(Left) Map of Puerto Rico showing study area location (red box), the oceanographic buoys (orange triangles), and the track of María with eye timing and locations (black dots) in 6-hour increments and the wind radii of 64-knot winds (gray circular outlines).
In September 2017 Hurricane María triggered more than 70,000 landslides across Puerto Rico that caused loss of life and widespread damage to transportation, communication, and power-supply infrastructure, and to other public and private property.
Reduction of Hazards from Intense Rainfall-Induced Landslides in Puerto Rico
![damaged home at bottom of short steep muddy cliff](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/side_image/public/thumbnails/image/pr-rain-ls-bldg_0.jpg?itok=d6__-ClF)
To help to reduce the hazards from future landslide events, the USGS Landslide Hazards Project (LHP) and their partners are performing a 3.5-year-long study that will improve understanding of landslides in Puerto Rico and methods for spatially and temporally forecasting landslide occurrence. More specifically, the LHP is leveraging advances in remote sensing (primarily lidar, InSAR, and optical imagery), laboratory testing, and field observation, monitoring, testing, and data collection to map, characterize, and analyze landslides throughout Puerto Rico. These studies will improve understanding of where and when landslides are most likely, which is of critical importance, but also the characteristics of landslides as they form and move downslope; most landslides in Puerto Rico display long travel distances making them hazardous far from their initiation sites. Led by partners at the University of Puerto Rico – Mayagüez, the USGS has published an inventory of landslides triggered by Hurricane Maria and an island-wide map depicting susceptibility to intense rainfall-induced landslides that was developed using the inventory and analyses of multiple factors contributing to landslide occurrence. The LHP also continues development of state-of-the-science tools for modeling and forecasting where landslides are likely to occur, and where they are likely to travel after occurrence. Models are being developed and tested using input obtained from our remote sensing, field, and laboratory studies. Following validation, models will be applied to create landslide susceptibility maps for areas having highest priority for landslide hazard reduction.
For More Information
- Other USGS science activities and research in Puerto Rico
- Puerto Rico Landslide Hazard Mitigation Project - Natural Hazards Center
- Puerto Rico Landslide Susceptibility Tool - English
- Puerto Rico Mapa De Susceptibilidad A Deslizamientos De Tierra Aplicación Web - Spanish
- SLIDES-PR: Storm-induced Landslide Impact Dynamics on Environment and Society in Puerto Rico (Hughes UPRM Geology)
- Have you thought about what would happen if your property were affected by a landslide? (Natural Hazards Center)
- ¿Has pensado qué pasaría si tu propiedad fuera afectada por un deslizamiento de tierra? (Natural Hazards Center)
Puerto Rico Landslide Hazard Mitigation Project
Below are data or web applications associated with this project.
Map data from landslides triggered by Hurricane Maria in the greater karst region of northwest Puerto Rico
Map data from landslides triggered by Hurricane Maria in four study areas in the Utuado Municipality, Puerto Rico
Map data from landslides triggered by Hurricane Maria in a section of Naranjito, Puerto Rico
Map data from landslides triggered by Hurricane Maria in three study areas in the Lares Municipality, Puerto Rico
Map data from landslides triggered by Hurricane Maria in four study areas of Puerto Rico
Infiltration data collected post-Hurricane Maria across landslide source area materials, Puerto Rico, USA
Below are multimedia items associated with this project.
![A series of three images arranged side by side, one a map of an island, one zoomed to the island study area, and a plot of data.](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/image/Maria.jpg?itok=6tCSk3pw)
(Left) Map of Puerto Rico showing study area location (red box), the oceanographic buoys (orange triangles), and the track of María with eye timing and locations (black dots) in 6-hour increments and the wind radii of 64-knot winds (gray circular outlines).
![Four USGS scientists on mountainside with landslides and downed trees](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/image/PR%20landslide%204%20ground%20view%20las%20Marias%20Schulz_smaller.jpg?itok=Pz2jF7n6)
USGS ground failure experts examine landslides after Hurricane Maria in the municipality of Las Marias, Puerto Rico.
USGS ground failure experts examine landslides after Hurricane Maria in the municipality of Las Marias, Puerto Rico.
![Aeirial view of landslides blocking roads in Utuado, Puerto Rico](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/image/PR%20landslide%201%20Erin%20Bessette_Kirton%20Utualdo%20USGS_smaller%202.jpg?itok=PENJXGft)
An aerial view of landslide damage after Hurricane Maria in Utuado municipality, Puerto Rico.
