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Researcher Spotlight – Thomas Thelen

2023-24 Global Change Research Fellow

PhD Student, Department of Civil, Construction, and Environmental Engineering
Advisor: Dr. Katherine Anarde
Every year the Southeast Climate Adaptation Science Center funds a multi-disciplinary cohort of Global Change Research Fellows representing colleges across NC State University. Here are some highlights about 2023-24 Fellow, Thomas Thelen and the applied research he’s conducting.

About You

What do you study?
I am a civil engineer specializing in coastal engineering. I focus on problems where water meets land. Specifically, I study coastal flooding that occurs more and more frequently with sea level rise, even outside of extreme storms like hurricanes. Some things I spend a lot of time thinking about include where, when, and why these floods occur; how these floods impact coastal residents; and what coastal communities can do to reduce this chronic flooding.

What (or who) influenced you to go into this field of study?
While pursuing my undergraduate degree at the University of Wisconsin-Madison, I worked as a coastal engineering intern with the consulting firm Baird. In this position, I helped develop the plans for a system of flood barriers for New York City. This work opened my eyes to the threat that sea level rise (SLR) poses to coastal communities. Coastal engineers must select a design lifespan and SLR scenario to determine the water levels that a structure should be built to withstand. But, because SLR projections developed with different assumptions can vary by several feet, uncertainties in future water levels complicate engineering design. Drawing on my experience at Baird, I analyzed the financial impact of choosing one design SLR projection over another. For the New York City flood barriers, I found that construction costs using different SLR assumptions differed by more than one billion dollars! This finding drove home the critical role that climate change will play in shaping the future of our coastal communities. 

What do you think is the most pressing issue related to global change?
Researchers have generated a whole suite of engineering models and potential interventions to help coastal communities adjust to global change and sea level rise. I think the biggest challenge facing coastal engineers is identifying strategies that are not only effective in mitigating global change issues (like flooding from sea level rise), but also in line with the at-risk communities’ vision for their future. To identify effective climate adaptation strategies that are preferred by coastal communities, we need interdisciplinary, community-engaged teams with the background to both identify how global change issues impact communities and design interventions that reduce these impacts.

About Your Research

Flooding starting to come up through stormwater drains in Carolina Beach, North Carolina

What results are you finding?
Coastal flooding caused by sea level rise is not a future problem. It is happening now, and it is happening frequently. Flooding sensors we have deployed in North Carolina communities show that some places are flooding 50 or more times a year. Higher coastal water levels mean that high tides can now overtop low lying shorelines. Even if the tide is not high enough to cause flooding by itself, coastal stormwater infrastructure that is underwater at normal tidal levels has a reduced capacity to drain rainfall runoff from roads, leading to flash flooding from everyday rain events. These multiple interacting flooding drivers make it difficult for coastal communities to predict when flooding will occur. Relying on tidal forecasts to predict flooding misses 30% of the floods we have measured, meaning that communities may be underprepared to deploy flood management measures like road closures for a significant percentage of the floods that they experience.

Who will benefit from your research?
The community-engaged research I do as part of the Sunny Day Flooding Project team directly benefits our partner communities by informing their climate resilience planning. In the Town of Carolina Beach, we are partnering with town officials to distribute a survey assessing residents’ perceptions of chronic flooding impacts and their preferred flood reduction strategies. We will convene a working group of residents and town officials to discuss survey results and identify priority strategies to model. Model results showing the flood prevention effectiveness of each strategy at current and future sea levels will inform a working group discussion of how each strategy aligns with the town’s future plans and goals.

How would you describe your research to a 3rd grader?
Water on roads causes problems for people who live near the ocean. People driving cars through the water get stuck, and the yucky water is not nice to walk through. We want to know how so much water moves from the ocean onto roads so we can come up with good ideas to keep this water away from places where people live.

About Your Global Change Research Fellow Experience

How do you expect the SE CASC Global Change Research Fellows Program to impact you and your work?
The Global Change Fellows Program has already made me a better science communicator. As a researcher who relies on community partners to guide research questions and methods, this ability to explain scientific results in everyday language is essential. Ultimately, my objective as a graduate student is to improve lives by collaborating with at-risk communities to co-produce climate adaptation strategies – informed by interdisciplinary science – for long-term resilience of people, landscapes, and ecosystems. SE CASC helps me work toward this goal by exposing me to an interdisciplinary group of scientists and partners to investigate global change from multiple perspectives.

What advice would you give to a student that is interested in getting involved in your field?
Climate adaptation and global change issues are inherently interdisciplinary problems that span multiple academic fields. To address challenges in this space, you will need to learn skills and ways of thinking beyond your field of study. Take classes outside your major and attend talks from speakers in fields that are different from your own to better understand how other disciplines might perceive the issues you are working on. Learning to communicate effectively across disciplines and outside of academia will make your work more accessible and applicable to real world problems.

What has been the most rewarding part or your favorite part of being a SE CASC Global Change Research Fellow?
I learned a lot from the Global Change Fellows Field Intensive Retreat. Touring Cape Hatteras National Seashore and discussing sea level rise-related challenges with Superintendent Dave Hallac provided a firsthand look at how organizations and communities along the coast perceive their climate adaptation options. Following my graduation, I hope to be involved in similar discussions about solutions and policies that will help our coastal communities thrive over the next century. The Field Intensive Retreat equipped me with the community-engaged research, science communication, climate modeling, and decision-making skills that I will need to impact others for the better by sharing my coastal engineering research findings directly with the communities that benefit most from them


Want to see if it is flooding at the coast right now? You can view live and historic water levels plus real-time photos of flooding hotspot in our partner communities at Check in during king tides or rain events and you might see an image like this.

Chronic coastal flooding driven by rainfall at high tide in Carolina Beach, NC – June 10, 2022. Floodwaters have tipped over trash cans and caused a vehicle to stall. (Source: Sunny Day Flooding Project camera)