Developing sensor networks to inform environmental flow allocations in regulated rivers

Project outline

The regulation of river flows is one of the biggest stressors affecting river ecosystems across the world1,2. In many westernised countries, major legislative efforts are therefore underpinning the development of new approaches to mitigate the impacts of river flow regulation (e.g. EU Water Framework Directive (WFD), US Clean Water Act, South Africa National Water Act, Australian Water Resources Act). These approaches are based on optimising the management of river flows to maintain services to humans (e.g. water supply, hydropower) whilst protecting and/or rejuvenating the aquatic environment with water of adequate quantity and quality in space and time (i.e. environmental flows, aka e-flows)3.


In Europe, flow modification has contributed to <50% of water bodies meeting ecological status targets under the WFD4. Thousands of new reservoirs are also in planning or construction globally, adding to the existing >50,000 large dams (>15m height) and millions of smaller dams and abstraction points5,6. By managing river flows more effectively, the monetary, cultural and amenity value of these ecosystems can potentially be safeguarded and increased, thus contributing to economic growth, poverty alleviation and societal well-being as well as river ecosystem health.

Modifying river flow regimes, either for regulation or when implementing e-flows, drives changes in many other river ecosystem abiotic components which are still not well understood. Equally, the cause-effect relationships and feedbacks between multiple abiotic factors and biodiversity, ecosystem functioning and services are often also defined poorly. River managers need scientists to develop this fundamental understanding to inform decision-making in the light of projected climate and environmental change. The paucity of knowledge in this field is creating problems for river managers who are under pressure to identify and implement management measures (including e-flows) as a way of improving ecological status under the EU WFD for example4. Current decision making is hindered particularly by our inability to understand quickly how river ecosystems respond to flow changes, with field sampling and laboratory based analyses often delivering results months-years after flow changes are implemented. However, recent advances in environmental sensor design, datalogging, telemetry and computer science are underpinning the potential for the collection, analysis and visualisation of river ecosystem responses to flow changes in near real-time. For example, recent work has shown how sensors that underpin integrated estimates of river ecosystem metabolism can be used to show immediate effects of sedimentation7 as well as understanding river basin scale metabolic patterns and processes8.

This project will design and implement a sensor based monitoring network in selected strategically important water resource catchments. This will allow the successful applicant to examine the potential of environmental flows to improve regulated river ecosystem functioning. A specific focus will be on monitoring changes in river ecosystem primary production, respiration and net metabolism using dissolved oxygen, water temperature, PAR and flow sensors. It will provide recommendations to a major UK water utility, Yorkshire Water, on whether their operations can help the company to achieve good ecological potential downstream of reservoirs whilst optimising their water allocations to river flow. It will also determine the costs and benefits of the approach for wider consideration by the Environment Agency.

Project Goals

This research will address the potential for monitoring environmental flow changes (e.g. seasonal compensation flows, artificial floods) using sensors, to gain an improved understanding of how water managers can use technology in their efforts to improve the status of heavily modified, regulated river ecosystems. An interdisciplinary approach will allow the student to develop a project that integrates elements of (1) hydrology, (2) physicochemical processes (water quality, temperature), and (3) river functional responses (e.g. primary production, ecosystem respiration, whole system metabolism). There will be opportunities to work alongside UK water companies to inform their decision making through the development of automated data collection, quality control and visualisation techniques. The project will incorporate periods of fieldwork to install and maintain sensors in rivers downstream of reservoirs as well as paired unregulated ‘control’ rivers. Laboratory work will focus on developing automatic data quality control and visualisation techniques, for example to underpin a web interface for use by water managers.


The successful candidate will benefit from inter-disciplinary training in hydrology and aquatic science as part of the River Basin Processes and Management, and the Leeds institute of Data Analytics (LIDA) in the School of Geography. Training at Leeds deals fully with the elements described in the Joint Research Centre statement on skills training for research students. PhD students take modules provided by the staff development unit (e.g. starting your PhD, small group teaching) and a 15-week faculty-training course (covering elements such as planning, critical reading and writing, oral presentations, writing research papers). Students present results and receive constructive feedback from peers in a Research Support Group, from colleagues in the River Basins research group, and at a university postgraduate research day. The student will also benefit from being part of water@leeds, the largest interdisciplinary water centre in any UK university, which runs a postgraduate forum. You will furthermore be integrated into the European network Euro-FLOW ( led by Leeds, with 10 core institutes and 12 additional project partners across Europe.

The nature of the project means that the student will be trained in project specific research methods including literature reviews, field work techniques, laboratory water quality analysis, and modelling/statistics for analysing data, both internally and at external workshops. An additional important part of the training will be to attend national and international conferences to present results and gain feedback. The student will be encouraged to submit papers for publication in international journals during the project.


The prospective student should have, or expect to receive, a minimum 2.1 BSc and/or MSc degree in an appropriate discipline, and have interests and experience in most, if not all, of the following topics: hydrology, freshwater ecosystems, computing, the water industry and environmental policy/management. Informal enquiries should be directed to Megan Klaar at Further details about postgraduate research degrees at the School of Geography, University of Leeds can be found here.


  1. Vörösmarty et al. 2010. Nature 467: 555-561
  2. Grill et al. 2019. Nature569: 215–221
  3. Gillespie et al. 2015. Freshwater Biology 60: 410-425
  4. COM. 2012. 273 A Blueprint to Safeguard Europe’s Waters
  5. Poff & Matthews. 2013. Current Opinion in Environmental Sustainability 5: 667–675
  6. Winemiller et al. 2016. Science 351: 128-129
  7. Aspray et al. 2017. Ecohydrology 10: e1855
  8. Rodríguez-Castillo et al. 2017. Ecosystems 22: 892–911