Hossain, Mohammad Monowar
Department of Water Resources Engineering, BUET, Dhaka, Bangladesh, Tel: 8802-0672173, Fax: 8802-8613026, E-mail: monowar@wre.buet.ac.bd
Bangladesh is situated at the apex of the Bay of
Bengal and has a coastline of about 710 km., which extends from the mouth of
Naaf River in the southeast to the mouth of Raimangal River along the Indo-Bangladesh
border in the west. The population of the coastal districts is about 30
millions, which is about 25% of the total population of Bangladesh. The extent
of human impact on the coastal zone is directly related to the population
density not only in the coastal zone itself but also in the inland areas of the
country.
Pollutants washed down from lands and/or dumped directly threaten the marine water of Bangladesh. The large number of rivers and waterways that criss-cross the entire country drain surface runoff and sediment loads from watershed that spread over the upstream countries (India, Nepal, Bhutan and China) and finally emptied into the Bay of Bengal, play a vital role in carrying pollutants from different sources. Most of the pollutants are in the form of sediments, municipal and industrial wastes, agro-chemical residues and pollutant discharge from ships and boats.
A study has been conducted to assess the pollution loads from oil spills, industrial wastes, municipal wastes from coastal cities and agricultural wastes. Dissolved inorganic and organic carbon and associated sediment flux through the major river system into the Bay of Bengal has also been assessed. It is found that the pollution loads are on the increase in the costal zone and remedial measures are urgently necessary for minimizing degradation of coastal ecosystem. Land building due to sediment influx in the coastal zone through major river system is being compensated by dynamic erosion-deposition process.