Dhaka: Although salinity, which poses a threat to human health, is on the rise in costal aquifer due to the sea level rise, a new study reveals that most of the coastal people (84%) are not aware of the presence of salinity in groundwater in the country's coastal region.

Salinity has been affecting health of coastal inhabitants, including spread of diarrhoea, dysentery, itching, sore and other skin troubles.

The Department of Public Health Engineering (DPHE) and the Institute of Water Modelling (IWM) conducted the study titled, 'Joint Action Research on Salt Water Intrusion in Groundwater in the Coastal Area'. Starting from September 2010, the study was completed in December 2014. But the final report of the study is yet to be prepared.

Under the climate change condition in the year of 2050, area of fresh water zone (salinity less than 1000 ppm) will decrease compared to present situation. Within the saline zone, areas under severe salinity will increase by 14 percent by 2050, predicted the study.

The study was carried out in parts of three districts of Khulna, Jessore and Satkhira with about 1534 square kilometres, aiming to assess salinity extent and intrusion, and aquifer vulnerability in the area.

JAR Study project leader M Rezaul Hasan said salinity has been increasing in the coastal aquifer due to sea level rise caused by global climate change, but the people of the coastal region are not aware of the presence of salinity in groundwater as they are habituated with salinity.

The use of saline water for shrimp culture by the coastal people has been identified as a major reason for increasing salinity in the shallow aquifer.

At the present condition, the study identifies that the low-salinity zone (less than 1000 ppm -parts per milligram) lies along the western part of the study area while the high salinity zone (more than 1000 ppm) along the southern and eastern sides.

About the long term simulation for climate change options for 2050, the study indicates that the propagation of salinity from river to aquifer takes place.

Coastal aquifers are vital sources of fresh water throughout the world. Bangladesh, especially the low-lying coastal areas, is likely to be in extreme vulnerable condition under the current scenario of changes in climate condition because of its geographic location and low-lying topography.

This scenario is likely to be worsened by reduced dry period flow and increased abstraction of water for domestic, industrial, irrigation and other needs.

Rezaul Hasan said the study predicts that aquifer saline zone will increase by 2.27% by 2050 while fresh water zone will decrease by 3.44%.

‘But severe salinity zone will increase by 14% by 2050 accelerating fresh water crisis in the coastal region, which is a great concern for us,’ he added.