237 evacuated from sitio, MGB: Steer clear of sinkhole area

CEBU, Philippines - Following reports of sinkhole formation in an islet off northern Cebu, the Mines and Geosciences Bureau-7 of the Department of Environment and Natural Resources conducted a site inspection and further recommended no more habitation of the area where the subsidence occurred.

MGB-7 chief geologist Al Emil Berador led the inspection team that personally went to Sitio Dapdap, Barangay Langub, Kinatarcan islet, Sta. Fe town, Bantayan Island.

Berador noted the sinkhole continues to grow and its getting closer to the affected area is endangering residents, he added that the recommendation to put up a signage or to cordon off the area and conduct a continuous monitoring should be sustained.

He added sinkhole development is one of the geological "natural" processes that could occur in the islet.

A total of 237 persons comprising 102 families were evacuated to the Seventh Day Adventist Church in Sitio Dapdap as a result of the sinkhole which measures around 10 meters by 14 meters with a depth of one meter.

"The affected area including the subsidence or the sinkhole with some tension cracks is about 20 meters by 40 meters which continues to be progressing is underlain or carpeted with coralline limestone belonging to the Carcar formation," Berador said.

MGB-7 Regional Director Loreto Alburo earlier recommended to the local government units to take precautionary measures four days ago after he received a phone call from Sta. Fe Mayor Jose Esgana last July 26.

He said the collapse or cave-in of a cave roof which resulted to the formation of a sinkhole may have been trigged by the intense and prolonged precipitation brought about Typhoon Glenda and a low pressure area over the weekend.

The residents noticed last July 26 that a portion of a slight sloping ground in Sitio Dapdap started to develop some tension cracks. A number of houses were seen about 10 to 15 meters away from the subsidence or sinkhole area.

"We will be identifying a possible relocation site within the islet where these affected communities will be able to live safer and continue to live normally without fear on the geological hazards like sinkholes," said Alburo.

Alburo said the identification of a relocation site is part of the technical assistance that will be provided to the local government unit making sure the communities are away from danger.

The formation of sinkholes is a continuously developing throughout geologic time because of the nature of the underlying rocks, actions of rainwater, and the rise and fall of the water table.

Meanwhile, Berador conducted a lecture on the geological hazards present and some measures with Cebu Provincial Disaster Risk Reduction and Management Officer Baltazar Tribunalo Jr. who conducted a briefing on community-based disaster risk reduction to close to 200 residents including the affected ones in the said islet.

Also, Barangay Captains Rolando Villacarlos, Vilma Dawa and Romy Illut of Barangays Langub, Hagdan and Kinatarcan, respectively, attended the said activity.

In a related development, Berador inspected three elementary and one high school for possible damage brought about by the sinkholes.

Tribunalo described the occurrence of the sinkhole as "alarming" since it could appear anywhere in the province considering that Cebu is an area of karsts, or landscapes underlain by limestone that have been eroded by dissolution.

The International Association of Hydrologists have classified karsts as an aquifer. Karst areas consist of solid but chemically soluble rock such as limestone which can slowly be dissolved by water, triggering the appearance of sinkholes and caves.

Tribunalo further said that rain could have also contributed to the erosion of the soil, forming the sinkhole.

"But historically naa na gyod nay bangag sa ilawom, naa na'y space sa ilawom pero na-trigger lang tungod sa sige'g uwan," he added. — with Michael Vencynth H. Braga/BRP (FREEMAN)