Student Daily Digest

 

Abstract: This seminar synthesizes a series of modeling-based studies in fluvial geomorphology that examine how meandering rivers reorganize channel beds, build bars, erode banks, and evolve bends through coupled flow and sediment transport. The studies develop and apply process-based computational tools that (i) generate physically consistent synthetic riverbed topography for constant-width meanders to support bathymetry interpolation, laboratory design, and model initialization; (ii) resolve meander-neck cutoff as a fully coupled morphodynamic event across laboratory and large-river scales, quantifying transient erosion–deposition patterns and sediment redistribution during rapid planform reconfiguration; and (iii) augment deterministic hydrodynamic–morphodynamic solvers with stochastic bank-erosion formulations to represent material heterogeneity and episodic failures, enabling ensemble predictions of migration trajectories and erosion risk under uncertainty. Model behavior is evaluated against high-resolution field and experimental measurements of channel and point-bar morphology (e.g., multibeam sonar and structure-from-motion products) to constrain relationships among curvature, bed relief, transverse slope, and migration metrics. Across these studies, modeling frameworks emphasize mass conservation, feedbacks among hydraulics, sediment fluxes, and evolving topography, explicit representation of scale effects, and uncertainty quantification. The seminar concludes with analytical and reduced-complexity modeling that links channel geometry and vegetation-mediated roughness or coarsening to equilibrium meander form and long-term evolution, including the role of cutoff-driven adjustment with implications for river management, restoration design, and geomorphic hazard assessment.

 

Bio: Dr. Zhi Li is a computational hydrologist and Assistant Professor in the School of Civil & Environmental Engineering at UConn, where he leads the Environmental Flow Computing Lab. Prior to joining UConn in 2025, he worked at Pacific Northwest National Laboratory (PNNL) from 2022 to 2025. He earned his Ph.D. in Water Resources Engineering & Science from the Ven Te Chow Hydrosystems Lab at the University of Illinois Urbana-Champaign, an M.S. in Environmental Engineering from Michigan State University, and a B.S. in Geology from Nanjing University. Dr. Li develops and applies advanced hydraulic, hydrologic, geomorphological, and biogeochemical models for watershed, coastal, and ecosystem science and engineering. He also has extensive experience with numerical modeling tools and high-performance computing (HPC) to tackle complex, real-world environmental and engineering challenges.