ESTUARINE AND COASTAL SEDIMENTATION PROBLEMS

This keynote lecture addresses engineering sedimentation problems in estuarine and coastal environments and practical solutions of these problems based on the results of field measurements, laboratory scale models and numerical models. The three most basic design rules are: (1) try to understand the physical system based on available field data; perform new field measurements if the existing field data set is not sufficient (do not reduce on the budget for field measurements); (2) try to estimate the morphological effects of engineering works based on simple methods (rules of thumb, simplified models, analogy models, i.e. comparison with similar cases elsewhere); and (3) use detailed models for fine-tuning and determination of uncertainties (sensitivity study trying to find the most influencial parameters). Engineering works should be designed in such a way that side effects (sand trapping, sand starvation, downdrift erosion) are minimum. Furthermore, engineering works should be designed and constructed or built in harmony rather than in conflict with nature. This ‘building with nature’ approach requires a profound understanding of the sediment transport processes in morphological systems.