Lohachara Island

Overview

Lohachara is one of several vanishing islands in the delta; in the past two decades, four islands—Bedford (or Suparibhanga), Lohachara, South Talpatti Island, and Kabasgadi—have been permanently flooded. Only Lohachara was inhabited, with more than 6,000 residents. The loss of land has displaced thousands who moved to the mainland. Multiple causes contribute to island disappearances, including sea level rise, coastal erosion, cyclones (whose number has decreased but intensity increased), mangrove destruction, and coastal flooding.

In 1974 the Farakka Barrage began diverting water into the Hoogly River during its dry season. During each monsoon, almost all the Bengali delta is submerged, much of it for half a year. Sediment in the lower delta plain is primarily advected inland by monsoonal coastal setup and cyclonic events. A major challenge for residents is rising sea waters caused by subsidence in the region.

A 1990 study found no evidence that Himalayan environmental degradation or a greenhouse-induced sea level rise had aggravated floods in Bangladesh. The Bengal Basin is slowly tilting eastward due to neo-tectonic movement, making salinity in the Bangladesh Sunderbans much lower than in the Indian Sunderbans. The overall Sundarbans population has risen 200% to nearly 4.3 million.