<br />
<br />Figure K-l. Transpiration-induced depressions in the water
<br />table commonly are filled in by recharge during the following
<br />spring, but then form again to some extent by late summer
<br />nearly every year.
<br />Nevins Lake, a closed lake in the Upper Peninsula of
<br />Michigan, illustrates yet another type of interaction of lakes
<br />with ground water in glacial terrain. Water-chemistry studies
<br />of Nevins Lake indicated that solutes such as calcium provide
<br />an indicator of ground-water inflow to the lake. Immediately
<br />following spring snowmelt, the mass of dissolved calcium in
<br />the lake increased rapidly because of increased ground-water
<br />inflow. Calcium then decreased steadily throughout the
<br />summer and early fall as the lake received less ground-water
<br />inflow (Figure K-2). This pattern varied annually depending
<br />on the amount of ground-water recharge from snowmelt and
<br />spring rains. The chemistry of water in the pores of the lake
<br />sediments was used to determine the spatial variability in
<br />the di rection of seepage on the side of the lake that had the
<br />most ground-water inflow. Seepage was always out of the
<br />lake at the sampling site farthest from shore and was always
<br />upward into the lake at the site nearest to shore. Flow rever-
<br />sals were documented at sites located at intermediate
<br />distances from shore.
<br />
<br />'"
<br />~ 11,000
<br />"
<br />o
<br />"-
<br />~ 9,900
<br />ui
<br />'"
<br />"
<br />"
<br />"
<br />"
<br />o 7,700
<br />~
<br />"
<br />u
<br />"
<br />w
<br />~
<br />"
<br />'"
<br />'"
<br />is
<br />
<br />>-
<br />w
<br />194,205 ~
<br />u
<br />158,895 ~
<br />u
<br />Z
<br />123,585 -,
<br />~>
<br />0"
<br />88.275 i C
<br />~ffi
<br />",,,
<br />52.965 ~
<br />"
<br />~
<br />17,655 0
<br />o ;s
<br />-17,655 ~
<br /><.:>
<br />
<br />
<br />Dissolved
<br />calcium mass
<br />/
<br />
<br />6.600
<br />5,500
<br />'" > >- z '" ~ >- z ~ > >- z '" >
<br />"- ~ g " "- g " "- ~ u '\ "- ~
<br />" " , " " " " " " "
<br /> , , , , ,
<br />1989 1990 1991 1992
<br />
<br />Figure K-2. A large input of ground water during spring
<br />supplies the annual input of calcium to Nevins Lake in the
<br />Upper Peninsula of Michigan. (Modified from Krabbenhoft,
<br />D.P., and Webster, KE, 1995, Transient hydrogeological
<br />controls on the chemistry of a seepage lake: Water
<br />Resources Research, v. 31, no. 9, p. 2295-2305.)
<br />
<br />Dune terrain also commonly contains lakes and
<br />wetlands. Much of the central part of western Nebraska,
<br />for example, is covered by sand dunes that have lakes and
<br />wetlands in most of the lowlands between the dunes. Studies
<br />of the interaction of lakes and wetlands with ground water at
<br />the Crescent Lake National Wildlife Refuge indicate that most
<br />of these lakes have seepage inflow from ground water and
<br />seepage outllow to ground water. The chemistry of inflowing
<br />ground water commonly has an effect on lake water chem-
<br />istry. However, the chemistry of lake water can also affect
<br />ground water in areas of seepage from lakes. In the Crescent
<br />Lake area, for example, plumes of lake water were detected In
<br />ground water downgradient from the lakes, as indicated by the
<br />plume of dissolved organic carbon down gradient from
<br />Roundup Lake and Island Lake (Figure K-3).
<br />
<br />
<br />Nevins Lake, Michigan. (Photograph by
<br />David Krabbenhoft.)
<br />
<br />102025'
<br />
<br />41Q4S'
<br />
<br />~oundUP Lake
<br />21
<br />.
<br />O.
<br />
<br />.4 Well and concentration
<br />of dissolved organic
<br />1 carbon, in milligrams
<br />. per liter
<br />
<br />o
<br />.
<br />
<br />
<br />o 1 MILE
<br />I I
<br />
<br />o
<br />.
<br />
<br />4
<br />.
<br />
<br />Figure K-3. Seepage from lakes in the sandhills of Nebraska
<br />causes plumes of dissolved organic carbon to be present
<br />in ground water on the downgradient sides of the lakes.
<br />(Modified from LaBaugh, J. W., 1986, Umnological character-
<br />istics of selected lakes in the Nebraska sandhills, U.S.A.,
<br />and their relation to chemical characteristics of adjacent
<br />ground water: Journal of Hydrology, v. 86, p. 279-298.)
<br />(Reprinted with permission of Elsevier Science-NL,
<br />Amsterdam, The Netherlands.)
<br />
<br />
<br />Island Lake, Nebraska. (Photograph by Thomas Winter.)
<br />
<br />49
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