THE Mines and Geosciences Bureau (MGB) told the Cebu City Government on Monday, April 10, to evacuate the families and relocate the structures within the active landslide area in Barangay Sirao.
A team of geologists, led by Liza Socorro Manzano, found out last March that tension cracks in Sitio Tawagan and in the slope of the Sirao Flower Garden were striking and are "progressing laterally and vertically."
The cracks were noted after a landslide, triggered by heavy rains last January 16, damaged five houses in Sitio Tawagan 1. About 68 families were evacuated to Sirao Elementary School.
Aside from tension cracks, the geologists also found several ground depression, sinkholes, and fractured cave systems that indicate "active subsidence hazard" or the possibility that the ground will suddenly collapse.
"The team found 22 sinkholes within Mt. Kan-irag, Mt. Pung-ol, and Mt. Balisong with a depth ranging from 0.5 meter to three meters and a diameter of 0.5 to 250 meters," the MGB said in a statement Monday.
It added that the MGB-Central Office and the Cebu City Disaster Risk Reduction Management Office identified 50 houses and structures, including the barangay hall and gym, that are along the path of the debris flow.
It said the continuous movement or spalling-off of loose soil and rock materials from the slopes of Mt. Kan-irag is caused by its highly fractured rocks and highly weathered soil characteristics.
The bureau discouraged the construction of high-rise buildings along unstable slope and subsiding ground in the area.
It said areas declared as highly susceptible to subsidence and landslide should be free from permanent habitation.
"These areas may be designated for agro-forestry and other uses deemed appropriate by other agencies," the MGB said.
The bureau also recommended that an evacuation protocol and plan should be established and residents must be made aware of the geohazard in their locality.
"The phenomenon affecting Barangay Sirao for three decades is a complex type of mass movement, a combination of subsidence and hill slope debris flows and may occur anytime," it said.
MGB encouraged the public to help revegetate the mountains of the village. (SunStar Philippines)