Long‐Term Hydrologic and Biogeoehemieal Responses of a Soft Water Seepage Lake in North Central Wisconsin

Abstract

Hydrologic and chemical budgets were determined for the period October 1980 through September 1988 for Vandercook Lake, a 43-ha soft water seepage lake located in predominantly sandy outwash in northern Wisconsin. The 1951-1980 mean annual precipitation for the lake, based on nearby National Weather Service (NWS) stations, was 825 mm; volume-weighted p H of bulk atmospheric deposition during the 8-year study averaged 4.7. From October 1980 through September 1983, annual precipitation was 108% of the 30-year NWS average, annual recharge was 144% of the 8-year study period average, and annual groundwater inflow to the lake ranged from 5 to 9% of the total inflow. From October 1986 through September 1988, annual precipitation was 90% of the NWS average, annual recharge was 30% of the study period average, and the lake received no groundwater inflow. During the study, the lake changed from a system whose buffering mechanism was significantly influenced by mineral weathering in inflowing groundwater to one dominated by in-lake sulfate reduction. The functional differences exhibited by this lake during the 8 years of study demonstrate the tenuousness with which conclusions based on shorter-term studies of similar systems must be considered. 199 200 WENTZ ET AL ß SOFT WATER SEEPAGE LAKE IN NORTH CENTRAL WISCONSIN Vilas Northern Highland. --,Lake District (• 5•0 1 •0 Kilometers 89ø42 ' 89041 '

Estimation of water renewal times for the middle and lower sections of the Yellow River

“…These include renewal time (Tartinville et al, 1997;Cole and Pace, 1998;Chement et al, 2001;Jean-Baptiste et al, 2001), turnover time (Takeoka, 1984;Wentz et al, 1995;Tartinville et al, 1997;Cole and Pace, 1998;Jean-Baptiste et al, 2001), replacement rate (D'Abramo, 2000) and replacement time (Slutsky and Yen, 1997). Reconciling these definitions is difficult because different concepts are sometimes denoted by a single name, whereas at other times more than one name is used for the same concept (Takeoka, 1984).…”

The influence of landscape position on lake chemical responses to drought in northern Wisconsin

“…Hydrologic responses to drought -The late 1980s drought was initiated by one of the lowest snow seasons on record in winter 1986-1987 (Wentz et al 1995) followed by 3 yr of continued lower-than-normal precipitation (Fig. 2a).…”

“…2a). As a result, the groundwater table and the water level in many of the region's lakes declined substantially (Anderson and Cheng 1993;Rose 1993;Wentz et al 1995). …”

“…We chose these cations because their concentration in this region's lakes is closely tied to annual groundwater 977 inflow rates (Kenoyer and Anderson 1989;Wentz et al 1995) and because they can be considered semiconservative (Krabbenhoft et al 1994). To distinguish between the effects of altered groundwater inflow and evapoconcentration, we transformed the Ca+ Mg concentration time series into mass by accounting for changes in lake volume.…”

Bi-phasic trends in mercury concentrations in blood of Wisconsin common loons during 1992–2010

“…Previous hydrologic studies in this region have attributed analogous changes in lake-water chemistry to diminished groundwater discharge and (or) increased evapoconcentration during drought (e.g., Kenoyer and Anderson 1989;Wentz et al 1995;Webster et al 1996). However, neither of these mechanisms could account for the magnitude of the biphasic changes in SO 4 and meHg that were observed in LRL during 1988-2007.…”