Handpump vibrations could help secure water for millions of people in Africa

Innovative Oxford research demonstrates the potential of ‘smart’ handpumps to achieve low-cost, large-scale groundwater monitoring.

200 million people in Sub-Saharan Africa rely on handpumps to access water. Photo: Tim Foster/REACH

Shallow groundwater levels can be estimated by monitoring the up-and-down movement of handpumps, Oxford University researchers have discovered. The research has been published in the journal Environmental Modelling & Software, and featured on the BBC Science & Environment.

The research uses machine learning methods to analyse the data from low-cost sensors fitted to the handpump handles in Kenya. The vibrations produced by the handpumps vary according to the depth of the underground aquifer where the water is being drawn from.

Africa’s shallow aquifers supply water for around 200 million rural Africans lifted by one million handpumps. If this innovation was scaled up, these handpumps could be transformed into a distributed monitoring network, providing vital information on groundwater availability and how it changes over time. This in turn could enable action to prevent water supplies drying up and help manage a resource that is under increasing pressure.

The work is an output of Gro for Good, a project of the UPGro Consortium, funded by the UK Department for International Development, the Economic and Social Research Council, and the Natural Environment Research Council. This research is being taken forward by the REACH programme.

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A version of this post originally appeared on the REACH website.




Mars’ watery past

Researchers identify site within Martian crater which likely held water in the not-too-distant past.

The question of the existence of life beyond our planet has intrigued humankind since time immemorial. For many years, Mars has been the focus of the search for extraterrestrial life. The Red Planet is the most similar to Earth and is considered the most habitable planet in the Solar System after our own.

Water, or more specifically liquid water, is vital to life on Earth, and in their quest to discover evidence of biological life on Mars, scientists have adopted a “follow the water” approach, seeking sites which show signs of a watery past or present.

A collaboration between researchers from Trinity College Dublin and Oxford University recently pinpointed an ancient valley within a Martian crater – which shows characteristics of having held water in the not-too-distant past.

Trinity’s Dr Mary Bourke and Professor Heather Viles, Head of Oxford University’s School of Geography and the Environment, were struck by the similarities between patterns on the Martian surface with those associated with desert flooding on Earth.

“On Earth, desert dunefields are periodically flooded by water in areas of fluctuating groundwater, and where lakes, rivers and coasts are found in proximity. These periodic floods leave tell-tale patterns behind them,” explained Dr Bourke. “You can imagine our excitement when we scanned satellite images of an area on Mars and saw this same patterned calling card, suggesting that water had been present in the relatively recent past.”

These patterns – knowns as ‘arcuate striations’ – had been noted on the surface of migrating sand dunes in the Namib desert in remote sensing images taken from an earlier study. Subsequent fieldwork showed that these striations were the result of geochemically cemented dune salts left by evaporating groundwater. These sediments later become relatively immobile, and are left behind as the dunes migrate downwind.

Example of geochemically cemented crossbed strata in the interdune near Walvis Bay, Namibia. a) Google Earth image of crossbeds upwind of the windward slope of a barchan in Namibia. White arrows highlight particularly prominent examples b) Ground image of crossbeds showing general relief of interdune (<10cm) c) Wall of pit excavated in interdune (location seen in b) shows dipping sediment layers in subsurface are contiguous with protruding layers on the surface. Alternating high and low albedo layers have different salt composition and grainsize. The darker layer forms the more pronounced micro-ridges.

The researchers hypothesize that a similar process occurred on Mars, and that these arcuate striations exposed on the surface between dunes are indicative of fluctuating levels of salty groundwater, during a time when dunes were actively migrating down the valley.

Striations exposed on the surface between dunes indicate fluctuating levels of salty groundwater. a) Exposure of putative crossbeds on windward slope of dunes on Mars b) Interdune strata exposed in planform showing contrasting albedo and crosscutting relationships similar to that exposed in the dune. Subset of false-colour HiRISE image ESP_013319_1685. The Infrared, red and blue bands are displayed as red, green and blue.

The findings, recently published in Geophysical Research Letters, are significant. Not only do they shed light on Mars’ past hydrology, but also offer a geological target for detecting past life forms on the Red Planet, which is vital for selecting sites for future missions to Mars.

Resilient drought and water scarcity management in England and Wales in 2065

MaRIUS programme publishes findings from drought scenario building workshop.

The Oxford-led MaRIUS (Managing the Risks, Impacts and Uncertainties of drought and water Scarcity) programme is working to improve decision-making around drought and water scarcity in England and Wales using a risk-based approach. One element of the research is to explore and review options for drought management practice in England & Wales beyond the existing regulatory framework and to discuss qualitatively the potential effectiveness of and constraints upon these options with stakeholders.

In September 2016, MaRIUS reseacher, Dr Kevin Grecksh from Oxford University’s Centre for Socio-Legal Studies, hosted an explorative scenario building workshop to inform this research. A report from the workshop is now available online.

The workshop brought together more than a dozen researchers and stakeholders, including DEFRA, the Environment Agency, Ofwat and various water companies. Participants discussed influencing factors and drivers of resilient drought and water scarcity management in England and Wales in 2065. These included various aspects, such as society’s expectations on water supply, water regulation policy, economic development, climate change, extreme weather events and many more. The workshop resulted in the development of four scenarios: (1) “rising to the challenge”, (2) “enjoying their luck, (3) “passive acceptance” or (4) “accepting decline”.

To find out more about these scenarios and other MaRIUS research, visit www.mariusdroughtproject.org


Life on the banks of a polluted river

REACH post-doc, Dr Sonia Ferdous Hoque, recounts a recent visit to one of the most polluted stretches of Bangladesh’s Turag River.

