Warnings out anew on ‘geo-hazards’ in the Cordilleras

BAGUIO CITY — With the onset of rains that may trigger ground movements, authorities have renewed their warnings to residents of geologically hazardous areas in the Cordilleras to take extra precautions to prevent loss of lives.

The Office of Civil Defense and the Cordillera office of the Mines and Geosciences Bureau (MGB) of the Department of Environment and Natural Resources (DENR) have again raised their warnings on 40 government-identified geologically hazardous areas.

According to an updated geological map, these geologically hazardous areas include the following:

• City Camp, Rock Quarry and Crystal Cave where ground sinking is reported;

• Km 3 in San Luis Village, where there is a slope failure;

• La Trinidad Valley, where flooding and ground settlement liquefaction is possible;

• Balakbak, Kapangan, where the ground is unstable;

• Colalo where landslides are common;

• Let-angan and Aurora st., Poblacion, which have an "active ground subsidence"; and

• Sapid and Pacda, all in Mankayan, Benguet, where "pipe-outs" are reported.

Ground subsidence is also noted in Padcal, Tuba, where the Philex Mining Corp. operates.

Landslide-prone sites include portions of Mankayan, Abatan to Buguias toward the road going to Natubleng down to Kabayan; Daclan going to Bokod toward Nueva Vizcaya; portions of the road going to the Ambuklao Dam; parts of the Halsema Highway traversing the towns of Buguias, Atok, Tublay and La Trinidad; the areas toward Itogon town; and the Naguilian and Kennon Roads.

In 2001, continuous rains brought by typhoon "Feria" triggered landslides in these areas, claiming the lives of at least four dozen people.

Government authorities also see landslides possibly occurring in Tangadan, San Quintin, Abra; Taga, Pinukpok, Kalinga; and Tuyangan, Cabugao, Apayao; and flooding in Lamut, Ifugao; Lagangilang, Abra; Samoki, Bontoc, Mt. Province; Capagaypayan, Luyon, Luna and in Imelda, Alem and San Antonio in Pudtol, Apayao.

Ground subsidence and unstable ground hazards have also been reported in Pantikian, Balbalan, Kalinga and Butac, Natonin, Poblacion and Angkileng in Sagada, Mt. Province.

More than half of the Cordillera region, the MGB said, is classified as very steep and prone to landslides and other ground movements.

Authorities also fear that the presence of major faults criss-crossing the region, although most of them are classified as "non-earthquake generators," could trigger weak points that could eventually result in ground instability or landslides.

They said the Digdig fault, an extension of the Philippine fault zone extending toward the Abra River fault, could cause substantial damage, along with the San Manuel, Tuba and Tebu faults, among others.

In Baguio, the major faults include the ones in Mirador, Burnham, Bued River and the area in Loakan.

Baguio City, the vacation capital of the country, is considered by the World Bank as one of the seven disaster-prone cities in the world in its latest findings.

Last year, the MGB provided local government units (LGUs) updated and more comprehensive data on the geologically hazardous areas on which to base their respective plans of action.

Some LGUs are using the "geologic hazard" map in drafting their land zoning programs.

The map is also important in issuing permits for development projects and building permits and in the disaster preparedness programs of LGUs.