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Professor Geraldene Wharton, BSc Hons (Sheff) PhD (Soton)

Professor of Physical Geography

email: g.wharton@qmul.ac.uk
Tel: 020 7882 5439
Location: Geography building, Room 111

Profile

Geraldene Wharton

I am a Professor of Physical Geography and a Chartered Geographer (Geomorphology) with over 20 years’ research experience in hydrogeomorphology and hydroecology. My research on rivers focuses on:

  • interactions between water, plants and sediments;
  • entrainment and transport of fine cohesive sediments;
  • river restoration and natural flood management.

Bere Stream at Snatford Bridge is one of my study sites in the Frome-Piddle Catchment, Dorset, UK (photo: G.Wharton).

After completing a BSc Honours degree in Geography at the University of Sheffield and a PhD at Southampton University, I held a Natural Environment Research Council (NERC) Post-Doctoral Research Fellowship before joining the School of Geography at Queen Mary, University of London.

I am currently a member of the NERC Peer Review College, a Subject Editor for the Journal of Soils and Sediments, and a Director of the International Association for Water Sediment Science. Past appointments have included: Chair of the Board of Directors of the UK River Restoration Centre; Honorary Secretary of the Royal Geographical Society with Institute of British Geographers; and Secretary of the Geography Section of the British Association for the Advancement of Science.

Some of my key recent publications are:

  • Grabowski, R. C., Wharton, G., Davies, G. R., & Droppo, I. G. (2012). Spatial and temporal variations in the erosion threshold of fine riverbed sediments. JOURNAL OF SOILS AND SEDIMENTS, 12(7), 1174–1188. doi:10.1007/s11368-012-0534-9
  • Grabowski, R. C., Droppo, I. G., & Wharton, G. (2011). Erodibility of cohesive sediment: The importance of sediment properties. EARTH-SCI REV, 105(3-4), 101-120. doi:10.1016/j.earscirev.2011.01.008
  • Grabowski, R. C., Droppo, I. G., & Wharton, G. (2010). Estimation of critical shear stress from cohesive strength meter-derived erosion thresholds. LIMNOL OCEANOGR-METH, 8, 678–685. doi:10.4319/lom.2010.8.678
  • Heppell, C. M., Wharton, G., Cotton, J. A. C., Bass, J. A. B., & Roberts, S. E. (2009). Sediment storage in the shallow hyporheic of lowland vegetated river reaches. In HYDROLOGICAL PROCESSES Vol. 23 (pp. 2239–2251). doi:10.1002/hyp.7283

Teaching

I teach at all undergraduate levels and I am currently contributing to the following modules :

My teaching draws on my empirically-based research on rivers and, through my work in river restoration, students are introduced to current policy and practice in river restoration. Classes are interactive with frequent opportunities for discussion and debate, and site visits to restoration schemes allow students to gain first-hand knowledge of restoration design and develop an appreciation of the challenges and benefits of restoring rivers.

 

At Masters level, I teach on:

MSc Environmental Science: Integrated Management of Freshwater Environments

 

MSc Environmental Science by Research 
Current and recent supervisees and projects:

  • Michael Brierley (2012–3): Assessing the impact of stormwater outfalls on the sediment quality of the River Wandle. In collaboration with, and partly-funded by, the Wandle Trust.
  • Rebecca Shears (2008–9): Integrated pre-project appraisal of Mayesbrook Park river restoration scheme. Funded by the Environment Agency.
  • Claire Hulbert (2005–6): Integrated post-project appraisal of an urban river restoration scheme: the River Quaggy, Sutcliffe Park, South East London. Funded by the Environment Agency.

Research

Research interests:


Submerged aquatic vegetation (Ranunculus sp. / Watercrowfoot) on the River Frome at Maiden Newton, Dorset, UK (photo: G.Wharton)

Interactions between water, plants and sediments in rivers
Many rivers contain aquatic plants growing in the centre of the channel (submerged) and at the margins (emergent) and they act as important ecosystem engineers, modifying flow patterns and the processes of sediment deposition, entrainment and transport (Cotton et al., 2006). Invertebrates (such as blackfly larvae) that live on these plants modify sediment properties, resulting in organic-rich and highly-aggregated fine sediments (Wharton et al., 2006). These are some of the processes that were investigated and quantified as part of the NERC Lowland Catchment Research Thematic Programme (NER/T/S/2001/00932: Fine sediment and nutrient dynamics of lowland permeable streams: establishing the significance of biotic processes for sediment modification). Because contaminants such as fertilisers and pesticides adsorb to fine sediments and the nutrient-rich sediments within the aquatic plants release methane (Sanders et al., 2007) there are implications for river health.  

