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News from ICTP 99 - Features - Bangladesh
Satellite and computer technologies have helped improve disaster management in Bangladesh, one of the world's most disaster-prone nations. ICTP has provided essential training for this effort.
Weather Matters in Bangladesh
Bangladesh is a nation where
catastrophic weather events are so common that it's fair to say
such events have become a part of everyday life--continually testing
the resiliency of a resilient people. That's why the introduction
of satellite technology and computerised assessments, which are
designed to provide and analyse detailed information about weather
patterns and potential weather-related impacts, have become such
a welcome addition to the nation's long-standing battle against
nature's fury.
One of the pioneers of this effort has been Abdul Musawwir Choudhury,
a former ICTP Regular Associate (1981-1994), who has served as
director of research and chairperson of the Space Research and
Remote Sensing Organization (SPARRSO) since 1980. SPARRSO is a government-sponsored
research organisation specialising in remote sensing and computer
modelling. With a staff of 150 (including about 50 research scientists),
SPARRSO, headquartered in the capital city of Dhaka, works closely
with other governmental agencies responsible for water, forestry,
fishery and land-use management.
"A unique confluence of circumstances--both natural and human-made--has
placed social and environmental well-being in Bangladesh at risk
year-in and year-out," says Choudhury.
"First, Bangladesh sits on a broad delta plain--a sea of
silt--built by soil deposits from the Ganges and Brahmaputra rivers.
While this gives the nation potentially some of the most fertile
soil on Earth, it also makes it vulnerable to flooding. In fact,
half of the nation's land mass is less than 25 meters above sea
level. Think of Bangladesh as The Netherlands of the Asian subcontinent."
While Bangladesh may look like The Netherlands in terms of topography,"
Choudhury adds, "the size of its land mass is comparable
to England, but with a population 2.5 times as large." That
makes Bangladesh, with a total of about 130 million people, one
of the most densely populated nations on Earth.
And, as endless news stories and research reports have noted,
the people of Bangladesh are poor. The World Bank estimates that
the annual gross national product per capita is about US$350 and
that 75 percent of the population lives on less than US$2 a day.
That makes Bangladesh one of the poorest countries on Earth.
"Simply put," notes Choudhury, "geography has created
natural hazards for Bangladesh; poverty has made it difficult
for the nation to respond effectively."
There is one additional factor, however, that makes the experience
of Bangladesh even more unique than the experience in other poor,
overcrowded coastal nations in the developing world. That factor
is the monsoons, seasonal winds that often carry heavy, sometimes
torrential, rainfalls between May and September each year, and,
at the same time, are one of the prime forces behind such catastrophic
weather events as cyclones and tornadoes. Bangladesh receives
85 percent of its annual rainfall (which can total more than 5
metres a year) during the monsoon season--and suffers most of
its weather-related catastrophes during this period as well.
Abdul Musawwir Choudhury
Choudhury explains: "In southeast Asia, land covers 60 percent
of the area; in the rest of the world, land cover averages 20
percent with the rest submerged in water. Since water tends to
absorb a much higher percentage of the sun's radiative heat, regions
with large water masses tend to have cooler, more temperate, climates.
"In Bangladesh," he continues, "temperature differences
between the land and the sea can sometimes reach 10°C. Such
differences generate variations in pressure that kick up the seasonal
monsoon winds and supply the energy that fuels cyclones and tornadoes."
Put another way, the vast Eurasian land mass dominated by the
Himalayan Mountains and Tibetan Plateau and encircled by the Indian
and Pacific oceans provide an ideal, one-of-a-kind, geographical
setting for the spawning of monsoons.
Bangladesh, as a result, is no stranger to devastating natural
events. In 1970, a cyclone left 300,000 dead and millions homeless
in one of the worst natural disasters in human history. In 1991,
another catastrophic cyclone left 100,000 people dead. And in
1998, two-thirds of the country was inundated by flood waters
that rose some 20 metres above normal in some places, forcing
more than 20 million people to evacuate their homes.
But that's not all. Shifts in monsoon winds can sometimes cause
rains to cease or not arrive at all. As a result, Bangladesh,
a land noted for too much rain, also periodically suffers from
too little rain. In 1770, the great Bengal drought wiped out an
estimated one-third of the population. In 1943, drought took the
lives of one-fifth of the population. More recently, droughts
in 1973, 1979 and 1994 left millions of Bangladeshis without access
to adequate supplies of food.