An aerial view of landslide damage after Hurricane Maria in Utuado municipality, Puerto Rico.
Rapid sensitivity analysis for reducing uncertainty in landslide hazard assessments
Hillslopes in humid-tropical climates aren’t always wet: Implications for hydrologic response and landslide initiation in Puerto Rico, USA
The devastating impacts of the widespread flooding and landsliding in Puerto Rico following the September 2017 landfall of Hurricane Maria highlight the increasingly extreme atmospheric disturbances and enhanced hazard potential in mountainous humid‐tropical climate zones. Long‐standing conceptual models for hydrologically driven hazards in Puerto Rico posit that hillslope soils remain wet through
Mobility characteristics of landslides triggered by Hurricane Maria in Puerto Rico
Map depicting susceptibility to landslides triggered by intense rainfall, Puerto Rico
Landslides in Puerto Rico range from nuisances to deadly events. Centuries of agricultural and urban modification of the landscape have perturbed many already unstable hillsides on the tropical island. One of the main triggers of mass wasting on the island is the high-intensity rainfall that is associated with tropical atmospheric systems. Puerto Rico’s geographic position and rugged topography re
Debris-flow growth in Puerto Rico during Hurricane Maria: Preliminary results from analyses of pre- and post-event lidar data
Landslides triggered by Hurricane Maria: Assessment of an extreme event in Puerto Rico
Hurricane Maria hit the island of Puerto Rico on 20 September 2017 and triggered more than 40,000 landslides in at least three-fourths of Puerto Rico’s 78 municipalities. The number of landslides that occurred during this event was two orders of magnitude greater than those reported from previous hurricanes. Landslide source areas were commonly limited to surficial soils but also extended into und
Below are news stories associated with this project.
Below are FAQ associated with this project.
What is a landslide and what causes one?
A landslide is defined as the movement of a mass of rock, debris, or earth down a slope. Landslides are a type of "mass wasting," which denotes any down-slope movement of soil and rock under the direct influence of gravity. The term "landslide" encompasses five modes of slope movement: falls, topples, slides, spreads, and flows. These are further subdivided by the type of geologic material...
Can major landslides and debris flows happen in all areas of the U.S.?
Landslides can and do occur in every state and territory of the U.S.; however, the type, severity, and frequency of landslide activity varies from place to place, depending on the terrain, geology, and climate. Major storms have caused major or widespread landslides in Washington state, Oregon, California, Colorado, Idaho, Hawaii, Virginia, Ohio, Pennsylvania, Tennessee, North Carolina, Puerto...
What is the difference between a landslide advisory, a landslide watch, and a landslide warning?
An advisory is a general statement about the potential of landslide activity in a given region relative to developing rainfall predictions. An advisory may include general statements about rainfall conditions that can lead to debris-flow activity, and list precautions to be taken in the event of heavy rainfall. A watch means that landslide-activity will be possible, but is not imminent. People in...
What is a debris flow?
Debris flows are fast-moving landslides that are particularly dangerous to life and property because they move quickly, destroy objects in their paths, and often strike without warning. They occur in a wide variety of environments throughout the world, including all 50 states and U.S. Territories. Debris flows generally occur during periods of intense rainfall or rapid snowmelt and usually start...
What is a landslide hazard map?
Several kinds of maps are used to depict danger from landslides. These maps might be as simple as a map that uses the locations of old landslides to indicate potential instability, or as complex as a map incorporating probabilities based on variables such as rainfall, slope angle, soil type, and levels of earthquake shaking. The following types of maps are used to describe and depict landslide...
Do human activities cause landslides?
Yes, in some cases human activities can be a contributing factor in causing landslides. Many human-caused landslides can be avoided or mitigated. They are commonly a result of building roads and structures without adequate grading of slopes, poorly planned alteration of drainage patterns, and disturbing old landslides. Detailed on-site investigation is required to determine the importance of human...
Under what circumstances do U.S. Geological Survey landslide personnel conduct field work in landslide-prone areas?
USGS landslide researchers have ongoing field projects in several areas of the United States, including parts of the Pacific coastal ranges, Rocky Mountains, and the Appalachians. USGS scientists also respond to major landslide events, including some that result in federally-declared disasters. In some cases, USGS scientists respond to landslides in foreign countries that request assistance...
