Geoscience Australia Contributes to Philippines Landslide Response

The Landslide

Following a prolonged period of very heavy rainfall a major landslide struck the village of Guinsaugon in the Southern Leyte Province of the Philippines (Figure 1) on 17 February 2006.

Figure 1: Location of the former village of Guinsaugon

Figure 1: Location of the former
village of Guinsaugon
(Reproduced with permission
from COEDMHA)

The landslide resulted in the death of 1 113 individuals, which included students and teachers when the village school was completely enveloped. The Philippines National Disaster Coordinating Council (NDCC) estimated the landslide caused approximately AUD $2.5M in damage to infrastructure and AUD $0.6M in damage to agriculture in the region. An area of approximately 3.5km² - 4km² was covered in mud and debris from the landslide, reaching depths of up to 30m at the base of the mountain where the village was located (Figure 2).

Geographic setting

The village of Guinsaugon was located at the foot of a steep mountain range, with the valley floor to its east under rice cultivation. The river is about 1.5km east of the village and a tributary watercourse flowed through the village itself. The landslide occurred close to a major seismically active geological structure known as the Philippines Fault, and relatively minor earthquakes were detected in the region around the time of the landslide which may have contributed.

Figure 2: View of the landslide from the nearby search and rescue base camp

Figure 2: View of the landslide
from the nearby search and
rescue base camp
© Geoscience Australia

Geoscience Australia's role

As part of the Australian Government's response, the Australian International Aid agency - AusAID - assembled a landslide assessment team to travel to the Philippines to provide assistance to Philippine authorities. Geoscience Australia's role was to provide geotechnical expertise in order to assess:

  • slope stability in the vicinity of the landslide site
  • the potential for flooding
  • the likelihood of further landslides.

Actions taken

In examining slope stability, the team worked with the Mines and Geoscience Bureau and the Philippine Institute of Volcanology and Seismology to assess the:

  • extent of landslide damage
  • potential for further landslides in the vicinity of the current landslide site and nearby region
  • potential for secondary flooding hazards due to landslide deposit blockage of water courses
  • options for further international assistance, including possible technical assistance in hazard mapping and further slope stability assessments.

Recommendations

As a result of the mission, the team put forward a series of recommendations including:

  • support for a United Nations Development Program proposal to provide both long and short term assistance in the Philippines for:
    • geohazard mapping for natural disaster assessment
    • development and implementation of community-based early warning systems
    • community and government disaster education initiatives
    • incorporation of disaster risk reduction into local development planning.
  • support for a Philippine National Red Cross community-based disaster preparedness program, along with the implementation of small-scale disaster mitigation activities in the provinces
  • potential provision of technical support to Philippine Government agencies responsible for geohazard mapping and risk assessment. This was envisaged to be scoped by AusAID in consultation with Geoscience Australia and other Australian agencies.

The benefits of working together

The development of partnerships between Philippine technical agencies, AusAID and Geoscience Australia will result in a better understanding of natural hazard events and provide opportunities for strategic long term reduction of natural hazard risk. A sound understanding of the risk posed by natural hazards can enable communities to develop targeted education and emergency response systems, and underpin improved building codes and practices.

Topic contact: hazards@ga.gov.au Last updated: March 21, 2011