Bangladesh will start performing monthly sonar surveys in a bid to ward off progressing climate change-related erosion of its biggest island.
A joint project between Dutch and Bangladeshi companies, the monthly surveys will be carried out using an advanced 1.5-metre long sonar that will assess the condition of protective sand bags framing the coast of the Bhola island at the mouth of the Meghna River.
The sonar will be towed behind a boat around the low-lying 130 km long island which is home to 1.7 million people.
According to historical evidence, the now banana-shaped island used to be oval in the 18 century, documenting the fast progress and extent of the erosion process.
Due to frequent and powerful floods, the protective sand bags, weighing about 250 kg each, shift in waters that are too muddy and fast-flowing for divers. The erosion early warning system would allow damaged bags to be replaced, preventing further progress of the erosion.
"This will save a lot of money on repair work," Jan Bron, project manager at Dutch engineering consultancy Royal HaskoningDHV, said.
If successful, the project will be expanded to other areas of Bangladesh, one of the countries most vulnerable to climate change. It could also be applied to other low-lying countries.
The Bangladeshi and Dutch governments will both contribute €22 (£18m) towards the project to protect a vulnerable part of Bhola's coastline.
The consortium comprises Royal HaskoningDHV, technology firms AGT Netherlands and TechForce Innovations from the Netherlands and Bangladesh's TigerIT, engineering group EPC and the Institute of Water Modelling.
"The system will provide a good insight into how erosion takes place," Pieter-Christiaan van Oranje-Nassau, Chief Executive of AGT Netherlands, said in a statement.
Bhola "is just six feet above sea level at the highest point. Climate change will have an effect," Bron said.
Global sea levels have risen by about 20 cm (8 inches) since 1900 and could rise by almost a metre in the worst case this century due to a melt from Greenland to Antarctica, according to a UN panel of climate experts.