Pathfinder: The use of multibeam echo-sounding in quantifying and monitoring water quality and sediment fluxes in aquatic environments

All natural water flows on the Earth's surface transport sediment (including muds, sands and silts), both along their beds and also suspended within the flow. Sediment transport and deposition result in a wide scale of features from the smallest-scale sand ripples to the largest river deltas and submarine sediment fans. Additionally, understanding the transport of sediment is vital in assessing the fate of pollutant particles in many environments and in a range of industrial applications, such as the erosion and transport of sediment around engineering structures, for instance around bridges and sub-sea installations and during dredging operations.

In order to better understand the transport and deposition of sediment in the natural environment, and thus feed this into environmental management strategies (and the meeting of the water framework directive), we require methods that will allow us to measure the shape, or morphology, of the bed (sea bed, lake bed, river bed) surface and measure the transport of sediment. Recent years have seen astonishing progress in the development of multibeam echo sounding (MBES) systems, which use an array of echo-sounder beams to measure the form of the surface at the base of water flows (such as the bed of oceans or rivers) at a very high accuracy (down to millimeters in vertical precision). These instruments use the reflection of sound from the bed to measure the depth of the fluid, and hence construct detailed maps of the bed sediment surface. These instruments allow us to view the bottom of rivers and oceans as if all the water had been slowly drained, and the depositional form left untouched and perfectly displayed. This technique has generated a step change in how we can view the Earth's surface, which depositional forms are present and how we may interpret them and such high-resolution surveys also allow us to look at the change in shape at different time periods, and thus assess changing sediment volumes in time, in response to both human impacts and natural changes.

Under a recently completed NERC Partnership Grant the applicants, with Project Partners RESON, have developed a methodology using MBES for concurrently quantifying bathymetry and the concentrations and fluxes of suspended sediment within the water column, using information contained in the acoustic returns derived from the passage of the acoustic sound beams through the water column. We have developed a suite of processing codes and software that conducts the analysis of these vast data sets and have assembled a set of calibrations for converting the acoustic returns into quantifiable sediment concentrations. The goal of this follow on fund project will be to examine and define the full potential for the commercial exploitation of the technique, most likely through the integration of our codes and routines within IVS3D's Fledermaus, one of the world leaders in the processing and display of 3D time-varying datasets. IVS3D are project partners in this application and the full route to market and commercial exploitation analysis will be conducted by TechnologyfromIdeas (included in the project as partners), who are an independent technology transfer consultancy contracted by the University of Leeds Business and Enterprise Centre. They will provide full market assessments and reports related to the potential commercialisation of the technology.