DELINEATION OF FLOW PATHS AND PROCESSES AFFECTING CHEMICAL VARIABILITY, ALLEQUASH BASIN, WISCONSIN
Flow paths delineated on the basis of the chemistry data showed groundwater derived from terrestrial, wetland, and lake source areas, which exhibited differing degrees of transient effects. Monthly/seasonal chemical variability observed along two transects with aquatic sources was caused by fluctuations in lake levels, which significantly affect the short-term orientation of the flow paths. These effects were also demonstrated in the particle tracking simulation where path lines pass both through and under a lake before finally discharging into strong sinks at the downgradient end of the basin. Thus, groundwater at the upgradient end of a flow path may discharge in different areas of the basin under different lake stage conditions. Transient effects in a discharge area near a 2-m wide stream was larger than transience near a relatively wide (> 400 m) lake. The study demonstrates that both aquatic and terrestrial components of flow are important in this watershed.