Due to heavy rains, a landslide occurred at Brgy. Anilawan, Igbaras, Iloilo last October 7, 2009, according to the residents interviewed by the Mines and Geosciences Bureau, Region 6.
MGB-6 conducted geohazard assessment of the landslide site on October 14-15, 2009.
During the assessment, MGB-6 observed huge cracks, lateral spreading, sliding and slumping in the area.
MGB-6 geologist Dr. Leilanie Suerte who led the team reported that the head of the landslide in Brgy. Anilawan is located at the mid-slopes of the hills used as rice fields. She said that a semi-circular crack indicated the head of this landslide and huge cracks formed all over the moving mass.
The cracks range from several meters to about 200 meters long and the width ranges from several centimeters to two (2) meters. The whole landslide mass is moving downslope towards the east-southeast direction.
At least five houses made up of concrete, bamboo and mixed materials and approximately 2 hectares of rice fields were affected.
The main causes of the landslide in Brgy. Anilawan are the inherent planes of weaknesses in the underlying lithology, dip direction of the bedding planes and the heavy rains in the area.
The MGB-6 team recommends that all areas in the Municipality of Igbaras with similar types of lithology, topography or slope and showing signs of mass movements such as in Brgy. Anilawan must be declared as danger zones and must be continuously monitored for presence of cracks, landslides, and mass movements.
Previous geohazard assessment of Brgy. Anilawan in 2006 by MGB indicated that the barangay was already classified as highly prone to landslides. A landslide threat advisory with appropriate recommendations was given to the barangay officials.
The MGB-6 team explained the current situation and future scenarios in the area to the affected residents and barangay officials of Brgy. Anilawan present during the ocular inspection.
MGB-6 also attended the meeting of the Liga ng mga Barangay in the Municipality of Igbaras on October 29, 2009 and discussed the results of the rapid geohazard assessment they conducted to all barangay captains.
MGB-6 further recommended to the local officials that houses and families affected by the landslides or those in danger zones must be relocated to safer areas, preferably far from bodies of water such as creeks and rivers and in flat to gently sloping areas. Further, it is recommended that houses in sloping terrains must be made up of light/mixed materials.
In the report given to the Municipality of Igbaras, MGB-6 also recommended that the local government must conduct continuous disaster preparedness training for barangay officials and residents especially for barangays with moderate to high landslide susceptibility rating.
Igbaras is one of the thirty seven municipalities of the province of Iloilo assessed by MGB-6 as part of its geohazard mapping. Geohazard mapping is one of the priority programs of the national government.