Hachem is a coastal engineer and oceanographer working at the interface between ocean engineering, and environmental geoscience. Hachem's expertise lies in experimental, numerical, and field investigations of coastal hydrodynamics and sediment transport (cohesive, granular, and mixed sediments). His teaching and research interests span a range of coastal and shallow marine processes and geohazards, exploring environmental and anthropogenic drivers and impacts of coastal change and informing the design of adaptive, resilient and nature-inclusive solutions to climate-mediated hazards such as coastal erosion, flooding, and habitat degradation, and the sustainable provision of renewable energy and marine resources.
Hachem also runs the three coastal teaching and research laboratories within the School of Ocean and Earth Science, which host recirculating and annular flumes and sediment analysis facilities, and associated field monitoring equipment.
- Nearshore hydrodynamics and coastal sediment dynamics
- Coastal and ocean engineering and flow-structure-seabed-biota interactions
- Adaptive, nature-inclusive solutions to climate-mediated geohazards, including flooding, erosion and habitat degradation
- Turbulence, boundary layers and loose boundary hydraulics
Hachem's research spans a range of coastal and marine processes and hazards, exploring environmental and anthropogenic drivers and impacts of coastal change, and informing the design of adaptive, sustainable, and nature-inclusive solutions to promote coastal resilience, and ensure sustainable provision of energy and resources.
Hachem currently leads an Environment Agency-funded project (2019-2023) in Pevensey Bay, UK, applying novel field monitoring tools for rapid characterisation of the nearshore of a composite, mixed shingle barrier beach. The project integrates X-Band radar, benthic landers and rapid shallow surveys using autonomous systems to provide near real-time spatial and temporal measurements of nearshore hydrodynamics and shoreface sediment transport, allowing a step-change in understanding of composite beach dynamics and recovery.
Hachem also studies the interactions between ocean and atmosphere, linking regional climates to coastal hazards to assess vulnerability and resilience of key infrastructure, and examining sea surface temperature trends and their impacts on coastal ecosystems.
Hachem works with industry, government agencies, NGOs and local authorities, optimising nature-inclusive or bio-inspired scour protection, eco-reefs and on-bottom cable protections for offshore renewable energy; monitoring benthic roughness to improve parametrisations of friciton in flood models, studying biogeochemical cycling across the sediment-water interface; assessing the role of saltmarshes, mangroves and seagrasses in flow attenuation, sediment stabilisation, carbon sequestration and microplastic retention; and examining particle settling in aquaculture sites.
External roles and responsibilities
2022 - Lecturer in Ocean Engineering, University of Southampton
2017 - 2021 Teaching and Research Fellow in Coastal Morphodynamics, University of Southampton
2015 - 2017 Teaching Fellow in Coastal Morphodynamics and GIS [Part-time], University of Southampton
2010 - 2012 Lecturer in Civil Engineering, The London College - University College Kensington