I focus on using my research to inform my teaching and I use a variety of different teaching methods to engage my students. This includes large lecture-based learning, small group study and enquiry-based learning. I am particularly keen on using the research facilities, such as the hydraulic flumes we have at Brighton, to run practical sessions where students can design and run their own experiments to collect data for analysis and subsequently compare their own data with current research outputs. I am also interested in how students learn within the geoscience discipline and have a current project looking at how augmented reality can be used to support teaching and learning.

All fluvial and estuarine environments exhibit temporal variations in flow discharge, which creates unsteady changes in the flow field. The sediment-water interface responds to and organises these changes over a wide range of spatial and temporal scales, primarily through adjustment of a variety of bed roughness elements. My research area concentrates on this adjustment via analysis of river bed stability and structure using novel and high resolution data capture methods. Within gravel river beds, my work has shown that periods of sustained low flow as well as periods of sediment transporting conditions can cause bed re-structuring and hence alter the timing of sediment re-mobilisation during subsequent floods. Within sand bed rivers, my current work concentrating on understanding the dynamic response of sand bedforms to differing hydrographic controls has shown that hydrograph shape and duration fundamentally alter bedform dynamics primarily through changes to surface complexity.

My work has been undertaken using innovative non-invasive, high resolution measurement techniques. For example, by coupling high resolution surface based laser scanning with detailed near bed hydraulic measurements, my work makes it possible to begin to separate out the governing parameters which control channel stability. I have also used techniques such as 3D MRI scanning to measure subsurface sediment bed porosity and vertical structure change as well as 3D printing and surface casting which has allowed me to begin to investigate the mechanisms of momentum exchange between the flow and the sediment boundary.

Results from my work are pertinent to understanding flow and sediment conveyance through river systems, the effects of artificial hydrograph maintenance, sediment transport modelling and the generation of more realistic characterisations of sediment-water boundary exchange mechanisms.

CURRENT RESEARCH PROJECTS

1)                  Predicting remobilisation of microplastics from fluvial sediment during storm events - Funded by University of Brighton Research Infrastructure Grant (2017-2018) and University of Brighton PhD studentship (2018- 2021)  Dr Annie Ockelford (Brighton), Professor Andy Cundy (National Oceanographic Centre), and Dr James Ebdon (Brighton)

The sediment bed of a river potentially plays a vital role in mediating contaminant transfers of micro plastics between the sediment bed in which they are buried and the overlying water column.  Using a combined field, laboratory and numerical approach this work will determine the link between the sediment bed disturbance depths, near bed momentum and sediment fluxes and the flow regime such as to predict the type, timing and magnitude of micro plastics release during flood conditions. 

2)                  Quantifying the impact of engineered log jams on flood risk - Funded by University of Brighton Rising Stars Initiative (2017-2018) Dr Annie Ockelford (Brighton), Dr Joanna Curran (Northwest Hydraulics Consultancy), Professor Dan Parsons (Hull), Professor Chris Joyce (Brighton), Dr Treva Coe (Nooksack Indian Tribe)

In channel wood is being added back into channels as ‘engineered log jams’ to potentially reduce flood risk by attenuating flood waves.  Using a combined field, laboratory and numerical approach this work will produce a quantitative understanding of the effect of engineering log jams on reach scale flow and sediment dynamics across different discharges.  Results will be used to inform strategic flood risk measures and inform river restoration design.

3)      Impacts of stress history on water resources in the Chilean Andes- Funded by Royal Society (ongoing) Dr Annie Ockelford (Brighton/ Hull) and Dr Luca Mao (University of Lincoln/ Pontificia Universidad Catolica De Chile)

Climate models predict more frequent flooding events in the near future. Changes will be exacerbated in mountainous areas such as the Andes where discharge and sediment regimes are moderated by the presence of glaciers, themselves particularly sensitive to climate change. Yet the water supply from the Andes is critically important given 80% of freshwater supply originates from glaciated basins and hydropower constitutes a major source of energy. Thus understanding and predicting changes in discharge or sediment flux is critically important. Using an integrated field and laboratory modelling approach, the aim of this research is to use high resolution survey methods to quantify the relationship between flow regime and sediment flux such as to identify the likely impacts of a changing flood frequency.

4)                  Quantifying Fluvial Bedform Unsteadiness- Funded by NERC (ongoing) Professor Dan Parsons, and Dr Annie Ockelford (Brighton/ Hull), Professor Phil Ashworth (Brighton), Professor Rich Hardy (Durham), Professor Jim Best (Illinois)

All fluvial and estuarine environments exhibit temporal variations in flow discharge, which creates unsteady changes in the flow field. The sediment-water interface responds and organises itself to these changes over a wide range of spatial and temporal scales, primarily through adjustment of a variety of bed roughness elements. This project seeks to generate a new quantitative, process-based understanding of bedform adjustment to unsteady flows using both laboratory and field measurements, and link these new data to the development and application of a new numerical model of flow-bedform-roughness response.

5)                  Characterisation Of RiverBed SurfaceStructure  Funded by NERC (ongoing) Dr Mark Powell (Leicester), Professor Stephen Rice, Professor Ian Red (Loughborough) and Dr Annie Ockelford (Loughborough / Brighton)

Changes to the sediment boundary in gravel bed rivers to accommodate both the overlying fluid flow regime and the upstream sediment supply fundamentally changes the overall stability of the river.  To date, being able to describe changes to river stability in response to changing ‘bed structure’ and explicitly linking this development with changes to the overlying hydraulic signatures and sediment transport characteristics has been severely limited.  This project addressed this deficiency specifically examining how sediment grade, sediment supply characteristics and hydrograph shape affect the development of surface structures in gravel-bed rivers.

6)      The Effect of Porosity on Vertical Momentum Exchange in Gravel-Bed Rivers Dr Annie Ockelford (Brighton/ Loughborough), Professor Stephen Rice (Loughborough), Dr James Cooper (Sheffield), Dr Mark Powell (Leicester)

Momentum exchange is a key control of fine sediment ingress, pollutant exchange spawning success and hyporheic flows with porosity having a significant influence on this exchange processes.  Previous attempts to examine this exchange have been undertaken in an engineering context where experimental conditions lack the complexities of natural river beds.  Consequently it has not been possible to isolate the influence of bed porosity from that of bed topography. This on-going research uses bed surface casts to directly compare between the hydraulics of porous and non-porous beds of the same topography.  This will allow us for the first time, to isolate the influence of bed porosity, across sorting and structure gradients.

I am interested in supervising postgraduate research students in the following areas: fluvial geomorphology; environmental change in response to changing flood hazards; microplastic contamination in fluvial systems.