Dynamic Processes in Capillary Fringes

Capillary fringes are highly dynamic and periodically changing zones at the interface between the water-saturated aquifer and the unsaturated zone. As a consequence, we observe steep gradients in terms of hydraulic state variables, biogeochemical conditions, and thus, biological activity (Berkowitz et al., 2004). With fluctuations of the groundwater table, this reactive zone moves dynamically along the vertical direction, further complicating our understanding of specific processes that occur in both space and time. This special compartment is not only an interesting and challenging subject of research, it is also highly relevant for mass fluxes with terrestrial systems (Silliman et al., 2002; Haberer et al., 2011) and especially the biodegradation of contaminants (Lahvis et al., 1999; Dobson et al., 2007).