LESSONS LEARNED FROM PAST NOTABLE DISASTERS.

TAIWAN PART I: EARTHQUAKES

Walter Hays, Global Alliance for Disaster Reduction, Vienna,

Virginia, USA 

NATURAL HAZARDS THAT PLACE TAIWAN’S NATURAL HAZARDS THAT PLACE TAIWAN’S COMMUNITIES AT RISK COMMUNITIES AT RISK

EARTHQUAKES

TYPHOONS

FLOODS

LANDSLIDES

ENVIRONMENTAL DEGRADATION

GLOBAL CLIMATE CHANGE

ENACT AND IMPLEMENT POLICIES HAVING HIGH BENEFIT/COST FOR COMMUNITY RESILIENCE

GOAL: DISASTER GOAL: DISASTER RESILIENCERESILIENCE

EARTHQUAKES

EARTHQUAKES OCCUR FREQUENTLY IN TAIWAN AS A RESULT OF COMPLEX

INTERACTIONS OF THE PHILIPPINE AND EURASIAN PLATES

JI JI, TAIWAN EARTHQUAKE

OCCURRENCE

M 7.3Shallow depth (about 2 km)1:47 amSEPTEMBER 21, 1999

• This earthquake was a subduction zone earthquake caused by interaction of the Philippine plate with the Eurasian plate.

THE CAUSATIVE FAULT

• The quake was generated by slip on the Chelongpu fault.

• The regional compression caused thrust faulting. • Over 60 km of surface faulting with lateral and vertical displacements reaching 9 m and 5 m, respectively, occurred in the center of the Island.

TAIWAN’STAIWAN’S

COMMUNITIESCOMMUNITIESDATA BASES DATA BASES AND INFORMATIONAND INFORMATION

HAZARDS: GROUND SHAKING GROUND FAILURE SURFACE FAULTING TECTONIC DEFORMATION TSUNAMI RUN UP AFTERSHOCKS

•QUAKE HAZARDS•BLDG. INVENTORY•VULNERABILITY•LOCATION

EARTHQUAKE RISK EARTHQUAKE RISK

RISK

ACCEPTABLE RISK

UNACCEPTABLE RISK

GOAL: EARTHQUAKE GOAL: EARTHQUAKE DISASTER RESILIENCEDISASTER RESILIENCE

• PREPAREDNESS•PROTECTION•EARLY WARNING•EMERGENCY RESPONSE•RECOVERY and RECONSTRUCTION

POLICY OPTIONSPOLICY OPTIONS

INADEQUATE RESISTANCE TO HORIZONTAL GROUND SHAKING

EARTHQUAKES

SOIL AMPLIFICATION

PERMANENT DISPLACEMENT (SURFACE FAULTING & GROUND

FAILURE)

IRREGULARITIES IN ELEVATION AND PLAN

TSUNAMI WAVE RUNUP

POOR DETAILING AND WEAK CONSTRUCTION MATERIALS

FRAGILITY OF NON-STRUCTURAL ELEMENTS

CAUSES OF DAMAGE

“DISASTER LABORATORIES”

POLICY POLICY ADOPTIONADOPTION

RISK ASSESSMENT

• VULNERABILITYVULNERABILITY

• EXPOSUREEXPOSURE

• EVENTEVENT

POLICY ASSESSMENT

• COSTCOST

• BENEFITBENEFIT

•CONSEQUENCESCONSEQUENCES

TOWARDS EARTHQUAKE DISASTER TOWARDS EARTHQUAKE DISASTER RESILIENCERESILIENCE

QUAKESQUAKES EXPECTED EXPECTED LOSSLOSS

LESSONS LEARNED FOR DISASTER RESILIENCE

• ALL NOTABLE EARTHQUAKES

• PREPAREDNESS PLANNING FOR THE INEVITABLE GROUND SHAKING IS ESSENTIAL FOR COMMUNITY RESILIENCE.

PHYSICAL EFFECTS: GROUND SHAKING

• Strong motion records showed that ground shaking was characterized by long-period energy related to the magnitude and local site conditions.

• It was several times greater than the level prescribed in the building code.

LESSONS LEARNED FOR DISASTER RESILIENCE

• ALL NOTABLE EARTHQUAKES

• PROTECTION OF BUILDINGS AND INFRASTRUCTURE IS ESSENTIAL FOR COMMUNITY RESILIENCE.

BUILDING IMPACTS

• 44,338 buildings collapsed, and an additional 41,336 houses and buildings were severely damaged.• Twenty 10- to 20-story residential buildings either collapsed or experienced significant damage, suggesting frequency-dependent site amplification.

• Strong ground shaking from the main shock and its large aftershocks caused the collapse of mid-rise buildings in Taipei, the capitol, which is located about 140 km north of the epicenter in a deep alluvial basin.

• Strong ground shaking, ground failure, and surface fault rupture caused power outages and severe damage to lifelines.

• Some kinds of lifeline damage had NEVER been observed in previous earthquakes.

• The loss of power had wide ranging effects, including disruption of Taiwan’s semi-conductor fabrication facilities.

• A 30-km-long surface fault rupture caused major destruction to schools, residences, dams, embankments and bridges located in or near the rupture zone.

• Most of the bridges that suffered significant damage were located in the area bounded by two thrust faults that ruptured the surface.

• Liquefaction caused damage in a residential neighborhood of Yuanlin located in Changhua County. •Extensive liquefaction-induced damage was also observed in parts of Taichung Harbor.

LESSONS LEARNED FOR DISASTER RESILIENCE

• ALL NATURAL HAZARDS

• CAPACITY FOR INTELLIGENT EMERGENCY RESPONSE IS ESSENTIAL FOR COMMUNITY RESILIENCE.

LESSONS LEARNED FOR DISASTER RESILIENCE

• ALL NATURAL HAZARDS

• CAPACITY FOR RECOVERY AND RECONSTRUCTION IS ESSENTIAL FOR COMMUNITY RESILIENCE.

IMPACTS

• The death toll reached 2,416. •11,446 were injured.• Economic losses reached $9.2 billion. • Short-term global stock market prices were influenced by impacts on the semi-conductor industry.

BASED ON REPORTS BY USGS, EERI, ASCE/TCLEE,

MCEER, TAIWAN AGENCIES, AND OTHERS