The International Research Fellowship Program enables U.S. scientists and engineers to conduct nine to twenty-four months of research abroad. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad.
This award will support a twenty-four month research fellowship by Dr. Matthew Covington to work with Dr. Franci Gabrovsek at Karst Research Institute in Postojna, Slovenia.
Roughly 20-25% of the global population relies on groundwater from karstic aquifers. Despite the importance of this resource, current models do not accurately predict flow rates and contaminant transport due to lack of knowledge concerning the location and geometry of the karst conduits in a given aquifer. Speleogenetic models, which calculate the formation and evolution of karst aquifers, have been developed in recent years. However, current models do not account for many of the processes that occur in real conduit systems, and connections between these models and field data are limited. The purposes of this work are to: 1) study the effects of variable flow on the evolution of conduits, 2) develop a framework for modeling sediment transport and its effects on speleogenesis, and 3) expand the applicability of speleogenetic models to real karstic systems. These purposes are addressed through field work, conduit flow network modeling, and the modification of a speleogenetic model previously constructed by the host. The PI is developing a set of idealized cave conduit network systems using the Storm Water Management Model (SWMM) and using post-processing to calculate dissolution rates and heat transport. These explore how simulated outputs vary with conduit geometery, roughness, and recharge. Continuous monitoring sites are in place in two different cave systems in the classical Slovenian karst. These sites are located along the length of known conduit systems and can record depth, temperature, and conductivity. The proposed project uses the SWMM to aid in the interpretation of these data and to explore the effects of variable flow and sediment transport on conduit evolution. The PI is developing algorithms for including these effects within speleogenetic models. The proposed study expands the applicability of speleogenetic models by including variable flow, sediment transport, and mechanical erosion. Because sediment transport is crucial for both contaminant transport and cave ecology, the study connects speleogenesis with these fields. Furthermore, cave sediments provide valuable age records, and the extended model will allow explorations of the relationship between passage genesis and sediment deposition.
