PUB00070

• Year: 1998
• Title: Ground Water and Surface Water A Single Resource U.S. Geological Survey Circular 1139
• CWCB Section: Interstate & Federal
• Author: T.C. Winter, J.W. Harvey, O.L. Franke, W.M. Alley
• Description: Overview of current understandimg of interaction of ground water and surface water in terms of quality and quantity
• Publications - Doc Type: Historical

the surface drainage system, and to reappear at the
surface at another place. Seeps and springs of all
sizes are characteristic features of karst terrains.
Springs having sufficiently large ground-water
recharge areas commonly are the source of small-
to medium-sized streams and constitute a large

part of tributary flow to larger streams. In addi-
tion, the location where the streams emerge can
change, depending on the spatial distribution of
ground-water recharge in relation to individual
precipitation events. Large spring inflows to
streams in karst terrain contrast sharply with the
generally more diffuse ground-water inflow char-
acteristic of streams flowing across sand and
gravel aquifers.
Because of the complex patterns of surface-
water and ground-water flow in karst terrain,
many studies have shown that surface-water
drainage divides and ground-water drainage

divides do not coincide. An extreme example is a
stream that disappears in one surface-water basin
and reappears in another basin. This situation
complicates the identification of source areas
for water and associated dissolved constituents,
including contaminants, in karst terrain.
Water chemisfry is widely used for studying
the hydrology of karst aquifers. Extensive tracer
studies (see Box G) and field mapping to locate
points of recharge and discharge have been used
to estimate the recharge areas of springs, rates of
ground-water movement, and the water balance of
aquifers. Variations in parameters such as temper-
ature, hardness, calcium I magnesium ratios, and
other chemical characteristics have been used to
identify areas of ground-water recharge, differen-
tiate rapid- and slow-moving ground-water flow
paths, and compare springflow characteristics in
different regions. Rapid transport of contaminants
within karst aquifers and to springs has been
documented in many locations. Because of the
rapid movement of water in karst aquifers, water-
quality problems that might be localized in other
aquifer systems can become regional problems in
karst systems.
Some landscapes considered to be karst
terrain do not have carbonate rocks at the land
surface. For example, in some areas of the south-
eastern United States, surficial deposits overlie
carbonate rocks, resulting in a "mantled" karst
ferrain. Lakes and wetlands in mantled karst
terrain inferact with shallow ground water in a
manner similar to that in sandy glacial and dune
terrains. The difference between how lakes and
wetlands interact with ground water in sandy
glacial and dune terrain and how they interact
in the mantled karst is related to the buried
carbonate rocks. If dissolution of the buried
carbonate rocks causes slumpage of an overlying
confining bed, such that water can move freely
through the confining bed, the lakes and wetlands
also can be affected by changing hydraulic heads
in the aquifers underlying the confining bed (see
Box L).

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