Disaster Readiness and Risk Reduction Management Study Notes

Core Disaster Concepts and Risk Factors

• Disaster: A serious disruption of a community's functioning causing widespread human, material, or environmental losses that exceed its coping ability using its own resources (UNISDR).
• Hazard: A dangerous phenomenon, substance, human activity, or condition with the potential to cause harm, property damage, or environmental loss.
• Vulnerability: Factors or constraints of an economic, social, physical, or geographic nature that reduce an entity's ability to prepare for and cope with hazard impacts.
• Capacity: All available strengths, attributes, and resources within a community or organization used to manage risks and achieve goals.
• Disaster Risk Equation:   $\text{Disaster Risk} = \frac{\text{Hazard} \times \text{Vulnerability}}{\text{Capacity}}$
• Risk Components: Hazard occurrence probability, elements-at-risk, and vulnerability of the elements-at-risk.
• Loss Management Areas:
  • Pre-disaster: Focuses on vulnerability reduction, mitigation, prediction, and preparedness.
  • Post-disaster: Focuses on emergency response and victim support.
• Impacts of Disasters: Human/biological (disease outbreaks), social (PTSD and physical disabilities), physical/material (loss of infrastructure/assets), psychological (fear and depression), economic (decapitalization and consumption reduction), environmental degradation (loss of harvests and habitat loss), and political (strain on government response capacities).

Hazard Categories and Vulnerability Sectors

• Natural Hazard Types:
  • Biological (bios): Disease-causing organisms (e.g., Ebola Virus, flu virus, rabies).
  • Geological (geo): Earth-process events (e.g., ground shaking, volcanic ballistic projectiles, landslides, lava flows, liquefaction, tsunamis).
  • Hydrometeorological (hydro + meteoros): Atmospheric and water processes (e.g., typhoons, floods, tornadoes, forest fires).
• Technological / Human-Induced Hazards: Originating from industrial or human conditions (e.g., chemical contamination, nuclear hazards, industrial accidents, armed conflict, environmental degradation).
• Categories of Vulnerability:
  • Physical / Material: Land, water, infrastructure type, housing location, and environmental quality.
  • Social / Organizational: Leadership quality, family structure, legislation, and administrative justice.
  • Attitudinal / Motivational: Awareness, self-reliance, cooperation, and openness to change.
• Vulnerability Sectors:
  • Most Vulnerable: Low capacity to withstand damage (e.g., farmers, urban poor, laborers, indigenous people, persons with disabilities, women, children).
  • Less Vulnerable: Possess capacity to acquire resources and training (e.g., professionals, small entrepreneurs).
  • Not Vulnerable: High position and abundant resources in society.

Earthquake Hazards and Features

• Definition: Unexpected and rapid ground shaking caused by seismic waves passing through subsurface rocks due to shifting layer faults (Arulsamy and Jeyadevi, 2011). Recorded by seismographs and monitored by PHIVOLCS (Department of Science and Technology).

• Earthquake Types: Tectonic (plate movements) and Volcanic (magmatic/volcanic activity) [Nelson (2015)].

• Anatomy of an Earthquake:

  • Focus / Hypocenter: The point inside the Earth where the earthquake originates.
  • Epicenter: The point on the Earth's surface directly above the focus.   

• Major Philippine Fault Lines: West Panay Fault, West Valley Fault, East Valley Fault, Surigao Fault, and Bangui Fault. High-impact activity along the West Valley Fault is referred to as "The Big One".

• Measurement Scales:

  • Magnitude: Energy released at the focus; calculated using seismographs via Moment Magnitude Scale ($M_w$) represented in Arabic numerals.
  • Intensity: Felt shaking and localized impact strength; measured via Modified Mercalli Intensity (MMI) Scale from I to XII in Roman numerals.

