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Scenario Overview
A simple loss estimation study was conducted for a repeat
of the 1934 earthquake in the modern day Kathmandu Valley. The
location and vulnerability of the Kathmandu Valley's infrastructure
was determined through interviews with approximately 30 institutions.
The information collected in these interviews was combined with
previously conducted studies, then a loss estimation study was
conducted using simple, order-of-magnitude methods. Loss estimates
were conducted for the road, water, electricity and telephone
systems and for typicial structures. In addition, possible death
and injury figures were determined by looking at statistics
from previous comparable earthquakes from around the world.
The Earthquake Scenario
A scenario document that explains the results of the earthquake
loss estimation study in layman's terms has been written and
published in English and Nepali languages (NSET-1, 1999). This
document includes a description of possible damages to various
vital systems in Kathmandu and an explanation of the repercussions
of this damage on life in the Kathmandu Valley. It also presents
the story of one common man, Bhaicha, for an entire year after
the scenario earthquake, illustrating how this character's life
is impacted. This document is being widely distributed along
with information on earthquake preparation methods and means
of obtaining additional earthquake safety information. It is
expected that this document will provide emotional understanding
of the earthquake phenomenon to complement the technical information
included in the loss estimation study.
Loss Estimation of the Bihar-Nepal Earthquake
The 1934 Bihar-Nepal earthquake produced shaking of intensity
X, IX and VIII (Modified Mercalli Intensity scale) within the
Kathmandu Valley. It is believed that this shaking was primarily
due to amplification of the local soil, lacustrine sediments
several hundred meters thick. Therefore, a similar distribution
of shaking can be expected from all major, distant earthquakes
affecting the Valley. In addition, there is a high probability
of liquefication in many of the Valley's urban areas, particularly
near rivers.
A brief summary of the loss estimates for a possible repeat
of the 1934 level of shaking follows:
- As many as 60 percent of all buildings in
the Kathmandu Valley are likely to experience heavy damage,
many beyond repair.
- Almost half of the bridges in the Valley could
be impassible, and ten percent of all paved roads will have
moderate damage, such as deep cracks or subsidence. The country's
only international airport may be inaccessible. The prevalence
of extremely narrow roads, which could easily be blocked by
debris, will exacerbate the problem.
- Approximately 90 percent of water pipes and
50 percent of other water system components (pumping stations,
treatment plants, etc.) could be seriously damaged. Almost
all telephone exchange buildings and 60 percent of telephone
lines are likely to be damaged, requiring significant to moderate
repair to operate. Approximately 40 percent of electric lines
and all electric substations are likely to be damaged.
- Simply applying the percentage of the population
killed or injured in the 1934 earthquake to the population
of the Valley today results in an estimate of 22,000 deaths
and 25,000 injuries requiring hospitalization. Applying more
recent earthquake casualty figures from cities comparable
to the Kathmandu Valley results in an estimate of 40,000 deaths
and 95,000 injuries in the Kathmandu Valley's next major earthquake.
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