2020 01 19 1

The structures on the left photo (February 12, 2019) are now the debris observed in the right photo (January 11, 2021).

2020 01 19 1

View of the landslide debris from the chapel, overlooking the subdivision and the bypass road.

The Mines and Geosciences Bureau Regional Office 8, through its Geology Division inspected the landslide that occurred on January 11, 2021 along Tacloban City Bypass road where the Holy Spirit Missionary Catholic Church is located on the upslope and the Regina Heights Subdivision just below the steep slope.

The landslide affected portion of the church structure that moved downslope towards the direction of the subdivision. However, no casualty was reported since the church structure is already abandoned and dilapidated. Likewise, no household of the subdivision were affected. However, the toe of the landslide was estimated to about 50 meters only from the nearest residential unit of the subdivision.

The landslide incident was a “debris slide” composed of thick unconsolidated soil layer underlain by weathered igneous rock (gabbro/basalt). During the survey, seepages that were observed indicated that soil materials were heavily saturated with water that triggered the debris to slide. 

The cause of landslide is believed to be a combination of the following factors: 1.) the prolonged downpour of the Tail-End of a Frontal System (Shear Line) and Intertropical Convergence Zone (ITCZ), 2.) the steep cut slope and 3.) the seepage of water and weathering that decreased the strength of soil material.

The character of the soil material in the Regina Heights Subdivision is susceptible to weathering and the steep cut slope rendered the site susceptible to landslide.  This Office recommended that the Barangay and City DRRMO must monitor ground movement or indication of another possible landslide should the existing weather condition or prolonged period of rainfall prevail.

It is also worthy to note that, previous assessments/reports of this Office in 2019 indicated that the site has high landslide susceptibility with ground manifestations of impending landslide.  As per Joint DENR-DILG-DND-DPWH-DOST Memorandum Circular No. 2014-01, dwelling should not be allowed in this zone.  This therefore reiterates the previous recommendation of this Office to relocate threatened residents to ensure their safety.