LESSONS LEARNED FROM PAST NOTABLE DISASTERS

NEW ZEALANDPART 2: WINDSTORMS AND

TORNADOES

Walter Hays, Global Alliance for Disaster Reduction, Vienna,

Virginia, USA 

Natural Phenomena that Cause Disasters

Planet Earth’s Seasonal Atmospheric Interactions Can Cause Tornadoes

NATURAL HAZARDS THAT HAVE CAUSED NATURAL HAZARDS THAT HAVE CAUSED DISASTERS IN NEW ZEALAND DISASTERS IN NEW ZEALAND

FLOODS

WIND STORMS AND TORNADOES

EARTHQUAKES

VOLCANOES

ENVIRONMENTAL CHANGE

GLOBAL CLIMATE CHANGE

HIGH BENEFIT/COST PROGRAMS FOR BECOMING DISASTER RESILIENT

GOAL: PROTECT PEOPLE GOAL: PROTECT PEOPLE AND COMMUNITIESAND COMMUNITIES

NEW ZEALAND’S CITIES

WINDY WELLINGTON (THE CAPITAL)

WELLINGTON

• Wellington is renowned for its winds and windstorms.

• The wind-funnelling effect of Cook Strait and the rugged topography lead to FREQUENT, strong, and highly variable wind fields and storms around the southern coast.

PAST SEVERE WINDSTORMS

• Wind records from Cape Palliser and Castlepoint show that maximum wind speeds of up to 200 kph at Kelburn occurred during the Wahine storm on April 10, 1968, and 215 kph at Hau Nui during the October 19, 1998 Wairarapa storm

BAD NEWS 2-WEEKS AFTER THE DEVASTATING CHRISTCHURCH

EARTHQUAKE

A SEVERE WINDSTORM “THE SIZE OF AUSTRALIA” IS ON

ITS WAY

SEVERE WINDSTORM FORECAST: SEPT. 17, 2010

Gale-force winds of up to 130 kph, accompanied by heavy rain, lightning and plunging temperatures, impacted the

capital, Wellington

IMPACTS: The power was out, trees and sheds were on fire after more than 100 lightning strikes in the Hutt

Valley and Kapiti Coast.

TORNADOES

New Zealand experiences, on average, about 20 damaging

tornado events each year, which are typically very narrow with short tracks and in the F0 to F2

range.

Most tornadoes in New Zealand have occurred in the North Island, particularly around the Bay of Plenty and down to Auckland

Another concentration of tornadic activity is on the western coast of Taranaki near New Plymouth

NEW ZEALAND’S WORST TORNADO

• New Zealand's worst tornado struck the community of Frankton then moved into neighboring Hamilton on August 25, 1948.

IMPACTS OF NEW ZEALAND’S WORST TORNADO

• The twister, rated as F2, killed 3, injured 80, and damaged or destroyed 163 buildings and 50 businesses.

IMPACTS OF NEW ZEALAND’S WORST TORNADO

• The winds lifted buildings, snapped off chimneys, pealed roofs off houses, and uprooted trees.

• The air was filled with flying corrugated iron, branches of trees, timber and kinds of debris.

ELEMENTS OF RISK AND DISASTER

HAZARDSHAZARDS

ELEMENTS OF TORNADO RISK ELEMENTS OF TORNADO RISK

EXPOSUREEXPOSURE

VULNERABILITYVULNERABILITY LOCATIONLOCATION

RISKRISK

A DISASTER CAN HAPPENWHEN THE

POTENTIAL DISASTER AGENTS OF A TORNADO INTERACT WITH

THE VULNERABLE BUILT ENVIRONMENTS OF NEW

ZEALAND’S COMMUNITIES

TORNADO HAZARDS:

HIGH VELOCITY WIND FIELDand

FLYING DEBRIS

ARE POTENTIAL DISASTER AGENTS

WIND PENETRATING BUILDING ENVELOPE

TORNADOES

UPLIFT OF ROOF SYSTEM

FLYING DEBRIS

UPROOTED TREES

IRREGULARITIES IN ELEVATION AND PLAN

SITING PROBLEMS

UNANCHORED CONTENTS

CAUSES OF DAMAGE

“DISASTER LABORATORIES”

A DISASTER is --- --- the set of failures that overwhelm the capability of a community to respond without external help  when three continuums: 1)  people, 2) community (i.e., a set of habitats, livelihoods, and social constructs), and 3) complex events (e.g., tornadoes, earthquakes,..) intersect at a point in space and time.

Disasters are caused by single- or multiple-event natural hazards that, (for various reasons), cause

extreme levels of mortality, morbidity, homelessness,

joblessness, economic losses, or environmental impacts.

THE REASONS ARE . . .

• When it does happen, the functions of the community’s buildings and infrastructure will be LOST because they are UNPROTECTED with the appropriate codes and standards.

THE REASONS ARE . . .

• The community is UN-PREPARED for what will likely happen, not to mention the low-probability of occurrence—high-probability of adverse consequences event.

THE REASONS ARE . . .

• The community has NO DISASTER PLANNING SCENARIO or WARNING SYSTEM in place as a strategic framework for concerted local, national, regional, and international countermeasures.

THE REASONS ARE . . .

• The community LACKS THE CAPACITY TO RESPOND in a timely manner to the full spectrum of expected and unexpected emergency situations.

THE REASONS ARE . . .

• The community is INEFFICIENT during recovery and reconstruction because it HAS NOT LEARNED from either the current experience or the cumulative prior experiences.

NEW ZEALAND’S NEXT STORM OR TORNADO IS INEVITABLE

• ---SO, DON’T WAIT TO BE REMINDED ONCE AGAIN OF THE IMPORTANCE OF BECOMING WINDSTORM DISASTER RESILIENT.

THE ALTERNATIVE TO A STORM OR TORNADO

DISASTERIS

WINDSTORM DISASTER RESILIENCE

New Zealand’s New Zealand’s COMMUNITIESCOMMUNITIES

DATA BASES DATA BASES AND INFORMATIONAND INFORMATION

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

• WINDSTORM HAZARDS•INVENTORY•VULNERABILITY•LOCATION

WINDSTORM RISK WINDSTORM RISK

RISK

ACCEPTABLE RISK

UNACCEPTABLE RISK

WINDSTORM DISASTER WINDSTORM DISASTER RESILIENCERESILIENCE

•PREPAREDNESS•PROTECTION•FORECASTS/SCENARIOS•EMERGENCY RESPONSE•RECOVERY and RECONSTRUCTION

POLICY OPTIONSPOLICY OPTIONS

LESSONS LEARNED ABOUT DISASTER RESILIENCE

ALL TORNADOES PREPAREDNESS FOR THE LIKELY DAMAGE IS ESSENTIAL FOR DISASTER RESILIENCE

LESSONS LEARNED ABOUT DISASTER RESILIENCE

ALL TORNADOES WIND ENG-INEERING FOR BUILDINGS IS ESSENTIAL FOR DISASTER RESILIENCE

LESSONS LEARNED ABOUT DISASTER RESILIENCE

ALL TORNADOES TIMELY WARNING AND PERSONAL PREPAREDNESS IS ESSENTIAL FOR DISASTER RESILIENCE