Human activity is likely a greater threat to coastal ground water used for drinking water supplies than rising sea levels from climate change, according to a study conducted by geoscientists from the University of Saskatchewan (U of S) and McGill University in Montreal.
Ferguson from the U of S Department of Civil and Geological Engineering worked
with Tom Gleeson from McGill's Department of Civil Engineering to examine data from
more than 1,400 coastal watersheds. What they found was that with the exception
of very flat coastal areas that can be inundated with sea water – rare in North
America – most coastal aquifers are relatively unaffected by rising sea level.
appear to affect these aquifers is humans pumping water from wells for
drinking, domestic use and irrigation.
bulk of the research in recent years has focused on climate change effects on
coastal ground water, but increases in water demand could be more important,"
"This is particularly true in growing coastal cities and towns where
ground water is often an important water supply."
are geological formations such as sand or gravel that are saturated with water,
much like a sponge. Wells draw fresh water from these aquifers, which then are recharged
through surface water such as rain and melting snow.
aquifers, however, are bordered on one side by seawater that can start to
migrate into the formation – and into wells – if too much fresh water is drawn
out. Similarly, rising sea levels can cause seawater to enter into the
formation. To date, only problems related to pumping have been documented in Canada.
aquifers are very vulnerable to increased water demand so we have real policy
opportunities," Gleeson says. "We can reduce consumption of ground water
in coastal areas or manage ground water use wisely."
estimated that one billion people world-wide live in coastal areas, and many
are dependent on ground water. In Canada, about 25 per cent of people
rely on ground water, with some areas almost totally dependent on the resource.
"Vulnerability of coastal aquifers to groundwater use and climate
change," was published online Feb. 19 in Nature Climate Change.
The research was made possible in part through support from the Natural
Sciences and Engineering Research Council of Canada and the Canadian Institute
for Advanced Research (CIFAR). Gleeson is a CIFAR Junior Fellow.
Water Use Impacts Coastal Ground Water More So Than Climate Change
March 9, 2012