Case Studies of Landslide Hazard Occurrences in Geothermal Fields: The PNOC-EDC Experience

Abstract

Two case studies am presented to demonstrate landslide hazard assessment in the PNOC-EDC geothermal felds. The first is in the Leyte Geothermal Production Field (LGPF) and the second is in the Mindanao Geothennal Pmduction Field (MGPF). Using simple yet reliable field criteria to assess slope instability, low to high slope failure potentials of specfic sites are qualitatively assessed.

Based on the risk classification timely installation of effective engineering measures are implemented. This is demonstrated in the case of the MGPF hazard assessment where the timely installation of pipe shelters shielded pipelines from frequent landslides and thus avert costly damage. Follow-up monitoring using improvised and locally fabricated tools in selected high-risk areas are implemented in selected sites to monitor, if any, future landslide and ground movements. This is shown in the case of Tower No. 7 in LGPF.