Proceedings of the RCEM Symposium 2003 : 3rd Symposium on River, Coastal and Estuarine Morphodynamics (RCEM) Barcelona, 2003

Morphodynamics is a topic rapidly changing and evolving in the last years.

Several decades ago, it was essentially a descriptive discipline, while now it offers a range of predictive tools which combine advanced modelling techniques with scientific formulations.

This combination still provides a tough challenge for the various communities which have contributed to this field and which include geologists (among the first group entering into morphodynamics from a descriptive standpoint), engineers (which contributed the hydraulic know-how and the predictive impetus), applied mathematicians and physics (providing the knowledge on complex non-linear dynamic systems).

The first IAHR Symposium on River, Coastal and Estuarine Morphodynamics (RCEM) was held in Genoa, Italy (1999), and, as written by Prof.

G. Seminara in the preface of the 1999 proceedings, the aim was to "offer the above communities a forum to enhance their scientific interaction".

The second IAHR - RCEM Symposium took place in Obihiro, Japan (2001), and, as expressed by Prof.

S. Ikeda in the preface of the 2001 proceedings, the aim was also to "stimulate mutual interaction" among "rivers, coasts, estuaries and debris flows" which have been so far "treated in different contexts" by various disciplines.

The third IAHR - RCEM Symposium will be held in Barcelona, Spain (2003), and will pursue the two above mentioned aims while trying also to strengthen the weakest links in the morphodynamic "chain".

If we consider, for instance, the suite of morphodynamic models required to predict how a beach with a coastal engineering structure evolves under breaking wave action, several paradoxical facts immediately appear.

First, the chain of wave-current-sediment transport-bottom evolution models does not offer comparable levels of accuracy, being the sediment/morphodynamic components the less advanced ones (conveniently forgetting, for the time being, the role of turbulence).