The application of quantitative fluorescent dye tracing to evaluate karst hydrogeologic response to varying recharge conditions in an urban area.

Quantitative dye-tracing methods were utilized in a portion of the greater Springfield, Missouri metropolitan area. These methods were used to evaluate factors influencing groundwater movement through the shallow karst system in the area. Fortuitous timing of these studies with a summer drought allowed for very low-flow conditions to be tested, and the results of these tests suggest that shallow groundwater in the study area occurs in fractures and along bedding planes, with a significant input component from flow along bedding planes or other sub-horizontal features. Based on one unique trace, it appears that recent dye traces may be affected by groundwater elevations, where crossover from one conduit system to another occurs under most water level conditions, but ceases under the lowest flow conditions. [ABSTRACT FROM AUTHOR]