NICK CRAWFORD’S INFLUENCE BEYOND KARST SCIENCE: CONTAMINANT TRANSPORT IN OTHER HYDROGEOLOGICAL SETTINGS

Nick Crawford’s vision and influence as a pioneer of karst science and education has reached beyond the realm of karst science. His integrated approach using dye tracing, automated sampling, and hydrograph analysis techniques, which he developed for understanding karst hydrology, can effectively be used in understanding hydrologic processes in non-karst environments. Nick introduced this researcher to the fundamental concepts of hydrology as well as techniques for designing investigative methods for understanding hydrologic systems. Although much of Nick’s work over the past 30 years has focused on tracking water-quality through karst, the methods learned as an early student of Nick’s, have been applied to numerous investigations in which this researcher has participated.

An accounting of local hydrology—the amount of water that enters the watershed, the residence time, how it moves within the watershed, and leaves the watershed—forms the foundation for understanding the movement of contaminants and can guide selection of the most effective management practices for particular environmental settings. In karst environments contaminants typically move quickly through the system, however, in other settings contaminants may take years to move through a system. Many of the concepts, methods, and techniques introduced by Nick helped me better understand how the unique characteristics of each system determine the fate of these contaminants and provided me with the foundation for participation in the U.S. Geological Survey, National Water-Quality Program, Agricultural Chemical Transport team. Our team conducted a comprehensive and comparative study of agricultural contaminant transport in a variety of hydrogeological settings across the Nation. This presentation describes how methods, techniques, and concepts, initially introduced by Nick, were applied to investigations in other hydrogeological settings and contributed to increasing the understanding of contaminate transport in diverse environments.