In September 2017 Hurricane María triggered more than 70,000 landslides across Puerto Rico that caused loss of life and widespread damage to transportation, communication, and power-supply infrastructure, and to other public and private property.
Reduction of Hazards from Intense Rainfall-Induced Landslides in Puerto Rico
![damaged home at bottom of short steep muddy cliff](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/side_image/public/thumbnails/image/pr-rain-ls-bldg_0.jpg?itok=d6__-ClF)
To help to reduce the hazards from future landslide events, the USGS Landslide Hazards Project (LHP) and their partners are performing a 3.5-year-long study that will improve understanding of landslides in Puerto Rico and methods for spatially and temporally forecasting landslide occurrence. More specifically, the LHP is leveraging advances in remote sensing (primarily lidar, InSAR, and optical imagery), laboratory testing, and field observation, monitoring, testing, and data collection to map, characterize, and analyze landslides throughout Puerto Rico. These studies will improve understanding of where and when landslides are most likely, which is of critical importance, but also the characteristics of landslides as they form and move downslope; most landslides in Puerto Rico display long travel distances making them hazardous far from their initiation sites. Led by partners at the University of Puerto Rico – Mayagüez, the USGS has published an inventory of landslides triggered by Hurricane Maria and an island-wide map depicting susceptibility to intense rainfall-induced landslides that was developed using the inventory and analyses of multiple factors contributing to landslide occurrence. The LHP also continues development of state-of-the-science tools for modeling and forecasting where landslides are likely to occur, and where they are likely to travel after occurrence. Models are being developed and tested using input obtained from our remote sensing, field, and laboratory studies. Following validation, models will be applied to create landslide susceptibility maps for areas having highest priority for landslide hazard reduction.
For More Information
- Other USGS science activities and research in Puerto Rico
- Puerto Rico Landslide Hazard Mitigation Project - Natural Hazards Center
- Puerto Rico Landslide Susceptibility Tool - English
- Puerto Rico Mapa De Susceptibilidad A Deslizamientos De Tierra Aplicación Web - Spanish
- SLIDES-PR: Storm-induced Landslide Impact Dynamics on Environment and Society in Puerto Rico (Hughes UPRM Geology)
- Have you thought about what would happen if your property were affected by a landslide? (Natural Hazards Center)
- ¿Has pensado qué pasaría si tu propiedad fuera afectada por un deslizamiento de tierra? (Natural Hazards Center)
Puerto Rico Landslide Hazard Mitigation Project
Below are data or web applications associated with this project.
Map data from landslides triggered by Hurricane Maria in the greater karst region of northwest Puerto Rico
Map data from landslides triggered by Hurricane Maria in four study areas in the Utuado Municipality, Puerto Rico
Map data from landslides triggered by Hurricane Maria in a section of Naranjito, Puerto Rico
Map data from landslides triggered by Hurricane Maria in three study areas in the Lares Municipality, Puerto Rico
Map data from landslides triggered by Hurricane Maria in four study areas of Puerto Rico
Infiltration data collected post-Hurricane Maria across landslide source area materials, Puerto Rico, USA
Below are multimedia items associated with this project.
![A series of three images arranged side by side, one a map of an island, one zoomed to the island study area, and a plot of data.](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/image/Maria.jpg?itok=6tCSk3pw)
(Left) Map of Puerto Rico showing study area location (red box), the oceanographic buoys (orange triangles), and the track of María with eye timing and locations (black dots) in 6-hour increments and the wind radii of 64-knot winds (gray circular outlines).
(Left) Map of Puerto Rico showing study area location (red box), the oceanographic buoys (orange triangles), and the track of María with eye timing and locations (black dots) in 6-hour increments and the wind radii of 64-knot winds (gray circular outlines).
![Four USGS scientists on mountainside with landslides and downed trees](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/image/PR%20landslide%204%20ground%20view%20las%20Marias%20Schulz_smaller.jpg?itok=Pz2jF7n6)
USGS ground failure experts examine landslides after Hurricane Maria in the municipality of Las Marias, Puerto Rico.
USGS ground failure experts examine landslides after Hurricane Maria in the municipality of Las Marias, Puerto Rico.
![Aeirial view of landslides blocking roads in Utuado, Puerto Rico](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/masonry/public/thumbnails/image/PR%20landslide%201%20Erin%20Bessette_Kirton%20Utualdo%20USGS_smaller%202.jpg?itok=PENJXGft)
An aerial view of landslide damage after Hurricane Maria in Utuado municipality, Puerto Rico.
