Collaborative Research: 
Suspended Sediment Transport in Karst
Laura Toran, Temple University
William B. White, Pennsylvania State University

Understanding sediment transport is important for a number of reasons.  First, sediment may enhance transport of contaminants that are mobilized by attaching to sediment.  Second, the mobility of sediment also reflects the potential mobility of bacteria and viruses, which are of concern in evaluating groundwater quality.  And third, the mobility of sediment is a measure of velocities and transport pathways in karst, a complex issue involving mixing from different reservoirs, which is difficult to quantify.  Unraveling mixing from different reservoirs is important in both karst and non-karst systems, and this study will help show how temporal heterogeneity (changes between storm events, not just within storm events) can provide clues to the internal structure of a system.   This research is sponsored by the National Science Foundation Hydrology Program.

Research questions

How does sediment transport vary with seasons? How does sediment transport vary with storm events?  What size fractions are transported?  What velocities are represented by the sediment suspension? What is the composition of the sediment transported?  How does the type of karst network affect sediment transport?

Research plan

These questions will be addressed by measuring sediment transport in a set of karst aquifers over the course of a year and during several different types of storm events.  Storm events will include small and large storms, plus storms with wet and dry antecedent conditions.  Three distinct karst aquifers (see map above) have been selected that include a high, medium, and low discharge system.  At each site, continuous loggers will be installed to monitor conductance, discharge, and turbidity to record seasonal variation and antecedent conditions for storms.  In additional, stormwater samplers will automatically trigger to sample during the selected storm events.  Samples collected monthly and during storms will be analyzed for detailed water chemistry, sediment composition, and sediment size distribution.  These data will be used to test hypotheses related to the above questions, and to classify the karst systems using the mixing ratios implied by sediment transport. Revised: December 07, 2004 Questions or comments about this web page, email Laura Toran, Temple University