Intrusion of surface water salinity in the Western Coastal belt of Bangladesh
Ishtiaq Ahmed, Md. Nurul Kadir, Md. Hafez Ahmed
Abstract
South-West zone of Bangladesh is located in a position very susceptible to water resources related issues and climate change. The South-West region of Bangladesh is a low lying delta with a complex crisscross river system. From last few decades surface water salinity intrusion in the South–West zone in our country has become one of the major concerns. The entire river system of the South-West region is susceptible to extravagant saline water intrusion from the sea with high tide especially during dry season. This problem is exacerbated by decrease of upstream flow due to Farrakka barrage, sea level rise, expansion of shrimp farms and CEP (Coastal Embankment Project) implemented during the 1960s. These facts will lead us to acute problems like decrease in farming lands, increase in groundwater salinity and soil salinity, increased food insecurities, strong scarcity of safe drinking water and loss of biodiversity. This paper evaluates the trend of change in the surface water salinity from the year 2001 to 2008 and analyzes the reasons behind this change. Surface water salinity data source is BWDB. ArcMap 10.1 is used for this purpose combining with analytical analysis and geostatistical analysis. This paper shows increasing trend of surface water salinity majorly due to decrease in upstream fresh water flow rather than the climate change phenomenon.
Keywords: Salinity intrusion, GIS, Geostatistical analysis, Climate change, Fresh water