It is evident, that for a number of ecological and technical problems in rivers and lakes a better knowledge of sediment transport and sedimentation is needed together with the ability to predict and simulate sediment behaviour. On the other hand, a stagnation of research in these topics could be observed in the last decades. At the Symposium an attempt was made to present new results in mathematics and natural sciences relevant for the sediment problem. New strategies were discussed to tackle the complexity of the problem. Basic theoretical research and laboratory experiments alone are...