SEDAC Hazards Mapper Provides a Rapid Assessment of Risk

Determining risk from a wide range of natural hazards is only a mouse click away thanks to SEDAC's Hazards Mapper application.

October 16, 2015, was an ordinary day on our active planet. Sumatra’s Mount Sinabung volcano erupted, spreading ash, lava, and pyroclastic flows across northern regions of this Indonesian island. On this same day, a tropical depression churned toward the Hawaiian Islands as it slowly strengthened into Hurricane Olaf. Meanwhile, much of South Carolina was still recovering from storms that dropped more than a half-meter (two feet) of water across parts of the state between September 26 and October 5. Those responding to and reporting on these and other natural disasters occurring every day around the globe need a rapid approximation of the number of individuals impacted by these events. This information is only a mouse click away thanks to NASA’s Socioeconomic and Data Applications Center (SEDAC) Hazards Mapper.

Users can designate geographic areas using circles or polygons and receive population and area estimates for the designated region. Image: NASA SEDAC, 10/08/15.
Users can designate geographic areas using circles or polygons and receive population and area estimates for the designated region. Image: NASA SEDAC, 10/08/15.

SEDAC’s Hazards Mapper enables users to rapidly get an idea of the population, land area, dams, and nuclear power plants that could be impacted by a wide range of natural events, including floods, earthquakes, fires, and volcanic eruptions. “The population layers we produce have always been a critical component in understanding degrees of exposure to different natural hazards,” says SEDAC deputy manager Alex de Sherbinin. “The Hazards Mapper allows users to interface with numerous data sets we have that relate to hazards and exposure.”

The Hazards Mapper was just released as an app through the Apple iTunes Store that is compatible with the Apple iPhone, iPad, and iPod touch. The Hazards and Population Mapper app features three SEDAC data sets (Gridded Population of the World v3 [GPWv3], Nuclear Power Plants Locations v1, and Global Reservoirs and Dams v1.1) along with NASA near real-time active fire and aerosol optical depth (AOD) data, USGS global earthquake alerts, and NOAA flood and tornado alerts (for the US only).

SEDAC is one of NASA's Earth Observing System Data and Information System (EOSDIS) Distributed Active Archive Centers (DAACs) that process, archive, and distribute discipline-specific data from NASA’s satellite, airborne, and field-based Earth observing missions. Located at the Lamont Campus of Columbia University in Palisades, NY, SEDAC is hosted by the Center for International Earth Science Information Network (CIESIN), which is a center of Columbia’s Earth Institute. SEDAC focuses on developing and operating applications supporting the integration of socioeconomic and earth science data and serving as an “information gateway” between the earth and social sciences.

As de Sherbinin notes, the Hazards Mapper unites several SEDAC data sets into one easy-to-use application. “We wanted to develop a user-friendly tool to integrate some of our population and infrastructure data—such as information about large dams and nuclear power plants—to give a better picture to users about the numbers of people who might be impacted by natural hazards like earthquakes, tornadoes, and floods as well as fires and their associated smoke plumes,” he says.

The Hazards Mapper home page is a base map of the world with darker shaded areas indicating higher population densities. Custom population estimates generated by the Hazards Mapper are provided by SEDAC’s Population Estimation Service (PES). Population and settlement data are based on SEDAC’s Global Rural-Urban Mapping Project (GRUMP) and Gridded Population of the World, version 3 (GPWv3) data collections. GPWv3 provides a resolution of roughly 4 km (2.5 miles) at the equator. This population resolution will increase significantly when the updated version, GPWv4, is released in 2016. “Our new population layer will be at a resolution of 1 km (0.6 miles) at the equator, which will give higher precision for smaller areas,” says de Sherbinin.

Continuously updated data layers that can be overlaid on the base map are available from NASA’s EOSDIS, including data from SEDAC; NASA's Land, Atmosphere Near real-time Capability for EOS (LANCE); and Global Imagery Browse Services (GIBS). Additional data are available from sources including USGS and NOAA.

This image of Papua New Guinea shows population densities indicated by brown and yellow shaded areas, with darker colors indicating higher densities. Red dots indicate fires or other hotspots detected by NASA’s MODIS instrument. Green and blue circles indicate earthquakes detected in the past seven days. Blue icons indicate dams. Image: NASA SEDAC, 09/24/15.

The default base map includes:

  • Red dots indicating fires and other hotspots detected over the past 48 hours by NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS) instrument;
  • Colored circles indicating earthquakes over the past seven days from the USGS Earthquake Hazards Program;
  • Icons indicating the location of individual dams, dam clusters, and nuclear power plants from SEDAC’s Global Reservoir and Dam and Population Exposure Estimates in Proximity to Nuclear Power Plants, Locations databases; and,
  • Colored polygons indicating tornado and flood warnings issued by NOAA (U.S. locations only).

An aerosol optical depth layer from NASA’s GIBS can be added to the base map by checking a box in the home page drop-down menu. In addition, clicking on a dam or nuclear plant icon pulls up a satellite image of the structure or power plant in question along with information about the facility. For dams this information includes location and, if known, primary use (irrigation, flood control, etc.); for nuclear plants this includes the number and type of reactors and the plant’s power output over the past several years.

Image: NASA SEDAC, 09/24/15.
Image: NASA SEDAC, 09/24/15.

The application has a broad range of uses, and de Sherbinin points out that it is a good resource for information about large, global events. “We expect that humanitarian organizations will benefit by being able to get a quick estimate of how many people may be affected by a large natural disaster. For example, if there’s an earthquake anywhere in the world, they can draw a polygon around an area that’s affected and come up with a population count that can give them a first order assessment of the potential for mortality, potential displacement, and other information to enable them to make initial assessments of the impact and to estimate the level of response required,” he says. “Another use case is for journalists who want first order assessments of the number of people who might be in harm’s way in an event.”

The SEDAC Hazards Mapper’s combination of socioeconomic data and continuously updated natural hazard information from a variety of sources provides a powerful, easy to use application for a wide range of users, de Sherbinin observes. “Combining our population data with different natural hazards is one way we can help better understand risk,” he adds.

Additional Resources

SEDAC Hazards Mapper

SEDAC Hazards and Population Mapper app from the Apple iTunes Store



SEDAC presented Hazards Mapper webinar on Wednesday, November 18, at 2 pm, EST. View this webinar.


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