Satellites Show, Stories Tell

A Life of Science: A Series by New Scientists

 
Floods are not just natural disasters—they act as agents of entrapment and displacement, perpetuating cycles of vulnerability for those living in precarious communities.

Sara’s words from 2021 echoed in my mind as I walked through the barrios of San Pedro Sula, Honduras. It was 2023.The bright sun beaming down on me and the children gathered in the community center was a stark contrast to the flood-ravaged landscape I had imagined based on the dozens of stories I’d heard from immigrants who fled this area two years prior. While there wasn’t active flooding during my visit, the traumatic impacts of Hurricanes Eta and Iota lingered in the memory of all Sampedranos, the people from San Pedro Sula. When I interviewed her, Sara had reflected on how the hurricanes tragically shaped her new life as an immigrant en route to the U.S., explaining to me how the hurricanes left all of Honduras destroyed. Sara, like many other immigrants I interviewed while they were staying temporarily at a migrant shelter in Matamoros, Mexico in 2021, had lost everything to those floods.

Growing up around immigrant family and friends, I was familiar with some of the challenges faced by those who leave their home countries. However, listening to countless stories of loss and determination through interviews with migrants made me realize that the relationship between disasters and human migration was even more complex than I previously imagined. Previously, I assumed this relationship existed in a linear manner: disaster strikes, people move.  What I came to realize is that numerous factors weigh on these decisions, and they aren’t necessarily straightforward. My journey to the research that would change my perspective began in the summer of 2021 in the border town of Matamoros, Mexico, where I was conducting fieldwork as a master’s student in geography at Texas State University. Matamoros was a common destination for migrants on the final stretch of their journey before crossing into the U.S. and had established migrant shelters. There, my research lab and I interviewed immigrants across different shelters, each person brave enough to share their harrowing story of displacement with us.

The descriptions of the hurricanes they fled painted vivid images in my mind: neighborhoods submerged under murky brown water rising to rooflines, entire hillsides collapsing in landslides, families wading through flood waters while carrying children above their heads, remains from horses, cows, dogs, and cats that decomposed in people’s yards and emitted unimaginable smells into the very air people were breathing, the eerie quiet that follows after a community has drowned beneath the flood’s surface. They spoke of a Honduras where rivers ignored their banks with violent force, where rainfall continued for days without end, where homes that stood for years disappeared overnight. These mental pictures haunted me long before I ever set foot in San Pedro Sula. Little did I know that I would be walking those very streets they had described two years later.

My background in geography frames how I understand these stories of displacement. In studying interactions between humans and their environment, I’ve come to realize that floods are not just natural disasters—they act as agents of entrapment and displacement, perpetuating cycles of vulnerability for those living in precarious communities. My research as a Ph.D. student in geography at the University of Arizona focuses on these complex and powerful dynamics. I examine how floods interact with other factors to influence human displacement and how recurrent floods in flood-vulnerable settlements create persistent states of instability. However, like many Central American countries, Honduras lacks consistent and reliable climate data. This data gap makes it challenging to understand where repeat floods occur, which communities are at higher risk, and the long-term impacts of these events. It is this critical knowledge gap that I aim to fill through my research.

Patterns began to emerge during my interviews in Matamoros in 2021. I noticed how floods had pushed people from rural areas into precarious urban settlements, where they faced the same flood risks in their new homes. These precarious settlements typically lack the infrastructure to mitigate flood risk, thus enabling a second wave of flood exposure for those who have recently relocated. This pattern results in already-vulnerable displaced peoples facing cycles of repeat flood exposure. Despite what I learned from the interviews, it wasn’t until my exploratory fieldwork in San Pedro Sula in the summer of 2023 that the total weight of these narratives hit me. For one month, I experienced firsthand the landscape I had only heard about through the stories of those who previously fled. I spoke with several current residents about their experiences with Eta and Iota, and that’s when something caught me by surprise.

During a conversation with Vanessa, a local Sampedrano who had welcomed me into her home, she reflected on her experiences with Eta and Iota. Vanessa balanced a baby on her hip while she opened up to me about her experiences. She mentioned a certain neighborhood park where the flooding had been particularly severe, trapping many people. A chill ran up my spine as I realized I had heard about this exact location before—from an immigrant I had interviewed in Matamoros two years earlier, Sara. Sara and Vanessa had experienced the same catastrophic floods, at the same park, yet their paths had diverged completely. One had managed to flee to the U.S.-Mexico border, while the other was still fighting to rebuild her life in San Pedro Sula.

This moment of connection between two separate interviews, conducted years and countries apart, highlighted the sometimes arbitrary nature of who leaves and who doesn’t, who seeks a better livelihood elsewhere and who remains to rebuild. Despite Sara and Vanessa’s vastly different outcomes, the eerie similarity of their stories underscores the profound impact that disaster events such as Hurricanes Eta and Iota have on individual lives and entire communities.
  

    
Bridging these personal narratives with scientific data has become central to my research methodology. I combine on-the-ground interviews with satellite imagery analysis in what’s called a mixed-methods approach. Through satellite data, I detect flood events. From miles above the Earth’s surface, satellites capture what our human eyes cannot. I spend hours at my desk looking over these digital canvases: false-color imagery that transforms Honduras’s landscape into hues of blues, greens, and reds to help visualize where water has claimed its place. The satellites pass overhead, silently witnessing the events, their sensors collecting light reflected from the Earth’s surface. Each pixel objectively capturing the scene, telling nothing of the human experience. What my screen shows in silent pixels, people like Sara or Vanessa describe with lived detail. I use these narratives to ground and refine the satellite findings.

The combination of both methods allows me to further gather comprehensive insights to provide nuance in these complex relationships, helping us better navigate current challenges and future scenarios. Throughout this research journey, I’ve been struck repeatedly by the thin line between displacement and remaining. In my conversations with both those who fled and those who stayed, I’ve come to see that this line isn’t just geographical—it’s economic, social, political, and sometimes simply a matter of timing or circumstance. The same flood that becomes the final breaking point for one family becomes another chapter of rebuilding for another. Understanding these decision points—the thresholds where environmental pressures translate to migration decisions—is crucial for developing interventions that support both those who leave and those who remain.

Elise Arellano-Thompson is a Ph.D. student in Geography at the University of Arizona, focusing on human-environment geography. Her research examines the complex relationships between floods and vulnerability, investigating how floods can perpetuate existing inequalities and exacerbate vulnerable circumstances. Further, she explores how neocolonial histories of landscape modifications continue to shape flood patterns today. Currently, Elise is living in Honduras under a Fulbright scholarship, conducting field research that brings her academic work into direct conversation with affected communities. Her approach combines spatial analyses with an understanding of the lived experiences of those navigating environmental challenges.

Header photo—flooding along the Rio Copan in Honduras following Hurricane Iota—by Diaz Hernandez Daniel, courtesy Wikimedia Commons.