• Specific Earthquake Hazards:

  • Ground Shaking: Structural movement that causes building collapse (e.g., 1990 Luzon Earthquake / Hyatt Hotel collapse).
  • Ground Rupture: Visible displacement and fissures along an active fault trace.
  • Tsunami: Giant ocean waves ($> 5\,m$) generated by underwater seismic disturbances.
  • Liquefaction: Transformation of saturated loose soil into a fluid-like state during intense shaking.
  • Land Subsidence: Lowering of the ground surface due to disrupted subterranean groundwater reserves.
  • Landslides: Mass movement of rock and earth down a slope accelerated by ground motion.

• Emergency Response: Drop, Cover, and Hold On; turn off gas, water, and electricity; use stairs instead of elevators; cover mouth and avoid shouting if trapped under debris.

Hydrometeorological Hazards and Storm Signals

• Typhoon Overview: Rapidly rotating storm system featuring cumulonimbus clouds, low-pressure center (eye), and squalls (Typhon / Dafeng).

  • Hurricanes: Formed in the Atlantic and Northeastern Pacific Oceans (Huracan).
  • Typhoons: Formed in the Northwestern Pacific Ocean.
  • Tropical Cyclones: Formed in the South Pacific and Indian Oceans.

• Key Historical Typhoons in the Philippines:

  • Typhoon Ondoy (International Name: Ketsana, 2009): Triggered massive flooding and landslides.
  • Super Typhoon Yolanda (International Name: Haiyan, Nov 2013): Winds exceeded $300\,km/h$ with a $5\,m$ storm surge, displacing over 4 million people.   

• Tropical Cyclone Classifications:

  • Tropical Depression (TD): Maximum sustained winds up to $61\,kph$.
  • Tropical Storm (TS): Maximum sustained winds between $62-88\,kph$.
  • Severe Tropical Storm (STS): Maximum sustained winds between $89-117\,kph$.
  • Typhoon (TY): Maximum sustained winds between $118-220\,kph$.
  • Super Typhoon (STY): Maximum sustained winds exceeding $220\,kph$.

• Public Storm Warning Signals (PSWS):

  • PSWS #1: Lead time of $36\,hrs$; winds of $30-60\,kph$ (no to very light damage).
  • PSWS #2: Lead time of $24\,hrs$; winds of $61-120\,kph$ (light to moderate damage).
  • PSWS #3: Lead time of $18\,hrs$; winds of $121-170\,kph$ (moderate to heavy damage).
  • PSWS #4: Lead time of $12\,hrs$; winds of $171-220\,kph$ (heavy to very heavy damage).
  • PSWS #5: Lead time of $12\,hrs$; winds over $220\,kph$ (very heavy to widespread damage).

• Associated Phenomena:

  • Flash Floods: Sudden high-velocity water accumulations lasting up to $6\,hours$.
  • Storm Surge: Wind-driven onshore water rise generated by low pressure and marine surface winds of a cyclone.
  • El Niño & La Niña: El Niño involves sea surface warming in the central/eastern Pacific causing dry spells; La Niña involves cooler-than-normal sea surface temperatures.

Fire Hazards and Disaster Risk Management Tools

• Fire Definition: A rapid oxidation process that evolves light and heat at varying intensities (National Fire Protection Association).

• Fire Triangle: Requires three simultaneous elements: Fuel, Heat, and Oxygen ($O_2$).   

• Extinguisher Operation Protocol (PASS):

  • P: Pull the pin.
  • A: Aim low at the base of the fire.
  • S: Squeeze the lever slowly and evenly.
  • S: Sweep nozzle from side to side.

• Fire Prevention Best Practices:

  • Maintain safe clearance between kitchen stoves and flammable items.
  • Use qualified electricians and avoid overloading double adaptors or power boards.
  • Keep matches, lighters, and open flames away from unattended children.
  • Do not dry clothes directly over home heating equipment or leaves fires lit overnight.

• Project NOAH (Nationwide Operational Assessment of Hazards):

  • Background: Initiated post-Tropical Storm Sendong (Dec 2011) under President Benigno Aquino III; managed by DOST from 2012–2017, now led by the University of the Philippines.
  • Functionality: Mobile and web platform tracking real-time weather outlooks, local flood, landslide, and storm surge hazard levels, as well as nearby critical emergency facilities.