 

 


Measurement of flow velocity on the River Lambourn at Boxford using an Acoustic Doppler Velocimeter (photo: G.Wharton)

The Environment Agency is using these findings, including a knowledge of the sediment habitats associated with different plants (Wharton et al., 2006; Clarke and Wharton, 2001) to develop and refine a software tool called LEAFPACS. The tool helps in the assessment of a river’s ecological status by predicting what plants should be present and comparing this to actual observations.

Another important issue in lowland vegetated rivers is weed cutting, routinely carried out for flood risk management. Current research is being conducted on the River Lambourn (Adam Sutcliffe, CEH NERC Studentship) to measure and model the detailed flow hydraulics following different weed cutting strategies to inform management decisions about the optimum levels of aquatic plant cover.

 

 


Excessive fine sediment deposits within a macrophyte stand over a gravel bed affecting river health (photo: L. Baldock)

Entrainment and transport of fine cohesive sediments
In recent decades increased inputs of fine sediments to lowland rivers have resulted in the ingress of silts, clays and sands into gravels, excessive surficial deposits, and elevated levels of sediment-bound contaminants.

Recent research in the Frome-Piddle Catchment, Dorset, (Robert Grabowksi QMUL PhD Studentship) in collaboration with Ian Droppo (Environment Canada) examined the spatial and temporal variations in the erodibility of fine sediment deposits, using a Cohesive Strength Meter (Grabowski et al., 2012). And associated experimental flume work developed a calibration to allow CSM measurements taken in the field to be expressed as critical shear stress values to help further knowledge of entrainment thresholds for fine cohesive sediments (Grabowski et al., 2010) based on an understanding of the physical, biological and chemical factors that determine a sediment’s erodibility (Grabowski et al., 2011). Parallel research (Luke Warren NERC PhD Studentship; Grieg Davies NERC PhD Studentship) focused on quantifying how much fine sediment is transported in vegetated river reaches (Warren et al., 2009) under seasonally changing vegetation cover and how much fine sediment is stored (Heppell et al., 2009). This work is being developed to consider the residence times of fine sediments and sediment-bound contaminants in vegetated rivers. 


Measuring the erodibility of surficial fine cohesive sediments in the field using a Cohesive Strength Meter (photos: R. C. Grabowski).

Publications

For full details, see my online published profiles on ResearcherID and Google Scholar

