LESSONS LEARNED FROM PAST NOTABLE DISASTERS: LANDSLIDES. Large volume landslides occur in association with an earthquake’s ground shaking or a typhoon’s rainfall. Presentation courtesy of Dr. Walter Hays, Global Alliance for Disaster Reduction
3. NATURAL HAZARDS THAT PLACE CHINA’S
NATURAL HAZARDS THAT PLACE CHINA’S
COMMUNITIES AT RISK
COMMUNITIES AT RISK
FLOODS
GOAL: DISASTER
GOAL: DISASTER
RESILIENCE
RESILIENCE TYPHOONS
ENACT AND IMPLEMENT
ENACT AND IMPLEMENT EARTHQUAKES
POLICIES HAVING HIGH
POLICIES HAVING HIGH
BENEFIT/COST FOR
BENEFIT/COST FOR LANDSLIDESS
COMMUNITY
COMMUNITY
RESILIENCE
RESILIENCE
DROUGHT EPISODES
GLOBAL CLIMATE CHANGE
4. LANDSLIDE RISK
ACCEPTABLE RISK
• LANDSLIDE
HAZARDS RISK
• BLDG. INVENTORY
•
UNACCEPTABLE RISK
VULNERABILITY
• LOCATION
GOAL: LANDSLIDE
CHINA’S DISASTER RESILIENCE
DATA BASES
AND INFORMATION COMMUNITIES
POLICY OPTIONS
• PREPAREDNESS
HAZARDS: • PROTECTION
GROUND SHAKING
GROUND FAILURE • EARLY WARNING
SURFACE FAULTING
TECTONIC
• EMERGENCY RESPONSE
DEFORMATION • RECOVERY and
TSUNAMI RUN UP
AFTERSHOCKS RECONSTRUCTION
10. PHYSICAL CHARACTERISTICS
OF THE EARTHQUAKE
• Epicenter was located 100 km (60
miles) from Chengdu, the
provincial capital, which is on edge
of the Tibetan foothills and home
to about 10 million people.
• This earthquake occurred on a well
known fault zone, which has
generated destructive earthquakes
in the past (e.g., on 25 August
1933).
12. COMPARISON WITH 1976
TANGSHAN EARTHQUAKE
• The Beichuan earthquake was
more than 2 x larger than the
July 28,1976 Tangshan
earthquake, which caused
255,000+ deaths.
13. EMERGENCY RESOURCES
• More than 20,000 military
personnel were ordered
immediately to assist in high-
damage areas.
• The number was increased
substantially to deal with the
“earthquake lakes.”
14. SOCIETAL IMPACTS OF THE
LANDSLIDES
• Some roads were impassable
because of landslides, which
hindered search and rescue,---
• but, worst of all, 69 unique
“earthquake lakes” were
created by the landslides in
mountainous regions.
15. CAUSES OF DAMAGE
CAUSES OF DAMAGE
SITING AND BUILDING ON
UNSTABLE SLOPES
SOIL AND ROCK SUCEPTIBLE
TO FALLS
SOIL AND ROCK SUCEPTIBLE
TO TOPPLES
SOIL AND ROCK SUCEPTIBLE
LANDSLIDES
LANDSLIDES TO SPREADS
SOIL AND ROCK
CASE HISTORIES
CASE HISTORIES SUSCEPTIBLE TO FLOWS
PRECIPITATION THAT TRIGGERS SLOPE
FAILURE SHAKING
GROUND SHAKING THAT
TRIGGERS SLOPE FAILURE
20. ONE OF 69 "QUAKE LAKES":
BEI HE RIVER DAMMED BY
LANDSLIDE DEBRIS
21. DAYS 14-17: CHINA
EARTHQUAKE SURVIVORS
NOW HAVING TO COPE WITH
THREAT OF FLOODS FROM
69 EARTHQUAKE LAKES
22. DAYS 14-17: GOVERNMENT MAKES
RISK REDUCTION ON 69 "QUAKE
LAKES" A TOP PRIORITY
•Sixty-nine “Quake Lakes” created in
mountainous areas by the debris
from landslides appeared ready to
burst their banks, and continuing
rainfall was exacerbating the threat.
23. $29 million in emergency
funds and increased military
resources were allocated
for the priority effort.
24. DAYS 14-17: GOVERNMENT PLANS
EVACUATIONS TO REDUCE RISK IF
A "QUAKE LAKE" SHOULD BURST
•Authorities announced plans
to evacuate more than a
million people in anticipation
of failure of the rock-and-mud
embankments.
25. EVACUATION CHALLENGE
•Evacuation would have to be
accomplished within one to four
hours, the time for the wall of water to
reach and inundate scores of cities
and rural villages that were already
devastated.