Welcome, guest. You are not logged in.
Log in or join for free!
Stay logged in
Forgot login details?

Stay logged in

For free!
Get started!

Text page

Floods in Bangladesh

The South Asian countryof Bangladesh is prone to the natural disaster of flooding due to being situated on the Ganges Deltap and the many tributaries flowing into the Bay of Bengal . The coastal flooding twinned with the bursting of Bangladesh's river banks is common and severely affects the landscape and Bangladeshi society. 75% of Bangladesh is less than 10m above sealevel and 80% is flood plain, therefore renderingBangladesh a nation verymuch at risk of further widespread damage despite its development.Whilst more permanent defences, strengthened with reinforced concrete,are being built, many embankments are composed purely of soil and turf and made by local farmers. Flooding normally occurs during the monsoon season from June to September during the monsoon. Theconvectional rainfall of the monsoon is added toby relief rainfall caused by the Himalayas. Melt-water from the Himalayas is also a significant input and flood every year.
Each year in Bangladesh about 26,000 km 2 , (around 18%) of the country is flooded, killing over 5,000 people and destroying 7 million homes. During severe floods the affected areamay exceed 75% of the country, as was seen in 1998. This volume is 95% of the total annual inflow. By comparison, only about 187,000 million m 3 , of streamflow is generatedby rainfall inside the country during the same period. The floods have caused devastation in Bangladesh throughout history, especially during the years 1966, 1987, 1988 and 1998. The 2007South Asian floods also affected a large portion of Bangladesh.
Small scale flooding in Bangladesh is required tosustain the agricultural industry, as sediment deposited by floodwaters fertilises fields. The water is required to grow rice, so natural flooding replaces the requirement of arteficial irrigation, whichis time consuming and costly to build. Salt deposited on fields from high rates of evaporation is removed during floods, preventingthe land from becoming infertile. The benefits of flooding are clear in El Niño years when the monsoon is interrupted. As El Nino becomes increasingly frequent, and flood events appear to become more extreme, the previously reliable monsoon may besucceeded by years of drought or devastating floods. Also, some 3 thousand people were left homeless or killed.


In Bangladesh the following types of floods are normally encountered.
*. Flash floods in the eastern and northern rivers are characterizedby a sharp rise followed by a relativelyrapid recession, often causing high flow velocities that damage crops and property.
*. Local floods due to highlocalized rainfall of long duration in the monsoon season oftengenerate water volumes in excess of the local drainage capacity, causing localized floods due to drainage congestion.
*. Monsoon floods from the major rivers generally rise slowly and the period of rise and fall may extend from 10 to 20 days or more. Spilling through distributaries and over the banks of the majorrivers causes the mostextensive flood damage, particularly when the three major rivers rise simultaneously.
*. Floods due to storm surges in the coastal areas of Bangladesh, which are generated bytropical cyclone, cause extensive damage to life and property. These cyclones are predominant during thepost-monsoon (October and November) and pre-monsoon (April to June) period.

This page:

Help/FAQ | Terms | Imprint
Home People Pictures Videos Sites Blogs Chat