Satellite data show barangays affected by ashfall from Mayon 

Satellite data show barangays affected by ashfall from Mayon | (05 May 2026, Quezon City) The Philippine Space Agency (PhilSA) produced a map showing areas covered by ash deposits (bounded in red) from the reported pyroclastic density current along the Mi-isi gully of Mayon Volcano on 02 May 2026. The ash deposits (shaded in red) were classified using change detection on a Sentinel-2 satellite image from 04 May 2026 (shown top) compared with a reference image from before the event (28 April 2026). The bottom map overlays the estimated ash deposit extent to show potentially affected barangays. Based on the analysis, at least 8,544 hectares (~85,440 sqkm) were covered by ashfall. For comparison, this area is around half the size of Quezon City. 

The amount of information derived from satellite data is oftentimes constrained by cloud cover. For areas obstructed by cloud cover, ash deposition cannot be directly determined. However, the ash deposit extent could be extrapolated by delineating a region around areas classified to have ash deposits. These results are consistent with projections from atmospheric trajectory modeling and reports from the ground. The map is still subject to ground validation. 

PhilSA’s support through the analysis of satellite data provides wide-area coverage that assists the National Disaster Risk Reduction and Management Council (NDRRMC) in monitoring the situation and prioritizing areas for response. By making space data accessible to stakeholders, PhilSA enables informed decision-making and strengthens disaster response. 

PhilSA will continue monitoring satellite data as the situation requires. Please follow local and national agencies for the latest advisories. 

Access the high-resolution map and shapefile of the estimated ash deposit extent here: https://bit.ly/MayonAshfall 

Read this on our website: https://philsa.gov.ph/news/satellite-data-show-barangays-affected-by-ashfall-from-mayon/  

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