Cyclone and Storm Surge - Iczmpwb.org

2.50
embankments. Crops and properties over Rs.900 million have been destroyed and around 500
people have lost their lives. These numbers are likely to increase manifold in future.
The study also notes that the Sagar Islands is the most populated and vulnerable island of the
Hoogly estuary. Over the last few decades the island has been seen to register a land loss of 12 Km2
with marginal accretion on the portion of the southern and eastern fringe. Within the last few
decades, nearly 3800 persons have been rendered homeless from Sagar Island itself due to sea
level rise, coastal erosion and flooding due to cyclones and consequent storm surges. In addition,
four refugee colonies for the displaced persons from other islands (Lohachara, Ghoramara etc) have
been set up at Sagar. A mathematical model coupled with GIS database developed by the School of
School of Oceanographic Studies, Jadavpur University; demonstrate that with the current rate of sea
level rise, the Sagar island will loose around 15% of its existing land area by the 2020. An estimate
considering the population growth rate and future population density of Sagar indicates that the
number of displaced persons due to sea level rise and associated storm surges/coastal flooding will
be around 30,000 by 2020.
2.7.3. Inundation
As mentioned before, the problem of inundation due to high rainfall within the circuit embankments of
the inhabited islands is inevitable at the time of a high tide, coupled with a storm surge. As such,
proper drainage is required along with right kind of sluices and vents. At the time of a high sea level,
the island dwellers are also at a constant threat of further inundation likely to be caused by possible
embankment failure. Since the dwellers here have settled before the full maturity of development of
the islands, they continue to suffer from the gradual rise of the surrounding riverbeds compared to
their lands. Due to premature reclamation, the average ground level of some of the populated islands
remains between 1.55 m to 0.75mts below the mean high water level of the tides and in the coastal
area, the ground level remains about 2.60m below. This accentuates further the risk of embankment
failure and washout. These embankments have now become the lifeline of the Sundarbans islands,
as because, the safety of the lives and properties as well as agriculture and subsistence are
dependant on the stability of the embankments.
Excess rain water is drained from the fields into a system of canals and ponds. Some of the canals
and ponds are excavated by the farmers for this purpose. Others are the result of the construction of
embankments and roads. On many islands the canal system partly consists of small natural creeks in
which dams has been constructed at their downstream end. The internal system of canals and ponds