The Negros Occidental Provincial Environment and Management Office (PEMO) ensured continued coordination with concerned agencies to safeguard communities affected by ground depressions in a remote village of Toboso town.
As of yesterday, final technical findings are pending until further investigation, following the initial surface-based assessment conducted by the PEMO-One Stop Shop Division in coordination with the Mines and Geosciences Bureau – Negros Island Region (MGB-NIR) and the Municipal Disaster Risk Reduction and Management Office.
The joint team initiated a technical field investigation on February 18, following reports of ground depressions in Sitio Bairan and Sitio Bugho of Barangay General Luna.
“Due to proximity to residential areas, the hazard level is provisionally assessed as high, pending detailed subsurface and geophysical investigation by MGB-NIR,” the PEMO official advisory said.
In Sitio Bairan, the ground subsidence is approximately 60 meters in diameter, five to 11 feet deep, and around 80 meters from the nearest houses occupied by five households.
In Sitio Bugho, a collapse of about two feet was observed around 40 meters from the nearest residential area with 15 households, while structural cracks were also found in one residential structure.
Based on the field validation, there is “confirmed presence of ground subsidence features in both areas” and surface observations indicated that “the formations are initially interpreted as possibly karst-related ground subsidence.”
However, “no clear evidence of fault rupture associated with the East Negros Fault System was observed during the inspection,” the report added.
The PEMO-One Stop Shop Division said authorities continue to monitor the areas and are advised to enforce access restrictions and install warning signage to ensure public safety. Access has been restricted within at least a 50-meter radius.
Other recommendations include the conduct of a geophysical survey and structural assessment of the affected houses.
“Final technical determination will be issued by the MGB-NIR after geophysical evaluation,” the report added. (PNA)