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Research
Interests
The following materials
are summaries from proposals that were awarded to Dr. Woodbury and
collaborators. These are Dr. Kenneth Snelgrove (Memorial)
on the Assiniboine Delta Aquifer work below, Dr. Grant Ferguson (St.
Francis Xavier) on
the Manitoba Hydro geothermal work, and Dr. James Hendry (Saskatchewan)
on the
South Okanagan project for the Canadian Water Network (Dr. David
Rudolph is the team leader).
Drought Research
Initiative: Climate and
Atmospheric
Sciences
Global
climate change is emerging as a major issue in the public and
scientific minds
in Canada.
It
is well known that many areas of North America
have already experienced climate change impacts. For example, ground
surface
temperatures have increased, on average in Canada, by 0.8o
C since
predevelopment times. This deceptively small amount will have a major
impact on
future soil conditions and river flows. Computer-climate model
predictions
indicate that much of the North American central plains will likely
become
extremely variable in terms of weather. This will create huge problems,
not
only in the agricultural economy of Canada but in the ecosystems of our
waterways and in our major groundwater aquifer systems.
This research addresses sustainability of water resources and
agricultural
practice in the Province
of Manitoba. The
project
is being carried out by a team of researchers with expertise in several
areas,
namely groundwater modeling, surface water resources, geology, and
economics.
Bringing this multi-disciplinary team together to investigate, Manitoba’s
water
resources will lead to new and innovative solutions. More particularly
the
combination of groundwater models and land surface schemes has yet to
be
attempted anywhere in the world to investigate ground water resources
under
climate change scenarios. This will be ground breaking research. Also
the
interaction of engineering and economics will lead to cost effective
solutions
which may be more easily implemented as climate change become more
acute.
NSERC
Disovery and Collaborative R&D Program
Geothermal
energy is classified as a renewable-clean resource, along with solar,
wind and biomass. The ultimate source of energy for geothermal systems
is the enormous heat stored within and flowing through the earth. This
is estimated at 40 million MW; an enormous number, although the
ultimate potential for development is variable (Rybach, 2003). Most
importantly, by using reasonable production rates and strategies,
energy can be extracted and sustainable energy production can be
achieved. Some of this energy is stored in high temperature
systems ( > 150 C), but the vast majority of energy is stored in low
temperature (low-grade; < 150 C) environs.
“Conventional” geothermal resources are exploited worldwide for
electric generation by withdrawing fluid from deep reservoirs and
specific geologic features, and extracting the heat content. There are
many examples where this has been carried out in an environmentally
sensitive and sustainable manner. In Canada, the focus has been on
relatively low-temperature sources; those of the shallow subsurface at
less than 100 C. The method of extraction is typically in the form of a
heat pump and these are often referred to as geoexchange systems.
Relatively little is known about the environmental impacts of heat pump
systems, although it is commonly assumed that impacts are
negligible (Hunt, 2001). Younger (2006, 2008) considered this
topic at length and concluded that inadequate geoexchange design can
lead to significant ecological and sustainability problems. Increasing
geothermal development will require a greater degree of understanding
of heat flow and groundwater flow in the subsurface. Energy
experts agree that in a few years time all large-sized building
environmental controls will revolve around heat pump technology.
However, greater effort will be required in the design of individual
systems and associated hydrogeological investigations to ensure that
they are, in fact, environmentally sound and sustainable.
Although growing rapidly in Canada, installations are often based on
experience and empirical know-how, and are far from optimized. Studies
from Manitoba indicate that in many cases these systems are not
sustainable or at least not sustainable at maximum efficiency (e.g.
Ferguson and Woodbury, 2006). The operation of these systems must not
only consider the viability of the thermal application itself, but also
whether it is sustainable in an environmental sense. This can only be
done by addressing possible impacts on physical hydrology and water
quality in surrounding areas.
Understanding the sustainability and environmental issues revolving
around low temperature geothermal energy represents the long-term
objectives of my overall research program. I intend to move
forward along the same direction as recommended in a recent MIT
report (Tester, 2006), namely to help provide an evaluation of
geothermal energy as a major supplier of energy in Canada. The
concentration of my research though, will be on the use of geothermal
energy in direct-use applications rather than electricity generation.
My goal over this next phase of NSERC research is to investigate the
thermal, environmental and geotechnical characteristics and properties
of ground (soil, geology, aquifers, etc.), which may be needed to
develop better construction and monitoring methods, and for a greater
understanding of hydrogeology and heat flow. This work will
be vital to prioritize the important scientific issues and further
refine societal and regulatory needs so that the groundwater and
geo-exchange communities can work together for continued growth
in this sector.
Canadian Water Network : Assessment of
Regional
Water Resource Impacts from Agriculture
The
water research community in Canada
is large and multidisciplinary, and includes numerous pockets of
internationally recognized excellence. The community is diffuse
however, and in
the absence of a national vision tends to respond to the needs and
situations
of particular stakeholders or to react to local and regional issues.
While many
issues are indeed of a local scale, it is also true that there are many
interdisciplinary problems of national scale. If we are to address
these
problems effectively, and if Canada
is to assert herself in international markets, then it is essential
that
greater cohesion and greater communication within and between
disciplines be
developed. If this can be accomplished by the Network, then the more
tangible
benefits such as improved water management and public health,
technology
development and wealth creation will readily follow.
The
Assiniboine Delta Aquifer (ADA) is a large, unconfined sand and gravel
aquifer
system located in the south west of Manitoba.
The ADA
area
supports extensive potato farming. Irrigation water is derived from the
ADA
and the cropping
practices require extensive use of fertilizers. The ADA
system is also heavily relied on as a drinking water source and the
impacts of
the agricultural operations on the ADA
are of considerable concern to the Province. Significant subsurface
data are
available on geologic structure and hydraulic characterization.
Long-term
implications of the agricultural activities combined with anticipated
variations in precipitation patterns due to climate change will be
investigated
through the application of innovative regional modeling approaches.
Specifically, a tightly coupled land surface scheme (LSS) and
groundwater model
will be developed.
Coupling
of these models will be required to simultaneously simulate the impacts
of
irrigation/recharge on both surface water and groundwater. Impacts that
will be
addressed include: i) alteration of groundwater recharge and nitrate
loadings
due to irrigation and changes to the frozen/unfrozen distributions
affecting
spring infiltration of snowmelt, ii) determination of low stream flows,
iii)
surface soil moisture prediction necessary to implement advanced
irrigation
management, and iv) well drawdown profiles, necessary for determination
of
pumping cost and long-term aquifer capacity. Socio-economic analysis
will also
be used to examine alternative groundwater extraction strategies such
as
short-term reallocation of water from lower valued to higher valued
uses to
reduce stresses placed on the aquifer by agricultural practices.
Adaptive
scenarios including site-specific BMPs will be evaluated in
consultation with
current user groups from a social perspective using the coupled Model.
Dr.
Allan Woodbury
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