Lessons from the Naga probe
THE geologists who conducted the investigation into the massive landslide that hit Barangay Tina-an in the City of Naga last Sept. 20 called it “ground penetrating radar (GPR) and georesistivity (GRS) surveys.” The probe is supposed to have gotten deep— both literally and metaphorically— into the causes of the tragedy.
The verdict: both nature and man contributed to the collapse of more than two hectares of Sitio Tagaytay, covering an area that extended down to Sitio Sindulan with two hectares of soil and rocks, killing 78 persons (with four still missing) and destroying properties and an entire community.
But the geologists who conducted the study refused to go deep into the “whodunnit” phase— or answering the question of who should primarily be blamed for the tragedy. They apparently did not dwell on it for a reason: because that would end up to be a chicken-and-egg thing.
Obviously, the quarrying alone can’t be blamed for the landslide; the degradation of the soil had a role in it, too, plus other factors contributed to it aside from the quarrying. Like the fact that the site is within an active fault line.
Two interesting questions: Would the landslide have occurred and would it have been massive with the quarrying activity alone? Or, conversely, if the slope wasn’t quarried, would the natural degradation of the slope alone have caused a massive landslide?
We also won’t go deep into that territory. But there is one lesson that policy makers should keep to heart in this probe. Let us listen to Liza Manzano, the supervising geologist of the Mines and Geosciences Bureau (MGB) central office, who explained the role of the trapped underground water looking for an exit in the collapse of the slope:
“Kun gi-change mo ang natural (formation), any activity, not only quarry, gi-change mo ang natural land form, magbag-o sad ang giagian sa mga tubig.”
Now you know why in every place where people dipped their fingers into the natural order of nature, tragedies and other calamities occur. That could strike closer to home: the flooding that regularly occurs in Metro Cebu is the product of people changing the natural land form and blocking the natural waterways. — Sunnex