More than 1,200 hectares of farmland surrounding Mayon Volcano may have been affected by ashfall following a pyroclastic density current (PDC) that flowed down the Mi-isi gully on 2 May, based on new satellite maps released by the Philippine Space Agency (PhilSA).

In a statement, PhilSA said its analysis showed that 1,039 hectares of rice areas and 191 hectares of other crops fall within the estimated ash deposit extent, a zone identified using satellite imagery first released on 5 May.

The total affected area — about 1,230 hectares, roughly the size of Mandaluyong City — underscores the scale of Mayon’s recent activity.

“These crop areas are considered potentially affected because they are located within the estimated ash deposit extent,” PhilSA said.

Rice area data were sourced from the Philippine Rice Research Institute, while other crop areas were identified through vegetation analysis using Sentinel-2 imagery from January to December 2024.

PhilSA also noted that at least 158 kilometers of road networks fall within the ashfall zone, raising concerns over mobility, access, and possible disruptions to the transport of agricultural goods.

The agency said the crop exposure maps and analysis have been made publicly available to support disaster response planning and help local governments assess potential damage.

“PhilSA produced a crop exposure map showing ash-affected rice areas (orange) and other crop areas (yellow),” it added.