GROUP 1 LAHAR

Volcano Related Hazard: Lahar

Definition and Explanation

• Lahar is a destructive natural hazard, fast-moving volcanic mudflow.

• Composed of water, volcanic ash, ice, and rock fragments.

• Occurs through:

  • Volcanic Eruption

  • Saturation with Water

  • Mobilization of Materials

  • Flow Dynamics

  • Destructive Impact

Signs of an Impending Lahar

• Drying vegetation on upper slopes of the volcano.

• Change in chemical content of springs and crater lakes.

• Increased temperature of hot springs, wells, and crater lakes.

• Forceful steam and ash ejections.

Record of Destruction in the Philippines

1991 Mount Pinatubo Eruption

• Damage:

  • Over 100,000 homes destroyed.

  • Buried San Guillermo Parish Church and Bamban Bridge.

  • Left 500,000 people homeless.

• Flooding:

  • Caused flooding in low-lying areas.

• Damming:

  • Damming of river systems (e.g., Pasig-Potrero River).

• Lakes Created:

  • Mount Pinatubo crater lake, Mapanuepe Lake.

1994 Mount Pinatubo Eruption and Lahars

• Triggered by monsoon rains in June.

• Lahars noted beginning June 23rd, causing damage to downstream villages.

• Heavy rains in September affected 15 Pampanga villages:

  • Destroyed 1,369 houses and 7 schools.

  • Impacted 9,891 families (45,762 individuals).

  • Caused damage to agriculture (livestock, rice, sugar cane).

Appropriate Measures Before, During, and After a Lahar

Before the Hazard

• Stay Informed

• Prepare an Emergency Kit

• Have an Evacuation Plan

• Join Community Awareness Meetings

• Conduct Property Assessment

• Make Landscaping Adjustments

• Develop a Communication Plan

During the Hazard

• Evacuate Immediately

• Monitor Early Warning Systems

• Avoid River Valleys and Low-Lying Areas

• Seek Sturdy Shelter

• Protect Water Sources

After the Hazard

• Inspect Your Property

• Check for Hazards

• Use Protective Gear

• Avoid Contaminated Water

• Stay Clear of Rivers and Streams

• Stay Connected

• Plan for Future Events