Last month, Brazil faced a humanitarian and environmental disaster when a dam containing 15 million cubic yards of mine waste material abruptly collapsed. A deluge of muddy waste engulfed the area and stretched several kilometers away reaching the Paraopeba River.
When catastrophic disasters like this occur, both emergency responders and scientists look to satellite observations to obtain an accurate picture of the extent and details of the damage. Many choose the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) to obtain expedited observations of disaster-stricken areas since ASTER data can be acquired on-demand.*
An ASTER L1BE and ASTER L1T image are provided below to capture the magnitude of the dam collapse that occurred on January 25, 2019, at an iron ore mining complex located near Brumadinho, Brazil. The ASTER L1T image (left), acquired on April 6, 2017, shows the area prior to the dam collapse. The ASTER L1BE image (right) is an unprocessed, expedited radiance image that was specifically tasked on January 31, 2019, to observe the area where the dam collapse took place. Expedited and tasked acquisitions such as these enable scientists and response teams to perform quick and detailed assessments of global disasters. The ASTER L1BE data will be processed into a series of higher level products, such as the precision terrain corrected radiance image, known as ASTER L1T. ASTER is often tasked to support emergency situations because of its ability to acquire and distribute expedited data during critical situations.
The usefulness of ASTER data in disaster management doesn’t stop here. Some scientists are going beyond visual analysis and are also extracting the information derived from ASTER higher level products to learn more information about disaster prone areas. For instance, a recent study used ASTER L1T data over an area prone to landslides in the south of Mexico to develop change detection techniques that can be used to build landslide inventory maps (Ramos-Bernal and others, 2018). Forkuo and others (2011) used topographic information derived from ASTER L1B to develop flood hazard maps in Ghana. Studies such as these highlight the important role that ASTER plays in disaster management.
*For information on how to apply to be an approved user and submit a request for on-demand ASTER data, visit the NASA JPL ASTER website on Requesting New Acquisitions. All users with a NASA Earthdata Login Account can access archived ASTER data through NASA Earthdata Search.
Forkuo, E.K., 2011, Flood hazard mapping using Aster image data with GIS: International Journal of Geomatics and Geosciences, v. 1, no. 4, p. 932–950, accessed February 8, 2019, at http://www.ipublishing.co.in/jggsvol1no12010/EIJGGS2051.pdf.
NASA, 2019, Another deadly dam collapse in Brazil: Earth Observatory, February 4, 2019, accessed February 7, 2019 at https://earthobservatory.nasa.gov/images/144501/another-deadly-dam-collapse-in-brazil?src=nha.
Ramos-Bernal, R.N., Vázquez-Jiménez, R., Romero-Calcerrada, R., Arrogante-Funes, P., Novillo, Carlos J., 2018, Evaluation of unsupervised change detection methods applied to landslide inventory mapping using ASTER imagery: Remote Sensing, v. 10, no. 12, art. no. 1987, accessed February 7, 2019, at https://dx.doi.org/10.3390/rs10121987.
Material written by Sydney Neeley¹
¹Innovate!, Inc., contractor to the U.S. Geological Survey, Earth Resources Observation and Science (EROS) Center, Sioux Falls, South Dakota, USA. Work performed under USGS contract G15PC00012 for LP DAAC².
²LP DAAC work performed under NASA contract NNG14HH33I.