science environment

Study: East Portland Is Most Vulnerable To Flooding And Extreme Heat

By Meerah Powell (OPB)
April 11, 2019 7:14 p.m.

A Portland State University study found that east Portland residents are most vulnerable to extreme weather including extreme heat and flooding.

The PSU study used a topographic wetness index and urban heat index to model how seasonal flooding and extreme heat affect Portland. Researchers also looked at variables in neighborhoods such as education and income levels for comparison.


They found that poorer, low-lying areas in east Portland, specifically along Interstate 205, were most affected by seasonal hazards. Conversely, more affluent areas like Portland’s west hills and central northeast and southwest neighborhoods showed the lowest risk.

Heejun Chang, a professor and chair of the geography department at PSU and one of the researchers in the study explained that one of the biggest things the city can do to improve weather-vulnerable areas is to increase the amount of green infrastructure to absorb water and increase shade.

Whereas wealthier areas have more parks and trees, areas in east Portland have less "vegetative surfaces."


“Installing green infrastructure, or even like a green roof on those industrial and commercial buildings, they can help mitigate flooding and heat islands,” Chang said.

The city also needs to do more than just installation, he said.

“Maintaining those green infrastructures also becomes important. Like any infrastructure, that green infrastructure has a life span. Unless it’s well-maintained, it will not function in the way it’s been designed,” Chang said. “So that does require some outreach and education to citizens that live in those areas.”

Chang said the communities living along I-205 are especially unique in their demographics.

“Particularly in east Portland, I found that in the past 10 or 15 years those minority ethnic groups have increased exponentially in those areas; those folks may not speak English, but the city still needs to reach out to educate those folks,” he said.

Along with east Portland, other areas affected by both flooding and high-heat are southeast Portland and north Portland.

Chang said he hopes this research can be used as framework for other cities looking to do similar studies.