Winners and losers of infrastructural development: water systems in Kenya’s Kakuma refugee camps.

Cory Rodgers, DPhil candidate at Oxford University’s Institute of Social and Cultural Anthropology, discusses how water infrastructure affects relations between refugee and host communities in the Kakuma camps of northwestern Kenya.

Two water towers, Kakuma. Photo credit – Cory Rodgers.

Compared to the remote, arid plains that surround it, the refugee camps of Kakuma, Kenya stand out as a busy hub of bustling streets, noisy schoolyards and hectic market-places. This is no Nairobi, but Kakuma’s urban character has largely supplanted the images of desolation and austerity that once defined popular representations of the refugee camp: so much so, that Bram Jansen (2011) – focusing on the cosmopolitan character of Kakuma as a site of habitation and place-making – refers to Kakuma as “an accidental city.” While Kakuma is governed as a closed camp for humanitarian relief, the reality of the region’s reliance on the camp economy is apparent. When a government announcement in April 2015 (later retracted) suggested that camp closure was imminent, many locals were confident in their assessment of the potential repercussions: without the camp, Kakuma Town would be nothing.

Recognizing the economic potential of those residing in refugee camps, aid agencies are increasingly promoting and implementing settlement models that place fewer restrictions on refugee mobility and economic activities. In 2014, UNHCR released its Policy on Alternatives to Camps, suggesting that where camps exist, they can be phased out through integration of the refugee residents into the local host community. The policy recognizes that in countries like Uganda that support refugee livelihoods and encourage local integration, “the presence of refugees has stimulated local economies and development.”

As in any urban economy, infrastructure is a crucial foundation on which camp businesses and livelihood activities depend. The development-oriented aid strategies preferred by the international community, from the 1960s zonal development models to the 2014 Alternative to Camps policy, have stressed the importance of finding synergies between humanitarian service provision and national development goals. In its recent policy brief on refugee protection, the UNHCR argues that integration of refugees into local development plans may “prevent the creation of parallel systems for refugees and nationals of a host country, and foster greater social cohesion” (UNHCR 2016).

As sites of humanitarian service provision, camps are already full of infrastructure. The UNHCR’s protection mandate requires it to provide a certain standard of support to those registered in the camp. For water, the Sphere Protocol specifies 20 litres per person per day. Achieving distribution to this standard in a camp of thousands of people requires an elaborate system of boreholes, immersive pumps, generators and solar panels, reservoir tanks, treatment facilities and taps, as well as the plumbing networks that connect these facilities. For this reason, some host countries see it as a matter of national interest to choose remote areas when allocating land for refugee camps, positioning humanitarian to implement infrastructure projects in what would otherwise be neglected peripheries (Kibreab 1989:485).

In Kakuma, camp protection services are generally for refugees exclusively, with parallel projects undertaken for the host community. However the UNHCR and Turkana County Government are currently partnering to implement an innovative settlement model focused on economic integration, just 12km north of Kakuma near the town of Kalobeyei. Refugees and Kenyans will live in close proximity (refugee residences remain restricted to a designated area with demarcated boundaries) with shared markets, community gardens, schools and other social amenities. The novelty of this approach is evident in the plans for water provision. Taps will be provided at the Kalobeyei site for both refugee and host community use. Additionally, rather than limiting refugees to the minimum rations of water for Sphere compliance, agencies aim to provide adequate water for both domestic and livelihood use. The plan has required careful design of infrastructure, with shelters arranged in rectangular compounds of 28 units, each sharing a 5,000 or 10,000-litre water tank.

The appearance of organization and order suggests progress compared to the community water taps in the old Kakuma camps. Taps are located in public spaces, each consisting of four nozzles emerging form a single steel pipe. Residents queue behind their designated nozzles, waiting with their jerry-cans as those in front take their fill. The nozzles do not have any controls; water is released from steel reservoirs perched high above the camp according to a schedule written by the Norwegian Refugee Council, the implementing partner in charge of WASH. During this time, water flows freely from the taps, but jerry-cans and their bearers wait to collect the precious resource. A water system assessment in 2011 indicated that each tap serves an average of 77 people. However, usage/tap varies across the camp, and it has likely increased in many areas due to influxes of new arrivals from conflict areas such as South Sudan.

