Increasing salinity now threatens 17% of land in Bangladesh, according to new research carried out by the Bangladesh Agricultural Development Corporation (BADC).
Bangladesh, a country with one of the highest population densities in the world, is also the country most vulnerable to sea-level rise. Most of the country is low-lying; and in some areas groundwater levels have dropped below sea level, due to climate change, overuse of groundwater and river diversion projects.
Today, the coastal nation is one of the first places to feel the effects of melting ice caps and rising sea levels. Rising sea levels are increasing the salinity of the water and soil of the region, endangering crops, biodiversity, and the health of people living in region.
“It’s troubling. In the last three decades, salinity has insidiously intruded 120 kilometres into the mainland,” said Dr. Md. Eftekharul Alam, chief of irrigation at BADC. The research, carried out by the government organization, paints a detailed picture of the extent of the damage: 19 out of Bangladesh’s 64 districts have been affected by salinity and salt water has penetrated main areas of the country.
Pervasive salinity could now potentially reach the capital city, Dhaka, according to the new study’s perturbing findings. Kothalipara village in Gopalgoanj not far from Dhakahas already been affected by saline water, the research confirmed.
“The condition is critical. It could become more hazardous within a short period of time because it [saline water] is moving rapidly towards the mainland,” said Eftekharul. Expressing grave concern, he said that saline water has pushed 60 kilometres north from the coastal belt within the past decade alone.
Saline observatories were set up in 19 districts for the survey. “Based on the findings, we are certain that in time, one fifth of Bangladesh stands to be affected by salinity,” warned Eftekharul. The study was motivated by the sudden drop in crop production despite the application of excessive fertilizers and the chronic failure of the farmers to meet production targets.
Eftekharul explained the causes of increased salinity: “Less rainfall in this region and a rise in the use of ground water have taken down the level of ‘pure water’ precipitously, triggering a shortage. The elevation of sea level and the reduction of groundwater do not portend well for the future,” the government specialist warned.
Water levels in the northern districts of the country have plummeted by between 9 and 37 metres, while in the capital water levels have plunged by a staggering 50 metres, according to the research project. And indiscriminate use of groundwater has exacerbated salinity problems; as groundwater tables fall, more salt water seeps in.
Imamul Haque, professor at the Bangladesh University of Engineering and Technology argued that unless rivers flow freely, it would be difficult to stop the disaster spreading further. A decrease of water flowing from the mainland upstream down into the Bay of Bengal will compound the risk, he added.
Mohammed Khalequzzaman, a professor at the department of Geology and Physics of Lock Haven University in the US, urged the Bangladeshi government to take swift action and said: “Bangladesh should rely more on surface water for drinking purposes not ground water…and reduce its use of groundwater.”
But river pollution prevents people from using surface water for drinking, so the government must also take steps to control pollution and the negative impacts of rapid urbanisation. “Recharging groundwater might be another possibility,” added the Bangladeshi-born water expert.
Eftekharul also observed that that allowing rivers to flow freely towards the Bay of Bengal is “essential to counter future harm; otherwise, salinity will come towards the middle of the country.”
In order to find solutions he suggested “fruitful discussion and sharing of expertise” with upper riparian countries like India and Nepal: “If this does not yield any result then the matter must be raised in an international platform.”
Pantho Rahaman is senior staff correspondent for Channel i, Dhaka.