Helping protect livelihoods among poor communities in Bangladesh
Our research is helping the Bangladesh government protect livelihoods and enhance wellbeing among poor communities in the country’s delta regions.
Deltas are among the most fertile environments on the planet due to the nutrient-rich sediments that are deposited when rivers meet the sea. They are also densely populated – worldwide they are home to around 500 million people, many of whom rely on subsistence farming. However, these low-lying delta environments are vulnerable to numerous stresses that affect ecosystem services (natural resources such as clean water, agriculture, fisheries, soil and forests).
Robert Nicholls, Professor of Coastal Engineering, explains: “Sinking land levels, rapid urban expansion, changes in agricultural and land management practices, the building of dams upstream, extreme weather events and climate change – these are some of the factors that lead to increased flooding, soil salinisation and land loss, which in turn affect people’s ability to support themselves.”
Powerful predictive modelling
To protect and enhance the livelihoods of poor communities that depend on delta ecosystem services in Bangladesh, Southampton engineers and scientists have worked with a range of partners to develop a powerful predictive modelling tool that simulates the social, physical and ecological elements of the Ganges-Brahmaputra-Meghna delta.
Called the Delta Dynamic Integrated Emulator Model (ΔDIEM), this sophisticated tool shows how different scenarios might impact on the delta environment and the wellbeing of its population. “By linking science to policy at the landscape scale, the model is enabling decision makers to evaluate the effect of policy decisions on ecosystem services and livelihoods,’ says Robert.
As principal investigator, Robert coordinated a 100-strong multidisciplinary team in the Ecosystem Services for Poverty Alleviation (ESPA) Deltas Project – a four-year, £4m project funded by the ESPA programme – to complete this ambitious task. The team included engineers, oceanographers, geographers social scientists and policy experts from seven partner organisations in the UK, 12 in Bangladesh and two in India.
Unique data integration
“The project was distinctive for its scale – ΔDIEM describes an area inhabited by 14 million people and can analyse the effect of different scenarios on this population up to the year 2050,” says Robert. “It was also unique in its integration of data about the delta’s biophysical characteristics with measures of human health and wellbeing. That’s really exciting because it means ΔDIEM can provide a much richer range of indicators than more traditional cost-benefit appraisals.”
As well as working on the hydrological modelling aspect of the project, engineering researchers tackled the challenge of building the informatics to integrate numerous, disparate datasets and models. These included a range of simulation models selected to represent biophysical processes such as the quality, flow and sediment load of the delta’s rivers, as well as changes in climate, fisheries, agriculture and mangroves. They also included the results of a specially designed survey that gathered information from 1,500 delta households about income, health and wellbeing, and people’s use of ecosystem services.
Stakeholder involvement
The researchers engaged with local stakeholders from the outset, running workshops to identify the most pressing environmental issues and concerns. “This informed the development of a range of scenarios for the model to analyse, for example to test the long-term effects of variations in upstream fresh water supply, sea-level rise, cyclones, changing agricultural cropping patterns, or changes in population density,” explains Robert. Stakeholders were also involved in defining what types of intervention would be considered, helping the model design to be flexible and appropriate.
Informing long-term plans
The modelling tool was put into practice to assess the impact of the proposed Ganges Barrage, a plan to divert water to areas impacted by salinisation during the dry season. Now, additional ESPA funding has been awarded for a one-year project to put the model to further use.
Southampton scientists and colleagues from the Bangladesh University of Engineering and Technology will work with the Government of Bangladesh, using ΔDIEM to evaluate selected proposals within its Bangladesh Delta Plan 2100. The Delta Plan is a long-term government water management plan that aims to protect against future environmental stresses, including climate change, and support the region’s economic development and achievement of the United Nations’ Sustainable Development Goals. The selected measures tested include natural flood management through mangrove development, and the development of new dams and barrages.
“The fact that our original project coincided with the formulation of the Delta Plan means we have a fantastic opportunity to feed into the national policy development process,” says Robert.
To disseminate their work to a wider audience, Robert and his colleagues are writing an open-access book, to be published in 2018, in which they’ll share the project methodology. “Our model could be applied to similar regions in other parts of the world and we hope that it will go on to benefit delta populations globally,” he says.