Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Larger cities have smaller water footprint than less populated counterparts

08.10.2018

Global sustainability is important now more than ever due to increasing urban populations and the resulting stress it can have on natural resources. But increased populations in cities may lead to greater efficiency, as a team of Penn State researchers discovered when they analyzed the water footprint of 65 mid- to large-sized U.S. cities.

"Human life on the planet has never been more complex," said Caitlin Grady, assistant professor of civil engineering. "We're so intertwined with so many aspects of the global trade and global economy. People in rural areas are still buying food like bananas from across the world and because of this we need more complex and rigorous tools to analyze how to manage our limited resources."


Water footprint of consumption and production for the analyzed US cities. The water footprint of consumption is separated into direct and indirect contributions.

Credit: Penn State

In order to develop these tools, researchers first need to better understand the urban water footprint. Grady and her colleagues set out to do just that.

"We looked at the overall picture of water consumption," Grady said. "Not just the water that comes out of your tap but also the water that goes into the food that each city produces and consumes, so it's both the direct water use and indirect water use, which we call your water footprint."

They analyzed agricultural, livestock and industrial commodity flows, and the corresponding virtual water contents using data from the U.S. Department of Agriculture, the U.S. Geological Survey and the U.S. Department of Transportation. The team then used these values to calculate an overall water footprint for each city. Their results were published in August in PLOS ONE.

What they found was that on average, larger cities, for their populations, consume less water.

"As the population increases, cities are consuming less per capita of the water resources, so the larger cities are getting more out of the water that they have based on population," Grady said.

Tasnuva Mahjabin, a doctoral student in civil engineering and contributing researcher on the project, said that multiple factors are likely contributing to these results.

"Water footprint consumption and production are tied to the changing composition of urban economic activities with city size, suggesting that large cities are more service-oriented with less prevalence to secondary sector industries," Mahjabin said. "This allows large cities to have reduced water footprints by shifting water-intensive economic activities to less populated regions."

And although the overall water usage decreased in correlation with a city's size, the researchers noted that not all types of water usage yielded a more efficient footprint.

Water that has been sourced from surface or groundwater resources mainly mirrored water-related weather patterns and showed little correlation with population. However, the amount of water used from precipitation contributed to consumption both positively - by transferring the dependence of food consumption on population into the water footprint - and negatively - by increasing diversity.

Several exceptions did arise. New Orleans, for example, has a much larger water footprint for their size and their population compared to the trend, whereas Las Vegas falls well below the average for water footprint production. The team is tracking the complexity of these findings in an effort to more accurately dissect the results.

The researchers hope to use their findings to benchmark cities and potentially set realistic targets to support the development of strategies for reducing the water footprint. This information could also be valuable to policy makers and city planners concerned with designing economic incentives that support water sustainability.

"A city in California may have a very strong campaign to have people take shorter showers and reduce water consumption, but they may also be a huge food producer," said Grady. "That's not necessarily a bad thing, but if you look at these things together you have a more complete picture of how you can manage the limited resources you have, and how you can prioritize the use of those resources."

In the future, the researchers plan to make their analyses more robust by incorporating more locations and including the water consumption needed to provide electricity to different regions. They would also like to analyze network resilience and network risk. Ultimately, they hope to create a platform where not only the public could investigate linkages but the government, as well.

###

Penn State aims to become a leader in sustainable water-energy-food nexus research. This research was partially supported by the National Science Foundation. Additional researchers included Alfonso Mejia, associate professor of civil engineering, and Susana Garcia, civil engineering doctoral student.

Media Contact

Jennifer Matthews
jas6149@engr.psu.edu
814-867-6224

 @penn_state

http://live.psu.edu 

Jennifer Matthews | EurekAlert!
Further information:
http://dx.doi.org/10.1371/journal.pone.0202301

More articles from Power and Electrical Engineering:

nachricht Researchers measure near-perfect performance in low-cost semiconductors
18.03.2019 | Stanford University

nachricht Robot arms with the flexibility of an elephant’s trunk
18.03.2019 | Universität des Saarlandes

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: The taming of the light screw

DESY and MPSD scientists create high-order harmonics from solids with controlled polarization states, taking advantage of both crystal symmetry and attosecond electronic dynamics. The newly demonstrated technique might find intriguing applications in petahertz electronics and for spectroscopic studies of novel quantum materials.

The nonlinear process of high-order harmonic generation (HHG) in gases is one of the cornerstones of attosecond science (an attosecond is a billionth of a...

Im Focus: Magnetic micro-boats

Nano- and microtechnology are promising candidates not only for medical applications such as drug delivery but also for the creation of little robots or flexible integrated sensors. Scientists from the Max Planck Institute for Polymer Research (MPI-P) have created magnetic microparticles, with a newly developed method, that could pave the way for building micro-motors or guiding drugs in the human body to a target, like a tumor. The preparation of such structures as well as their remote-control can be regulated using magnetic fields and therefore can find application in an array of domains.

The magnetic properties of a material control how this material responds to the presence of a magnetic field. Iron oxide is the main component of rust but also...

Im Focus: Self-healing coating made of corn starch makes small scratches disappear through heat

Due to the special arrangement of its molecules, a new coating made of corn starch is able to repair small scratches by itself through heat: The cross-linking via ring-shaped molecules makes the material mobile, so that it compensates for the scratches and these disappear again.

Superficial micro-scratches on the car body or on other high-gloss surfaces are harmless, but annoying. Especially in the luxury segment such surfaces are...

Im Focus: Stellar cartography

The Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI) at the Large Binocular Telescope (LBT) in Arizona released its first image of the surface magnetic field of another star. In a paper in the European journal Astronomy & Astrophysics, the PEPSI team presents a Zeeman- Doppler-Image of the surface of the magnetically active star II Pegasi.

A special technique allows astronomers to resolve the surfaces of faraway stars. Those are otherwise only seen as point sources, even in the largest telescopes...

Im Focus: Heading towards a tsunami of light

Researchers at Chalmers University of Technology and the University of Gothenburg, Sweden, have proposed a way to create a completely new source of radiation. Ultra-intense light pulses consist of the motion of a single wave and can be described as a tsunami of light. The strong wave can be used to study interactions between matter and light in a unique way. Their research is now published in the scientific journal Physical Review Letters.

"This source of radiation lets us look at reality through a new angle - it is like twisting a mirror and discovering something completely different," says...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

International Modelica Conference with 330 visitors from 21 countries at OTH Regensburg

11.03.2019 | Event News

Selection Completed: 580 Young Scientists from 88 Countries at the Lindau Nobel Laureate Meeting

01.03.2019 | Event News

LightMAT 2019 – 3rd International Conference on Light Materials – Science and Technology

28.02.2019 | Event News

 
Latest News

Solving the efficiency of Gram-negative bacteria

22.03.2019 | Life Sciences

Bacteria bide their time when antibiotics attack

22.03.2019 | Life Sciences

Open source software helps researchers extract key insights from huge sensor datasets

22.03.2019 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>