Ethan Yang and Team Receive $1 Million, 3-Year Research Award from the Department of Energy to Establish a Climate Resilience Center in the Lehigh Valley

According to the Department of Homeland Security, 90 percent of natural disasters in the United States involve flooding. While dealing with the actual flood can be difficult, after the water recedes there are often significant human and economic costs–the average cost of a flood event from excessive rainfall in the US is $4.7 billion. And costs could climb in the future, because more people are living in areas prone to flooding thanks to increasingly intense rainfalls, land development that eliminates rainwater-diverting features, and more housing built in flood-prone areas. Currently, 21.8 million homes and businesses are in the path of a potential flood, and 25 percent of the US’s critical infrastructures, such as hospitals and airports, are at risk of flooding. Another phenomenon is flash drought, which intensifies rapidly due to changes in rainfall, temperature, wind, and radiation. Flash droughts can cause extensive damage to agriculture, economies, and ecosystems and impact people's daily life on water supply curtailment.

Because of these risks, federal regulations require state and local governments to develop Climate Action Plans (CAPs) for their communities. These plans usually lay out strategies and priorities for a community, region, or state that will help the region adapt to and mitigate the negative impacts of climate change. They focus on areas such as transportation, agriculture, and industry; for example, the 2024 draft CAP for the Lehigh Valley, where Lehigh University is located, focuses on carbon emissions. However, in this as in many CAPs, there’s little information aimed at the local scale–smaller communities and towns that may lack the tools and resources to mitigate climate harm specific to their demographics and geography.

This “scale gap” between regional plans and local needs is the area Ethan Yang, Associate Professor of Civil and Environmental Engineering at Lehigh University, focuses on. “That is what we do,” he says, referring to himself and his team on this project. “We have devoted ourselves to these smaller-scale issues for almost a decade.”

This summer, Yang’s research efforts were recognized by the US Department of Energy (DOE), which awarded him and his team a $1 million, three-year grant, based on his proposal, “A Regional Climate Resilience Center for Water Extremes Adaptation Strategies Implementation,” to develop a climate resilience center (CRC) in the Lehigh Valley. In addition to Yang, the team includes Paolo Bocchini, Professor of Civil and Environmental Engineering and Director of the Catastrophe Modeling Center at Lehigh University; Maryam Rahnemoonfar, Associate Professor of Civil and Environmental Engineering and Computer Science and Engineering at Lehigh; David Casagranda, Professor of Anthropology and Director of Environmental Studies at Lehigh; Shalinee Kishore, Professor of Electrical and Computer Engineering and Director of the Institute for Cyber Physical Infrastructure and Energy at Lehigh; Farrah Moazeni, Assistant Professor of Civil and Environmental Engineering at Lehigh; Ruby Leung, Chief Scientist at Pacific Northwest National Laboratory; Hong-Yi Li, Associate Professor of Civil and Environmental Engineering at the University of Houston; Alka Sapat, Professor and Director School of Public Administration at Florida Atlantic University; and Anna Smith, Community Action Lehigh Valley in Bethlehem, Pennsylvania.

The goal of the research is to develop a climate resilience center for the Lehigh Valley. The center, which will be housed/operate under the Catastrophe Modeling Center, Lehigh’s first University Research Center, will analyze location-based extreme water events, particularly with floods and droughts, related to climate change. The researchers will consider the effects of CAP coordination in a region, assess the effects of the CAPs’ actions (for example, do they offset or amplify extreme weather effects), and investigate how different population groups respond, with particular interest in the responses of people who are members of disadvantaged communities. In this research, Yang is drawing on the principles of catastrophe modeling, a field of study with roots in the insurance industry that helps predict risk when risk is unpredictable–it’s a way of helping insure items or property when there are few historical precedents, such as an off-the-scale hurricane, for example.

Yang explains the purpose behind the DOE Biological and Environmental Research (BER) funding effort. “Through this call they want to figure out what science can do to help local people with climate change. One of the proposal requirements–to explain how existing DOE products, including computer models, databases, anything else that is created in a DOE project–can be leveraged to help the local people or the climate action plan.”

In the research, Yang and his team will incorporate the reactions of the members of the Lehigh Valley community to floods and drought. This community focus stems in part from the requirements of the award, but also, Yang says, derives from his interest in finding ways to incorporate human responses to climate change into a computer model. This approach also lets him explore both climate justice and water justice. Climate justice, he explains, is “the disproportional impact of climate change on a vulnerable population.” It focuses on the unequal impacts of climate change on vulnerable people, and the larger climatic effects on populations. But water justice involves the infrastructures that deliver water to homes–pipes, for example. But not all communities receive equal service; as Yang says, “there’s always some community where it’s easy to lose power, easy to lose water, or the water is too dirty. There’s a human component involved in the justice calculations, mostly driven by climate change.”

