River deltas and climate change: Reducing vulnerability through a better understanding of migration and adaptation in the Ganges delta in Bangladesh
Jon Lawn and Michele Leone

  • In Bangladesh the levels of salinity in the soil is a growing concern for farmersI. Increasing soil salinity reduces the productivity of farmland, putting pressure on families to abandon their homes for other sources of income, often in the cities 
    Photo- Derek Clarke

An abundance of scientific evidence shows that the people living in deltas have an increased vulnerability to sea-level rise and effects of climate change. In 2007, the Intergovernmental Panel on Climate Change (IPCC) reported that low-latitude and less developed areas generally face greater risk, for example in dry areas and mega-deltas. These risks increase vulnerability of specific groups such as the poor.

The poor and vulnerable have migrated in different forms to cope with the disruptions climatic changes has brought upon their lives. Research is crucial to understanding the suitability of migration as an adaptation option to the threats of climate change, and the implications migration has on society and the environment. There is a new project tackling these issues in Bangladesh: a research collaboration between the Bangladesh University of Engineering and Technology (BUET) and the University of Southampton in the UK, which is part of a larger initiative studying migration and adaptation across Africa and South Asia.

The “Deltas, vulnerability and Climate Change: Migration and Adaptation” (DECCMA) project is a five-year long program of applied research which started in early 2014, focusing on the potential and limits of adaptation options in deltaic environments.  The project will analyse the impacts of climate change and changes in other environmental  pressures (such as demand for agriculture or damming rivers) across three contrasting deltas: The Ganges-Brahmaputra-Meghna in both Bangladesh and West Bengal, the Mahanadi delta in India, and the Volta delta in Ghana. The University of Southampton provides the overall lead on the project, partnering with BUET, Jadavpur University in Kolkata, India and the University of Ghana, who lead research in the delta study sites. 

We aim to understand the effectiveness of adaptation options for individuals and communities in the coastal zone of the Ganges-Brahmaputra delta, whilst also evaluating the potential for migration to be an active and positive response to climate change. Ultimately, the project team anticipates that the uptake of a robust scientific evidence base for decision-makers and practitioners will lead to improved livelihoods and reductions in poverty in delta regions. 

Which areas of deltas will be hardest hit?

Defining a boundary for a delta is a complex task!  Where does it start and is all of it going to be affected by sea-level rise?  After discussing many parameters the project team concluded they would focus research in areas that lie between zero and five metres above mean sea level. They acknowledge that areas where people migrate to (major cities and international destinations) would be outside of the 5m contour. Experts in Geographic Information Systems (GIS) and biophysical environmental modellers are collecting data on multiple hazards such as flooding, salinity levels, and land subsidence to map which areas of deltas have historically experienced the worst exposure to environmental risks.  Combining these maps with a geographical analysis of census data (for example where levels of education or income per household are lowest) creates detailed vulnerability maps for each delta, giving an indication of where those most likely to be adversely affected by climate related hazards are located.

How do delta residents decide whether to move?

Initial results from the study reveal that there is much greater out-migration from coastal zones in deltas and the greatest portion of migrants are female.  We will be investigating these results further to understand the reasons why individuals and families chose to migrate, and conversely the factors involved in men and women’s decision to stay.  Focused interviews with thousands of delta residents will enrich the project’s understanding of community decision-making and how open people are to migration and other adaptation schemes (such as constructing polders or financing new technology).  One of the key questions we hope to draw attention: are policies planned by central governments (such as the Bangladesh Delta Plan) understood and utilised by those living in the coastal zone?  Interviewing migrants in their final destinations, will allow researchers to define whether migration has been successful for families by looking at the specific criteria that made migration a success.

To fully understand decisions made by households, we also need to understand the economic condition of the delta. Future development of deltas will depend on employment opportunities, the price of tradable commodities and economic growth.  We are the first research project to attempt to scale down national economic statistics to a sub-national level to classifiy the economic value of the delta to the entire country. Economic factors are linked to the availability of jobs and livelihoods, and in turn, the potential for migration.

A key component of this scientific research is to understand what has already happened (a baseline). Inventories of adaptation schemes have been collated by local research teams, and in the case of Bangladesh, these inventories are already being utilised in conjunction with the United Nations Development Program.

Integrated assessment, a method of evaluating multiple factors together, will be utilised to combine the vast range of elements that contribute to decision-making, from government level through to the household level. Regular stakeholder engagement in each delta is vital to understand the key and relevant issues, and to validate and implement project results for the benefit of deltaic communities, especially those most vulnerable to climate change.

The larger picture

In these efforts DECCMA is not alone; we are one of four research projects funded under the Collaborative Adaptation Research Initiative in Africa and Asia (CARIAA) program, which focuses on three climatic hotspots across sub-Saharan Africa and South Asia: Large river deltas, Himalayan fed river basins, and semi-arid regions. In Bangladesh, BUET is working with the Refugees and Migration Movements Unit (RMMRU, University of Dhaka), Bangladesh Institute of Development Studies (BIDS), Bangladesh Space Research and Remote Sensing Organisation (SPARSSO), Water Resources Planning Organisation (WARPO), Jagrata Juba Shangha (JJS), South Asian Network on Economic Modelling (SANEM), and Centre for Environmental and Geographic Information Systesms (CEGIS) to study the Bangladesh delta.

The CARIAA initiative is funded by Canada’s International Development Research Centre (IDRC) and the UK’s Department for International Development (DFID), aiming to build the resilience of vulnerable populations in these hot spots by supporting collaborative research to inform adaptation policy and practice. The program will run until 2019.

This research has dual importance; to provide a basis for the poorest delta residents to make informed decisions when considering how they respond to the effects of climate change, and to work with policy-makers to ensure the most vulnerable communities are identified and included in the highest level discussions. 

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Jon Lawn and Michele Leone

Jon Lawn is the Consortium Coordinator for the DECCMA Project, based at the University of Southampton, UK. Michele Leone is a CARIAA Senior Program Officer at the International Development Research Centre. He is based in Nairobi, Kenya.