UNHCR tanker supplying potable water. Photo credit – Cory Rodgers.

The scene appears chaotic, and a newcomer may be confused to see many Turkana people from the local host community standing in the queues. However, each household is assigned a nozzle and a daily allowance, sometimes specified on a card, and order is maintained – as much as possible – by local WASH committees recruited from the community. The Turkana people present have been incorporated as proxies employed by refugee families to fetch water for their homes and, if they can manage on their daily rations, their businesses. Most water carriers earn 500 shillings (about 3 GBP at the time of the research) per month per household for their work. During periodic water shortages, usually due to maintenance problems, Turkana people collect water at shallow wells on the nearby River Taarash and carry them to the camp for sale, asking about 50 shillings (30 pence) per 20 litre jerry-can. They also supply water for the cooling tanks in locally operated electricity generators, which need not be potable.

Through the carefully designed infrastructure layout at Kalobeyei, UNHCR and its partners hope to support economic growth and local integration. However, in places like Kakuma where resource provision is achieved through local ad hoc arrangements, plans to improve formal infrastructure need to recognize the informal systems that they replace. A more integrated water distribution system serving both the refugee and host communities could bring people together around better infrastructure, funded by humanitarian agencies but serving everyone. For those in the Turkana community who sell and transport water for a living, they are the existing water infrastructure, and many may feel robbed of livelihood opportunities if the system is altered. Development-oriented aid strategies have much to offer those with the skills and capital to pursue livelihoods, but decision-makers must acknowledge that these strategies may entail both winners and losers.

This article is a product of research undertaken by Louise Bloom (Humanitarian Innovation Project, Refugee Studies Centre, University of Oxford) and Cory Rodgers (Institute of Social and Cultural Anthropology, University of Oxford) in July and August 2016. Fieldwork was made by possible by seed funding at the Refugee Studies Centre, provided by the Swiss Federal Department of Foreign Affairs.

A framework for a joint hydro-meteorological-social analysis of drought

New research published by Oxford-led collaboration as part of the NERC-funded “Historic Droughts” project.

A new paper, led Dr Bettina Lange, Associate Professor of Law and Regulation at Oxford University’s Centre for Socio-Legal Studies, sets out a framework for a joint hydro-meteorological-social analysis of drought.

The research, published in Science of the Total Environment, defines and links, in an innovative way, ‘drivers’ of, ‘responses’ to, and ‘impacts’ of drought. It explores how these work at various temporal and spatial scales, with particular reference to the 1976 and 2003-6 drought episodes in the UK.

The key objective of the framework is to develop a more integrated understanding of the ‘drivers’, ‘responses’ and ‘impacts’ of drought, that bridges their natural and social dimensions.

The article is the result of a cross-disciplinary collaboration between hydrological, socio-legal and agricultural studies involving the Centre for Socio-Legal Studies, the British Geological Survey and Cranfield University. The work is part of the UK government Natural Environment Research Council (NERC) funded ‘Historic Droughts’ Project (NE L010356/1).

A version of this post first appeared on the Faculty of Law website.

The Swarovski Foundation supports scholarship in Water Science, Policy and Management

The Swarovski Foundation strengthens its commitment to safe and sustainable water usage worldwide by supporting a scholarship on the MSc course in Water Science, Policy and Management in the School of Geography and the Environment at Oxford.

Ameerah Anathallee is the 2016-17 Swarovski Foundation Scholar, currently undertaking the MSc course in Water Science, Policy and Management. Photo by John Cairns.

Unpredictable floods, water scarcity and droughts, inadequate water supply and sanitation services, and degraded freshwater ecosystems threaten the lives of millions of people worldwide. Decision-makers are increasingly forced to make challenging choices on water development, allocation and management issues at local, regional and international levels, under conditions of increasing climate unpredictability and risk. The University of Oxford’s cross-disciplinary Water Science, Policy and Management master’s course equips the next generation of water professionals with the necessary skills and knowledge to make a significant contribution to tackling the increasingly complex global challenge of sustainable water management.

In 2016-17, the Swarovski Foundation is supporting an exceptional student to take this unique course, enabling them to join Oxford’s growing international network of graduates addressing water issues worldwide.

