See more from this Division: Topical Sessions
See more from this Session: Innovative Methods for Investigating Flow and Transport in Karst Systems I
Abstract:
Comparative tracer testing implemented at a vadose zone karst test site, located away from known conduit systems, permitted assumptions concerning mass transport through the uppermost part of a fissured limestone rock mass to be evaluated. Testing employed particle tracers with different properties, and compared their responses to a conservative solute. Particle and solute tracer breakthrough revealed that particles traveling through the epikarst can experience exclusion. This resulted in higher peak relative concentrations that arrived earlier than those of conservative solutes, despite being susceptible to attenuation. Moreover, differently-sized micro biological tracers had almost identical breakthrough curves suggesting that particle diffusion was not a significant process.
Experimental results indicate that particles can travel through the test site vadose zone with higher mean velocities than solutes, and reach receptors at higher relative concentrations. This in turn highlights the vulnerability of karst groundwater quality to micro organisms reaching groundwater, not only via conduits, but also through less karstified fissures. Such information indicates the need to consider exclusion-driven enhanced particle mobility when developing groundwater protection strategies against contamination by particulate matter.
See more from this Division: Topical Sessions
See more from this Session: Innovative Methods for Investigating Flow and Transport in Karst Systems I