth of the Scheldt estuary described in reports [1] and [2]. Using this framework to asses 5 alternative nourishment locations, the area on the southern edge of the Vlakte van de Raan, north of the Wielingen tidal channel, turned out to be the preferential nourishment zone.

 

Task 3.7 Sediment transport paths in the mouth of the Scheldt estuary (in Dutch, with English summary)

Rijkswaterstaat aims to construct a pilot nourishment in the mouth of the Scheldt Estuary in order to 1) increase the knowledge of nourishing ebb-tidal deltas, 2) develop knowledge of the nourishment effect on local hydrodynamics, morphodynamics and ecology and 3) to use this knowledge to improve large-scale numerical models to improve our capabilities to answer questions such as the impact of sea-level rise. To make a decision about the exact location of the pilot nourishment, in this report the sediment transport patterns in the mouth of the Scheldt estuary are studied making use of numerical modelling in Delft3D and SedTRAILS.

 

Task 3.7 Morphological development of the southern part of the Vlakte van de Raan, mouth of the Scheldt estuary (in Dutch, with English summary)

Rijkswaterstaat aims to construct a pilot nourishment in the mouth of the Scheldt Estuary in order to 1) increase the knowledge of nourishing ebb-tidal deltas, 2) develop knowledge of the nourishment effect on local hydrodynamics, morphodynamics and ecology and 3) to use this knowledge to improve large-scale numerical models to improve our capabilities to answer questions such as the impact of sea-level rise. Report [3] presented the area on the southern edge of the Vlakte van de Raan, north of the Wielingen tidal channel, as the preferential nourishment zone and this report aims to describe and explain the morphological development of this area.

 

Task 3.7 Pilot nourishment in the mouth of the Scheldt estuary: nourishment variants (in Dutch, with English summary)

Rijkswaterstaat aims to construct a pilot nourishment in the mouth of the Scheldt Estuary in order to 1) increase the knowledge of nourishing ebb-tidal deltas, 2) develop knowledge of the nourishment effect on local hydrodynamics, morphodynamics and ecology and 3) to use this knowledge to improve large-scale numerical models to improve our capabilities to answer questions such as the impact of sea-level rise. Report [3] presented the area on the southern edge of the Vlakte van de Raan, north of the Wielingen tidal channel, as the preferential nourishment zone. In this report 10 nourishments variants for this area are presented, discussed and assessed. These all have a total volume of 1,5 million m3 and consist of a combination of four different locations, two thicknesses (1 m and 2 m) and one or two nourishment elements.

 

Task 3.7 Information and monitoring requirements for the pilot nourishment

Rijkswaterstaat aims to construct a pilot nourishment in the mouth of the Scheldt Estuary in order to 1) increase the knowledge of nourishing ebb-tidal deltas, 2) develop knowledge of the nourishment effect on local hydrodynamics, morphodynamics and ecology and 3) to use this knowledge to improve large-scale numerical models to improve our capabilities to answer questions such as the impact of sea-level rise. The construction of the pilot nourishment starts in 2023. To achieve objectives 1 and 2 the knowledge gaps and knowledge questions will be translated into information requirements that will be presented in this report. The information requirements are divided in two themes, i.e. (1) hydrodynamics, morphology and sediment; and (2) ecology. For the ecology theme, the information requirements are also translated into a monitoring plan in this report.