192
These three categories are defined three types of divisions based on the physiographic and ecological characteristics such as;
Atlantic Type: The western region is part of the Ganges deltaic floodplain. The
Sundarbans is largely covered by mangrove forests. The western region is known
as Atlantic type coastal region in Bangladesh. This western part of coast is more
stable than other part of the coastal region; its character is like the Atlantic characteristics (Figs. 6.1 and 6.2).
Central Region: The Ganges-Brahmaputra-Meghna (GBM) River systems fall into
the Bay of Bengal through the Meghna estuary. The Meghna estuary is located in
the central region of the coastal Bangladesh. The central region is more unstable
and most vulnerable. Coastal char formation, river erosion and accretions are the
regular activities and character of region (Figs. 6.1 and 6.2).
Pacific Type: The eastern region of Chittagong specially a narrow strip with a long
sandy beach in Cox’s Bazar, known as Eastern Region. It is a long strip until
Teknaf and St. Martins Coral Reef Island. The eastern part of Bengal coastal
region is hotspot of biodiversity and displaying coastal narrow floodplain and
mountainous characters. This eastern region has Pacific characteristics (Figs. 6.1
and 6.2).
The GBM system is discharged through the low-lying area of the central coastline, heavy sediment at inputs from the rivers result in a morphologically dynamics
coastal zone. The central region has deltaic characteristics (Pramanik 1983; Miah
1989). The coastal zone is highly affected by high spring tides when water is saline
during the dry season. The coastal areas are highly prone to cyclone induced storm
surges that bring about the most catastrophic damage here (Chowdhury 2009).
The geology of Bengal basin began 130 million years ago. The initial breakup of
Gondowana land possibly occurred in early Cretaceous (130 million years ago) with
separation of India from combined Australian and Antarctica, the sea floor was created in what is now the Bay of Bengal (Anwar 1988). The coastal morphology is a
characterized by different features like vast networks of rivers and channels, heavy
water discharge carrying sediments, many islands in the coastal channels, strong
tidal waves, cyclone and surges, physiographically funnel shape and Swatch of No
Ground is located in the continental shelf about 24 km south of the Bangladesh
coast (Figs. 6.1 and 6.2). There is a coastal mangrove landscapes and wetland ecosystem in the south western region of Bangladesh coast. Beside there are some other
delineate of the coastal region are high salinity, tidal waves, influence of shrimp
cultivation, and administrative management of the coastal region.
The GBM Rivers discharge is 1.5 million m
3
/s during the peak period (Hasan and
Mulamoottil 1994). The Ganges-Brahmaputra-Meghna (GBM) rivers system is the
largest river systems in the world which is passing through Bangladesh on its way
to the Bay of Bengal and carries sediments 1.8–2.4 billion tons (Nishat 1988), These
are subject to coastal dynamic process generated by the river flow, tide and wide
actions leading to accretion and erosion in the coastal area of Bangladesh (Nishat
1988).
S.N. Islam et al.
These three categories are defined three types of divisions based on the physiographic and ecological characteristics such as;
Atlantic Type: The western region is part of the Ganges deltaic floodplain. The
Sundarbans is largely covered by mangrove forests. The western region is known
as Atlantic type coastal region in Bangladesh. This western part of coast is more
stable than other part of the coastal region; its character is like the Atlantic characteristics (Figs. 6.1 and 6.2).
Central Region: The Ganges-Brahmaputra-Meghna (GBM) River systems fall into
the Bay of Bengal through the Meghna estuary. The Meghna estuary is located in
the central region of the coastal Bangladesh. The central region is more unstable
and most vulnerable. Coastal char formation, river erosion and accretions are the
regular activities and character of region (Figs. 6.1 and 6.2).
Pacific Type: The eastern region of Chittagong specially a narrow strip with a long
sandy beach in Cox’s Bazar, known as Eastern Region. It is a long strip until
Teknaf and St. Martins Coral Reef Island. The eastern part of Bengal coastal
region is hotspot of biodiversity and displaying coastal narrow floodplain and
mountainous characters. This eastern region has Pacific characteristics (Figs. 6.1
and 6.2).
The GBM system is discharged through the low-lying area of the central coastline, heavy sediment at inputs from the rivers result in a morphologically dynamics
coastal zone. The central region has deltaic characteristics (Pramanik 1983; Miah
1989). The coastal zone is highly affected by high spring tides when water is saline
during the dry season. The coastal areas are highly prone to cyclone induced storm
surges that bring about the most catastrophic damage here (Chowdhury 2009).
The geology of Bengal basin began 130 million years ago. The initial breakup of
Gondowana land possibly occurred in early Cretaceous (130 million years ago) with
separation of India from combined Australian and Antarctica, the sea floor was created in what is now the Bay of Bengal (Anwar 1988). The coastal morphology is a
characterized by different features like vast networks of rivers and channels, heavy
water discharge carrying sediments, many islands in the coastal channels, strong
tidal waves, cyclone and surges, physiographically funnel shape and Swatch of No
Ground is located in the continental shelf about 24 km south of the Bangladesh
coast (Figs. 6.1 and 6.2). There is a coastal mangrove landscapes and wetland ecosystem in the south western region of Bangladesh coast. Beside there are some other
delineate of the coastal region are high salinity, tidal waves, influence of shrimp
cultivation, and administrative management of the coastal region.
The GBM Rivers discharge is 1.5 million m
3
/s during the peak period (Hasan and
Mulamoottil 1994). The Ganges-Brahmaputra-Meghna (GBM) rivers system is the
largest river systems in the world which is passing through Bangladesh on its way
to the Bay of Bengal and carries sediments 1.8–2.4 billion tons (Nishat 1988), These
are subject to coastal dynamic process generated by the river flow, tide and wide
actions leading to accretion and erosion in the coastal area of Bangladesh (Nishat
1988).
S.N. Islam et al.