BUDGET MODELS FOR THE EVOLUTION OF DELTAS DEFINITION OF PROCESSES AND SCALES  <B>BUDGET MODELS FOR THE EVOLUTION OF DELTAS DEFINITION OF PROCESSES AND SCALES</B><P></B><B>Michele Capobianco </B><I><BR> R&D, Environment, Tecnomare SpA, San Marco 3584, 30124, Venezia, Italy. Tel: +39 41 796711, Fax: +39 41 796800, EMail: cpbncm01@cidoc.iuav.unive.it</I><B><BR> Jose A. Jimenez, Agustin SanchezArcilla </B> <I><BR> LIM, Catalonia Univ. of Technology, c Gran Capita' s/n, 08034, Barcelona, Spain. Tel: +34 3 4016468, Fax: +34 3 4017357, EMail: jimenez@etseccpb.upc.es </I><B><BR> Marcel J.F. Stive</B> <I><BR> Delft Hydraulics, NCK, P.O. Box 152, 8300 AD Emmeloord, The Netherlands. Tel: +31 5274 2922, Fax: +31 5274 3573, EMail: marcel.stive@wldelft.nl</I><P> Abstract<BR> Global climatic change is taking place and it will likely affect Mediterranean deltas and other lowlying coastal regions in terms of relative sea level rise, salinity increase and changes in temperature and weather patterns and of river discharge regime. This will have serious implications on the natural resources of the deltaic areas and on the related economic activities. The MEDDELT project focuses on three northwestern Mediterranean deltas, the Ebro Delta (Spain), the Rhone Delta (France) and the Po Delta (Italy) in an attempt to cover the lack of understanding about their integral functioning. The main objective is to determine the vulnerability and response of these deltaic systems to large scale change phenomena, such that informed decision making can be made. In order to do this we make combined use of existing and new field measurements (accretion, sedimentation, soil formation, coastal fringe response) and of integrated (physical/ecological) conceptual models of deltaic behaviour having socio economics scenarios as boundary conditions. The paper illustrates the methodological effort which is being undertaken in order to organize a modelling system that can be used to conduct budget computations at various scales with reference to the most significant processes. The final objective that appears at the horizon is the implementation of a simulation environment to handle the evaluation of different scenarios.<P>