SPRING FLUX AS AN INDICATOR OF SOURCE GEOMORPHOLOGY, SUBSTRATA, TEMPERATURE CONDITIONS, AND GEOCHEMICAL CONDITIONS IN SPRINGS

Spring flux (m/s), defined as spring flow (m³/s) divided by the area over which groundwater emerges (m²) at a spring, provides a simple, yet meaningful way to distinguish between fracture and seepage-filtration source geomorphologies for rheocrenes in Wisconsin, USA and may be useful in distinguishing spring source geomorphologies in other regions, as well. For twenty fracture and seepage-filtration springs investigated in this study, the median spring flux for fracture springs is nearly two orders of magnitude greater than the median spring flux for seepage-filtration springs, whereas median discharges are similar. Relationships were also found to exist between spring flux and spring habitat characteristics. High spring flux due to focused discharge from a few large fractures, is associated with spatial consistency in water temperature and more heterogeneous substrata near the spring source. Lower spring flux due to the emergence of water from numerous water sources across a spring pool is associated with greater spatial variation in water temperature and more homogeneous substrata near the spring source. Initial results suggest that geochemical conditions are similarly consistent across high flux springs, whereas low flux springs create a more heterogeneous geochemical environment. Used in association with other environmental conditions, the basic spring flux metric could be useful in predicting spring habitat conditions where detailed ecological assessments are neither available nor feasible.