MANILA, Philippines —The Philippine Space Agency released satellite maps showing areas in the country that have been affected by Typhoon Inday.
landslides in Lanao del Sur and flooded areas in Southern Luzon, Cotabato, and Maguindanao del Sur over the past few days due to Typhoon "Inday."
In a statement, PhilSA said that it produced flooded area maps from very high resolution satellite images in Cotabato and Maguindanao del Sur using imagery from the KOMPSAT-3 satellite of the Korea Aerospace Research Institute.
It also generated a landslide area map for Ngingir, Calanogas, Lanao del Sur using the Pleiades Neo satellite of Airbus that was provided by the National Disaster Risk Reduction and Management Center.
Philsa also produced flood extent maps in the Calabarzon (Cavite, Laguna, Batangas, Rizal, and Quezon) and Mimaropa (Mindoro, Marinduque, Romblon and Palawan) regions using EOS-4 Synthetic Aperture Radar satellite imagery from the Indian Space Research Organization (ISRO) captured last July 14.
It said that the flooded areas were detected by analyzing the signal values in the captured radar image and separating flooded areas from non-flooded areas,
Flooded areas in Mindanao were also analyzed using data from the Canadian Space Agency's RCM-1 satellite.
According to Philsa, SAR or Synthetic-aperture radar satellite imagery is useful in flood mapping as its signals can penetrate through clouds that often cover large areas during storms, and regardless of daylight conditions, unlike optical imagery.
"However, SAR may underestimate flooding in urban and densely vegetated areas because complex surfaces may affect the backscatter data being measured and reduce flood detection accuracy. These maps remain subject to ground validation," Philsa added.
The analysis of satellite data from these agencies were made possible due to international cooperation projects of Philsa, supporting the NDRRMC in monitoring the situation and prioritizing areas for response through the analysis of wide-area coverage satellite data.
