Origins of groundwater in a fiuviokarst basin: Bonne femme basin in central Missouri, USA
The temporal variation of the hardness of water in karst springs has been used to classify springs as 1) those that are fed by water from diffuse flow (internally drained basins), and 2) those that are fed by water from conduit flow (allogenically drained basins). The residence time of groundwater in a fluviokarst basin, Bonne Femme Creek drainage basin, was determined from the coefficient of variation of the hardness of the water. The residence time of groundwater that was from the conduit-flow source was 3-4 days. This was an insufficient period for thermal or chemical equilibrium to be achieved, as indicated by observed seasonal cycles in the temperature (13 ± 2 °C) and the coefficient of variation of the hardness (typically 18 percent) of the water. The residence time of groundwater that was derived from internally drained sources was nearly 8 days. The internally drained water, having a longer period of contact with surrounding bedrock, more closely approached thermal and chemical equilibrium. A dampened seasonal cycle in the temperature (13 ± 0.6 °C) and a lower coefficient of variation of the hardness (typically 12 percent) of the water were observed for the internally drained water. The findings of this study support the conceptual model of groundwater baseflow through a fluviokarst basin that is governed by a mixture of conduit-flow and diffuse-flow end members.
Publication Source (Journal or Book title)
Wicks, C. (1997). Origins of groundwater in a fiuviokarst basin: Bonne femme basin in central Missouri, USA. Hydrogeology Journal, 5 (3), 89-96. https://doi.org/10.1007/s100400050124