Role of Census of population and
Housing on Disaster Management
What is a disaster ?
“Disaster is a serious disruption of the
functioning of a society, causing widespread
human, material, or environmental losses,
caused by hazards, which exceed the ability
of affected society (community) to cope using
only its own resources.”
What is a disaster management ?
Disaster management is skillful ways
and methods of controlling a disaster.
Any disaster management technique
requires use of country’s demographic
and socio-economic data.
Disaster management approaches
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The general approach to disaster
management remained reactive in
nature, focusing on relief and then
rehabilitation, reconstruction.
However, prevention planning or
community preparedness and policy
priority are important components of
disaster management
Disaster management is a cyclical
process (ASSESS – PRESCRIBE –
EDUCATE)
Assessing RISK, demands for data on
disasters, their impacts etc.
Census of population and housing is
one of the important source of data
for disaster mitigation.
Census of Population and Housing
The characteristics of the population and
attributes of buildings are derived from the
Census of Population and Housing
Data derived from Census of Population and Housing
• Population by
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Sex
Age group
Ethnic group
Religious group
Occupation
Level of education
Literacy level etc.
• Building attributes
– Type of buildings
– Materials used for
construction of buildings
– Availability of electricity,
water, sanitation etc.
Some census information crucial for disaster management
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Population density gives an indication on
– Number of people who are to be affected by a hazard
– Chances of the hazard culminating into a disaster
– Cost and time involved for relief programmes
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Literacy
– Literacy is again a major factor in creating awareness.
– Literate people can be made aware easily as they understand easily
and with less effort and money.
– Literacy also decides the media that has to be used to create
awareness among people.
Uses of national census data for disaster mitigation
Census of population and housing mainly provide data on characteristics of
people and attributes of buildings. This information is crucial for following:
• For measuring populations at risk from the impacts of
natural or human-induced disasters
• To enhance decisions on humanitarian intervention
• Disaster relief operations
• Development assistance to populations vulnerable to a
wide range of hazards potentially leading to disasters
• Early warning systems and emergency actions
• Designing awareness programmes
Population data needs to be available at finer scale units such as at census block
level or grid of size 150 m for assessing damages as otherwise errors committed in
estimations would be high.
GIS on census data
Mapping has now become a first
stage in census taking operations
Based on the number of housing
units, census blocks are
demarcated and census of
population and housing data can
be disaggregated at census block
level paving the way to
preparation of GIS on census data
at census block level
These Geographic information
Systems can be used for planning
and monitoring of disaster
management operations
Quick estimates on people and buildings affected by disasters
Population data from censuses can be made
available per census block. The datum
includes the spatial representation of the
census block unit as vector polygon and the
associated attribute reporting the total
population value by age, sex etc.
After identifying the affected census blocks
quick estimates of affected people and
buildings can be estimated which is more
reliable compared to estimates prepared based
on numbers reported by field officers without
following a proper methodology.
At the Tsunami disaster, affected population in
Sri Lanka, was quite accurately estimated
using census data for immediate relief
operations.
Identification of disaster prone areas
Disaster prone areas can be identified by geographic analysis of socio-economic
data collected by census together with hazard information and land use data
Identification of disaster prone areas contd.
Classification of census blocks by gravity of impact
Geographic analysis of census data together with hazard data and land use data,
can be used to estimate number of people and buildings in disaster prone areas at
different disaggregated levels.
Designing awareness programmes for disaster mitigation
GIS is used for designing an awareness
program based on the following factors
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Zonation of hazard, based on the risk,
Land use,
Population density,
Literacy rate and
Media usage.
Designing awareness programmes
overlay is performed by giving weights
and ranks to the various factors: hazard
map, land use map, population density
map, literacy map and media usage
map
The result of the overlay gives an
indication on areas where the
awareness should be created, on what
disaster, to what level, its intensity and
the type of media that can be best used.
Conclusion
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Census of population and housing data plays a vital role in
disaster management operations
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It is the main source of data for characteristics of people and
buildings
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Census data alone may not be sufficient for taking decisions
and census data should be analyzed together with other
crucial information such as hazard and land use data
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GIS is very important for integrated analysis of disaster
related data
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internationally standardized method for assessing damages,
should be developed and put forward for global use as
technology is largely concentrated in developed countries
Thank You
Census of Buildings and Persons affected
by the Tsunami – 2004
Sri Lanka
Introduction
• The Department of Census and Statistics conducted a Census to assess the
impact of the Tsunami on 26th December, 2004 on the Buildings and people living in
those buildings , within a very short period of time.
Stage I - Listing and updating of all the buildings
Frame used
• Census blocks (part of a GN Division) pertaining to the affected G.N. Divisions were
first identified. If at least one damaged unit was found in a census block it was
identified as an affected census block.
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These census blocks were prepared at the Population and Housing Census – 2001
and lists were prepared for all building units in those census blocks.
Listing and updating of all the buildings
• Field staff of the Department of Census & Statistics (DCS) updated the lists of
damaged housing units in each of the affected census blocks due to Tsunami.
• Housing units belong to the affected census blocks were categorized in this listing
stage as follows:
1. Totally damaged housing units
2. Partially damaged housing units (Cannot be used)
3. Partially damaged housing units (Can be used)
4. Housing units not damaged.
• Above categorization was made by the field staff of DCS (an eye estimation) at the
time of listing which was carried out in the field in February 2005.
Galle District
Matara District
Hambantota District
Kalutara District
Colombo District
Gampaha District
Puttalam District
Ampara District
Trincomalee District
Batticaloa District
Jaffna District