Sabrina Rashid Sheonty
Salinity of water is another name of suffering for the southern coastal community of Bangladesh. The community frequently faces severe natural calamities due to the geographical location of the region. The recent cyclones Sitrang (2022), Jawad (2021), Amphan (2020), Fani (2019) are evidence of that. When the cyclones strike, the salinity intrusion increases in the surface and ground water sources of the nearby areas. Intrusion of saline water causes the salinity which impacts drinking water, agriculture and many social and economic aspects of life of coastal community. For understanding the salinity level with clarity, the entire coastal region of Bangladesh may be divided into four distinct geo-morphological zones. The southwest zone contains the Sundarbans and it is surrounded by the Baleswar River in the east, and the Raimongal River in the west. The Gorai River is the main source of freshwater for this zone. The boundary of southeast zone starts from the Feni River to Badarmokam having the Lower Meghna River as the western boundary of this region. The south-central zone is situated between the southeast zone and southwest zone that receives considerable freshwater from the Padma River and the Lower Meghna rivers. The Eastern-Hill zone is in the Chittagong and Cox’s Bazar Districts with several flat beaches comprised of clay and sand. In this region, the Karnaphuli, Matamuhuri, Sangu, and Naf Rivers discharge freshwater through the plain. This region. At present, the rivers of the southwest zone suffer mostly from salinity intrusion among the four coastal zones. A groundwater salinity map of the coastal part of Bangladesh was prepared by Bangladesh Agricultural Development Corporation (BADC) using salinity observation wells data where it is evident that the south-western zone is the highest saline water zone.

The salinity is the terms that refers to the salt content dissolved in water. The general predominant ions in the water are sodium and chloride, and the substantial concentrations of ions are magnesium, calcium, and sulfate ions etc. In 2003, a technical report prepared by WHO and the FAO recommends not taking more than 5 g sodium chloride (or 2 g sodium) per day, while ensuring that the salt is iodized. But recent research shows Sodium concentrations above 1000mg/l surrounding the high-moderate south western salinity zone of Bangladesh. Acute salinity and impurity in the drinking water has already affected 43 million people of Bangladesh. The financial condition has worsened the situation for people living under the poverty line. They are compelled to consume saline water regularly of which pasts the danger level. Consumption of saline water over the years can cause serious long-term health issues. There are evidences for the relationship between excessive salt intake and cardio-vascular disease, such as heart disease, strokes and high blood pressure. In case of pregnant women, excessive salt intake can cause gestational hypertension and (pre)eclampsia which can end up in maternal death.

According to Soil Resources Development Institute (SRDI), Ministry of Agriculture, Bangladesh, over the last 35 years, salinity has increased to 26% within the country. As per the 2020 edition of Germanwatch’s Climate Risk Index, Bangladesh is ranked seventh in the list of countries that are most affected by climate calamities during 1999–2018. The salinity amount is expected to increase in near future as a result of climate change which can be catastrophic for coastal community living at that region. Some researches show that the aquifer saline zone may increase by 2.27% by 2050 and fresh water zone will decrease by 3.44%. As a result, severe salinity zone is expected to increase by 14% by 2050.

Last but not the least, we need to acknowledge that salinity and its impact on southwest coastal community is a serious issue which is going to be amplified in near future. Thus, the government and non-government institutions need to be come forward to find solutions and adaptation strategies for it.