1) Bangladesh is bestowed with the sands and silts that break out from the boulders and stones coming down the Himalayan slopes. In fact the land here was non-existent a few million years ago. Himalyan soil filled up the Ocean here and built up a new land part of which now is Bangladesh. The Himalayan nature is still sending us this gift that keeps on accumulating in the river beds.
2) BD has at least 1 billion cubic meter of sand and silt accumulated in the river beds across the country. It can use this soil to raise dykes (say, 5m high) along the coastal belt. So, no big problem when we become a little richer after 2020.
3) Problem of salinity is also possible to solve, but it will require huge efforts and money. Barrages must be built across the mouths of rivers. Intrusion of sea water can be stopped by closing the sluice gates at the barrages when sea water level is higher than the river water level. However, this may cause an ecological disaster.
4) An alternative to closed sluice gates is to hammer down sheet piles along each bank of rivers (say, for a 5 km length, but a backwater curve must be produced by computer simulation to decide on the length) that connect to the Sea. Saline water will enter into the rivers, but will not enter the rice fields along the rivers because of sheet pilings. This is how the problem of salinity can be resolved.
However, India, being one of the worst performers in controlling its CO2 emissions from its low technology industries, should be ready to pay a heavy penalty that can be used to develop BD's sea coasts and river embankment systems. A day is coming when the UN will enact laws to punish offender countries like India to make an yearly payment for the carbon it produces in excess of its quantity allowed by the world organization.
