Flow versus transport connectivity: What can we infer from pumping and tracer tests

Description of solute transport connectivity between different aquifer locations is one of the major challenges for making reliable transport predictions in risk analysis. For instance, accurate representation of the pathway that connects the contamination plume with a given exposure location will largely dominate model predictions. Unfortunately, most aquifer characterization tools provide information on heterogeneity at different scales but little direct information on how well connected are two different locations of the aquifer with respect to transport. Pumping tests provide direct information on flow connectivity as it largely affects the aquifer response. Nonetheless, this information is seldom used for characterizing transport connectivity partially because of the lack of theoretical basis. In this presentation, we address the problem of the joint characterization of connectivity through pumping and tracer tests at a given location. To achive this, we present a general theoretical framework with companion numerical simulations that explains the relationship between the head response in pumping tests and transport connectivity.