Supercomputer aids Bengali people and farmland
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Researchers have used ARCHER, a state-of-the-art supercomputer, to create a model of the river channels in the Bengal delta – the largest river delta in the world – which will allow them to predict changes in tidal water level and salinity in the Bangladesh delta region, and to advise on irrigation and crop choice.
- River delta is estimated to support livelihoods of 300 million people
- ARCHER supercomputer was used to identify safe areas of drinking water and determine what crops to grow
- The supercomputer helps policymakers make decisions on managing the environment, such as where to take irrigation water and what crops to grow
Future scenarios forecast by the model show the tidal range increasing by up to half a metre in places, which could see a large area of the delta flooded during high tide; affecting farmland, as well as the Sundarbans mangrove forests – a UNESCO world heritage site.
The model is the first ever to link the open ocean with the limit of tidal interaction in Bangladesh, and is being used to make decisions about how to manage the physical environment, such as where to take irrigation water from and what crops to grow, and thus preserve farmland and identify safe areas of drinking water.
The research is led by Dr Lucy Bricheno, from the National Oceanography Centre (NOC). She says: “This region is home to large numbers of people whose wellbeing is critically dependant on the land, and so are vulnerable to changes in the physical environment. By providing high quality evidence and forecasts, the outputs of the model could really help policymakers to make more informed decisions about how to best manage that environment.”
The project harnessed huge amounts of information, including data drawn from other models such as river discharge, ocean tides, water temperature and salinity. Such was the complexity and volume of this source material that only a supercomputer such as ARCHER could be used to make sense of it within realistic timeframes.
ARCHER, which can make one million billion calculations a second, is the UK’s primary academic research supercomputer, enabling UK researchers from industry and academia to run simulations and calculations involving massive data sets, such as those used to simulate the airflow around cars and aircraft, and in the design of new materials.
Based around a Cray XC30 supercomputer, the ARCHER service is provided by its partners: EPSRC, the Natural Environment Research Council (NERC), the Edinburgh Parallel Computer Centre (EPCC), Cray Inc and The University of Edinburgh. EPSRC has invested over £40 million in the ARCHER system.
Dr Bricheno’s use of ARCHER resulted in a series of high-resolution 3D maps of the Bangladesh delta, its rivers, and the Indian Ocean. The maps enabled the simulation of various properties under a range of possible future climates, including projections on agricultural crops, drinking water salinity, poverty and human wellbeing.
The model also showed that in general the west of the delta and the Sundarbans mangrove forest got saltier, particularly during the dry season, which has important implications for the health of the forest and any crops planted there. The western part of the delta is also home to some of the poorest farmers in Bangladesh and is the habitat of the Royal Bengal Tiger.
Dr Bricheno says: “What is interesting about the tidal change evident in the model is that it has a complex spatial pattern – not just rising everywhere. This is important because it wouldn’t be captured in a coarse ocean model – we need to simulate the whole delta.”
The research is both timely and necessary. There is a lack of observed data regarding water levels and river salinity in the region, making computer simulations all the more valuable. In total, the delta is estimated to support the livelihoods of around 300 million people, and is one of the most densely populated regions on Earth, with around 400 people per square kilometre.
The research also has benefits beyond the Ganges delta, helping to model other areas of the world that are heavily affected by changing water conditions.
Dr Judith Wolf, who leads the NOC’s contribution to this project, says: “This international collaborative research is pushing oceanography into new areas, working further inland than ever (to reach the limit of tidal penetration), and leading us to collaborations with human geographers and social scientists.”
The Finite Volume Coastal Ocean Model employed in this study has been used across the UK and Bangladesh, contributing further to understanding these changes, which will enable more accurate predictions of water changes in future. External partners have been trained to use the technology, further adding to its worldwide effectiveness.
Dr Bricheno’s research is part of the Ecosystem Services for Poverty Alleviation (ESPA) Deltas programme, funded by the Department for International Development (DFID), the Economic and Social Research Council (ESRC) and NERC.