The Philippine Space Agency (PhilSA) released satellite-based maps showing the extent of ashfall from Mayon Volcano following a pyroclastic density current on May 2, 2026, affecting at least 8,544 hectares.
Using change detection from Sentinel-2 images, PhilSA identified ash deposits along the Mi-isi gully by comparing satellite data captured on May 4 with a pre-event image from April 28. The mapped ashfall area is roughly half the size of Quezon City, giving authorities a clearer view of the scale of the impact.
The agency said the red-shaded zones in the map show ash deposits, while overlays highlight barangays that may have been affected. The data helps pinpoint communities that may need immediate assistance as volcanic activity continues.
PhilSA noted that cloud cover remains a limitation in satellite analysis, as some areas could not be directly observed. In these cases, scientists estimated ashfall spread by outlining nearby affected zones. The agency said the results align with atmospheric trajectory models and field reports, but emphasized that ground validation is still needed.
The satellite data supports the work of the National Disaster Risk Reduction and Management Council (NDRRMC), which is using the information to monitor conditions and prioritize response efforts in affected areas.
“PhilSA’s support through the analysis of satellite data provides wide-area coverage that assists the NDRRMC in monitoring the situation and prioritizing areas for response,” the agency said. “By making space data accessible to stakeholders, PhilSA enables informed decision-making and strengthens disaster response.”