The Swarovski Foundation was established in 2013 to pursue charitable goals to honour the philanthropic spirit of Daniel Swarovski, who founded the crystal business in 1895. Since then, five generations of the Swarovski family have reinforced the company’s commitment to philanthropy and charitable giving. The new Swarovski Foundation Scholarship further demonstrates the Foundation’s mission to aid, amongst other causes, charitable initiatives and organisations working to conserve natural resources.

The Swarovski Foundation strengthens its commitment to safe and sustainable water usage worldwide by supporting a scholarship on the MSc course in Water Science, Policy and Management in the School of Geography and the Environment at Oxford.

Further information

From waterpumps to rowing gold

A brief summary of water-related alumni goings-on at Oxford’s School of Geography and the Environment.

Water featured prominently in the recent School of Geography and the Environment (SoGE) alumni update. Alumni from Oxford University’s Water, Science, Policy and Management (WSPM) master’s were notable in their achievements: taking Olympic Gold at Rio on the water, and accolades at World Water Week in Stockholm.

Stockholm was one of a number of international events that provided WSPM alumni the opportunity to get-together, and reconnect with staff. The Stockholm reunion is now an annual fixture, so if you plan to attend in 2017, and would like to hook up with Oxford contingent, get in touch.

For a full round-up of recent SoGE alumni news click here.

John Fell Award to explore water scarcity and management

Oxford University’s Centre of Socio-Legal Studies receives new funding to advance research into UK’s industrial water abstraction.

Dr Kevin Grecksch, Research Officer in the Regulation of Water Resources, has been awarded funds to help investigate strategies and options for the UK’s large industrial water consumers.

New funding will enable additional research to shed light on a new and under-explored issue in water resource management: how large UK water consumers such as thermal power stations, pulp and paper mills, and the food and drinks industry prepare for water shortages which are becoming increasingly frequent as part of a changing climate.

These industrial abstractors are often forgotten in academic research and policy debates which are focused on domestic consumption of water, yet water is used by industry either directly, for manufacturing products, or for washing, cooling, and heating during production processes. Hence, businesses need water in order to maintain supply chains and production lines.

Water consumers are generally discussed in a general sense, with limited distinction between the public and private sectors, and the different types of large private industrial abstractors who have different needs and organisational histories in dealing with water. According to the latest report by the UK’s Committee on Climate Change (2016, p.37):

…some water intensive industries are clustered in areas at risk of water scarcity such as paper manufacturing in Kent and chemicals manufacturing in the northwest of England.

This research aims to answer the question as to whether those industries have strategies and plans to (i) react to drought and water scarcity and (ii) if they already apply any proactive measures, to prevent potential disruptions from drought and water scarcity. It will locate and analyse academic and grey literature, as well as industry positions on drought and water scarcity.

The outcome will be a report aimed both at academics as well as practitioners comparing the approaches in literature and across the different industries highlighting strengths, e.g. innovative drought and water scarcity management options such as greywater (re)use, deficits, i.e. non-action with regard to drought and water scarcity management and areas for further research.

A version of this post originally appeared on Oxford University’s Law Faculty website.


Analysing the impact of climate change and land-use change on the water quality of the River Thames

Dr Gianbattista Bussi, Postdoctoral Research Assistant, and Prof Simon Dadson, Associate Professor in Physical Geography, present the results of the POLLCurb project.

Human activities can cause changes in climate and land cover, which affect the water cycle and the water quality of rivers and lakes. These drivers of change, coupled with natural climate variability, lead to alterations in water quality that can have strong repercussions on water supply, ecosystems, navigation, conservation and recreational uses of water.
The River Thames, in Southern England, is a prime example of a river subject to strong human pressure. It is the main source of drinking water for around 14 million people and the recipient of the effluent for around 3 million people. It is also of very high conservation and recreational value for local communities.

In order to study the impact of land-use and land-cover changes over river water quality under a changing climate, the Natural Environment Research Council funded the POLLCurb project (Changes in Urbanisation and its Effects on Water Quantity and Quality from Local to Regional Scale), as part of the Changing Water Cycle programme. The project, which ended in September 2016, was led by the Centre for Ecology and Hydrology in Wallingford and was carried out jointly with the University of Oxford, the University of Bath and the University of Surrey.

As part of the project, Dr Gianbattista Bussi and Prof Simon Dadson, of Oxford University’s School of Geography and the Environment, analysed the joint impact of climate and land-use changes on the sediment transport and water quality at the scale of the River Thames catchment.

