Roughness modeling for managing natural shallow water systems


Suzanne Hulscher

Saskia Hommes

Mindert de Vries

Rolien van der Mark

Arjan Tuijnder

Pieter Roos

Henriette Otter

Astrid Blom

Denie Augustijn

Jan Ribberink


University of Twente


Netherlands Technology Foundation (STW)


June 2004 – June 2009


Current roughness models are insufficient for predicting water motion in rivers, estuaries and along coasts. This uncertainty causes a large degree of social agitation regarding safety against flooding. Briefly, this proposal will improve (hydraulic) roughness modelling, so that the effects of measures against flooding can be adequately predicted.

Roughness plays a central role in shallow-water systems with sandy beds: in hydrodynamics, sediment transport and morphodynamics. Its modelling is as complex as modelling turbulence: feedbacks on various scales, stochastic processes and links to ecology make a bottom-up approach simply impossible. Due to recent progress in morphodynamics, we are close to taking an enormous step forward. Solutions lie in a multidisciplinary approach using self-organisation models for morphodynamics, field/laboratory measurements, including biological effects and uncertainties.


The proposed project will pay large attention to management needs: appropriate models for supporting management of large-scale infrastructural projects will be developed. Such projects – e.g., construction of artificial islands or windmill parks in the North Sea, deepening of the Western Scheldt and measures against river floods – require an integrated assessment of future effects. The University of Twente's Water Engineering and Management group (WEM) and IMPACT institute provide the ideal environment for this ambitious project, which has both applied scientific and management dimensions.

The applicant proposes subprojects for analysing data, developing realistic models for roughness and investigating the knowledge requirements for decisions on future developments of rivers, estuaries and coasts. Clearly, this topic also has management implications: how can roughness models truly assist in decision-making processes? This proposal addresses scientific and management issues, strengthened by the fact that scientific specialists as well as end users play a significant role in it. The applicant will synthesise all research into scientific roughness parameterisations ready to evaluate integrated water management solutions.