At The University of Queensland, researchers have employed satellites with radar imaging sensors to observe through clouds and map flooding. They also state that the method can offer faster, more elaborate data to ensure the safety of communities.
Map of inundated western Brisbane suburbs on 28 February 2022 derived from PlanetScope (purple) and Capella (pink) satellite data. Image Credits: ©OpenStreetMap (and) contributors, CC-BY-SA
Professor Noam Levin of the School of Earth and Environmental Sciences from UQ stated that the project integrated images from optical satellites with data from imaging radar satellites.
Monitoring floods in towns and cities is challenging, with flood waters often rising and then receding in a few days. While large satellites in the past provided images every 7-14 days, now groups of small satellites can collect several images a day over the same location. Radar imaging sensors can provide images at night or on days with thick cloud cover – a huge advantage in stormy conditions.
Professor Noam Levin, School of Earth and Environmental Sciences, The University of Queensland
Levin added, “They use a flash, like on a camera, and the light is sent at wavelengths between 1mm and 1.0m, which can pass through clouds and smoke.”
Image Credit: thanatphotothanatphoto/Shutterstock.com
During the February 2022 floods in Brisbane, scientists integrate satellite day-time images that were displaying the extent of the flood with imaging radar and optical night-time data of the lights linked with human activity.
We could see which areas became dark as the flood waters encroached. We matched this with data from river gauges operated by the Bureau of Meteorology, and with changes in electricity loads reported by Energex, the power supplier.
Professor Noam Levin, School of Earth and Environmental Sciences, The University of Queensland
Professor Stuart Phinn believed the technique can play a key part in safeguarding Australians in the event of forth-coming floods.
In combination with existing flood monitoring and modeling technologies, satellites could change the way we monitor major flood events, understand how they occur, and direct emergency and other responses. With faster update times—at least twice a day—and more accurate and timely data, agencies monitoring the floods can assess changes and alert people in at-risk areas.
Professor Stuart Phinn, The University of Queensland
“This technique can also be used post-disaster to assess the extent of damage, direct recovery efforts and for the assessment of insurance claims,” he concluded.
The research group employed optical satellites from Planet Inc. and VIIRS of NASA, along with Capella’s imaging radar satellites.
Journal Reference:
Levin, N. and Phinn, S. (2022) Assessing the 2022 Flood Impacts in Queensland Combining Daytime and Nighttime Optical and Imaging Radar Data. Remote Sensing. doi.org/10.3390/rs14195009.