The research provided great insights into the sediment dynamic of the River Thames. Sediment dynamics of lowland rivers like the Thames are of vital importance in building resilient strategies to manage environmental change.

The project described the seasonal and inter-annual variability of suspended sediment concentration in Thames, by analysing long-term, intermittent records collected by the Environment Agency since 1974. In particular, the flushing effect, i.e. the increase in sediment load that takes place with the first floods after a dry period, was quantified. This is responsible for increasing the sediment concentration of the Thames by 1.5 – 2 times. A decrease in the flushing effect which began in the 1990s was also observed.

Furthermore, the joint impact of climate change and changes in the extension of arable land was analysed by using a mathematical model called INCA (INtegrated CAtchment model). The results showed that climate and land cover each exert an individual control on sediment transport. The suspended sediment yield of the River Thames is expected to decrease by 4% by the 2030s, although this figure will be strongly affected by the future variations of extreme precipitation and future agricultural practices.

Lastly, the impact of climate change, land management change and waste water treatment strategies on the nutrients and phytoplankton of the river Thames was also assessed. Phytoplankton pose a serious threat to the use of surface waters for water supply purposes. In this project, a river phytoplankton model was employed to evaluate the effects of climate alterations on flow, phosphorus concentration and phytoplankton concentration of the River Thames.

The model demonstrated that an increase in average phytoplankton concentration, especially potentially harmful Cyanobacteria, is highly likely to occur due to climate change. However, an optimal mitigation strategy, which combines reduction of fertiliser and phosphorus removal from wastewater, can help to reduce the phytoplankton concentration, and in some cases, compensate for the effect of rising temperature.

Find out more:

Water use in China’s thermoelectric power sector

New research from Oxford University’s Environmental Change Institute sheds light on China’s water-for-power nexus. Lead author, DPhil student Xiawei Liao, provides an overview of the challenges and trade-offs facing the Chinese energy sector.

Despite being historically managed in isolation, water and energy are two closely interlinked resources. For thermoelectric power plants, water is critical for power production, providing both steam and cooling. Water shortages have caused power curtailments at a number of thermoelectric power plants around the world (Byers et al., 2014), highlighting the critical nature of the water-for-energy nexus, and bringing it to the fore of science and policy debates.

In China, the relationship between water and electricity is a particularly pressing concern. The country is heavily reliant on thermoelectric power, with many plants drawing water from inland waterways vulnerable to water shortages. The vast majority these plants are coal-fired, with coal accounting for over 75% of China’s electricity production (National Statistics Bureau, 2014).

Cooling technology is the key determinant of a coal-fired power plant’s water intensity, defined as water use per unit of electricity produced (Macknick et al., 2012). Water use comprises both water withdrawal and consumption, with water consumption defined as water which is withdrawn from, but not returned to, water bodies (AQUASTAT, 1998).

There are three main types of cooling technology: open-loop, closed-loop and air cooling: the first dissipates heat using running water; the second by recirculating water; while third employs air circulation. Consumptive water use in an open-loop system is around 70–80% lower than a closed-loop cooling system, but the water withdrawal is around 30–60 times higher (WRI, 2015).

Our research, recently published in Global Environmental Change, first quantified the current water use of China’s coal-fired power plants, using plant-level data. We identified two major hot spots for surface water consumption: the Yellow River basin in eastern China, and the Yangtze River basin in southwestern China. Groundwater abstraction for power generation was outlawed in water-stressed Northern China in 2004, but continues to be heavily abstracted, particularly around the North China Plain (Huang-Huai-Hai basin). Reclaimed water is also used in water-scarce North Eastern China, but accounts for a smaller portion of water use overall. In 2014, Chinese coal-fired plants used 0.79 billion m3 of reclaimed water compared to 4.64 and 1.05 billion m3 for surface water and groundwater respectively.


Fig. 1 Water consumption of coal-fired power generation by source.

In order to avoid unsustainable future investments and technology lock-ins, our research also investigated future water use scenarios for China’s thermoelectric power sector.


Fig.2 Annual fresh water withdrawal (left) and consumption (right) by China’s thermoelectric power sector under different scenarios (billion m3).

