Inner cities as well as suburbs show distinctly warmer temperatures--known as the urban heat island effect--than rural areas as a result of land use and human activities, which can affect rainfall, air quality and public health.
A University of Georgia study using a new method for calculating urban heat island intensities clarifies the conflict on whether urban density or sprawl amplify these effects more. It also provides a ranking of the top urban heat island cities among the 50 largest metropolitan statistical areas.
The urban heat island effect describes how the spatial configuration of cities, the materials in them (such as asphalt), lack of vegetation and waste heat can modify temperature.
The study, published in the journal Computers, Environment and Urban Systems, identifies Salt Lake City, Miami and Louisville as the top three urban heat island cities in the U.S.
Urban morphology--the patterns of a city's physical configuration and the process of its development--has long been associated with the formation of urban heat islands. By examining the UHI intensities of 50 cities with various urban morphologies, the researchers evaluated the degree to which city configuration influences the UHI effect.
"The overall goal of our study was to clarify which urban form--sprawl or more-dense development--is most appropriate for UHI mitigation," said the study's lead author Neil Debbage, doctoral student in the Franklin College of Arts and Sciences' department of geography.
The study establishes a method for estimating UHI intensities using PRISM--Parameter-elevation Relationships on Independent Slopes Model--climate data, an analytical model that creates gridded estimates by incorporating climatic variables (temperature and precipitation), expert knowledge of climatic events (rain shadows, temperature inversions and coastal regimes) and digital elevation.
The use of spatially gridded temperature data, rather than urban versus rural point comparisons, represents a new method for calculating a city's canopy heat island intensity. The results identify the spatial contiguity of developed areas as a significant factor influencing the magnitude of the heat island effect.
"Not just whether cities have high-density development, but how the built infrastructure is connected--and disconnected by green spaces--has a great impact on heat island intensity," said study co-author Marshall Shepherd, the UGA Athletic Association Distinguished Professor of Geography and Atmospheric Sciences.
"We found that more contiguous sprawling and dense urban development both enhanced UHI intensities. In other words, it does not appear to be a simplistic either-or situation regarding sprawl or density," Debbage said.
The researchers hope the results can help influence local governments and city planners in the formulation of effective codes and policies to mitigate the urban heat island effect.
"It's crucial to work toward a better understanding of the complex processes at the intersection of urbanization, climate and human health," Shepherd said. "Current and future cities will be modified or designed with weather and climate in mind, and research at UGA will play a key role.
The study on "The Urban Heat Island Effect and City Contiguity" is available at http://www.
Neil Debbage | EurekAlert!
World’s oldest known oxygen oasis discovered
18.01.2018 | Eberhard Karls Universität Tübingen
A close-up look at an uncommon underwater eruption
11.01.2018 | Woods Hole Oceanographic Institution
On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.
We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...
What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...
For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.
Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...
At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.
No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...
Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.
Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...
08.01.2018 | Event News
11.12.2017 | Event News
08.12.2017 | Event News
19.01.2018 | Materials Sciences
19.01.2018 | Health and Medicine
19.01.2018 | Physics and Astronomy