Disasters Program Highlights week of 3/25/19

ARIA Team Uses Multiple Satellites to Create Flood Proxy Maps for Mozambique

The Advanced Rapid Imaging and Analysis (ARIA) team at NASA's Jet Propulsion Laboratory in Pasadena, California, created these flood proxy maps depicting areas of Mozambique that are likely flooded as a result of Cyclone Idai. The likely flooding zones ar

The Advanced Rapid Imaging and Analysis (ARIA) team at NASA's Jet Propulsion Laboratory in Pasadena, California, created these flood proxy maps depicting areas of Mozambique that are likely flooded as a result of Cyclone Idai. The likely flooding zones are indicated by light blue pixels. Credits: NASA / JPL-Caltech. This product contains modified Copernicus Sentinel data (2019), processed by ESA, NASA 

NASA's Advanced Rapid Imaging and Analysis (ARIA) team combined images from several Earth-observing satellites to create flood proxy maps that show the progression of the post-cyclone flooding from March 18, 2019, through March 23, 2019. The spread of flooding is evident in the blue pixels that increase through the several-day period.

The maps were derived from synthetic aperture radar (SAR) images from the ICEYE-X2 (March 18), Sentinel-1 (March 19, 20), and ALOS-2 (March 23) satellites operated by ICEYE (Finnish satellite manufacturer Every Square Meter, Every Hour), European Space Agency (ESA), and Japan Aerospace Exploration Agency (JAXA), respectively. The processed images were compared to each other for cross-validation. These flood proxy maps should be used as guidance to identify areas that are likely flooded, and may be less reliable over urban and vegetated areas.

Although the data may be less reliable over urban and vegetated areas, these flood proxy maps can be used as guidance by first responders, aid providers and others to identify the most impacted areas.


Landsat 8 Used to Identify Landslides and Flood Areas in Zimbabwe from Cyclone Idai

These Landsat 8 images from March 8th, 2015 and March 21st, 2019 show a particularly distinct landslide in Chimanimani National Park about 13 kilometers (8 miles) northeast of Chimanimani. Credit: NASA Earth Observatory

These Landsat 8 images from March 8th, 2015 and March 21st, 2019 show a particularly distinct landslide in Chimanimani National Park about 13 kilometers (8 miles) northeast of Chimanimani. Credit: NASA Earth Observatory images by Joshua Stevens, using Landsat data from the U.S. Geological Survey.

Tropical Cyclone Idai barreled into southern Africa on March 15, 2019, leaving a deadly path of destruction. According to reports from the International Charter, Zimbabwe’s most affected area was the Chimanimani District—a mountainous area close to the border with Mozambique. 

Using the Landsat 8 satellite's OLI instrument, scientists can compare imagery of the same region before and after a disasters strikes to identify areas of change. This helps to determine where floods and landslides have occurred, information which can then be passed to local disaster agencies and ground responders to aid in recovery. 

Rainfall totals in Zimbabwe were not as high as in coastal and Central Mozambique, but they were still higher than usual for the region and likely contributed to the prevalence of landslides, according to Robert Emberson, a researcher with the landslides team at NASA’s Goddard Space Flight Center. The terrain was also a factor. “The area around Chimanimani has much greater topographic relief and slope than the flat coastal plain, and thus is much more susceptible to landsliding,” he said.

 

Suomi NPP VIIRS Detects Hundreds of Wildfires in Venezuela

Actively burning fires, detected by thermal bands, are shown as red points. Credit: NASA Worldview, Earth Observing System Data and Information System (EOSDIS).

Actively burning fires, detected by thermal bands, are shown as red points. Credit: NASA Worldview, Earth Observing System Data and Information System (EOSDIS).

Hundreds of wildfires dot the Venezuelan landscape in this NOAA/NASA Suomi NPP satellite image from March 27, 2019.  The cause of these fires is most likely environment related meaning the hot, dry weather coupled with lightning creates a powder keg effect and fires tend to erupt in this type of weather. Two Venezuelan engineers studied NASA imagery and found that three fires were burning near power transmission lines on March 7, 2019 according to AP News. 

Interestingly, there were reports of a meteorite striking the country on February 09, 2019 causing fires to break out. There were nine separate persons who reported this to the American Meteor Society and there was one video of the event.  https://fireball.amsmeteors.org/members/imo_view/event/2019/676   

VIIRS and other NASA fire products enable people on the ground, including those responsible for mobilizing fire-fighting resources around the world, detailed information about the locations of fires. These data are provided to responders in near-realtime, which allows firefighter to more effectively deploy their resources.