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Environmental Engineering Graduate Seminar

Gangfeng Ma, Ph.D., Senior Coastal Scientist at DHI

Abstract:

Deep-sea mining emerges as a promising yet controversial frontier for mineral extraction, garnering global scrutiny for its profound environmental and societal implications. A paramount concern is the dispersion of sediment plumes and their cascading effects on deep-ocean biodiversity and ecosystem integrity. These plumes typically unfold in three distinct phases: the near-field discharge, buoyancy-driven phase, and far-field passive transport. This study employs three-dimensional hydrodynamic and mud transport (MT) modeling to investigate far-field benthic and mid-water plume dispersion and its potential repercussions for deep-sea ecosystems. Near-field mid-water plumes were simulated using the integral jet model (Jirka, 2004), which resolves steady-state plume trajectories by balancing conservation equations for mass flux, momentum, salinity, temperature, and suspended sediment concentration amid ambient conditions. Benthic plume sources were parameterized via a dredger model, informed by sediment spill rates from the Polymetallic Collector Vehicle (PCV). To capture flocculation's influence on plume evolution, a population balance-based flocculation module was seamlessly integrated into the MT framework, enabling nuanced predictions of particle aggregation and settling dynamics.

Bio:

Dr. Gangfeng Ma is a Senior Coastal Scientist at DHI Water & Environment and global lead in RD&I focus area “water-resilient society”. Prior to joining DHI, Dr. Ma served as an Associate Professor in the Department of Civil and Environmental Engineering at Old Dominion University, where he specialized in coastal engineering, surface wave dynamics, hydrodynamic modeling, and sediment transport. He received his Ph.D. from the Center for Applied Coastal Research at the University of Delaware.