Speaker: Evan Heberlein, Postdoctoral Associate, DeFrees Hydraulics Laboratory, School of Civil & Environmental Engineering, Cornell University

Topic: Measuring tidal flows to support estuarine restoration using infrared quantitative image velocimetry

The Herring River Estuary at Cape Cod National Seashore in Massachusetts was diked over a century ago, severely restricting tidal exchange with dramatic ecological and biogeochemical consequences in this ecosystem's former salt marshes. A $60 million federal restoration project is underway to replace this dike with adjustable tide gates, enabling controlled reintroduction of tidal inundation. During construction of these tide gates, a winter storm's large waves in Cape Cod Bay breached a dune barrier into the upper estuary, creating a secondary channel for seawater to enter the system during high tide overwash events which have accelerated and complicated tidal restoration. During my PhD, I conducted two field campaigns to measure tidal flow through the former dike and the overwash breach using a near-field remote sensing method called infrared quantitative image velocimetry (IR-QIV). This method uses an infrared camera to derive a surface velocity field by tracking subtle thermal patterns on the surface of flowing water. My research leverages IR-QIV measurements of coastal hydrodynamics to derive rating curves for tidal flow rate and invert bathymetry in tidal channels, with direct applications to ongoing restoration efforts in the Herring River Estuary.