When we think of early warning systems for flood protection, we typically think of sensors that gauge rising water levels in a stream and notify officials in real time so they can begin evacuating neighborhoods or take steps to protect property. What if there were an early warning system for the slow process of erosion?
Dutch engineers are setting up such a system as part of a larger project in Bangladesh. The company Royal HaskoningDHV is leading the effort to develop coastal protection at the mouth of the Meghna River, specifically for Bhola Island, which has long experienced erosion, flooding, and cyclones.
Especially on the east coast of the island, land is disappearing quickly, including developed areas and farmland. Just as in many heavily populated areas of the coastal US, simply picking up and moving isn’t an option for the island’s residents. About 1.7 million people live on the island, and each year thousands of them are displaced as a few more square miles are lost.
Coastal and bank protection measures are of course already in place on the island and along the riverbanks, but they’re expensive to build and maintain, and it’s hard to predict where they will fail. Engineers are placing underwater acoustic detection devices throughout the area to detect where and how erosion is occurring. Seeing the damage at its earliest stages will allow authorities to make repairs quickly, and at less cost than if a catastrophic failure has already occurred. Over time, a more thorough understanding of the erosion processes taking place will allow better long-term planning and maintenance.