The Gol - UNDP Disaster Risk Management Programme is a National initiative to
reduce vulnerabilities of communities in some of the most hazard prone districts ( 169
districts in 17 states ) of India . The programme (2002-2007) aims to contribute to the
social and economic development goals of the National and State Governments , enable them
to minimize losses to development gains and by reducing their vulnerability to natural
disaster.The programme relies upon a community based approach to disaster preparedness and
management and seeks to build capacities , government functionaries at all the leveld\s
and other stake holders in disaster management in an organized manner. The Ministry
of Home Affairs (the nodal Ministry for disaster management in the country)is the
executing agency for the programme with UNDP country office support for
implementation.
Earthquake is a natural event which may cause tremendous loss of life and property damage.
One of the major challenges facing our country
is to reduce the vulnerability to this uncontrollable and unpredictable hazard by having a
greater understanding about its causes and effects. As per the latest seismic zoning map
of India brought by the Bureau of Indian standards, over 65% land area of the country is
prone to seismic intensity of MSK VII or more during damaging earthquakes. Some of the most intensive earthquakes of the world
have occurred in India, but fortunately, none of these have occurred in the vicinity of
the major cities . India has highly populous cities including the National Capital of New
Delhi , located in zones of high seismic risk Typically majority of the constructions in
these cities are not earthquake resistant . Thus any earthquake striking in one of these
cities would turn into a major disaster.It is most important in the medium and long term
to formulate strategies to reduce the vulnerability to and losses arising from a possible
earthquake striking any of these cities . Six significant earthquakes have struck
different parts of India over a span of last 15 years. Five of them occurred in rural or
semi urban areas and hence the damage in terms of human lives and property were relatively
small. On the other hand , the 2001 Bhuj earthquake struck both rural and urban areas and
reiterated the scale of vulnerability . If any of these earthquakes strike the populous urban centers, the damage would
be colossal.
Capacity: |
The
resources of communties to cope with a threat or resist the imapct of the harazd.
|
Risk:
|
The Probabilty/likelihood of disaster happening. |
Vulnerability: |
The degree to which communities are susceptible to
loss,damage, suffering and death, in disaster.(also nature of
bulding,types,ages etc.) |
Hazard: |
The physical event that can potenially triggger a
disaster.Such a phyiscal event in itself need not necessaily result in disaster. |
Disaster Proneness: |
Likeihood of location being affected by disaster. |
Earthquake: |
Shaking of the Earth caused by a sudden
movement of rock beneath its surface. (USGS National Earthquake Information
Center, 1999) The release of stored
elastic energy caused by sudden fracture and movement of rocks inside the Earth. Part of
the energy released produces seismic waves, like P, S, and surface waves, that travel
outward in all directions from the point of initial rupture. These waves shake the ground
as they pass by. An earthquake is felt if the shaking is strong enough to cause ground
accelerations exceeding approximately 1.0 centimeter/second squared. (Noson, et.al.,
1988
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Epicenter: |
That point on the Earth's surface directly
above the hypocenter of an earthquake. (USGS National Earthquake Information Center,
1999) The location on the surface of the Earth directly above the focus, or place
where an earthquake originates. An earthquake caused by a fault that offsets features on
the Earth's surface may have an epicenter that does not lie on the trace of that fault on
the surface. This occurs if the fault plane is not vertical and the earthquake occurs
below the Earth's surface. (Noson, et.al., 1988) |
Fault |
A break in the Earth along which movement
occurs. Sudden movement along a fault produces earthquakes. Slow movement produces
aseismic creep. (Noson, et.al., 1988) |
Focus: |
That point within the Earth from which
originates the first motion of an earthquake and its elastic waves. (USGS National
Earthquake Information Center, 1999) |
Intensity: |
A measure of severity of shaking at a
particular site. It is usually estimated from descriptions of damage to buildings and
terrain. The intensity is often greatest near the earthquake epicenter. Today, the
Modified Mercalli Scale is commonly used to rank the intensity from I to XII according to
the kind and amount of damage produced. Before 1931 earthquake intensities were often
reported using the Rossi-Forel scale. (Noson, et.al., 1988) A measure of the effects of an earthquake at a particular place on
humans, structures and (or) the land itself. The intensity at a point depends not only
upon the strength of the earthquake (magnitude) but also upon the distance from the
earthquake to the opint and the local geology at that point. (USGS National Earthquake
Information Center, 1999)
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Magnitude: |
A quantity characteristic of the total
energy released by an earthquake, as contrasted with intensity, which describes its
effects at a particular place. A number of earthquake magnitude scales exist, including
local (or Richter) magnitude, body wave magnitude, surface wave magnitude, moment
magnitude, and coda magnitude. As a general rule, an increase of one magnitude unit
corresponds to ten times greater ground motion, an increase of two magnitude units
corresponds to 100 times greater ground motion, and so on in a logarithmic series.
Commonly, earthquakes are recorded with magnitudes from 0 to 8, although occasionally
large ones (M=9) and very small ones (M= -1 or -2) are also recorded. Nearby earthquakes
with magnitudes as small as 2 to 3 are frequently felt. The actual ground motion for, say,
a magnitude 5 earthquake is about 0.04 millimeters at a distance of 100 kilometers from
the epicenter; it is 1.1 millimeters at a distance of 10 kilometers from the epicenter. (Noson,
et.al., 1988) A numerical expression of the
amount of energy released by an earthquake, determined by measuring earthquake waves on
standardized recording instruments (seismographs). The number scale for magnitudes is
logarithmic rather than arithmetic; therefore, deflections on a seismograph for a
magnitude 5 earthquake, for example, are 10 times greater than those for a magnitude 4
earthquake, 100 times greater than for a magnitude 3 earthquake, and so on. (Foxworthy
and Hill, 1982)
|
Richter Magnitude
Scale |
The Richter magnitude scale was developed in
1935 by Charles F. Richter of the California Institute of Technology as a mathematical
device to compare the size of earthquakes. The magnitude of an earthquake is determined
from the logarithm of the amplitude of waves recorded by seismographs. Adjustments are
included for the variation in the distance between the various seismographs and the
epicenter of the earthquakes. On the Richter Scale, magnitude is expressed in whole
numbers and decimal fractions. For example, a magnitude 5.3 might be computed for a
moderate earthquake, and a strong earthquake might be rated as magnitude 6.3. Because of
the logarithmic basis of the scale, each whole number increase in magnitude represents a
tenfold increase in measured amplitude; as an estimate of energy, each whole number step
in the magnitude scale corresponds to the release of about 31 times more energy than the
amount associated with the preceding whole number value. (USGS National Earthquake
Information Center, 1998) |