ABSTRACT
We focus on the problem of delineation of the capture zone of a pumping well superimposed to a regional flow in a heterogeneous aquifer. Modeling aquifer heterogeneity through a random hydraulic conductivity spatial distribution renders uncertain transport predictions, with significant implications in the shape and extent of the well capture zone or protection areas. In the case of large extended plumes, uncertainty in the hydraulic properties translates into uncertainty assessment of the mass of contaminant eventually reaching the well. This itself can be translated into environmental or human health risk. Improvement in well influence region delineation and reduction of the uncertainty associated with transport predictions is typically performed by means of very expensive hydrogeological sampling campaigns. We focus on the assessment of the impact of data acquisition on the reduction of uncertainty linked to the environmental scenario analyzed. We investigate the significance of the amount of available hydrogeological measurements to yield predictions at an acceptable level of uncertainty of (a) contaminant concentrations captured by the well and (b) adverse health effects due to exposure of population to such concentrations. We do so by elucidating the role of the dimensionless length scales that characterize and control the well capture zone and its delineation.
