Three dimensional model for solute transport induced by groundwater abstraction in river-aquifer systems

Abstract

This study consider the development of three dimensional analytical solutions for contaminant transport induced by a pumping well near a stream. The solutions were derived for both line-width and finite-width streams based on Green's function approach. These solutions were implemented in an aquifer that was partially penetrated by the stream and were general enough to be applied to both unconfined and confined aquifers. The analytical solutions were checked to show the effect of stream width, leakance coefficient, distance from the river edge to pumping well and pumping rate on contaminant concentration. Generally, it was found that higher values of these parameters increased the contamination in the well area for both line and finite width stream. The graphical representation of the analytical solution shows that the contaminants attenuated vertically along z axis as well as horizontally along × axis. The finite width model produced more realistic estimate for the distribution of contaminants due to the effect of river width. In particular, the results shows higher contamination near the stream for finite width model. However, this impact of river width on contaminant concentration appear to be neglected if the distance between river and pumping well was more than twice the stream width.