This proposal is done for the organization of the workshop IMPACTS. This workshop will provide scientific exchanges and discussions between the partners of 18projects funded by the EU (EESD) and linked in the CLUSTER IMPACTS. This workshop will be the first international meeting of this CLUSTER. It is proposed in order to develop links, exchanges and scientific cooperation between complementary projects. This workshop will be held in the city of Pau (France) from the 10th to the 12th of September 2001, and coordinated by Prof.P.Caumette who is the leader of one of the linked projects in the CLUSTER.