Keywords: Fourier polynomial, water salinity modelling, river estuaries, Sundarbans, environmental management, Bangladesh, tidal inundation, salt water
Fourier polynomial approximation of estuaries water salinity in the Sundarbans region of Bangladesh
The geographical location, characteristics of the coastal region and the monsoon climate render Bangladesh highly vulnerable to natural disasters. The reduction of upstream fresh water in the Ganges basin caused for high saline water penetration in the estuaries of the Sundarbans region. The five estuaries namely Baleswar, Bangra, Kunga, Malancha and Raimangal are highly affected by saline water intrusion and tidal inundation which is a new threat for estuaries ecosystems. The time series water salinity data were used for water salinity approximation. The estuaries water salinity modelling was done through Fourier polynomial approach using MATLAB software and GIS used for environmental data analysis and visualisation. Almost four estuaries water salinity has crossed the water salinity threshold line and the Baleswar estuary is in the marginal situation. The objective of this study is to understand the water salinity fluctuations and threatened ecosystems in the river estuaries of the Sundarbans mangrove region.