But the news of late is not all bad. Improved irrigation systems
and agricultural practices have raised the level of food production
in Bangladesh, helping to mitigate the adverse, life-threatening,
impact of droughts. Moreover, recent weather-related catastrophes
in Bangladesh have not caused as much havoc and death as in the
past, in part because both citizens and government officials have
been able to respond more effectively to the risks posed by natural
disasters. For example, Bangladesh experienced two weeks of floods
in September 2000 but the loss of lives and the extent of property
damage were minimal compared to previous floods. In fact, less
than 1000 people died--a catastrophe in its own right but of a
much lesser dimension than in the past.
One reason for the thankfully limited impact of the storms in
2000 was the fact that the most intense rain storms were confined
to the southwest quadrant of the country. Another reason, however,
lies in significant improvements that have taken place in Bangladesh's
disaster management programmes, which are better funded and more
sophisticated than in the past. In fact, Bangladesh's disaster
management strategy has moved increasingly from post-disaster
response (cleaning up the mess after it takes place) to preparedness
(trying to anticipate potential disasters before they occur and
putting plans in place to minimise their potential damage).
That's where the work of Choudhury and SPARRSO comes into play.
For more than two decades, SPARRSO, with the help of satellite
and computer technologies, has been assembling detailed statistical
profiles of Bangladesh's weather and climate. More recently, it
has begun to develop computer models that have become increasingly
adept at anticipating rain and temperature patterns throughout
the country.
The government of Bangladesh has found such information invaluable
in addressing a host of vital environmental problems ranging from
its annual projected levels of water-irrigation releases for farmland
(which helps boost agricultural productivity) to anticipated changes
in water quality (which help improve the management of the nation's
fish industry, an important source of nutrition for many people)
to projected levels of rain associated with monsoons (which is
instrumental in devising effective strategies for risk management).
One of the most important insights provided by SPARRSO has to
do with the development of a computer model that can accurately
project whether a particular monsoon season will result in moderate
or heavy rainfall. The model, which draws on information related
to barometric pressure readings across the globe, has proven instrumental
in anticipating the impact of El Niño and La
Niña on rain levels in Bangladesh, thus helping to
determine whether a particular monsoon season is likely to leave
excessive flooding in its wake. The conclusion of these studies,
in their most simple form, is this: El Niño tends
to blunt the force of monsoon rains. La Niña, meanwhile,
tends to fuel the quantity and intensity of rainfall during monsoons,
making a dangerous situation even more dangerous.
Choudhury recently visited ICTP to give a lecture during the Course
in Inverse Methods in Atmospheric Science. But this was by no
means the first time that he has been to Trieste. Indeed Choudhury's
affiliation with the Centre dates back to the late 1970s when
he attended an international workshop on monsoon dynamics in Dhaka,
which was jointly organised by ICTP in cooperation with the World
Meteorological Organization (WMO) and the Canadian International
Development Agency (CIDA). His participation in Centre-sponsored
activities accelerated after 1981 when he was appointed an ICTP
Associate. As a result, in the early 1980s, Choudhury attended
Trieste-based training and research activities related to numerical
weather prediction, geophysics, applications of physics to meteorology,
geomagnetism and mathematical ecology.
"While other organisations--for example, the US National
Aeronautics and Space Administration (NASA)--provided staff at
SPARRSO with access to satellite data that made it possible for
us to conduct research at home, ICTP provided the training and
know-how to effectively use this information in ways that addressed
compelling national needs. This is an untold story of how ICTP
has helped put physics and math to work to deal with one of Bangladesh's
most critical problems--weather-related disasters."
"Despite our recent modest measures of success, we still
have a long way to go," says Choudhury. "Nevertheless,
we should be proud of the science-based progress that has recently
been made in dealing with the inevitable risks that Bangladesh
experiences due to an unusual mix of natural and social conditions
that, in turn, have created an unusual set of challenges for a
nation struggling to improve the quality of life for its people."
For additional information about the Bangladesh Space Research
and Remote Sensing Organization (SPARRSO), please contact A.M.
Choudhury, sparrso2@bangla.net.