Climate change is one focus of a new community partnership among the mayor's offices of Allentown, Bethlehem, and Easton that will allow the cities to work on problems common to them, including the effects of climate change. It’s an effort to see the area as a region, and Yang and Kishore will attend meetings to get a feel for how the communities are reacting to flooding and drought. It’s also a community partnership that will enhance the human side of flood and drought response.

The research project has been designed as three tasks, each with subtasks, and each builds on the previous one. The first task will focus on data: the team will collect data on factors such as precipitation and temperature, and will administer a survey to residents to collect information about them, such as socioeconomic status, their perceptions of climate change, and their actions around flood and drought. Yang says the “questions will be along the lines of what do you think about future climate, have you experienced a flood or drought before, did you do anything to try to mitigate your future impact on drought or flood? The questions will help us collect the data that we need to build our model later.” The team will also downscale the climate data they pull from various sources. The downscaling of the data is one challenge to researchers' interest in local needs; climate data is often collected or created at a large scale. To work at the community level, the data needs to be “downscaled,” and this is a task for the research team. They will also analyze the use of household water affordability as an index for water justice, exploring this index’s usefulness. As Yang says, they plan to do “a more comprehensive review to see if there’s a better metric we can use to cover more justice issues.”

In the second task, the team will build four numerical models: hydrologic, flooding, water distribution, and human behavior. The hydrological model will produce simulated runoff and streamflow using the downscaled data from task 1, and the results will be used in a 2D flood inundation model to estimate flood damage as well as to simulate water distribution during drought. And the fourth model introduces an agent-based human behavior model derived from task 1’s survey of residents; in this model, household “agents” built from survey data will make climate action decisions based on factors like household income, previous experience, and homeownership.

The third task will develop various scenarios with residents and stakeholders’ data and look at various climate change projections to see what happens under the various scenarios. This will allow the researchers to see what conditions cause the most stress for various categories of resident, and it will allow them to see how various circumstances affect water justice.

Yang identifies four innovations in the research project. First is the simultaneous look at drought and flooding. Yang decided to add drought to this proposal, he says, partly due to feedback from a previous proposal and partly because he was feeling a little tired of a focus on floods. But introducing drought to the research presents another innovation to the field of catastrophe modeling: time. Most natural hazards, Yang says, happen in an instant: “Traditional catastrophe modeling usually focuses on the instant natural hazards, like flooding, earthquake, hurricane, tornados. They happen in very quick time.” Droughts, however, last for months or even years, and will require a different model-building philosophy. “Drought is a long-term phenomenon,” Yang says. “Traditional catastrophe modeling doesn’t cover drought. However, right now there are insurance companies trying to provide drought insurance. There might be a drought that happens in the next few years, the crop is going to die or people won’t have clean water supply for months, and insurance companies will pay. Because of that, drought also becomes an interest for insurance companies, and the insurance industry is a driver for catastrophe modeling.”

Another innovation Yang identifies is the combination of modeling approaches. He says “Other people have tried to do this, but there’s no universal rule about how to do it. So I want to use this project to evaluate different ways of connecting different models together.” And the final new approach Yang notes is the simultaneous consideration of the local environment and local community. “That’s also relatively rare, at least from the engineering perspective. Usually when we collaborate with the real-world stakeholders, it’s usually just one side, either from the NGO or the government.” This project’s focus on community groups and vulnerable populations as well as the role of government is unique, Yang says. “In this research we emphasize both the top-down and bottom-up approach, so we actually have both.”

The research officially begins in fall 2024. Because the team is geographically distributed and each member has other duties, they can’t meet as a group often, but the modular, task-progression nature of the research makes that a minor issue, Yang says. Although the name–climate resilience center–implies a physical space, the research will mostly happen computationally, although Yang and co-PI Kishore will attend the regional and local climate action plan meetings.

Awards for CRCs were made to universities in 10 states, from Alaska to Texas to Missouri, and encompasses natural phenomena from extreme heat to riverine threats to extreme rain and drinking water quality. Each locality offers a specific location for researchers to understand the effects of natural hazards. The combination of a variety of locations, varied approaches, and interdisciplinary research should help expand the understanding not just of the way our environment is constructed, but also how people react to extreme weather and how they can best manage and protect their communities.