The Government of Bangladesh has an ambitious plan to eradicate most poverty by 2033, and completely by 2050, in line with the United Nations Sustainable Development Goals (SDGs)18,24. It also plans for the country to be resilient and prosperous in the face of climate change, with significant mobilisation and allocation of resources towards disaster risk reduction24,47. Previous studies have argued that disaster risk management and poverty alleviation go hand in hand4,47. Here, we demonstrate that the joint efforts in disaster risk and poverty reduction ought to also consider geomorphic hazards.
This study quantifies the dynamism of Bangladesh’s landscapes, with vast areas undergoing geomorphic change at the annual and decadal scales. These geomorphic processes can be both episodic and chronic. The geomorphic hotspot modelling results in this study have shown that there are significant areas in Bangladesh that are prone to continuous and persistent geomorphic changes, both in terms of erosion and subsidence, and accretion and drying up of land. The erosional or subsiding processes can degrade or completely consume valuable floodplain lands, leading to losses of livelihoods, reduced agricultural productivity and income, food insecurity, unemployment, and ultimately social unrest and internal displacement17. Contrastingly, the drying up or accretion of land may provide benefits such as newly created land, but may also result in siltation of waterways, which has negative impacts on biodiversity, fishing livelihoods and navigation19. Unlike other hazards, such as flooding, there are limited options for coping with erosion hazards; if a household’s land is removed by a river or the sea, temporary or permanent relocation is inevitable22,48. Migration in Bangladesh is a historical phenomenon; the country’s census of 2011 states that 10% of the total population of Bangladesh are lifetime internal migrants49. A large proportion of internal migration is not permanent, but rather seasonal or temporary, predominantly as a response mechanism to environmental factors and shocks or due to seasonal or temporary employment opportunities elsewhere49,50.
Charlands (river islands), where cyclical relocation is widespread, are a striking instance of a more-or-less constant process of internal migration which is driven by geomorphic change. There are approximately 6.5 million chaura people (charland dwellers) who cope with regular flooding and riverbank instability, of which approximately 65% live on the Jamuna River chars22,28,51−53. Population relocation is driven by landscape changes of fluctuating erosion and accretion patterns within the rivers22,28. When considering different charland communities across Bangladesh, erosion-prone households have been shown to experience relocation every five years on average, although some households experience displacement as much as three times within a single year of severe river erosion (for example in 1997-98)28,51. Resettlement is most commonly localised, with average distances of around 12km51. Typically, displaced landowners temporarily resettle on other areas of the same char, or on a nearby char, and then return to their land when it re-emerges from the river28,51. Many dwellings have, for instance, converted from traditional clay, straw and bamboo houses to tin sheds, as these are much easier to dismantle and shift in the case of erosion28. This localised re-settlement pattern is most likely linked to not being able to afford to move greater distances, as well as the hope that their land will re-emerge from the river, allowing them to return to their place of origin in the future22.
Insecure land ownership and an uneven distribution of accessibility to land plays a significant role in driving inequalities to geomorphic risk6,28,54. Even land-rich households struggle finding suitable areas to relocate to when their homesteads are lost to erosion28. Moreover, given the high prices of land on the mainland, selling charland (which is, in itself, restricted due to limited ownerships rights) to acquire land on the more stable mainland is not feasible for many charland dwellers28. Oftentimes, in response to such land losses or agricultural unproductivity, farmers or fishers are forced to sell their productive assets, reduce their food consumption, stop children’s education and take informal loans6,55,56. Thus, households living in these high-risk areas tend to have fewer alternative livelihood opportunities, fewer financial resources to spend on housing, and tend to also have a lack of access to regional and global markets, which combined, furthers their vulnerability to these geomorphic hazards2,4,6.
The changing river courses therefore stimulate a process of involuntary migration, and can accentuate the process of impoverishment, resulting in enormous economic, social and psychological costs for the displaced populations22. The most severely impacted households may fall into poverty traps as a result of geomorphic shocks or more gradual riverine or coastal erosion, as the losses induced by these hazards repeatedly exceed the local recovery capacity, impeding longer-term future recovery and economic growth6,18,57,58. In response to this, the Bangladeshi government, with funding support from the UK and Australia, initiated the Chars Livelihoods Programme (CLP) in 2002, lasting until 2016, with the aim of substantially reducing extreme poverty for people living on the chars in Bangladesh59. As a result of the programme, 88% of targeted households escaped extreme poverty, which was achieved predominantly through promoting sustainable livelihoods and improving markets for the poor, better protecting communities from flooding and erosion, increasing access to water, sanitation and hygiene services, improving food security and supporting women’s empowerment and social development59. The lessons learnt by the people facing these stresses is fundamental in successfully alleviating both geomorphic risks as well as poverty22,55.