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Richmond, Virginia, located on the banks of the James River and nestled in the Virginia Piedmont, has a population nearing 225,000, making it one of the oldest cities in the United States. As one traverses this vibrant city, they encounter a rich tapestry of culture, diverse landscapes, and varying weather conditions.
During the summer months, Richmond, like many mid-Atlantic cities, can experience hot and humid weather. This phenomenon is exacerbated by the urban heat island effect, where densely developed areas, with their unshaded roads and buildings, absorb and retain heat throughout the day, resulting in elevated temperatures compared to surrounding rural regions.
Using a forward-looking infrared (FLIR) camera, researchers have visually represented these heat variations, where lighter colors signify warmer areas and darker shades indicate cooler spots.
The urban heat island effect suggests a significant temperature disparity not only between urban and rural areas but also among neighborhoods within a city. For instance, dark asphalt surfaces tend to heat up more compared to lighter surfaces, and materials like brick and concrete retain more heat than grass or trees. Consequently, some areas within Richmond may experience notably higher temperatures than others during heat waves.
A graph from the Climate Explorer illustrates the increasing number of days in Richmond when temperatures exceed 95°F. This summer heat trend, which has been escalating since the 1970s, raises concerns, particularly since higher temperatures correlate with an uptick in heat-related emergency visits in local hospitals.
To pinpoint which neighborhoods in Richmond are most susceptible to extreme heat and how this impacts vulnerable community members, researchers needed a systematic approach to assess temperatures throughout the city.
Investigating Heat Patterns
Dr. Jeremy Hoffman and Dr. Eugene Maurakis, affiliated with the Science Museum of Virginia, teamed up with Dr. Vivek Shandas from Portland State University, alongside local community organizations and educational institutions, to delve into the city’s heat island concerns.
To gather temperature data, they enlisted local citizen scientists from several organizations, including universities and nonprofits focused on environmental and social issues. These volunteers actively participated in measuring temperatures across the city during significant heat events.
On July 13, 2017, in the grips of a major heat wave, 15 teams of volunteers set out equipped with simple devices designed to measure the air temperature, documenting their location and the time as they moved throughout Richmond. They recorded temperatures at three intervals during the day: in the early morning, mid-afternoon, and evening.
This temperature data was integrated into open-source software developed by Shandas’ team, enabling researchers to connect land use types with the recorded temperatures. The resultant mapping provided a comprehensive view of Richmond’s urban heat distribution.
The mapping revealed temperature variations of as much as 16°F across neighborhoods during peak heat hours. For example, a shaded area of the city might record a temperature of 87°F in the afternoon, while a more urbanized neighborhood could experience temperatures soaring to 103°F. Additionally, hotter areas exhibited wider temperature swings between morning and afternoon compared to cooler neighborhoods.
The data indicated that Richmond’s neighborhoods with the highest amounts of impervious surfaces and the least tree cover were typically the warmest. These areas often host residents living below the poverty threshold, heightening their vulnerability to heat-related health risks, particularly for those without air conditioning. Emergency response data confirmed that incidents of heat-related distress disproportionately occurred in these hotter regions.
To evaluate heat vulnerability across different neighborhoods, researchers created an index that factored in temperature measurements, tree canopy coverage, and the presence of impervious surfaces, along with socio-economic data. This index allows for identification of areas most at risk and highlights where interventions could effectively reduce heat exposure, such as increasing tree planting, installing shade structures, or revising building codes.
Community Engagement and Solutions
Many volunteers involved in the mapping project are committed to disseminating their findings to the community. They aim to collaborate with neighborhoods at risk of excessive heat through the development of customized adaptation strategies.
As part of their educational initiatives, youth volunteers from Groundwork RVA explored the impact of different surfaces on heat absorption. In a project named “Throwing Shade in RVA,” they utilized model homes to assess heating variances, employing heat sensors and FLIR cameras to visualize how different materials conduct heat. This project has been partially funded by NOAA’s Office of Education, promoting awareness of green infrastructure solutions.
Broadening Adaptation Efforts
The overarching goal of the heat mapping initiative is to inspire community-based adaptation strategies. While satellite imagery can reveal overall urban heat patterns, it lacks the granularity required to assess temperature variations at a localized level. This project emphasizes the human experience within the urban landscape: the involvement of citizen scientists collecting data through practical means has lent a more relatable and precise dataset than typically available.
With the insights gained, the next phase of the project will focus on exploring potential solutions to mitigate heat impacts, particularly in the city’s hottest regions. These solutions may be integrated into urban planning processes such as Richmond 300, RVA Green 2050, and the RVAH2O watershed management program, focusing on reducing stormwater runoff and enhancing climate resilience initiatives.
As climate projections indicate increasingly warmer summers, urban heat islands will likely pose significant challenges across the U.S. The methods used in Richmond could serve as a model for other cities, drawing on available data from resources like the National Land Cover Database and the U.S. Census Bureau, and utilizing accessible open-source analytical tools.
This collaborative research effort in Richmond demonstrates how community engagement paired with systematic data collection can lead to actionable insights that address critical issues of urban heat vulnerability, serving as a template for similar initiatives nationwide.
Reference
Virginia Department of Health. “Weather-Related Surveillance: Summer 2017 Heat-Related Illness Surveillance.” Accessed 28 March 2018.
Adapted from the U.S. Climate Resilience Toolkit.
Source
www.climate.gov