ARS | Publication request: PRACTICAL LIMITS OF HIGH-RESOLUTION EVALUATION OF CARBONATE CHEMISTRY WITHIN KARST FLOW SYSTEMS

Submitted to: Conference on Limestone Hydrogeology Proceedings
Publication Type: Proceedings
Publication Acceptance Date: July 20, 2006
Publication Date: September 21, 2006
Citation: Bolster, C.H., Groves, C., Meiman, J., Fernandez-Cortes, A. 2006. Practical limits of high-resolution evaluation of carbonate chemistry within karst flow systems. Conference on Limestone Hydrogeology Proceedings.

Technical Abstract: Karst flow systems often experience rapid variation in the flow and water chemistry conditions that govern system evolution and function, both with regard to background chemistry and anthropogenic inputs such as nutrients and bacteria from animal waste as well as other agricultural contaminants. Evolving methods utilizing electronic/digital data logging systems offer important tools for clarifying details of these processes. While these methods easily provide high temporal resolution, challenges remain in the quantitative evaluation of data quality resolution in terms of reported accuracy (associated with reproducibility of a result) and precision (conformity with the true value of the measured parameter). An effort underway within Cave Spring Caverns, Kentucky USA is rigorously defining the practical limits of karst water monitoring by working under essentially ideal access and working conditions. An epikarst waterfall below is monitored for temperature, pH, and specific conductance (spC) by three independent probe/data logger (Campbell CR10X) systems with two-minute resolution. Redundancy reduces the probability for data loss by equipment malfunction and allows calculation of a standard deviation to quantify measurement precision. Early results show that over at least a month of logging data can be obtained within one standard deviation of <0.2oC for temperature, <4 'S/cm@25oC for spC, and <0.01 for pH; accuracy is similar for temperature and spC, but about ±0.1 unit for pH.