Selected publications since 2000

  • Wharton, G., Kronvang, B., Ogrinc, N., & Blake, W. H. (2012). Interactions between sediments and water: perspectives on the 12th International Association for Sediment Water Science Symposium. JOURNAL OF SOILS AND SEDIMENTS, 12(10), 1497–1500. doi:10.1007/s11368-012-0606-x
  • Grabowski, R. C., Wharton, G., Davies, G. R., & Droppo, I. G. (2012). Spatial and temporal variations in the erosion threshold of fine riverbed sediments. JOURNAL OF SOILS AND SEDIMENTS, 12(7), 1174–1188. doi:10.1007/s11368-012-0534-9
  • Sgouridis, F., Heppell, C. M., Wharton, G., Lansdown, K., & Trimmer, M. (2011). Denitrification and dissimilatory nitrate reduction to ammonium (DNRA) in a temperate re-connected floodplain.. Water Res, 45(16), 4909–4922. doi:10.1016/j.watres.2011.06.037
  • Grabowski, R. C., Droppo, I. G., & Wharton, G. (2011). Erodibility of cohesive sediment: The importance of sediment properties. EARTH-SCI REV, 105(3-4), 101-120. doi:10.1016/j.earscirev.2011.01.008
  • Grabowski, R. C., Droppo, I. G., & Wharton, G. (2010). Estimation of critical shear stress from cohesive strength meter-derived erosion thresholds. LIMNOL OCEANOGR-METH, 8, 678–685. doi:10.4319/lom.2010.8.678
  • Warren, L. L., Wotton, R. S., Wharton, G., Bass, J. A. B., & Cotton, J. A. (2009). The transport of fine particulate organic matter in vegetated chalk streams. ECOHYDROLOGY, 2(4), 480–491. doi:10.1002/eco.86
  • Heppell, C. M., Wharton, G., Cotton, J. A. C., Bass, J. A. B., & Roberts, S. E. (2009). Sediment storage in the shallow hyporheic of lowland vegetated river reaches. In HYDROLOGICAL PROCESSES Vol. 23 (pp. 2239–2251). doi:10.1002/hyp.7283
  • Sanders, I. A., Heppell, C. M., Cotton, J. A., Wharton, G., Hildrew, A. G., Flowers, E. J., Trimmer, M. (2007). Emission of methane from chalk streams has potential implications for agricultural practices. FRESHWATER BIOL, 52(6), 1176–1186. doi:10.1111/j.1365-2427.2007.01745.x
  • Wharton, G., Cotton, J. A., & Clarke, S. J. (2006). Spatial and temporal variations in the sediment habitat of Ranunculus spp. in lowland chalk streams - implications for ecological status?. Water, Air and Soil Pollution, 6, 393–401. doi:10.1007/s11267-006-9051-4
  • Wharton, G., Cotton, J. A., Wotton, R. S., Bass, J. A. B., Heppell, C. M., Trimmer, M., Warren, L. L. (2006). Macrophytes and suspension-feeding invertebrates modify flows and fine sediments in the Frome and Piddle catchments, Dorset (UK). J HYDROL, 330(1–2), 171–184. doi:10.1016/j.jhydrol.2006.04.034
  • Cotton, J. A., Wharton, G., Bass, J. A. B., Heppell, C. M., & Wotton, R. S. (2006). The effects of seasonal changes to in-stream vegetation cover on patterns of flow and accumulation of sediment. GEOMORPHOLOGY, 77(3–4), 320–334. doi:10.1016/j.geomorph.2006.01.010
  • Wharton, G., & Gilvear, D. J. (2006). River restoration: meeting the needs of both the EU Water Framework Directive and flood defence?. International Journal of River Basin Management, 5, 1–12.
  • Clarke, S. J., Bruce-Burgess, L., & Wharton, G. (2003). Linking form and function: towards an eco-hydromorphic approach to sustainable river restoration. AQUAT CONSERV, 13(5), 439–450. doi:10.1002/aqc.591
  • Clarke, S. J., & Wharton, G. (2001). Sediment nutrient characteristics and aquatic macrophytes in lowland English rivers. SCIENCE OF THE TOTAL ENVIRONMENT, 266(1–3), 103–112.

PhD Supervision

Postgraduate research opportunities in Earth Surface Science

Current PhD Students (with source of funding)

  • Adam Sutcliffe (NERC CEH Studentship) Effects of seasonal plant growth and weed cutting regimes on river flow hydraulics. Supervisors: Dr P Rameshwaran (CEH, Wallingford), Dr P Naden (CEH, Wallingford), Dr G Wharton (QMUL).
  •  Matthew Cashman (Erasmus Mundus PhD Studentship) Hydromorphological and ecological responses to habitat heterogeneity and large wood. Supervisors: Dr G Harvey (QMUL), Dr G Wharton (QMUL), Dr M Pusch (IGB).
  • Francesca Pilotto (Erasmus Mundus PhD Studentship) River channel response to changes in wood and sediment load: woody debris as a trigger for invertebrate habitat diversity in lowland rivers. Supervisors: Dr Martin Pusch (IBG), Dr G Harvey (QMUL), Dr G Wharton (QMUL).
  • Seyed Hossein Mohajeri (Erasmus Mundus PhD Studentship) Experimental study of the effects of colmation in a gravel bed in a free surface flow. Supervisors: Dr M Righetti (UniTN), Dr G Wharton (QMUL), Professor V Nikora (University of Aberdeen).
  • Tesfaye Haimonot Tarekegn (Erasmus Mundus PhD Studentship) Environmental impacts of river impoundments: reservoir and watershed sediment management. Supervisors: Dr.M Toffolon (UniTN), Dr M Righetti (UniTN), Dr G Wharton (QMUL) .
  • Sepideh Ramezani (Erasmus Mundus PhD Studentship) Nutrient dynamics and hydrological connectivity in agricultural floodplains. Professor A Bellin (UniTN), Dr C M Heppell (QMUL), Dr D Tonina (University of Idaho), Dr G Wharton (QMUL).
  • Mahdi Khademishamami (Erasmus Mundus PhD Studentship) Effects of colmation on fine sediment dynamics in gravel-bed rivers. Supervisors: Professor A Armanini (UniTN), Dr M Righetti (UniTN), Dr G Wharton (QMUL), Professor J Brasington (QMUL).
  • Stuart Smith (part-time, self-funding). Defining environmental flows in modified rivers. Supervisors: Dr G Harvey (QMUL) and Dr G Wharton (QMUL).
  • 2013-16: co-supervisor of two PhD students as part of the Marie Curie International Training Network with the University of Lyon and gIR Engineering, Germany.

