Geohazard assessment on 186 barangays completed

CEBU, Philippines - A team of geologists from the Mines and Geosciences Bureau-7 has completed a rapid geohazard assessment to 186 barangays covering seven municipalities in the southern part of Cebu this month.

As of September, the municipalities of Argao, Carcar, Dalaguete, Oslob, Pinamungajan, San Fernando and Sibonga joined the lists of municipalities in Central Visayas that have completely undergone geohazard mapping.

MGB-7 regional head Roger de Dios said that all barangays of all towns in Oriental Negros were also completely mapped last June and landslide threat advisories have been issued to these areas.

In Cebu, there are only 23 areas to be assessed because 30 cities and municipalities of 57 percent were already covered.

The geohazard mapping and assessment is one of the priorities or flagship program of the Department of Environment and Natural Resources to protect and preserve lives and properties.

Its objectives include identification of various geologic features, hazards associated to these geologic features, settlement sites, and identification of properties and infrastructures to be affected.

 It should also generate a geohazard map and reports incorporating all gathered information which shall determine the vulnerability of certain areas to various types of geologic and natural hazards.

Geohazard maps must be able to provide information on potential areas of landslides, liquefaction, subsidence and other underground instabilities in the country. It shall identify not only areas prone to disasters but also relocations for victims.

Examples of phenomena that can produce geohazards are frequent floods and flashfloods as well as landslides that may be rain-induced or earthquake related.

 “The rapid filed assessment will take note of whether barangays are located near the shoreline, on foot slopes, mid slopes or mountain ridges. Each barangay will be given a rating of either with low, moderate or high landslide susceptibility,” de Dios said.

The rating parameters are from high, moderate and low. “High” rating is that which indicates the presence of active or recent landslides, numerous and large tension cracks that would directly affect the community and areas with drainages that are prone to landslides damming and steep slopes.

Areas with “moderate” rating are with indicative or history of landslides, presence of small tension cracks and are located away from the community. It also has moderate slopes.

The “low” rating was given to areas that are low or gently sloping but still with presence of tension cracks.

 MGB-7 aims to finish the mapping of the whole Central Visayas by 2010. With this progress, MGB-7 is optimistic that it will able to meet its target next year despite the lack of geologists doing the field work. — Jessica Ann R. Pareja/MEEV (THE FREEMAN)