Project highlights

  • Assess the synchrony of water, nutrient, and pollutant inputs to river systems
  • Provide the first large scale assessment of pollutant dynamics and freshwater ecosystem dependence on synchrony
  • Provide meaningful insights for water and catchment managers on when and where impacts occur and are changing


Rivers convey and transform the water, nutrients and pollutants they receive from the landscape. High concentrations of nutrients such as nitrogen and phosphorus may act as pollutants, damaging freshwater and estuary ecosystems through processes such as eutrophication. Anthropogenic activities, including agriculture and fertiliser application, are the main causes of polluting levels of nitrogen and phosphorus in many river systems, leading to overall poor river health across many regions of the UK (The Rivers Trust, 2021). Dissolved organic carbon (DOC) is an important component of landscape carbon cycling, and at the same time another potential pollutant of river water quality. The carbon available to river networks, and how it is cycled, has also been altered by land use and climate change. The main source of DOC to streamwater in the UK are from soils and peatlands (e.g., Ritson et al., 2019), but human activity like sewage treatment plant inputs is known to also play an important role (Worrall et al., 2019).

Interestingly, the input of these nutrients and pollutants is not constant over time but varies with changes in peak supply from sources and removal by natural reaction processes. Furthermore, the potential impact of nutrients and pollutants on river systems fundamentally depends on how much water river systems are conveying, which can vary seasonally due to the seasonality of precipitation and evapotranspiration. Moreover, under changing climates and anthropogenic stress, the frequency, magnitude, and timing of all these inputs are shifting, leading to changing nutrient and pollution dynamics that both ecosystems themselves and water managers have to adapt to.

A fundamental and large-scale knowledge gap for both understanding the processes involved and how they could be better managed revolves around the question of how synchronous all these inputs (water, nutrients, pollutants) are with one another (Abbott et al., 2017). This project will be the first to use existing large datasets to estimate how synchronous (or asynchronous) the inputs of water, carbon, nitrogen and phosphorus are across the UK and Europe, and how and why this synchrony might be changing in both time and space. Helping to answer this question of synchrony will provide deeper insights into the functioning of river ecosystems, and a template for priorities in pollution and water management.

CENTA Flagship

This is a CENTA Flagship Project

Case funding

This project is suitable for CASE funding


University of Birmingham


  • Climate and Environmental Sustainability
  • Organisms and Ecosystems


Project investigator


How to apply


The project will leverage large datasets already available from government environment and water agencies. These datasets compile extensive information on water quality and water flow for river systems across the UK and Europe. The project will then focus on novel and interesting analysis of the data to interrogate synchrony, including interesting temporal and spatial dimensions. An important aspect of this analysis will be to link back to causal effects, and so the project will also look at hydroclimatic, land use, and pollution source information to establish the key reasons and drivers for synchrony (or asynchrony).

Training and skills

This project offers the opportunity to increase fluency in data science and analysis, as well as the opportunity to work at the interface of hydrological and biogeochemical processes relevant to water resource and catchment management. Through the extensive project partnerships and collaborations listed below, the project will provide considerable opportunities to put research into practice through both government and industry avenues. The project will also provide important opportunities for training in presentation and networking skills through specialised workshops and participation in national and international conferences

Partners and collaboration

This project will work collaboratively between multiple institutions, based at the University of Birmingham, but with opportunities to interact at Durham University as well. Additional CASE support and funding will be provided by the Environment Agency, with opportunities to work and train with the research division of the Environment Agency a key part of the project. Further training, support and collaboration will be provided through the Centre for Ecology and Hydrology (CEH) in Wallingford, and UK Water Industry Research (UK WIR), enabling thorough independent and industry research experience.

Further details

For further information on the project, please contact Joshua Larsen at the University of Birmingham ([email protected]) or Julia Knapp at the University of Durham ([email protected])

Possible timeline

Year 1

Compile and begin analysis on datasets, framing of analysis around the key research questions working with supervisory team and stakeholders

Year 2

Working towards delivery of first analysis on synchrony and increased engagement with government and industry stakeholders

Year 3

Attendance at international conferences and workshops, dissemination of results, knowledge exchange with government and industry stakeholders, and working on final analysis of causation in river synchrony

Further reading

Abbott, B.W., Gruau, G., Zarnetske, J.P., Moatar, F., Barbe, L., Thomas, Z., Fovet, O., Kolbe, T., Gu, S., Pierson-Wickmann, A.-C., Davy, P. and Pinay, G. (2018) Unexpected spatial stability of water chemistry in headwater stream networks. Ecol Lett, 21: 296-308.

J.P. Ritson, J.K. Croft, J.M. Clark, R.E. Brazier, M.R. Templeton, D. Smith, N.J.D. Graham. (2019) Sources of dissolved organic carbon (DOC) in a mixed land use catchment (Exe, UK). Science of The Total Environment, 666, 165-175.

Worrall, F, Howden, NJK, Burt, TP, Bartlett, R. (2019) The importance of sewage effluent discharge in the export of dissolved organic carbon from U.K. rivers. Hydrological Processes 33, 1851– 1864.

The Rivers Trust (2020) The state of our rivers. Available at:


This project research will by and large not be sensitive to future lockdowns or restrictions. Although disruptions to the working life and access to the University may occur, we have developed frequent hybrid online and in person connection strategies to ensure a strong and collegial research environment is maintained in the case that these restrictions re-occur.