Bangladeshi experts defend coastal dikes
- Bangladeshi experts say coastal dikes protect people against climate change impacts
- British scientists opine that the embankment systems constrict estuaries and worsen floods
- The World Bank is backing embankments as a way to mitigate climate change
Over the last 50 years Bangladesh, a low-lying deltaic country, has constructed 139 embankments stretching 625 kilometres that protect about 35 million people and 1.2 million hectares of agricultural land against cyclone surges, spring tides, wave attacks, salinity and risks related to climate change.
Last month (June), the New Scientist cited British scientists saying that the embankments, by constricting the width of the delta’s estuaries, are creating a ‘funneling effect’ that causes deeper and more widespread floods.
Armed with a 400-million-dollar grant from the World Bank, the government has now embarked on a seven-year project ending in 2020 to upgrade the embankments or dikes as a way of increasing the resilience of coastal populations living in a country considered to be at most risk from climate change.
Under the project, mud and concrete embankments in the Sunderbans delta are to be strengthened at vulnerable points and raised by up to a metre with sluice gates installed to allow the exit of water and sediments.
Ainun Nishat, vice chancellor of BRAC University and climate change specialist, tells SciDev.Net that the “improved embankments are designed to address all the important elements of climate change including medium storms surges, spring tides, stronger waves, rising salinity and of course, water logging”.
Nishat, who helped negotiate World Bank support for the project, and other Bangladeshi experts say the views of the British scientists are unfounded.
“The global projection for sea level rise in the delta is 28 centimetres if mitigation measures are taken now. The same projection says the sea level in the delta would rise up to 88 centimetres if no measures are taken. We are focusing on projections for the next 30 years considering all the merits and demerits,” Nishat said.
Mohammad Monowar Hossain, executive director of the Institute of Water Modeling tells SciDev.Net that the “improved and rehabilitated embankments are proposed on the basis of available study and research” and that they are designed to drain out sediments. “So there is no question of water logging and estuaries becoming narrower.”
Project director Sarafat Hossain Khan says that “the upgraded embankments would provide direct protection to some 760,000 people, living within the 100,817 hectares of the project area, from natural disasters.”
> Link to article in New Scientist
This article has been produced by SciDev.Net's South Asia desk.