Flooding in Bangladesh
Bangladesh is a low lying country and almost all of Bangladesh lies on
the largest delta in the world. It is situated between the Himalayas
and the Indian Ocean with a vast river basin made up of the Ganges,
the Brahamaputra, the Meghna and their tributaries. It also has the
highest population density in the world with 847 inhabitants per
Bangladesh is one of the world's least developed countries and prone
to natural disasters, such as cyclones, floods and droughts. Half of
it is less than five meters above sea level. Therefore any change in
the earth’s temperature that causes the level of the oceans to rise
would seriously affect the flooding of the delta area of Bangladesh.
A fifth to a third of the country is annually flooded by the river
Ganges and there are many factors both human and physical which
encourage the river Ganges and Brahmaputra to overflow its river
banks. The obvious physical cause of flooding in Bangladesh is that
about 90% of the land is below sea level, therefore any changes in the
sea level would cause serious problems for Bangladesh.
Another physical cause includes the snow melting in the Himalayas,
caused by global warming. The Himalayas are one of the few places in
the world that retain permanent glaciers. In the warmer summer season
however glacial ice goes through a period of melting. The source of
the Brahmaputra starts in the Himalayas and an increase in
melted-water flowing through its drainage basin will increase channel
flow, saturate soils and cause massive overland flow – a major cause
Another major cause is the cyclonic storms that frequent the Bay of
Bengal. Storm surges which are rapid rises in sea-level caused by
intense areas of low pressure i.e. depressions and tropical cyclones,
precede cyclonic storms and are often as high as seven to ten meters.
The heavy wet summer monsoons also contribute to the flooding, it
brings rain that adds to the flow of water in rivers. The summer
monsoon was responsible for the excessive rainfall of 1987 and 1988 in
An increased amount of precipitation can also cause flooding. An above
normal monsoon downpour in the Ganges-Brahmaputra-Megna drainage
system is thought to be the primary cause of the 1988 flood in
Bangladesh. It is not known, however, if the heavy precipitation is
actually an effect of other processes such as the greenhouse effect or
destruction of forests in the upstream region.
Another physical cause of flooding in Bangladesh is tectonic activity.
The Indian Plate is moving towards the Eurasian Plate. The land where
they meet (Himalayas) is getting higher and steeper every year (fold
mountains). As a result soil is becoming loose and is susceptible to
erosion. This causes more soil and silt in rivers,...