Hello! I’m Chris and I research how sediments (like sand) moves around and changes the shape of the Earth’s surface. To do this I’ve used the full spectrum of techniques; lab, field and numerical modelling, to investigate the fascinating interplay between flows - sediment movement and bedforms.

Currently I’m working on the SEACAMS-2 project with Martin Austin and Katrien Van Landeghem, we are focused on leveraging Bangor’s unique expertise in measuring and understanding turbulence and sediment transport for the renewable energy sector.

Recently I have been working on intertidal sediment transport in Morecambe bay, one of the few hyper-tidal sand flats in the world, and we have managed to get one of the first complete datasets measuring both bedform transport, suspended sediment transport, along with the hydrodynamics driving this sediment motion – this has created new knowledge of how sediment gets transported in this environment.

I have experience of using a variety of flow and sediment transport measurement equipment, including a wide range of acoustic instrumentation (SBES, ADCP, ADV, ADVP, Multi-Frequency Acoustic backscatter probes and Depth Sounders), light-based based instrumentation (PIV, LISST, IR cameras), and geo-location with dGPS systems. I have a wide range of experience in post processing the above instrumentation, as well as multibeam echosounder (MBES) data, commonly using high level codes such as MATLAB and python, with ArcGIS and Global-Mapper to process geo-spatial and image data and plot for presentations and publications. I use a mix of Adobe Illustrator and InkScape to produce professional-standard figures suitable for publications and presentations.

I undertook 4 field seasons as the lead field PDRA on the South Saskatchewan River in Canada, which has given me practical working experience in designing, planning and implementing field campaigns, often unsupervised > 10 hours. This fieldwork included measuring the flow structure and suspended sediment dynamics using a small launch with an aDcp, ABS and a LISST to quantify the flow-morphology-sediment transport interactions. This field dataset has been used to set the boundary conditions and validate my own and my collaborators modelling on the project.

My PhD thesis involved work the NERC project; http://www.bedform.co.uk/ and more recently as PDRA on http://www.sandyriverdynamics.co.uk/ and the BlueCOAST project (https://projects.noc.ac.uk/bluecoast/).

christopher.unsworth@bangor.ac.uk

https://twitter.com/UnsteadyRiver

  • PhD: River Dunes in Unsteady Conditions
    University of Hull, 2011–2015
  • MSc: MRes in Catchment Dynamics and Management
    University of Leeds, 2010–2011
  • BSc: JH Geology and Geography
    University of Birmingham, 2007–2010

2024

2023

2022

2024

  • Geomorphology (Journal)

    paper review

    Mar 2024

    Activity: Publication peer-review (Peer reviewer)
  • OT41B-07 To what extent do offshore windfarms create new seabed habitats far away from the monopiles?

    22 Feb 2024

    Activity: Oral presentation (Speaker)
  • CC44D-1380: Understanding Sea Level Rise Impact over Seabed Stress using Coupled Ocean-Wave modelling.

    The Irish Sea is characterised by a heterogenous seabed, where different sediment types vary over short spaces in adjacent regions. This means it is also characterised by various environments that are home to different fauna and flora, which can easily be affected by changes to the seabed composition. Ocean currents and waves both induce stress over the seabed in shelf and shallow water regions. There are complex feedback interactions between these two components, which are expected to be affected by future climate change and sea level rise (SLR). Future changes to ocean, waves and their interaction may therefor affect the bed-stress, changing the present seabed structure and related environments. Recent coupled model developments now allow us to better reproduce these interactions though numerical simulation; In this work, we implement a NEMO-WW3 coupled model at 1.5km resolution over the whole northwestern European shelf. For the first time, we can demonstrate the impact of SLR over the bed stress, considering only barotropic factors. Here we show the latest model results and discuss implications for seabed habitats.

    18 Feb 2024 – 24 Feb 2024

    Activity: Oral presentation (Speaker)
  • OT41B-07: To what extent do offshore windfarms create new seabed habitats far away from the monopiles?

    Offshore wind farms (OWFs) are a key component of our journey to Net Zero; however, this must be done in a sustainable manner, so understanding their impacts on the marine environment is important. Where tidal flows interact with OWF their flow field can become dramatically modified. Satellite data has shown disturbances such as kilometre-scale wake effects on the sea surface. Yet little attention has been paid to far field effects on the seabed. The ECOWind-ACCELERATE project focusses on how OWFs can modify seabed processes, and consequently, the habitats and the ecosystem services they provide. Here, we integrate large-scale physical laboratory and 3D numerical modelling to better understand these impacts. A 3 m wide, 35 m long flume was used to monitor flow, turbulence, and bed changes, assessing the influence of different monopile diameters representative of present-day and future OWFs. Experimental runs were varied to represent differing levels of bed mobility.

    Under mean flow conditions that would otherwise fall below the threshold of motion, new bedform fields were generated from the turbulence produced in the wake of the monopile. These bedform fields extended up to 17x downstream and 7x as wide as the monopile diameter; and longer experimental runs would likely have likely extended them further. Under mobile bed conditions the effect was less than expected. Changes to the bed extended to 14x the monopile diameter downstream, suggesting widespread existence of bedforms can reduce the effect of the monopiles turbulent wakes on near bed dynamics. A suite of velocimeter data from the flume laboratory tests were used as the basis for a 3D Telemac model of the flume laboratory environment. We then assessed how much of this induced sediment mobility is due to the turbulent wake from the monopile and rock armour, compared to that generated by the bedforms themselves.

    Our work indicates that installing offshore wind farms on seabeds that would otherwise be immobile can create newly active and dynamic seabeds with bedforms extending far beyond the monopile. This can modify existing habitats and potentially create new ones. Our findings provide a new evidence-base concerning the modification and recovery of the seabed around offshore wind farms, with implications for benthic biodiversity and opportunities for marine net gain.

    18 Feb 2024 – 24 Feb 2024

    Links:

    Activity: Oral presentation (Speaker)
  • VEPOSSSS Seminar: Seabed modification around offshore wind farms

    7 Feb 2024

    Activity: Oral presentation (Speaker)
  • Seabed modification around offshore wind farms

    17 Jan 2024

    Activity: Oral presentation (Speaker)

2023