Following the order of President Ferdinand R. Marcos Jr. to prepare for the worst of Super Typhoon Pepito, the Office of the Civil Defense (OCD) and the Department of Science and Technology – Philippine Institute of Volcanology and Seismology (DOST-PHIVOLCS) on Sunday issued preemptive warnings on lahar flows in affected provinces.

Recognizing the recent activities of Mayon, Pinatubo, and Taal volcanoes and the trajectory of Pepito, the DOST-PHIVOLCS strongly recommended increased readiness and vigilance of communities in pre-determined zones of lahar and related hazards.

PHIVOLCS said Mayon volcano’s pyroclastic density current (PDC) deposits may occupy the watershed areas while potential lahar and sediment-laden stemflows may occur along the Miisi, Buyuan, Binaan, Anoling, Quirangay, Mininila, Masawarag, Muladbucad, Nasisi, Mabinit, Matanag, Basud and Bulawan Channels in Albay province.

For Pinatubo, the agency said significant PDC deposits from the 1991 eruption remain in the watershed and may be confined to river channels. But they could become muddy steamflows in Sto. Tomas -Marella and the Bucao River systems and even floods on the lower and adjacent communities of San Marcelino, San Narciso, San Felipe, and Botolan in Zambales Province.

Muddy streamflows may also be generated along O’Donnel and Pasig-Portero River systems, draining the Pinatubo edifice in the north and southeast that may affect downstream communities in Tarlac and Pampanga provinces.

Meanwhile, PHIVOLCS issued warnings of muddy streamflow, muddy runoff, and volcanic debris flows around Taal Volcano to Agoncillo, Laurel and Talisay in Batangas province. | PND