Connor here: This weekend, Tropical Storm Chantal hit SEMS in a timely manner.
Brian J. Yanite, Associate Professor of Earth and Atmospheric Science and Professor of Sedimentary and Sedimentary Geology at Indiana University. It was originally published in conversation.
Hurricane Helen lasted only a few days in September 2024, but it combines the landscape of the southeastern United States in a deep way that affects the dangers local residents face in the future.
Landslide buried roads and remodeled river channels. The uprooted tree left soil on the hillsides exposed to the elements. The sediments washed away by the river changed the way the water flowed through the landscape, leaving a prone to flooding and erosion-prone child seas area.
Helen was a strong reminder that natural disasters do not disappoint when the sky is cleaned – they evolve.
These transformations are part of what scientists call cascade hazards. They change the landscape in a way that one natural event in Oscur Ken leads to dangers in the future. Landslides caused by storms can clog the river and lead to downstream flooding in months or years. Wildfires can change soil and vegetation and set stages of debris flow in the next storm.
Satellite images for the front (top) and after Hurricane Helen (bottom) show how the storm near Pensacola in Blue Ridge Mountains blew the scenery away. Google Earth, CC by
I am a geomorphologist studying disasters. In a new paper in the science journal, I and a team of scientists from 18 university universities and a US geological survey explain why the hazard model used to help communities prepare for disasters cannot be relied on the past. Inserted, they need to be resourceful to predict how danger will evolve in real time.
The science behind the cascade hazard
Random of Cascade Hazards. They emerge from physical processes that operate continuously across the landscape, such as sediment movement, weathering, and erosion. Together, the atmosphere, the biosphere and the Earth are constantly changing the conditions that cause natural disasters.
For example, earthquakes destroy rocks and shake loose soil. Even if the landslide does not oscrub during the earthquake itself, the ground can be weakened and ready for breakdowns during the later rainstorm.
That’s exactly what happened after the 2008 earthquake in Sichuan, China.
The surface of the earth holds a “memory” of these events. Sediments disrupted by earthquakes, wildfires, or severe storms can travel downhill over years or decades, reconstructing the landscape in that way.
The 1950 Assam earthquake in India is an impressive example. It caused thousands of landslides. The sediment from the landslide gradually passed through the river system, eventually causing flooding in Bangladesh and changes in the river channels 20 years later.
Intellectual threats in a changing world
These risks present everyday challenges, from emergency planning to home insurance. After a repeated combination of wildfires and confusion in California, the subinsurer was pulled entirely from the state, citing increased risk and costs among its reasons.
The dangers of cascades are not new, but their effects are tidy.
Climate change is increasing the frequency and severity of wildfires, storms and extreme rainfall. At the same time, urban development continues to expand into steep, at-risk terrain, putting more people and infrastructure at risk of evolving.
This increased risk of interconnected climate disasters is an overwhelming system built for isolated events.
However, climate change is only part of the equation. It often has long-term effects, such as the treatment of the Earth, volcanic eruptions, and the like.
Mount St. Helens is a powerful example. More than 40 years after the 1980 eruption, the US Army Corps of Engineers will continue to manage ash and sediment from the eruption, avoiding filling river channels in ways that increase flood risk in downstream communities.
Risk of risk and resilience of construction
Traditionally, insurance companies and disaster managers have estimated risks by examining past events.
But when the landscape changes, the past may no longer be a reliable guide to the future. To address this, a computer model is required based on the physics of how these events are needed to predict the evolution of danger in real time, such as weather models being updated with new atmospheric data.
A landslide on the Oregon Coast Range in March 2024 wiped out the trees on the road. Brian Yangite, June 2025
Drone images from the same March 2024 landslide on the Oregon Coast Range show the location of a violent damming on the river below. Brian Yangite, June 2025
Thanks to advances in earth observation technologies such as satellite imagery, drones and ledders, it resembles radar, but uses light, allowing scientists to track how hillsides, rivers and vegetation changes after a disaster. These observations can be fed to a topographical model that simulates how sediment moves and where the next danger is likely to appear.
Researchers have already combined weather forecasts with debris flow models after wildfire. The OTER model travels through a network of rivers simulating WHW sediments.
The dangers of the Cascade reveal that the Earth’s surface is not a passive background, but an active, evolving system. Each event reshapes the next stage.
Before connecting, it is essential to building resilience, allowing communities to withstand the problems that arise from future storms, earthquakes, and debris flows. A better forecast can inform building standards, guide infrastructure designs, and improve risk pricing and how risk is managed. They can help communities predict long-term threats and adapt before the next disaster occurs.
Most importantly, they challenge everyone to think beyond the immediate aftermath of a disaster, picking up a slow, quiet transformation towards the next disaster.
