MGB tests web-based sinkhole detection tool

CEBU, Philippines — Central Visayas has become the testing ground for a new web-based sinkhole detection tool developed by the Mines and Geosciences Bureau (MGB).

This came just in time as the region continues to assess geohazard risks, especially after the magnitude 6.9 earthquake that struck northern Cebu on September 30.

The earthquake, caused by movement along the Bogo Bay Fault, claimed 74 lives and injured at least 559 people. Close to 80,000 homes and hundreds of infrastructures were also damaged.

 The tremor also triggered thousands of aftershocks, some of which reached magnitude 5.1.

In response to the region’s vulnerability, the Department of Environment and Natural Resources (DENR) and MGB launched a pioneering application that automates preliminary sinkhole detection.

Spearheaded by the Lands Geological Survey Division (LGSD), the tool integrates manual digitization using National Mapping and Resource Information Authority’s (NAMRIA) topographic maps with automated geospatial analysis of satellite data and Digital Elevation Models (DEMs).

The manual digitization component involves identifying sinkholes using 1:50,000-scale Topographic Maps from the NAMRIA. This step establishes a baseline for comparing results obtained from automated analyses.

The automated process analyzes available DEMs and satellite images to delineate potential sinkholes and detect ground movement by observing changes in topography and ground deformation, according to the MGB.

The system identifies terrain anomalies, filters out non-geological features, and generates sink depth maps for validation by MGB geologists.

It is designed to reduce processing time during emergency hazard assessments and support karst subsidence susceptibility mapping.

Central Visayas, as per MGB, was actually selected due to its karst-rich geology and history of sinkhole activity, notably after the 2013 Bohol earthquake.

The new tool complements MGB’s ongoing efforts, which include remote sensing, geomorphological surveys, and Ground Penetrating Radar (GPR) studies.

This latest development is expected to improve disaster preparedness and geohazard resilience in one of the country’s most at-risk regions. (CEBU NEWS)