203
dependent on the local initiatives. Fresh water flows, drinking water supply, water
for irrigation and fishing are severely affected. Considering the present water
resource management condition a newly policy framework guideline is essential to
protect and maintenance the coastal water resources in Bangladesh.
6.6.2 Sea Level Rise and Its Impacts on Coastal Region
Climate change and sea level rise, induced by global warming, also compromise the
ecological stability of the coastal zone; in sum, due to various natural and anthropogenic factors, the natural resource base of the zone is declining. Failing ecosystem
productivity further degrades the quality of life of the local population (Dasgupta
2001). Relative Sea-Level Rise (SLR) movement has an immediate and direct effect
on the coastal inter tidal ecosystems, particularly on vegetation. Arise of relative
SLR decreases the influences of terrestrial processes and increases the influence of
coastal marine processes (Islam 2001). The world great deltas are among the most
densely populated and most vulnerable of coastal areas are threatened by sea level
rise (Broadus 1993). Global warming and sea level rise and vulnerability of coastal
wetland ecosystems are factors that have to be considered the long term management strategy for dealing with the coastal mangrove wetland issue. The impacts of
climate change in any given region depend on the specific climatic changes that
occur in that region. Local changes can differ substantially from the globally averaged climate change (Harvey 2000). The global warming and climate change a predicted sea level rise, accelerated by global warming will cause a further ‘Squeezing’
of the natural tidal land. In Bangladesh case it has been projected by IPCC (2007)
and MoEF that 3 mm/year sea level rise which will occurs before 2030 and 2500 km
2
land (2%) will be inundated. About 20% of the net cultivable area of Bangladesh is
located in the coastal and offshore island (Fig. 6.9).
A very recent study on coastal area in Bangladesh by Wolanski et al. (2009)
shows that the mean tidal level at Hiron Point is showing an increase of 4.0 mm/year
which is higher than the global rate. Soils in this area are affected by different
degrees of salinity (Rahman 1988). About 203,000 ha very slightly, 492,000 ha
slightly, 461,000 ha moderately and 490,200 ha strongly salt affected soils are
assessed in south western part of the coastal area (Fig. 6.9). The climate change
impact issue is a new threat for the coastal area of Bangladesh (Fig. 6.9). In the
Sundarbans case, sea level rise would result in saline water moving further into the
delta which would be the major threat for mangrove and coastal wetland ecosystems
(IECO 1980). The fate of the Sundarbans with different sea level rise the potential
impacts on environment if 10 cm SLR will inundate 15% of the Sundarbans and
with 1.5 m SLR about 17 million (15%) of the population will be affected and will
have to be displaced or homeless, whereas 22,000 km
2
(16%) land will permanently
be inundated (Fig. 6.9).
The Figs. 6.8 and 6.9 shows that with 3 m SLR would be worse scenario for
Bangladesh when almost one third of land could be inundated by saline water. The
6 Degraded Coastal Wetland Ecosystems in the Ganges-Brahmaputra Rivers Delta…
dependent on the local initiatives. Fresh water flows, drinking water supply, water
for irrigation and fishing are severely affected. Considering the present water
resource management condition a newly policy framework guideline is essential to
protect and maintenance the coastal water resources in Bangladesh.
6.6.2 Sea Level Rise and Its Impacts on Coastal Region
Climate change and sea level rise, induced by global warming, also compromise the
ecological stability of the coastal zone; in sum, due to various natural and anthropogenic factors, the natural resource base of the zone is declining. Failing ecosystem
productivity further degrades the quality of life of the local population (Dasgupta
2001). Relative Sea-Level Rise (SLR) movement has an immediate and direct effect
on the coastal inter tidal ecosystems, particularly on vegetation. Arise of relative
SLR decreases the influences of terrestrial processes and increases the influence of
coastal marine processes (Islam 2001). The world great deltas are among the most
densely populated and most vulnerable of coastal areas are threatened by sea level
rise (Broadus 1993). Global warming and sea level rise and vulnerability of coastal
wetland ecosystems are factors that have to be considered the long term management strategy for dealing with the coastal mangrove wetland issue. The impacts of
climate change in any given region depend on the specific climatic changes that
occur in that region. Local changes can differ substantially from the globally averaged climate change (Harvey 2000). The global warming and climate change a predicted sea level rise, accelerated by global warming will cause a further ‘Squeezing’
of the natural tidal land. In Bangladesh case it has been projected by IPCC (2007)
and MoEF that 3 mm/year sea level rise which will occurs before 2030 and 2500 km
2
land (2%) will be inundated. About 20% of the net cultivable area of Bangladesh is
located in the coastal and offshore island (Fig. 6.9).
A very recent study on coastal area in Bangladesh by Wolanski et al. (2009)
shows that the mean tidal level at Hiron Point is showing an increase of 4.0 mm/year
which is higher than the global rate. Soils in this area are affected by different
degrees of salinity (Rahman 1988). About 203,000 ha very slightly, 492,000 ha
slightly, 461,000 ha moderately and 490,200 ha strongly salt affected soils are
assessed in south western part of the coastal area (Fig. 6.9). The climate change
impact issue is a new threat for the coastal area of Bangladesh (Fig. 6.9). In the
Sundarbans case, sea level rise would result in saline water moving further into the
delta which would be the major threat for mangrove and coastal wetland ecosystems
(IECO 1980). The fate of the Sundarbans with different sea level rise the potential
impacts on environment if 10 cm SLR will inundate 15% of the Sundarbans and
with 1.5 m SLR about 17 million (15%) of the population will be affected and will
have to be displaced or homeless, whereas 22,000 km
2
(16%) land will permanently
be inundated (Fig. 6.9).
The Figs. 6.8 and 6.9 shows that with 3 m SLR would be worse scenario for
Bangladesh when almost one third of land could be inundated by saline water. The
6 Degraded Coastal Wetland Ecosystems in the Ganges-Brahmaputra Rivers Delta…