Technical personnel from the Mines and Geosciences Bureau (MGB) MIMAROPA Region’s Geosciences Division conducted geohazard database updating and risk exposure assessment of the Municipality of Coron, Palawan, February 26 – March 14.
Copies of geohazard IEC posters and pamphlets are turned over to Brgy. Captain Franklin F. Usorfacion and other officials of Brgy. Decalachao
This activity sought to update the flood and landslide susceptibility database in Coron, and gather necessary data for the risk exposure assessment of the municipality. Information and education campaign materials such as posters and pamphlets related to flooding, landslide, and karst subsidence geohazards were also distributed to the municipality and barangay local government units.
The MGB MIMAROPA geohazard mapping team discusses with an official of Brgy. Decalachao regarding the flood and landslide-prone areas in the barangay
Flood-prone areas were identified along the floodplains of major streams in the municipality, which include Borac River in Brgy. Borac,; Panggawaran River in Brgy. Decalachao; Langka, Kalibaong, and Suba Rivers in Brgy. San Nicolas; and downstream Labangan River in Brgy. Guadalupe. Communities situated along these active floodplains typically experience moderate to high flooding due to the swelling of the aforementioned streams.
The MGB MIMAROPA geohazard mapping team interviews a resident of Sitio Labangan, Brgy. Guadalupe regarding the frequent flooding that occurs in the area almost every year. Houses in the area are constructed with meter-high stilts to safeguard against the high flooding experienced by the community.
Coastal communities such as Sitios Maricaban, Kawayan, Pinilian, and Umukan in Brgy. San Jose, as well as Purok 2 in Brgy. Marcilla situated near the local lagoon, are also prone to flooding especially when heavy rainfall or storm surges coincide with high tides.
A resident of Purok 3, Brgy. San Nicolas points at the level of flooding in the area due to the swelling of the nearby Suba River during prolonged rainfall events.
Almost all barangays, save for those at the Poblacion area, have mountainous regions that are prone to mass wasting. Old landslide scarps along the mountain slopes were spotted in Barangays Buenavista, Banuang Daan. Additionally, numerous roadcut landslides can be observed along the national highway and barangay roads.
Adjacent rock fall and topple landslides that occupied half of the highway are observed in Sitio Minanga, Purok 5, Brgy. Turda.
Some 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.
The underlying lithologies (rock/soil) are some of the oldest rocks in the Philippines (Late Permian to Early Cretaceous in age) and very deformed formations which lend to its rather weak characteristic once exposed to the earth’s atmosphere.
A household at Sitio Proper, Brgy. Decabobo is recommended for immediate relocation due to an active earth slide that may affect their house. Landslide warning signs are noted in the area such as the sudden appearance of spring water along the slope and minor mass movements, the last of which occurred in 2019 during the onslaught of Typhoon “Quinta.”