"Effective management of coastal erosion is a major stakes for the European Union. In a context of global warming and overpopulation of the coasts, the overall purpose of this project is to improve understanding of the hydrosedimentary processes affecting the instantaneous land-sea interface (the beachface), at the origin of an erosion or accretion of a coast. The objectives are: (1) To study the impact of the various types of marine waves on the swash/beach groundwater/sediment transit interactions, starting from experiments carried out on 4 beaches representative of the Europe’s sandy coasts (North Sea, Atlantic and Mediterranean beaches). (2) To investigate the instantaneous effects of the drainage influence over swash in/exfiltration speeds and volume in order to improve the understanding of the operation of an innovative and promising - but still badly understood - method of fight against coastal erosion: the Beach Dewatering Systems. Response to these objectives will be made by the use of innovative experimental field methods (measurement of swash in/exfiltration speeds, use of a BDS for artificially generating erosion/accretion conditions), and by the data processing and analysis within the host institution (Coastal Group - University of Utrecht), highly recognized in the field. The obtained results will allow a better understanding of the physical aspects of the swash infiltration/exfiltration parameters, and to render BDS applicable to the greatest number of sites. Skills and knowledge acquired by Adrien Lambert (the applicant) within the framework of this project as its cooperation with the host (Associate Prof. Gerben Ruessink) will contribute to the quality of the results, like improving and widening the field of expertise of the applicant for his future recruitment. This project will contribute finally to the radiation of European research by allowing a significant advance within the field of soft engineering shoreline stabilization methods."