Sinkhole in Davao City?
Sinkhole in Davao City?
Sun Star Davao Editorial, June 3, 2010
It looks like a gateway to hell. A 200-foot-deep sinkhole in Guatemala City suddenly opened up in the aftermath of a storm and swallowed a three-story building into the bowels of the earth. The sinkhole, a nearly perfect circular shaft wider than a street intersection, appeared soon after a storm lashed the capital.
Such an alarming news report for the whole world including Davao region, which has a total of 905 flood and landslide-prone barangays, based on the recent geohazard map project completed by the Mines and Geosciences Bureau (MGB) 11.
The United States Geological Survey (USGA) defines sinkholes as natural depressions that can form when water-saturated soil and other particles become too heavy and cause the roofs of existing voids in the soil to collapse.
They can be human-induced. New sinkholes have been correlated to land-use practices, especially from ground-water pumping, construction, and development practices. Some sinkholes form when the land surface is changed, such as when industrial and runoff-storage ponds are created then the substantial weight of the new material can trigger an underground collapse of supporting material, thus causing a sinkhole.
Rewind… A formal assessment on Shrine Hills made by UP-Diliman National Institute of Geological Sciences geo-hazard specialist and associate professor Sandra Catane, presented by Davao City Councilor Leonardo Avila III to the City Council in February this year showed that “the rocks underlying the Shrine Hill are inherently unstable because they are made up of unconsolidated to weakly cemented sediments, soluble (limestones), and sediments unfavorably dipping away from slopes.”
The assessment added that the sinkhole observed in the Positano area was formed due to dissolution of the underlying limestone — which underlies the top of the ridge.
So, there is a sinkhole in the city. How come MGB 11 regional director Edilberto Arreza doesn’t know of its existence?
Admitting that the presence of aquifers in the city technically puts the area at risk, he said most of these aquifers are sandwiched by tough, impervious rocks thus, severely limits the possibility of sinkhole formation.
Nevertheles, Ma-a residents have more reasons to worry this time. The Guatemala sinkhole echoes a renewed call for the City Government to stop development activities on top of Shrine Hills and give way to a thorough and impartial geo-hazard study.
Comments
Thanks Sun Star for alerting our attention to the potential disasters that could hit Davao City (in particular Maa) if we don’t heed the warnings coming from other parts of the world, like the recent Guatemala sinkhole phenomenon.
I have family members and close friends living in Maa, so I am personally concerned about this issue. Their welfare is my concern. I do worry as to what could happen to them in case a disaster would strike.
As the new City administration headed by Mayor Sarah Duterte begins a new phase in the history of Davao City, we can only wish that they will address this issue in Maa and do something to protect its citizens. We affirm the councilors who have shown an interest in dealing with this issue and challenge the others to share the same concern.
We are indebted to media for monitoring this issue and to continue providing it the attention it requires. For in the end, if any disaster ever occurs, all of Davao City will suffer its consequences.
Why wait for a disaster to take place. Prevent the occurrence of such a crisis by taking the side of those who care for the welfare of the majority of the citizens of Davao City rather than a few whose only interests is to further their wealth at the expense of the majority and of the environment.
More power to media!
Karl M. Gaspar CSsR
karl gaspar CSsR
June 22nd, 2010