THE FIRE DISTINGUISHER: A BASELINE STUDY OF SEMI-ARID KARST DRIP WATERS IN WILDMAN’S CAVE AT WOMBEYAN, NSW, AUSTRALIA

Abstract:

This study addresses the impact of fire on karst systems in a semi-arid environment. There is limited knowledge of hydrological and geochemical changes that result from a fire over a karst system. Soil science literature has shown that fire can change surface properties and from this it has been hypothesized that these impacts will be mirrored in an underlying cave (see Figure). This project is the first phase of a pre/post-fire study of organic matter, drip rates, trace metal composition, and stable isotope composition changes in a semi-arid cave system.

This project aims establishes the baseline hydrogeochemical processes at Wildman’s cave, at Wombeyan in NSW, Australia. The Wildman’s cave site has not been studied previously, so this study adds to expanding literature on cave systems. This pre-fire monitoring provides a new dataset for semiarid karst processes.

We report the first 8 months of an ongoing dataset, obtained through collection of dripwater samples, with drip loggers indicating drip rates over the same period. Dripwaters were analysed for pH and EC, cation/anion content, organic matter content and stable isotope composition. Following the successful completion of this baseline study, post fire data will be obtained via a controlled burn. This will expand on current knowledge of the use of speleothems as accurate records of past climates and fire history.