If no new policies are implemented, China’s demand for water-for-energy – both withdrawn and consumed – is projected to increase to over 280 and 16 billion m3 respectively by 2050; this greatly exceeds the current volumes of 65.2 and 4.64 billion m3 currently used.

Improving energy efficiency, or shifting energy infrastructure to renewable, or low-carbon sources offers scope to reduce water withdrawal by over 50%. Under high-renewable and low-carbon scenarios, concentrated solar power and inland nuclear power would replace coal-fired power as the primary fresh water users. Replacing open-loop with closed-loop cooling systems in the south, and closed-loop cooling systems in the north with air-cooled systems, has potential to cut the power sector’s water withdrawal significantly. However, it may increase water consumption, particularly in the east and central China. While water withdrawal poses less threat to water availability for downstream users, it may cause thermal pollution to the water bodies. Trade-offs between water withdrawal and consumption need to be made.

At a regional level, central and eastern China withdraw the great volume of water for power generation due to the prevalence of open-loop cooling systems. In 2011, China issued its ‘most stringent water policy’ – ‘3 Red Lines’ – setting targets for total water use on a national as well as a regional scale for 2015, 2020 and 2030. Qin et al. (2015) showed that the water use of China’s power sector is likely to exceed its allowances under the ‘3 Red Line’ policy in 2035 on a national scale. Furthermore, we find that the power sector’s water use in the east will exceed its regional quota under all scenarios, unless steps to change cooling technology are taken. The above-mentioned policy is also likely to be violated in central and north China if the business carries as usual.


Fig. 3 Comparison between regional water demands by power sector with water targets set by the ‘3 Red Lines’ policy in 2030. (W-Fresh water withdrawal in 2030; C-Fresh water consumption in 2030; B-Baseline Scenario; HE-High Efficiency Scenario; HR-High Renewable Scenario; LC-Low Carbon Scenario; TC-Technology Change Scenario; IWA-Industrial Water Allowed).

Finally, Chinese electricity generation, and associated water demand, both peak in winter when water availability is especially low. This increases the potential for conflict during this period. In the context of a changing climate, the tension between water demand for power generation is unlikely to decrease. Institutional change and improved policy coherence is required to meet this challenge. The old paradigm, where each sector operated independently, uninformed and unconcerned about its impacts on the others, is no longer sustainable. China must transition to a new paradigm – one embracing a ‘system-of-systems’ approach.

Xiawei Liao is a DPhil student at the Environmental Change Institute supervised by Prof Jim Hall and Prof Nick Ayre. You can find out more about this research in Liao, X., Hall, J.W., Eyre, N. Water use in China’s thermoelectric power sector, Global Environmental Change, Volume 41, November 2016, Pages 142-152.



A framework for drought economics

An economic assessment of drought impacts demands an analytical framework which reflects the unique characteristics of this natural hazard.

New research by the Oxford-led MaRIUS project has developed an innovative framework for drought economics. The framework, which is outlined in a recent paper published in Ecological Economics entitled “The Economic Impacts of Droughts: A Framework for Analysis”, is the result of a collaboration between Dr Jaume Freire González, formerly of Oxford University’s Environmental Change Institute (ECI) and now a researcher at Harvard, Dr Chris Decker, an economist at Oxford’s Centre of Socio-Legal Studies, and Professor Jim Hall, ECI Director and MaRIUS lead.

The research is a key output of the economics work of the MaRIUS (Managing the risks, impacts and uncertainties of droughts and water scarcity) project, which seeks to develop a risk-based approach to decision-making around drought and water scarcity.

The paper argues that, in economic terms, droughts are a specific type of natural hazard, and failure to appreciate the differentiating characteristics of drought can lead to biased estimates of impacts, and poor short-term and long-term management practices.

The authors argue that traditional conceptual frameworks used to assess natural hazards do not adequately capture all of the factors that contribute to the economic impacts of droughts, such as the importance of the level, and composition, of hydraulic capital; the dispersion of economic impacts across different economic activities and agents; the temporality of drought events; and the critical importance of policy-making in shaping the short and long-term economic impacts of droughts. Traditional frameworks also fail to take account of the complex interaction between factors within the domain of decision-making, as well as underlying climate conditions.

