Author(s)

M. J. A. N. Bhuiyan & D. Dutta

Abstract

One potential impact of a global warming and rise in sea level would be an increase in the salinity of coastal zones, which would potentially threaten drinking water and aquatic ecosystems. There is a need to be better prepared to respond and adapt to these changes. This report examines the potential impacts of accelerated sea level rise on salinity in the South West region of Bangladesh. The study aims at determining the sensitivity of river salinity to upstream discharge and downstream sea level. To do that, the minimum upstream flow will be determined to protect the salinity intrusion from sea level rise. A one dimensional river salinity transport model has been developed and coupled with an existing surface and river flow model. The model has been proved to be robust with calibration and verification against observed data. The model outputs indicate a significant change of river salinity in the coastal zone. The results also indicate that a considerable advance in seawater intrusion can be expected in the coastal aquifer if current rates of sea level rise continue. The topography of the area is flat and gently sloping towards the Bay of Bengal. The consequences of salinity intrusion in the coastal area especially in the South West region of Bangladesh would be significant on many sectors like land fertility, agriculture, availability of fresh water, existence of the Sundarban forest etc. Pond culture in the coastal area will be affected by intrusion of salt water into ponds, unless embankments are made around them. Shrimp culture in the coastal area is a lucrative business. Increase in salinity is likely to jeopardize the shrimp culture. Keywords: flow, river, salinity, salt water intrusion, sea level rise.

Keywords

flow, river, salinity, salt water intrusion, sea level rise