Water levels and discharge in the Rhine and Meuse

Introduction

The Rhine-Meuse channel network (see figure) is an example of a river system that has been severely altered by human interventions. Already since the Middle Ages, humans have changed the location of branches and the distribution of discharge. Today, it is a heavily engineered system, with extensive harbor areas and a fully closed-off estuary in the south, the Haringvliet. Luckily, as a result of the high anthropogenic pressure on the system, a lot of monitoring data is available, for example on water levels or salinity intrusions.

Rijn_maas delta overzicht_CRwebsite
The Rhine-Meuse channel network

Despite all monitoring, it is still not fully understood how discharge is divided over the many different river branches, and what the role of human engineering is in the division of water and sediment at river junctions. To make good predictions about salt intrusion and morphological developments, we need to know how much water and sediment is going where.

Objectives

What are the consequences of historical interventions for water levels, discharge distributions and morphology in the Rhine-Meuse channel network?

  • How do water level changes relate to sea level rise and what is the main cause of changes in water level?
  • How is river water divided over river junctions, and what is the role of salt and bedforms in the discharge distribution?

Methods

The Rhine and Meuse are the two main rivers in The Netherlands, and together form one river network in the western Netherlands. This river network is subject to tidal influences and salt intrusion. The tidal influence causes highly variable water levels, which are measured every ten minutes.

A great deal of historical maps and studies on the area are available, which are put together to get an overview of the interventions and their consequences through time. With the help of a historical dataset of water levels through the system (obtained from Rijkswaterstaat, see www.waterbase.nl), changes in water levels can be analyzed.

To gain insight in the influence of salt and varying bed roughness on the water distribution, numerical models (Delft3D) are used in combination with field data.

Results

For the historical overview of changes in the system, only preliminary results are available. The first results on the analysis of water levels are expected to be published by the end of 2013.

Please contact Nynke Vellinga for more info on this project.