TIME-SERIES RELATIONSHIPS IN AN URBAN KARST WATERSHED IN SPRINGFIELD, MISSOURI

In an urban karst system, the characterization of transport properties is based on natural tracers observed at the outlets of a system. A comparison analysis of inlet recharge and outlet discharges of the watershed to storm events using hydraulic responses may be a key in understanding the karst system’s internal processes. This study hopes to give watershed managers a better understanding of the karst network and the impacts that humans have on its overall functioning as it relates to the entire watershed. The project area consisted of the central portion of the Ward Branch watershed in Springfield, Missouri. A six month continuous monitoring of water temperature at four exit points of the karst system (springs) and one entrance point (disappearing stream into a sinkhole) were used to compare the responses of the karst system using a time-series relationship. Thermograph analysis has shown rapid responses and high thermal variability involving inefficient heat exchange for all the spring sampling sites during storm events. Springs located on the edge of the city limits varied by up to 4^oC during storm events, while one spring located in the middle of a commercial district varied up to 8^oC indicating some human effect to the karst system. The goal of this project was to infer the structure of the karst conduit system and to determine the human impact on the karst system in an urban area. This will allow the overall watershed system and its intricacies to be better understood and future urbanization planning can use this knowledge to better manage water resources in the Ward Branch watershed.