Evolution of the Bhasan Char Island (Meghna Estuary, Bangladesh) and its Suitability for Refugee Resettlement

The Bhasan Char, a 68-km² offshore island (2021) of the Meghna Estuary, is situated in the eastern Ganga–Brahmaputra–Meghna Delta of Bangladesh. The island has gained prominence after its selection as a major relocation centre for the displaced Rohingya refugees of Myanmar.

25 images of the 2001–2021 period, pertaining to nine satellites (IRS 1D; Resourcesat 1, 2, 2A; Sentinel 1A, 2A, 2B; Landsat 5, 7) and the Google Earth repository, were used to trace the evolution and reclamation stages of the Bhasan Char. Cyclone tracks and intensities at the vicinity of island for 1970–2021 were considered to show its susceptibility to storm damage. Geological structures were also studied to assess its future stability.

The results show that the Bhasan Char was formed in 2002 with an area of 5.46 km² and it was shifted towards the southeast at a rate of 0.63 km/yr till 2007. The island became largely stable by 2012. Subsequently, rapid sedimentation was seen in its northern areas with some erosion in the south. Since 2017, 8.2 km² of the island was reclaimed to build shelters for the refugees. The Government of Bangladesh has implemented several protection measures to reduce erosion of the southern part of the island and policies to create land through sediment harvesting at its vicinity. The situation of the Bhasan Char on an active anticlinal axis aids to this endeavour. The recurrence interval of cyclonic storms (wind speed >= 62 km/hr) at the Bhasan Char is once every 3.5 years; a 2.5-km breakwater and the 2.74-m high paved embankment provide adequate protection from these.

Considering the above facts, it is concluded that the Bhasan Char is likely to remain stable in the foreseeable future and it is not unsuitable for locating rehabilitation shelters.