Effects of urbanization start to soak in | |
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Top row, from left: Matt Robertsen, grad student, geography; Ken Bradbury, Wis. Geologic and Natural History Survey; Richard Lathrop, Dept. of Natural Resources; Prof. Joy Zedler, botany and UW Arboretum; Prof. Ken Potter, CEE; Kristin Anderson, grad student, geology and geophysics. Middle row: Dawn Chapel, grad student, geology and geophysics; Prof. Jean Bahr, geology and geophysics; Suzanne Hoehne, grad student, CEE. Front row: Laura Parent, grad student, geology and geophysics; Chip Hankley, Wis. Geological and Natural History Survey; Jeff Steurer, U.S. Geological Survey. (34K JPG)
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gricultural landscapes are being urbanized throughout the United
States, resulting in the degradation of aquatic systems. The
construction of impervious surfaces like roofs, streets and sidewalks
are causing fundamental changes in watershed hydrology. As impervious
surface area expands, runoff peaks and volumes increase, and water
quality and ground-water levels decline. Increased runoff peaks cause
channel erosion and habitat degradation. Increased erosion of soil and
associated nutrients cause sedimentation and eutrophication of lakes
and wetlands. Diminished groundwater levels desiccate wetlands and
reduce the discharge of high-quality ground-water to springs, streams
and lakes. Wetland biodiversity declines as a result. These hydrologic
and ecological effects of urbanization are exacerbated in regions
where groundwater is pumped for domestic use and irrigation.
The north fork of Pheasant Branch Conservancy near Madison makes an
ideal subject for an interdisciplinary research effort aimed at
filling critical knowledge gaps and developing analytical and modeling
tools that will minimize the hydrologic and ecological effects of
urbanization. Professor Ken Potter and Center for Limnology Researcher
Richard Lathrop are co-principal investigators on the study which
includes scientists from UW-Madison and the Wisconsin Department of
Natural Resources.
The team is evaluating alternative management practices and patterns
of urbanization by considering a range of urban development issues,
including storm runoff, groundwater depletion, wastewater treatment,
growth of nuisance algae and wetland degradation. They are also
addressing interaction among these issues and the social and political
opportunities for, and constraints on, effective management.
A new path to cleaner water: Removing nitrogen from wastewater | |
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All organisms require nitrogen to live. It is fourth in place behind
oxygen, carbon and hydrogen as the most common chemical element in
living tissues. But in excessive amounts, nitrogen alters ecosystems
and contributes to environmental problems.
Assistant Professor Daniel Noguera is investigating the microbial
ecology of aerated-anoxic biological treatment processes for removal
of nitrogen from wastewater. His results will provide insight into
design of processes and their use in treatment systems ultimately
reducing adverse effects of excessive nitrogen discharge into
environmental waters.
Most wastewater treatment systems use a three-step
nitrification/denitrification process to change ammonia to nitrite,
nitrite to nitrate, and nitrate to nitrogen gas. Nitrification is an
aerobic process and denitrification is an anaerobic process. Noguera's
team is investigating a system in which tiny amounts of oxygen are
added to the anoxic step allowing nitrification and denitrification to
occur simultaneously. The amount of oxygen added is so small that it
is difficult to measure and is immediately absorbed by the
system. Noguera is testing various hypotheses that could explain
exactly how the oxygen aids the process and which organisms absorb
it. The work could lead to more efficient removal of nitrogen from
wastewaters.
Building a legacy of improved transportation | |
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Bottlenecks, potholes and traffic volume are among the targets of a
Wisconsin-wide research effort led by Professor Peter J. Bosscher. The
Wisconsin Highway Research Program teams UW engineers with state and
federal transportation offices, private industry and consultants to
set a strategic course for state highways. Like most states, Wisconsin
is on a collision course with rapidly rising traffic rates and highway
capacity.
"In the last 15 years, traffic loads have increased per lane by about
50 percent on all state highways," Bosscher says.
The partnership's two overriding goals are to reduce driver delays in
key areas and develop longer-lasting highway products without
additional costs. Some specific projects include: finding new surface
treatments to lengthen the life of concrete, investigating ways to
reduce bumps caused by road settlement at bridges, studying accident
rates caused by wet pavement and finding new surface designs to
improve traction, and developing a beneficial reuse program to turn
industrial waste into low-cost material for road construction.
"The question is, can we develop better materials so we only need to
revisit roads for maintenance every 30 or so years?" Bosscher
asks. "We hope to leave a legacy of improved materials and less
required maintenance on roads."
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