The Mines and Geosciences Bureau (MGB) MIMAROPA Region’s Geosciences Division commenced its geohazard databasing and vulnerability risk assessment (VRA) of Busuanga, Palawan, February 26 to March 14.
The updating of geohazard maps and database of Busuanga, and gathering of data for VRA will enable the office to calculate how many people, how much built-up zones (square kilometers), and determine the length of roads exposed to flooding and rain induced landslides.
Overflow of this river in Purok 4, Brgy. Sto. Niño reaches up to the location of the bamboo, even with just 2 hours of continuous heavy rainfall. The low-lying area on the other side of the river experience up to chest-deep flash flood
Flood prone areas identified are those adjacent to the coast due to occurrence of storm surges (Barangays Concepcion, Bogtong, Panlaitan, Salvacion, Buluang, New Busuanga, Maglalambay, and San Isidro). Meanwhile, some inner barangays experience localized flooding due to insufficient drainage systems.
Residents in Purok 3, Barangay Maglalambay have experienced mass movements nearby their houses during intense rainfall events.
Landslide prone areas in the municipality are mostly along road cuts, including Barangays Sto. Niño, Sagrada, Bogtong, Salvacion, Old Busuanga, Buluang, New Busuanga, Maglalambay, Cheey, Quezon, San Rafael, and San Isidro.
Steep cut slopes along the national highway nearby the boundary of Barangays Salvacion and Old Busuanga show evidence of landslide occurrences.
Most of the areas are underlain by chert beds of the Liminangcong Formation. The bedded structure of the underlying lithology can lead to daylighting structures that promote mass movements in the form of rockslides and topples along roadcuts.
A landslide prone area situated along a roadcut going to Purok 1, Brgy.Cheey
The underlying lithologies (rock/soil) are some of the oldest rocks in the Philippines (Late Permian to Early Cretaceous in age) and also very deformed formations which lend to its rather weak characteristic once exposed to the earth’s atmosphere.
Information, education, and communication (IEC) materials such as posters and pamphlets relating to flooding, landslide, and karst subsidence geohazards were distributed to the municipality and barangay LGUs.