The authors propose a new conceptual framework which distinguishes between ‘green’ and ‘blue’ water – the two primary sources of drought-induced economic impact. Green water describes water stored in the top layer of soil and vegetation, while blue water comprises fresh surface water and groundwater. The economic impact of a green and blue water drought is manifest via different mechanisms. Green water availability is largely determined by environmental conditions, particularly climate. The economic impact of a green water drought is felt foremost by the agricultural sector, particularly those reliant on rainfed production. Economic impacts arising from the initial phase of a drought are usually limited to those sectors reliant on green water.

Blue water impacts of drought arise from long-term choices about the water storage, interconnection and production capacity (i.e. hydraulic capital) as well as short-term management decisions regarding the timing, severity and allocation of water restrictions applied to different users.

The new framework provides insights on the drought management policies in the short and long term, and the economic consequences of different actions. By highlighting the trade-offs and choices involved in decision-making, the MaRIUS project hopes this framework will be able to assist policy-makers, regulators, water companies, water users and other stakeholders in managing and responding to drought over the short and long-term.

Citation: Freire-González, J., Decker, C., & Hall, J. W. (2017). The Economic Impacts of Droughts: A Framework for Analysis. Ecological Economics, 132, 196-204.

MaRIUS 2016 Drought Symposium presentations now online

The MaRIUS project hosted its third, annual, international Drought Symposium in Oxford in September. The event was a great success with over 90 attendees from a range of backgrounds.

The Symposium focused on aspects of drought science and drought management, both in the UK and globally. There were presentations and posted from a wide range of drought and water scarcity practitioners, from academia, industry and regulation.

The Symposium focused both on issues in the UK and also across the world, from an impressive array of international speakers who examined the situation in Australia, Europe and America.

Most of the presentations are now available to download as pdf slides from the project website.

Podcasts will be made from some of the talks and these will also be made available (soon hopefully) at the same page.

The speakers and titles of the presentations are as follows:

  • Doug Hunt, Atkins: Water Resource Management in the UK
  • Ian Pemberton, Ofwat: “Moving to a national approach to water management”
  • Mike Morecroft, Natural England: “Effects of drought on UK ecosystems and the implications for nature conservation in a changing climate”
  • Gianba Bussi, University of Oxford: “The impact of droughts on the water quality of the River Thames”
  • Sarah Whatmore and Catharina Landstrom, University of Oxford: “Co-producing knowledge for local drought resilience”
  • Gemma Coxon, University of Bristol: “Drought hydrology on a national scale”
  • Kevin Grecksch, University of Oxford: “Drought Management Practice in the UK – Opportunities to Overcome Innovative Scarcity”
  • Dustin Garrick, University of Oxford: “Transboundary Rivers and Adaptation to Climate Extremes (TRACE): Learning from Severe Droughts”
  • Henny van Lanen, Wageningen University, Netherlands: “Drought indicators – their usefulness for the assessment of drought types, impacts and management”
  • Lee Godden, University of Melbourne, Australia: “Water law and drought in Australia”

Innovation recognized in national flood risk management and modelling competition

Defra awards proposal to tackle flood risk in Cumbria led by Oxford fellow.

A team led by Oxford flood expert Paul Sayers received an innovation prize as part of Defra’s (Department for Environment Food & Rural Affairs) Flood Modelling Competition.

The submission entitled ‘Towards a flood resilient Eden catchment, Cumbria’, developed in collaboration with Horritt Consulting, was among a number of entries recognised for their innovation, with a proposal from JBA Consulting and Lancaster University taking the overall prize.

Defra launched the competition in response to the government’s National Flood Resilience Review that highlighted potential approaches to flood risk, including new techniques and models to assess land use, water flow, natural flood management, meteorological sensitivities, property-level resilience and economic impacts.

The competition – the first of its kind – drew entries from leading groups around the world, all seeking to apply their expertise to the following question:

“If you were responsible for managing the Eden catchment in Cumbria, what  flood risk management approaches would you recommend, and why?”

The Sayers and Horritt submission used the Future Flood Explorer – a model they originally developed to support the UK Climate Change Risk Assessment that uses local model results to support an emulation of the flood risk system (Sayers et al, 2015) – to quantify present and future risks in the catchment and how successful alternative adaptation measures could be in managing it.

The analysis, for the first time, attributed benefits to individual measures when implemented as a broader portfolio response: from natural flood management to traditional defences; from property level measures to flood forecasting and warning.