Rapid industrial growth attracts the rural poor to Dhaka City, Bangladesh. Image: Nushrat Yeasmin/REACH

During the past few decades, millions of poor people have migrated to Bangladesh’s capital city in search of work at the hundreds of ready-made garment (RMG) factories located along the Turag River. The rapid growth of the RMG industry – the largest export revenue earner for Bangladesh – has significantly boosted the country’s economic growth. However, at the same time, rampant discharge of untreated waste has polluted the Turag to such an extent that it is jeopardising the water security and health of workers and communities living on the riverbanks.

Our recent visit to low-income settlements along the Tongi Khal, the most polluted section of the Turag, revealed the hardships experienced by people who lack access to safe water for their daily drinking and domestic needs. Groundwater from deep boreholes, provided either by the local government or non-government organisations, is often the main source of water. These boreholes are equipped with electric pumps that draw water from the aquifers to overhead storage tanks. However, while water from these boreholes may be sufficient for drinking purposes, households often have to rely on surface water for other domestic needs.

Women in low income settlements along the Turag River use the polluted water for washing dishes and laundry. Image: Nushrat Yeasmin/REACH

We saw diverse water use behaviour between and within these communities, and across seasons. In one of the communities we visited, women said that they never use river water during the dry season as it is “dirty, smelly and disgusting”. However, during the wet season, when the water level rises, most of them prefer to wash and bathe in the river to avoid the hassles of collecting water and waiting in long queues. In another community nearby, we saw a number of women and children washing their dishes and clothes using the river water. The river was visibly polluted with chemicals, plastic bags and household waste. More alarmingly, there were hanging toilets just beside these water use points. Water from the small number of boreholes is sometimes used for rinsing the dishes or clothes after washing in the river.

Hanging toilets discharge human waste directly into the Turag River. Image: Nushrat Yeasmin/REACH

Improving water security for these low-income communities requires measures to stop the indiscriminate discharge of untreated effluent into the river. Effluent Treatment Plants (ETPs) are mandatory under existing laws; however, such environmental regulations are poorly enforced. Lack of financial capacity or reluctance to bear maintenance and operating costs, combined with a general disregard for environmental degradation, are often the reasons behind not having or running full capacity ETPs. While reducing pollution at source may improve water quality over the long term, with positive implications on human health, ecosystems and agriculture, achieving universal drinking water security will also require new infrastructure, possibly through construction of boreholes and small piped water schemes.

The REACH programme’s observatory Water security for an urban river aims to understand these hydrological and public health risks in stretches of the Turag River. We will explore how these risks, in turn, may affect industrial productivity due to avoidable illnesses faced by poorer residents of the area, particularly women working in these factories. The research will provide new models and tools for assessing the efficacy of pollution reduction initiatives at source and the impacts of different development interventions on the water security risks. Outputs will specifically enable decision-makers to prioritise investment plans to maximise returns in terms of water security risk reductions.

This blog was originally posted on the REACH website.

The Angola Low and Southern African rainfall in climate models

New research by Callum Munday, DPhil student at Oxford University’s School of Geography and Environment, sheds light on complex southern African climate dynamics, offering hope for improved regional climate prediction.

Understanding the 21st century changes in the patterns and characteristics of Southern African rainfall is critically important. The region’s socioeconomic activity is closely tied to rainfall and its variability: agriculture production is predominately rain-fed rather than irrigated, while electricity production is largely derived from hydropower e.g. in Zambia hydro accounts for almost all power generated.

Climate models are the best tools we have to predict future changes in rainfall. Unfortunately, in Southern Africa, the latest generation of more than 20 climate models vary greatly in their estimation of historical rainfall (the wettest model is 1.5 times wetter than the driest model). Most of the climate models also tend to overestimate rainfall compared to observational records. This poses a problem: which models can we trust for projecting future climate change?

The first step in addressing this problem is to understand why models differ in their simulation of rainfall in the present day. Our recent work, as part of the UMFULA climate project, attempts to address this question by looking at how well the range of models simulate the Angola Low; an important regional circulation feature.

The Angola Low is a low pressure system which is anchored over Angola and northern Namibia. In the summer months, December to February, it acts like a broker between the wet, tropical African region and the drier subtropical region. When active, it spins clockwise and diverts moisture in low levels of the atmosphere southward from the wet tropical area to the dry subtropical area. Our hypothesis was that wetter models would have a stronger Angola Low than drier models because more moisture would be transported into the subtropics in these models.

Our results supported this hypothesis. In the summer season, between 40 and 60% of the variability in model rainfall is associated with the strength of their simulated Angola Low. Wet models also simulate enhanced moisture transport from tropical to subtropical Southern Africa. Interestingly, the observationally-based reference datasets (“reanalyses”) simulate a weaker Angola Low than most models and are closer in their rainfall climatology to the drier models in the ensemble. This might suggest that drier models are producing a more realistic estimate of Southern African climate, although better observations of the Angola Low are needed to be confident in this assertion.

We are continuing this work by investigating in greater detail how the Angola Low affects rainfall in Southern Africa both in the present day and in the future. This work will help to identify credible models for projecting future climate change. These projections can be used to inform adaptation strategies ahead of climate change in the coming century.

This research is part of Callum’s DPhil, supervised by Richard Washington, and funded by the National Environmental Research Council (NERC). The work was carried out under the Future Climate for Africa UMFULA project, with financial support from the UK Natural Environmental Research Council (NERC) [Grant ref: NE/M020207/1], and the UK Government’s Department for International Development (DfID).The full paper can be found here.