WHAT DO SPRINGS TELL US ABOUT TIMING AND QUANTITY OF RECHARGE AND FLOW: A REVIEW (Invited Presentation)

Untangling recharge and flow signals using spring discharge, temperature, and chemistry remains one of the fundamental goals in karst hydrology. Springs are a common intersection point between karst aquifers and human consumption and are also very appealing places for scientists to monitor. Early research attempting to characterize karst aquifers based on spring behavior showed promise, but further investigation, particularly with high resolution monitoring, revealed a quite complicated story as a spring can exhibit a spectrum of behaviors requiring multiple approaches to characterize.

In this work, we examine the state of the science in spring characterization with particular emphasis on springs in Pennsylvania that have been repeatedly studied. We present coordinated storm response data on CO₂ concentrations, major ions, rare earth elements, temperature, isotopes in water, and other parameters at these springs to illustrate their temporal complexity. In short, for these springs and others, there is no single parameter that can characterize one spring, much less all springs. Instead, different parameters result in different groupings illustrating the complexity of flow paths and recharge. With an appropriate suite of parameters, source terms for different components related to flow behavior and recharge supply can be categorized to better sample and protect springs.