Paul, a Senior Visiting Fellow at Oxford University’s Environmental Change Institute (ECI) and founder of environmental consultancy Sayers and Partners, noted during the award ceremony that:

‘”Resilience to flooding”’ is not the same as being ‘defended from flooding’. It does mean however using a portfolio of responses to reduce the probability of a flood occurring, limit the exposure should a flood occur and reduce the vulnerability of those that are exposed. A critical barrier to progress in delivering such a portfolio is the lack of credible decision-relevant evidence. This lack of evidence in part reflects the short-comings of traditional modelling approaches that are often too computationally intensive to explore multiple futures and responses at a catchment scale. 

We’ve developed the Future Flood Explorer to fill this evidence gap – the FFE allows us quickly to explore the effectiveness of flood management measures across the whole catchment both now and in the future, under both climate change and population growth scenarios. We can also use the FFE to explore which measures are most effective at managing future risk.’ 

Dr Thérèse Coffey MP, Parliamentary Under-Secretary, Department for Environment, Food and Rural Affairs, herself an Oxford alumnus, hosted the ceremony and remarked at its success. The prize fund was generously supported by United Utilities, Aviva and the Natural Environment Research Council (NERC).

A summary of the submission is available here. If you would like find out more, you can contact Paul directly at


Why does liquid stay in a horizontally turned straw, but not in a glass?

A new paper, co-authored by Oxford University’s Prof Dirk Aarts, presents a precise mathematical criterion determining whether the liquid in a capillary of arbitrary cross-section will remain in it, or will flow out, when the capillary is at a horizontal position.

Have you ever noticed that liquid stays inside a straw when it’s held horizontally? Or that the same thing doesn’t happen when you turn a glass on its side?

A team of researchers including Professor Dirk Aarts from Oxford University’s Department of Chemistry has been investigating this phenomenon – one that’s ‘surprisingly difficult’ to explain from a scientific point of view.

Professor Aarts worked with colleagues Carlos Rascón from Universidad Carlos III de Madrid in Spain and Andrew Parry from Imperial College London for the study, which is published in the journal PNAS. Professor Aarts said: ‘We considered the following seemingly simple question: why does the liquid spill out when I hold a glass – say, of beer – horizontally, but stays in a straw when I do the same thing?

‘This question is actually surprisingly difficult, especially when considering non-circular cross-sections of the capillaries, or tubes.

‘For a liquid trapped between two parallel walls, and for a liquid trapped in a circular capillary like a straw, the answer is one that we would intuitively expect: the liquid wants to flow out because of gravity, but is trapped due to the surface tension.’

The ‘capillary action’ described here is the ability of a liquid to flow in narrow spaces, often in opposition to external forces such as gravity. For example, if you zoom in on the surface of water in a glass, you’ll see that it curves upwards by a couple of millimetres at the wall. This curve is known as the meniscus.

Professor Aarts said: ‘The competition between gravity and surface tension leads us to the capillary length, which sets the height to which a meniscus will climb at a wall. Indeed, if the separation between the two walls is less than roughly the capillary length, or if a circular capillary has a diameter less than roughly the capillary length, the liquids will stay put. If not, the liquids will flow out.

‘However, if you change the cross-sectional shape of the capillary – for example, making it a triangle – the situation may change completely, and for certain geometries the liquid may spill out at any length scale, well below the capillary length.

‘We figured out how to calculate this behaviour for general cross-sectional shapes, although the actual numerical calculations, carried out by Carlos Rascón, took almost seven years to complete. One of the reasons for this was that the spilling out may occur via different pathways, and the crossovers between those pathways were hard to understand.’

The researchers were able to solve the problem by reducing it down to an equivalent two-dimensional problem, which is numerically more accessible. The paper shows how ’emptying diagrams’ can be created by calculating the energy of the problem in 2D. As soon as the energy became smaller than zero, no 3D solution for the meniscus exists, and the liquid empties.
Professor Aarts added: ‘The surprising result here is that a capillary may empty even at lengths much smaller than the capillary length. This has implications for any technologies where liquids are used or are present on small scales, such as microfluidics, biomedical diagnostics, oil recovery, inkjet printing and so on.’

This article was written by Stuart Gillespie and originally appeared in the Oxford Science Blog.