A geological hazard investigation was conducted on July 29, 2021 by the technical personnel of the Mines and Geosciences Bureau IV-CALABARZON (MGB IV-CALABARZON) on the reported landslides in Barangay Luya, Calatagan, Batangas.

Two (2) landslides located along a road cut were identified at Sitio Ibaba, Barangay Luya, Calatagan, Batangas which occurred after the July 24, 2021 earthquake. The slump is approximately 24 meters wide and 18.4 meters high. Slope gradient is steep to very steep and is highly vegetated with fruit-bearing trees and wild grasses. The debris of the slump is a combination of soil, plant and tree debris with some weathered silt. Partial clearing operations were already done as some debris of the mass wasting event were no longer scattered along the road.

Oversaturation of the soil was considered to be the main factor for the mass-wasting incidence and the ground movement caused by the earthquake. The oversaturated soil and slope can no longer hold any rainwater and is unstable that when the earthquake struck, the slope eventually collapsed.

The two landslides were found to be inside a zone with High Susceptibility to Rain-Induced Landslide as per the Composite Landslide and Flood Hazard Map of Calatagan, Batangas. Residents living near the identified hazard zones are recommended to evacuate in times of strong rainfall, if necessary.

The first landslide that occurred on Sitio Ibaba, Barangay Luya, Calatagan. The slump is approximately 24 meters wide and 18.4 meters high to its top looking at the scarp. The debris of the slump is combination of soil, plant and tree debris with some weathered silt. 
MGB CALABARZON team assess the second landslide event in Sitio Ibaba, Barangay Luya, Calatagan.
The second landslide that occurred in Sitio Ibaba, Barangay Luya, Calatagan. It is a minor landslide which is only 3 meters high and about 2.5 meters wide. The debris is comprised of the same materials as the first landslide.


By: Chester A. Sta. Maria                        |                    23 August 2021