Grossman: Bangladesh is crowded. It has a population greater than Russia’s crammed into a space the size of Louisiana. And water is never far away here. The nation sits on a broad coastal plain that’s just above sea level. Civil engineer Ainun Nishat says the country’s geography puts the dense population at risk.
Ainun Nishat: “Bangladesh is nature’s laboratory on natural disaster. We have floods, we have droughts, we have heat waves, we have river bank erosion, we have storm surges, we have cyclones. “
Grossman: And global warming will make things worse, he says. Sea level is expected to rise two or three feet this century. To complicate matters, while the sea is rising, the land is sinking. You see Bangladesh sits on a big delta. This land was built up over thousands of years by sediment washing down the region’s major rivers to their mouths at the Bay of Bengal. But those rivers don’t deposit the sediment on land as they used to. They’ve been constrained by earthen embankments that force the sediment, about a billion tons a year, directly to the sea. Geographer Maminul Haque Sarker says without fresh sediment building up on land, the soil is compacting – it’s sinking – and the country is becoming even more vulnerable to sea level rise.
Maminul Haque Sarker: “If you can manage the sediment better — better way, then it can mitigate some of your losses due to climate change.”
Grossman: That’s what some in Bangladesh are now trying to do… manage the sediment better.
Grossman: A heavy-set man in pressed pants and a polo shirt is driving his car through the outskirts of Khulna, the third-largest city in Bangladesh. Shafiqul Islam is director of a small college, a former locally-elected official, and founder of the Pani or water-committee, a grassroots farmers’ rights group. He’s riding an a straight road on the crest of a dike along one of thousands of small rivers that criss-cross the delta. The water is murky, rich with soil washed down from the Himalayas.
Shafiqul Islam: “You need to understand, this is the river, and that is the farmland. Now you can see that the river is full of sediment.”
Grossman: The area around the river was once a mangrove forest. And though more than 50 miles from the sea, it’s so low and flat that the tide used to overflow the low banks of natural channels and flood nearly the entire region with mucky water. In the 1960′s, at the behest of the government, international aid organizations began constructing a system of dikes to create permanent river channels and stop the natural flooding. Islam says it was an attempt to protect farmers who grow rice here.
Shafiqul Islam: “Because in our country we always think that the Western countries’ manners are very good and they are very knowledgeable, they know everything. But we are very poor countries, we don’t have vast knowledge, we don’t have good engineers here and therefore we have to invite engineers from outside.”
Grossman: But channelizing the rivers robbed the surrounding land of fresh soil. In a matter of decades, once-productive rice paddies had sunk so low they could no longer be drained into the river, which is necessary to farm rice. So the paddies became stagnant and infertile. People had no food.
Shafiqul Islam and others proposed a radical idea: cut the dikes, and let silty water flow onto the farmland for a few years to replenish the depleted paddies. Water officials rebuffed their suggestion. So in 1997, a band of frustrated farmers defied the government and did just that – breached the embankment.
Shafiqul Islam: “There were many police and government officials present while we cut the channel. But thousands and thousands of people were there to help us, and we did it.”
Grossman: As an estimated 20,000 farmers watched, a team of men hacked a hole in the dike with shovels.
Shafiqul Islam: “A huge amount of water went to the wetland side with silt. After the high tide is in full, the water remains stagnant for about 15 or 20 minutes, and at this time, the silt is deposited in the wetland.”
Grossman: The plan to save the paddies outside the city of Khulna worked. In three years the land had collected four feet of new silt. Rice flourishes here once again. Government officials now agree that selectively opening dikes for a new dose of sediment is a good idea. They’ve done it themselves in other areas.
Ainun Nishat: “This is something which is working. And we are champion of it.”
Grossman: Civil engineer Ainun Nishat, who has advised Shafiqul Islam, says although the purpose of cutting the dike in 1997 was to improve agriculture, his country could use the same method to raise the level of the land and protect it from the slow advance of the sea.
Ainun Nishat: “We are pushing the government to do it more effectively. We find the government not doing it with the proper enthusiasm it should receive.
Grossman: Bangladesh does plan to breach more embankements. And other low-lying regions are also exploring this idea. Earlier this year the state of Louisiana announced that it will try restoring sinking wetlands by redirecting sediment from the Mississippi River. But Sheikh Nural Ala, an official with Bangladesh’s Water Development Board, says this technique alone won’t save his people from rising seas.
Sheikh Nural Ala: “Well, it can help, actually, to some extent but not fully because you know, we can apprehend that it may rise up to 1 meter of water level in the sea. So it is not the permanent solution. We have to search for permanent solution again.”
Grossman: A permanent solution, Ala says, will likely involve a mix of techniques – including selective flooding of some areas, and using accumulated sediment to build higher dikes. And a new study says such measures are urgently needed. The study found that most of the world’s major deltas are sinking… and as the sea rises, flooding in these areas could increase 50% this century – putting tens of millions of people at added risk.
For The World, I’m Daniel Grossman, Dhaka, Bangladesh.