A5030554109- Coastal and Marine Dynamics
- Coastal wetland ecosystem dynamics
- Geological formations and processes
- Hydrology and Sediment Transport Processes
- Aeolian processes and effects
- Soil erosion and sediment transport
- Ocean Waves and Remote Sensing
- Geology and Paleoclimatology Research
- Oceanographic and Atmospheric Processes
- Tropical and Extratropical Cyclones Research
- Lattice Boltzmann Simulation Studies
- Fluid Dynamics and Vibration Analysis
- Landslides and related hazards
- Aquatic Ecosystems and Phytoplankton Dynamics
- Atmospheric aerosols and clouds
- Hydraulic Fracturing and Reservoir Analysis
- Fluid dynamics and aerodynamics studies
- Marine and coastal ecosystems
- Evacuation and Crowd Dynamics
- Geotechnical and Geomechanical Engineering
- Fluid Dynamics and Heat Transfer
- Seismic Waves and Analysis
- Scientific Research and Discoveries
- Fluid Dynamics and Turbulent Flows
- Plant responses to water stress
Bangor University
2016-2025
University of Hull
2018-2022
University of Plymouth
2018
Sediment fluxes in aquatic environments are crucially dependent on bedform dynamics. However, sediment-flux predictions rely almost completely clean-sand studies, despite most being composed of mixtures non-cohesive sands, physically cohesive muds and biologically extracellular polymeric substances (EPS) generated by microorganisms. EPS associated with surficial biofilms known to stabilize sediment increase erosion thresholds. Here we present experimental data showing that the pervasive...
Abstract Biologically active, fine‐grained sediment forms abundant sedimentary deposits on Earth's surface, and mixed mud‐sand dominates many coasts, deltas, estuaries. Our predictions of transport bed roughness in these environments presently rely empirically based form predictors that are exclusively biologically inactive cohesionless silt, sand, gravel. This approach underpins paleoenvironmental reconstructions successions, which analysis cross‐stratification bounding surfaces produced by...
The dimensions and dynamics of subaqueous bedforms are well known for cohesionless sediments. However, the effect physical cohesion imparted by cohesive clay within mixed sand-mud substrates has not been examined, despite its recognized influence on sediment stability. Here we present a series controlled laboratory experiments to establish substrate content bedform mixtures sand exposed unidirectional flow. results show that steepness decrease linearly with content, comparison existing...
Abstract Background Plants play a pivotal role in soil stabilization, with above‐ground vegetation and roots combining to physically protect against erosion. It is possible that diverse plant communities boost root biomass, knock‐on positive effects for stability, but these relationships are yet be disentangled. Question We hypothesize erosion rates fall increased species richness, test explicitly how closely biomass associated diversity. Methods tested this hypothesis salt marsh grasslands,...
The present knowledge of cohesive clay-laden sediment gravity flows (SGFs) and their deposits is limited, despite clay being one the most abundant types on earth subaqueous SGFs transporting large volumes into ocean. Lock-exchange experiments were conducted to contrast laden with noncohesive silica flour, weakly kaolinite, strongly bentonite in terms flow behavior, head velocity, runout distance, deposit geometry across a wide range suspended-sediment concentrations.
Predicting seabed mobility is hampered by the limited accuracy of sediment transport models when bed composed mixed sediments. The hiding-exposure (HE) effect modifies threshold motion individual grain classes in mixtures and its strength dependent on size distribution. However, an appropriate method predicting this for bimodal remains to be developed. prototypical example a mixture that consisting well-sorted sand gravel fine coarse fractions respectively. Through comprehensive series...
The shape and size of sedimentary bedforms play a key role in the reconstruction processes modern ancient environments. Recent laboratory experiments have shown that mixed sand-clay develop at slower rate often smaller heights wavelengths than equivalent pure sand. This effect is generally attributed to cohesive forces can be physical origin, caused by electrostatic attraction between clay minerals, biological 'sticky' extracellular polymeric substances (EPS) produced micro-organisms, such...
Abstract. Wave–current ripples that develop on seabeds of mixed non-cohesive sand and cohesive clay are commonplace in coastal estuarine environments. While laboratory research forming these types mixed-bed environments is relatively limited, it has identified deep cleaning, the removal below ripple troughs, as an important factor controlling development. New large-scale flume experiments seek to address this sparsity data by considering two wave–current conditions with initial content, C0,...
Many coastal and estuarine environments are dominated by mixtures of non-cohesive sand cohesive mud. The migration rate bedforms, such as ripples dunes, in these is important determining bed material transport rates to inform assess numerical models sediment geomorphology. However, tend ignore parameters describing the physical biological cohesion (resulting from clay extracellular polymeric substances, EPS) natural mixed sediment, largely because a scarcity relevant laboratory field data....
Mixtures of cohesive clay and noncohesive sand are widespread in many aquatic environments. Ripple dynamics sand-clay mixtures have been studied under current-alone wave-alone conditions but not combined wave-current conditions, despite their prevalence estuaries the coastal zone. The present flume experiments examine effect initial content,
Abstract This study focuses on the interactions between sediment stability and biological physical variables that influence erodibility across different habitats. Sampling at short‐term temporal scales illustrated persistence of microphytobenthos (MPB) biomass even during periods frequent, high disturbance. The role MPB in stabilization along changing sedimentary habitat was also assessed. Key properties, such as biomass, composition, extracellular polymeric substances, were used to predict...
A model devised by Thorpe & Li ( J. Fluid Mech. , vol. 758, 2014, pp. 94–120) that predicts the conditions in which stationary turbulent hydraulic jumps can occur flow of a continuously stratified layer over horizontal rigid bottom is applied to, and its results compared with, observations made at several locations ocean. The identifies two positions Samoan Passage should where changes structure are indeed observed. amplitude observed mode 2 form transitions. predicted dissipation...