SwRI, UTSA collaborate to measure ‘felt heat’ in West Side communities

Over the next year, the two organizations will place sensors in locations around the West Side.

The main campus of the University of Texas at San Antonio on June 15, 2021.

SAN ANTONIO – A UTSA and Southwest Research Institute (SwRI) partnership will soon study and measure “felt heat” on the West Side.

The partnership is led by Stuart Stothoff, a principal scientist with SwRI’s Chemistry and Chemical Engineering Division, as well as Esteban López Ochoa, an assistant professor at UTSA’s School of Architecture and Planning.

López Ochoa defined felt heat as a more complete measure of how people experience heat.

“Felt heat is a more complete way to measure heat that includes additional metrics that aim to capture more closely how people experience heat,” López Ochoa said.

The built environment — trees, shading infrastructure and impervious surfaces — helps to contribute to how people feel the heat.

Extreme heat is a dangerous phenomenon. For researchers, understanding the various levels of felt heat is essential for developing ways to cope with it.

“As heat is the number one weather-related killer in the U.S., understanding the different levels of heat across different areas of the city can help us be better prepared to cope with it,” López Ochoa said.

Earlier this summer, KSAT compiled stories about how San Antonians from all walks of life tried to combat the extreme heat.

Why is the West Side warmer?

Lopez Ochoa believes there are two main reasons why the West Side is hotter.

First, according to researchers, the West Side has disproportionally less tree coverage than other parts of the city.

A tree equity score software allows users to view areas of San Antonio and their respective scores. The software helps cities to measure how equitable their tree canopy is.

Scores are scaled from zero to 100, where a lower score means a greater need for tree coverage.

A portion of the West Side directly south of Tafolla Middle School boasts the lowest tree equity score of 36, compared to areas of the city to the north at 100.

Because of less coverage from trees, the paved surface absorbs heat and drives temperatures.

“More paved areas are constantly absorbing heat and radiation from the sun, which is constantly being released into their atmosphere,” López Ochoa said. “It is like having a heater constantly on in the middle of the summer.”

San Antonio’s West Side boasts a more considerable amount of paved surfaces than other parts of San Antonio, a UTSA Today story says. Because of this, people experience more heat than the rest of the city. Measurements taken by López Ochoa showed temperatures as high as 154 degrees above the pavement.

Second, the West Side has disproportionally lower housing conditions than the rest of the city.

Homes without central air conditioning and wall or roof insulation are just some issues West Side residents face.

“Westside residents are less able to keep the heat outside their homes, making them substantially more exposed to the heat than residents in other cooler areas of the city,” López Ochoa said.

However, López Ochoa recognized that this is not only an issue local to San Antonio.

Redlining’s role

Redlining — started in the 1930s — was a discriminatory, racist federal practice in which mortgage lenders or insurance providers would deny or restrict services to areas of a city because of the racial landscape of their neighborhood, among other things.

Many of the housing areas in cities that were redlined were often low-income or economically disadvantaged.

While redlining ended under the Fair Housing Act in 1968, it leaves remnants of segregation-era policies in affected neighborhoods.

A report by Inside Climate News, analyzing marginalized neighborhoods in Miami and their hotter temperatures, suggests that redlining is a primary cause for temperature differences in cities.

“A growing volume of evidence suggests the temperature differences are no coincidence,” the report states. “Nationwide the hottest urban areas tend to be the neighborhoods with low-income communities and communities of color.”

Lopez Ochoa referenced research looking at the effect redlining had on temperature. It concluded that redlined neighborhoods are proportionally hotter than those not affected by redlining.

“We found that, in nearly all cases, those neighborhoods located in formerly redlined areas — that remain predominantly lower income and communities of color — are at present hotter than their non-redlined counterparts,” the study says.

Long-term goals from the collaboration

Over the next year, the two organizations will place sensors in locations around the West Side.

One of the sensors researchers will use to measure temperatures. (UTSA)

The sensors will gather data on airflow, wind speeds, relative humidity, air temperatures and dew points.

“The publicly available information about the heat measured on the West Side is satellite data, derived from visible or infrared wavelengths,” Stothoff said. “It’s useful, but it doesn’t characterize the actual felt heat ... By placing our sensors in various key locations, we can measure the temperatures people actually feel.”

Their study is supported by a $125,000 grant from the Connecting Through Research Partnerships (Connect) program — an opportunity for both organizations to enhance scientific collaboration.

UTSA has already participated in efforts to mitigate temperatures in San Antonio. Data gathered from the Cool Pavement Pilot Program will be presented to the city in December.

Stothoff and Lopez are considering placing sensors in homes on the West Side.

For that venture, the organizations are working with the Historic Westside Neighborhood Association and the Esperance Peace and Justice Center to connect with residents willing to participate.

“We hope that partnering with SwRI and the Westside Historical Residents Association in this initiative would help to form strong partnerships and shared consensus on the different aspects of heat,” López Ochoa said.

López Ochoa hopes that work can continue at a civic level. UTSA’s partnership with SwRI will hopefully begin to address the problem and help form solutions.

“We hope this is only the beginning of a long partnership that would help us further understand what are the causes of the differential rates of felt heat ... and mitigation strategies that can be put in place in each area of the city,” López Ochoa said.

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About the Author:

Mason Hickok is a digital producer trainee at KSAT. He graduated from the University of Texas at San Antonio with a communication degree and a minor in film studies. He also spent two years working at The Paisano, the independent student newspaper at UTSA. Outside of the newsroom, he enjoys the outdoors, walking his dogs and listening to podcasts.