An aerial view of landslide damage after Hurricane Maria in Utuado municipality, Puerto Rico.
Rapid sensitivity analysis for reducing uncertainty in landslide hazard assessments
Hillslopes in humid-tropical climates aren’t always wet: Implications for hydrologic response and landslide initiation in Puerto Rico, USA
The devastating impacts of the widespread flooding and landsliding in Puerto Rico following the September 2017 landfall of Hurricane Maria highlight the increasingly extreme atmospheric disturbances and enhanced hazard potential in mountainous humid‐tropical climate zones. Long‐standing conceptual models for hydrologically driven hazards in Puerto Rico posit that hillslope soils remain wet through
Mobility characteristics of landslides triggered by Hurricane Maria in Puerto Rico
Map depicting susceptibility to landslides triggered by intense rainfall, Puerto Rico
Landslides in Puerto Rico range from nuisances to deadly events. Centuries of agricultural and urban modification of the landscape have perturbed many already unstable hillsides on the tropical island. One of the main triggers of mass wasting on the island is the high-intensity rainfall that is associated with tropical atmospheric systems. Puerto Rico’s geographic position and rugged topography re
Debris-flow growth in Puerto Rico during Hurricane Maria: Preliminary results from analyses of pre- and post-event lidar data
Landslides triggered by Hurricane Maria: Assessment of an extreme event in Puerto Rico
Hurricane Maria hit the island of Puerto Rico on 20 September 2017 and triggered more than 40,000 landslides in at least three-fourths of Puerto Rico’s 78 municipalities. The number of landslides that occurred during this event was two orders of magnitude greater than those reported from previous hurricanes. Landslide source areas were commonly limited to surficial soils but also extended into und
Below are news stories associated with this project.
Below are FAQ associated with this project.
What is a landslide and what causes one?
A landslide is defined as the movement of a mass of rock, debris, or earth down a slope. Landslides are a type of "mass wasting," which denotes any down-slope movement of soil and rock under the direct influence of gravity. The term "landslide" encompasses five modes of slope movement: falls, topples, slides, spreads, and flows. These are further subdivided by the type of geologic material...
Can major landslides and debris flows happen in all areas of the U.S.?
Landslides can and do occur in every state and territory of the U.S.; however, the type, severity, and frequency of landslide activity varies from place to place, depending on the terrain, geology, and climate. Major storms have caused major or widespread landslides in Washington state, Oregon, California, Colorado, Idaho, Hawaii, Virginia, Ohio, Pennsylvania, Tennessee, North Carolina, Puerto...
What is the difference between a landslide advisory, a landslide watch, and a landslide warning?
An advisory is a general statement about the potential of landslide activity in a given region relative to developing rainfall predictions. An advisory may include general statements about rainfall conditions that can lead to debris-flow activity, and list precautions to be taken in the event of heavy rainfall. A watch means that landslide-activity will be possible, but is not imminent. People in...
What is a debris flow?
Debris flows are fast-moving landslides that are particularly dangerous to life and property because they move quickly, destroy objects in their paths, and often strike without warning. They occur in a wide variety of environments throughout the world, including all 50 states and U.S. Territories. Debris flows generally occur during periods of intense rainfall or rapid snowmelt and usually start...
What is a landslide hazard map?
Several kinds of maps are used to depict danger from landslides. These maps might be as simple as a map that uses the locations of old landslides to indicate potential instability, or as complex as a map incorporating probabilities based on variables such as rainfall, slope angle, soil type, and levels of earthquake shaking. The following types of maps are used to describe and depict landslide...
Do human activities cause landslides?
Yes, in some cases human activities can be a contributing factor in causing landslides. Many human-caused landslides can be avoided or mitigated. They are commonly a result of building roads and structures without adequate grading of slopes, poorly planned alteration of drainage patterns, and disturbing old landslides. Detailed on-site investigation is required to determine the importance of human...
Under what circumstances do U.S. Geological Survey landslide personnel conduct field work in landslide-prone areas?
USGS landslide researchers have ongoing field projects in several areas of the United States, including parts of the Pacific coastal ranges, Rocky Mountains, and the Appalachians. USGS scientists also respond to major landslide events, including some that result in federally-declared disasters. In some cases, USGS scientists respond to landslides in foreign countries that request assistance...