Most of the land of Bangladesh are actually silt over rivers. Bangladesh is a riverine country. More rivers and less land. Due to global warming Southern regoin of Bangladesh will shrink in Bay of Bengal. That is alarming situation.
Population density is also high in Bangladesh and West Bengal. If sea level rises it will be a massacre in Bengal.
Sea level rise risks land accretion in bay
june 5, 2014
Despite the trend of land accretion in the bay, the country is still at risk from the impact of a rise in sea level triggered by the global warming, say observers.
According to different climate studies, the sea level at the bay has been rising gradually in conjunction with the global rise.
The 5th Assessment Report of Inter-governmental Panel on Climate Change (IPCC) suggests that the country’s sea level rises at the rate of 1.5 millimeter (mm) annually, while the global trend is 2mm.
The report was based on sea level data between 1970 and 2010.
It said if the current trend continues, the country will see an annual 5mm sea level rise by 2100, while the global rise will be 6mm.
However, the IPCC 4th Assessment Report shows that the global rise during 1961 to 1993 was 1.8mm per year while the rate was almost double at 3.1mm per year between 1993 and 2003.
The report said of the 3.1mm sea level rise, factors like carbon emission contributed to 2.8mm of the rise.
Experts say the country’s coastal belt, mostly adjacent to the bay, are being highly vulnerable to scarcity of fresh water because of salt water intrusion from the sea.
A large portion of coastal arable land had already been contaminated by extreme salinity due to sea level
rise, said Dr Ahsan Uddin Ahmed, executive director of Center for Global Changes.
He added that the inhabitants in coastal districts had been suffering from potable water scarcity.
A number of studies suggest that climate change leads to frequent natural disasters like cyclones, depressions in the bay and floods.
Regarding the land accretion in the bay, Maminul Haque Sarker, deputy executive director of the Center for Environmental and Geographical Information Services, said with the rise in sea level, the main impact on the estuary would clearly be governed by the reduced flow of water and sediment input from upstream through the Ganges and Brahmaputra rivers.
He observed that the major part of tidal plain in Bangladesh wouldn’t receive any sediment and suffer drainage problems and the formation of new land in the Meghna estuary will continue at a lower rate depending on the rate of sea level rise.
Maminul Haque Sarker said the construction of cross dams towards the end of 1950s and in the early 1960s led to land accretion of several hundred kilometres, but now the sediment input to the estuary has been reduced and the rate of land acquisition has slowed down.
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