Mar. 28, 2013 ? Sometimes, little things can add up to a lot. In short, that's the message of a research study on small dams, streams and pollution by Steve Powers, a postdoctoral researcher at the University of Notre Dame's Environmental Change Initiative (ECI).
"Small dams, reservoirs and ponds trap water pollution, which provides an important benefit to water resources," Powers said. "This is especially relevant in agricultural lands of the Midwest U.S., where there are lots of small, but aging dams."
Although small individually, the sum total of the small reservoirs and ponds have a global surface area comparable to that of all large reservoirs added together.
Powers and his fellow researchers showed in detail how a small aging dam, which was more than 100 years old and located in agricultural Wisconsin, trapped water pollutants associated with fertilizer and manure runoff. They also showed an increase in downstream transport of nutrient pollution after the dam was removed, which occurred because of concerns about the dam's safety.
"Many small dams are threatened by long-term structural decline and are also filling with sediment," Powers said. "If we don't better incorporate how small dams affect the movement of water and wastes through the environment, their benefit to downstream water quality could be lost. Meanwhile, legacy sediment and pollution currently trapped behind dams could release as dams lose their water storage capacity, fall apart, or are removed deliberately."
Powers notes that there is a crucial need to gain a better understanding of what small dams mean for our water quality before they crumble and disappear.
"I am continuing to work on the subject at a broader regional scale by looking at hundreds of stream and river monitoring stations throughout the Midwestern U.S. to detect signals of dams," he said. "One current goal is to try and figure out which regions are most vulnerable to water quality changes caused by accumulation of sediment and phosphorus behind dams."
The research paper appeared in the Journal of Geophysical Research-Biogeosciences.
Powers is conducting his research as part of the Notre Dame Environmental Change Initiative's Land Use Project. The Environmental Change Initiative conducts policy-oriented research designed to help policy-makers manage environmental changes.
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The above story is reprinted from materials provided by University of Notre Dame.
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Journal Reference:
- S. M. Powers, J. P. Julian, M. W. Doyle, E. H. Stanley. Retention and transport of nutrients in a mature agricultural impoundment. Journal of Geophysical Research: Biogeosciences, 2013; DOI: 10.1029/2012JG002148
Note: If no author is given, the source is cited instead.
Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.
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The economy is like a pendulum, and when it starts to swing back toward prosperity?as it appears it has started to do?your organization might miss some of those talented employees you had to let go during the recession.
One of the things that’s frustrating about Apple’s Maps is that you don’t get the integrated transit information that’s the lifeblood of living in a place like New York City or San Francisco. Google Maps has always had that information integrated into the product, which is a huge help for people who live in those metropolitan areas. The difficulty for Google is to keep up with all of the transit options, especially when it comes to live information. Today, it announced updates for NYC, D.C. and Salt Lake City, which will show you live departure times for seven lines on the NYC Subway system (MTA) and buses, subway in D.C. (Metrorail) and trams in Salt Lake City (UTA). There are more than 800 cities with transit information available in Google Maps, but these three cities are getting more attention, since they have the most riders. Google Maps has been a massive success since launching on iOS last December, and transit information is a huge advantage. Here’s what Soufi Esmaeilzadeh, partnership development manager for Google Maps, had to say about the update: With transit information in Google Maps you get pick-up locations, departure times, estimated travel time, and even fare amounts for 800 cities* across more than 25 countries around the world ? that?s information for 100 million miles of daily public transit trips at your fingertips. These are clearly not easy problems to solve, since most of the information relies on the transit lines themselves reporting information in real time in a way that Google can access it. Those are relationships that the company has built over the years, which allows it to seamlessly integrate the data into its offerings. As I mentioned, this was the one thing that immediately turned me off of Apple Maps. Having to rely on third-party applications that are kind of woven into Apple’s service just didn’t cut it for me. When you are waiting to get on a bus or train, you need that information quickly. Seeing delays, for example, in real time, can help you decide on whether to taxi and give you enough of a heads up to let someone know that you’re going to be late. There’s nothing worse than standing there waiting for a train and having no idea when it’s coming. Google is actively seeking more transit partners, and has an entire site dedicated to it in which they
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Public release date: 25-Mar-2013
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