 

Former PhD students (with date of award and source of funding)

  • Helen Dangerfield (2000; College studentship) A study of channel geometry-discharge relationships in semi-natural British rivers as a basis for river restoration.
  • Stewart Clarke (2000; College Studentship and Environment Agency) Macrophyte-sediment interactions in British rivers.
  • Lydia Bruce-Burgess (2004; NERC-ESRC Interdisciplinary Studentship CASE with the Environment Agency) Evaluation of river restoration appraisal procedures.
  • Marta Timoncini (2004; College Studentship) Detection of soil moisture under changing vegetation cover from ERS-2 SAR satellite imagery.
  • Luke Warren (2006; NERC Studentship LOCAR Thematic Programme) The biogenic transformation of fine sediments in lowland permeable catchments.
  • Fotis Sgouridis (2010; College studentship awarded to Geography and SBCS) Nitrate dynamics in a re-connected river floodplain system: the River Cole, Wiltshire, UK).
  • Robert Grabowski (2011; College studentship) The erodibility of fine sediment deposits in lowland chalk streams.
  • Grieg Davies (2012; NERC studentship). The transport of fine sediments in vegetated chalk streams.

 

Former students have been successful in gaining employment in research (QMUL, Open University, Keele University), the water industry (Southern Water), and environmental consultancies and agencies (Environment Agency, Natural England, Babtie, Royal Haskoning, National Trust, APEM).

 

I would be pleased to discuss developing research projects in my main areas of expertise. Please refer to (http://www.geog.qmul.ac.uk/postgraduate/) for information on the application process. You may also wish to consider the EU Erasmus Mundus Joint Doctoral programme, SMART (Science for Management of Rivers and their Tidal Systems). Details on this programme can be found at: www.riverscience.eu

Public engagement


Sutcliffe Park, River Quaggy, South East London. Post-project appraisals have documented changes in river morphology, macrophyte cover, sediment and water quality (photo: G.Wharton).

River restoration and natural flood management
I have a keen interest in the restoration of urban rivers and have conducted several appraisals of river restoration projects in the Thames catchment, funded by the Environment Agency, and resulting in R&D reports (see below). Over the past 13 years, I have also been closely involved in river restoration in an advisory capacity through my work as a Director and Chair of the UK River River Restoration Centre. Currently, I am working with Professor Angela Gurnell to develop the Urban River Survey  for application by the Environment Agency’s National Environment Assessment Service (NEAS).

 

R&D Reports


  • Mayes Brook, Barking, East London. Pre and post project appraisals have focused on the water and sediment quality of this urban river (photo: L. Shuker).
    Wharton, G., Spencer, K., Peel, K., Shears, R. and Tekin, V. (2010) Mayesbrook Park River Restoration Baseline Monitoring: a summary report of the water and sediment quality of Mayes Brook and Mayesbrook Lakes, and the usage of Mayesbrook Park. Environment Agency R&D Technical Report, 8 pp.
  • Hulbert, C. A. V., Wharton, G. and Copas, R. (2009) Integrated Post-Project Appraisal of an Urban River Restoration Scheme: The River Quaggy, Sutcliffe Park, South East London. Environment Agency R&D Report, 80 pp.
  • Wharton, G. (2002) Ingrebourne River Geomorphological Overview. A report to Havering Wildlife Partnership and Land Use Consultants. Commissioned by the River Restoration Centre. March 2002, 6pp.
  • Clarke, S. J. and Wharton, G. (2001) Using macrophytes for the environmental assessment of rivers: the role of sediment nutrients. Environment Agency R&D Technical Report E1-S01/TR, Environment Agency, Bristol, 90 pp.
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