Objective Interest in groundwater resources is increasing in response to greater demands on water quality. Fractures form a wide-spread and important source of subsurface heterogeneity which strongly influence groundwater flow and contaminant transport. There has been a growing awareness in recent years that outcrop scale measurements cannot simply be extrapolated to large scales and that for evaluating the fate of contaminants over significant times and distances, scaling aspects of fracture systems are crucial. Recent research has revealed that fracture size distributions commonly approximate power laws. Recent theoretical and field studies have shown that the connectivity of the fracture system (i.e. the way in which fractures link to form continuous networks) is sensitive to the exponent in this power law. Fracture connectivity is a major controlling factor for flow and contaminant transport. These finding have implications for the bulk rock permeability and contaminant transport properties of fractured rock which remain to be explored. The proposed project is a study of the scale dependence of permeability and dispersivity in fractured rock masses, with the specific aim of evaluating these properties from outcrop scales up to scales important for long term contaminant transport. In the proposed project, scale dependence in flow and transport in fractured rocks will be studied through a number of approaches. Field studies will be aimed at characterizing natural fracture systems with reference to fluid flow. Data will be collected on different scales through outcrop investigations, aerial photography and satellite imagery. Constitutive rules will be developed through experimental studies of flow and transport properties in fractures under realistic in situ conditions (pressure, temperature). A perGolation theory approach will be used to derive analytical expressions for the percolation threshold, bulk rock permeability and dispersivity in the case of simple but geologically realistic fracture systems. Using both statistically based models and models that simulate the physical fracturing process, geometrical fracture system models which reflect the connectivity and other geological features of natural systems will be generated. These will be used as input to numerical models of flow and contaminant transport in fractured rock masses and the results will be compared to the analytical expressions. These models will be used to study the existence and size of homogenization length scales for transport properties, and to develop techniques for determining meaningful equivalent porous media. Finally, the results of the project will be applied to a number of field sites. The benefits of the proposed project arise from an increased understanding of groundwater flow and contaminant transport which will be of direct use in improving predictions of contaminant distribution, particularly of long term contamination. This will include an improved fundamental knowledge of the scale dependence of flow and dispersivity properties of fractured rock and the development of numerical modeling techniques that can utilize such information. Fields of science natural sciencesearth and related environmental scienceshydrologyengineering and technologymechanical engineeringvehicle engineeringaerospace engineeringsatellite technologynatural sciencescomputer and information sciencessoftwaresoftware applicationssimulation softwaresocial scienceslaw Programme(s) FP4-ENV 2C - Specific programme of research and technological development in the field of environment and climate, 1994-1998 Topic(s) 01010401 - European water resources Call for proposal Data not available Funding Scheme CSC - Cost-sharing contracts Coordinator NANSEN ENVIRONMENTAL AND REMOTE SENSING CENTER EU contribution No data Address 3A,EDVARD GRIEGSVEJ 3A 5059 BERGEN Norway See on map Total cost No data Participants (3) Sort alphabetically Sort by EU Contribution Expand all Collapse all CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE France EU contribution No data Address Avenue du Général Leclerc 263, Campus de Beaulieu 35042 RENNES See on map Total cost No data UNIVERSITY OF EDINBURGH United Kingdom EU contribution No data Address West Mains Road Kings Buildings EH9 3JW EDINBURGH See on map Total cost No data WEIZMANN INSTITUTE OF SCIENCE Israel EU contribution No data Address Herzl Street 2 76100 REHOVOT See on map Total cost No data