Abstract:
In Bangladesh, salinity in coastal aquifer is a common problem which is expected to be
exacerbated by climate change and sea-level rise. At present, salinity intrusion due to
reduction of freshwater flow from upstream, salinization of coastal groundwater and
increase in soil salinity are major concern of Bangladesh. Salinity is a vital issue to the
people of southwest region. Due to the presence of salinity in groundwater as well as
surface water, the people of the southwest region are suffering from problems related to
drinking water, irrigation, agriculture, fisheries and other uses. In this regard, the present
research is carried out on Kalia upazila of Narail district which is located in the southwest
region of Bangladesh, comprising an area of 317.64 sq km. The research is aimed at
evaluating the spatial (i.e. horizontal) as well as vertical distribution of groundwater
salinity in the study area and its impacts on drinking water and agriculture. For this
purpose, this study used two widely used parameters for evaluating salinity - electrical
conductivity (dS/m) and chloride concentration (mg/l) of groundwater at different unions
of Kalia upazila from BADC water quality reports from 2004-2007 and interpretation of
geophysical log from DPHE. Field visit has been carried out to investigate present
condition of salinity and its influences on community. A questionnaire survey has been
carried out in the study. The study shows that the eastern and western parts of Kalia
upazila have higher salinity trend whereas the north central part is more or less salinity
free. The Joynagar union has the highest electrical conductivity of 4.5 dS/m and Mauli
union has the lowest electrical conductivity of 0.7 dS/m. For drinking purpose only the
DTW water appears to be suitable from salinity. The study also shows that out of 14
unions, water from 7 unions has higher chloride concentration which is beyond acceptable
limit for irrigation.
