Transport of sediments in geophysical flows occurs in mountainous, fluvial, estuarine, coastal, aeolian and other natural or man-made environments on Earth, while also shapes the surface of planets such as Mars, Titan, and Venus. Understanding the motion of sediments is still one of the most fundamental problems in hydrological and geophysical sciences. Such processes can vary across a wide range of scales - from the particle to the landscape - which can directly impact both the form (geomorphology) and, on Earth, the function (ecology and biology) of natural systems and the built infrastructure surrounding them. In particular, feedback between fluid and sediment transport as well as particle interactions including size sorting are a key processes in surface dynamics, finding a range of important applications, from hydraulic engineering and natural hazard mitigation to landscape evolution, geomorphology and river ecology.
A) particle-scale interactions and transport processes:
- mechanics of entrainment and disentrainment (fluvial and aeolian flows)
- momentum (turbulent impulses) and energy transfer between turbulent flows and particles
- upscaling and averaging techniques for stochastic transport processes
- granular flows in dry and submerged environments
- grain shape effects in granular flow and sediment transport
- interaction among grain sizes in poorly sorted mixtures, including particle segregation
- discrete element modelling of transport processes and upscaling into continuum frameworks
B) reach-scale sediment transport and geomorphic processes
- links between flow, particle transport, bedforms and stratigraphy
- derivation and solution of equations for multiphase flows (inc. fluvial and aeolian flows)
- shallow water hydro-sediment-morphodynamic processes
- highly unsteady and complex water-sediment or granular flows
- flash floods, debris flows and landslides due to extreme rainfall
C) large-scale landscape evolution, geohazards, and engineering applications
- natural and built dam failures and compound disasters
- coastal processes, e.g., long-shore and cross-shore sediment transport and the evolution of beach profile/shoreline
- reservoir operation schemes and corresponding fluvial processes
- design of hydraulic structures such as fish passages, dam spillways, also considering the impact of sediment
- dredging, maintenance and regulation for large rivers and navigational waterways