The construction of embankments and polders in the south and western regions of Bangladesh have further increased the risk of natural calamities driven by climate change, experts said.
Environment scientists of several American universities in collaboration with the Khulna University have very recently conducted a research on 'Flood Risk of Natural and Embanked Landscape on the Ganges- Brahmaputra Tidal Delta Plain' suggest that the natural land formation has been disturbed due to polders and embankments.
The research report suggests the sea level has risen up due to climate change and again this embankment has further increased more danger.
It says that although this embankment has been constructed for prevention of saline water from entering inland, but again these embankments also prevent the natural siltation process in these areas.
Elaborating more on the worst impact of the polders, it also said that the silted soil area which is outside the polders have risen up due to construction of the embankments. The river and sea water which has also risen up is posing serious threat to the areas around the polders.
A couple of magazines such as Scientific American, the Nature Climate Change Journal, have published facts and figures in a report on the research work.
The research work suggests that in the 60s the construction of embankments has immensely disturbed the land formation in the areas of the west-central Ganges-Brahmaputra delta plain of Bangladesh.
It also says that some areas around polders have become low land than those having no polders, as a result the water has increased in the areas which have polders.
The research work has focused on land formation, the degree of sediment using Global Positioning System (GPS).
The research work had chosen 32 polder area (Kamarkhola and Sutarkhali Union, under Dacope Upazila in Khulna district.)
The Daily Observer has talked to a few environmentalists to get their opinions on the research work.
When asked Dilip Kumar Datta, Professor in the Department of Environment Science of Khulna University, said that he had observed the worst impact of embankments.
"Now we have essential information and facts based on this research work. So, confidently, we can say that embankments have destroyed the natural environment in the areas," he said.
The natural land formations have been disturbed, increasing water logging in the respective areas due to construction of embankments, he said.
He also mentioned large waterbodies, Dakatia, Bhavodhaho, Khuksia beels have been water-logged and turned into big lakes due to construction of polders.
L W Auerbach has commented in the Scientific American magazine, saying the polders are more harmful than the climate change that does not mean that the intensity of the climate change is being ignored.
"Rather the policymakers could follow this research report and take proper measures," he said.
He also noted that it is very easy for the common people to understand about the rising of sea level due to global warming. And Bangladesh will be submerged is nothing but a generalization.
"I think the sea level is rising not only because of melting of water in the polar region, but there must be something beyond that and people must have to understand it," he said.
He also said that the rising of sea level is a bad news for the country like Bangladesh in the global perspective. But the research report emphasized on the proper utilization of land which is more important.
Prof S L Goodbred Jr of Vanderbilt University and co-writer of the research work, said to the Scientific American, "The people of Bangladesh said they are in danger due to climate change. Therefore we did conduct this scientific research work. We clearly tried to understand the real picture. Beside we tried to raise a debate based on knowledge, what has happened, what is happening, and what is not happening," he said.
Asstt Prof Kushal Roy of Environmental Science of Khulna University, who is also a co-writer of the research work, while talking to The Daily Observer said, "While doing this research we came to know that the rise of sea level issue has been complicated by the construction of embankments in the southern and western regions of Bangladesh.
"Construction of embankments to prevent saline water from entering land has caused two consequences. The siltation process has been disturbed, and it is causing huge siltation in the areas where it is not required. As a result, the land inside the polders is low and outside it is elevated.
When asked what needs to be done, he suggested in order to redress the problems of water-logging, authorities may go for creating reservoir for Tidal Water Management and opt for even distribution of fluvial silt so that lopsided land elevation, which is the result of embankment or polders, is averted.