Landslide Forecasting in Puerto Rico
In November and December 2021, USGS scientists Kelli Baxstrom, Emily Bedinger, Mason Einbund, Bill Schulz, John Spritzer, and Bill Worthington of the Geologic Hazards Science Center and Corina Cerovski-Darriau of the Geology, Minerals, Energy, and Geophysics Science Center traveled to Puerto Rico to construct the first three stations of Puerto Rico’s new landslide forecasting network. The network is expected to have an estimated 15 stations when completed.
Designed in collaboration with the University of Puerto Rico-Mayagüez and the San Juan forecasting office of NOAA’s National Weather Service (NWS), the project was developed using supplemental funding to create the most comprehensive landslide hydrologic monitoring network in the United States. The data from these monitoring stations will be posted in near-real time on public-facing websites and will be used to develop a landslide forecasting and alerting system. The stations are solar powered, and staff scientists with the University of Puerto Rico-Mayagüez will maintain them to ensure they remain operational in the challenging jungle environment. USGS experts will use the island-wide hydrologic monitoring network to aid landslide research and forecasting in Puerto Rico.
Landslides are the downward movement of soil, rock, and organic material affected by gravity and influenced by the shape of the terrain. They can occur in just seconds or can develop slowly over the course of years. In Puerto Rico, landslides present significant hazards to human safety and property due to the mountainous terrain and tropical rainfall events. In 2017, rainfall associated with Hurricane Maria triggered more than 70,000 landslides that caused several fatalities both direct and indirectly along with widespread damage that disrupted transportation routes and other vital infrastructure and dislodged homes from their foundations. The USGS Landslide Hazards Program received supplemental appropriations to help reduce risk and loss from landslide hazards on the island. The USGS is also creating landslide susceptibility maps and other tools to predict where future landslides are likely to occur and how far they will travel.
In Puerto Rico, landslide science is at a point where we can approximately predict where they will happen and how far they will go. However, it’s also critical to know when landslides will occur. To predict this, scientists need to understand the conditions that allow for them to occur. This includes understanding soil moisture, the type of rock and soil, and the angle of the slope. The new USGS hydrologic monitoring network represents a key step forward in the collection of real-time data needed to improve landslide forecasting efforts in Puerto Rico. These on-the-ground measurements can be combined with satellite and radar datasets produced by other Federal agencies, including the National Aeronautics and Space Administration (NASA) and NWS, to refine soil moisture forecasts in time and space, thereby improving the ability to forecast landslides.