Abstract
We demonstrate that river discharge can be estimated by combining satellite-derived video imagery, alongside non-contact velocity estimation techniques and high-resolution topography. Large Scale Particle Image Velocimetry (LSPIV) was used to derive surface velocity maps from 28 s of 5 Hz satellite video acquired at a nominal ground sampling distance of 1.2 m over the Darling River, Tilpa, Australia during a 1-in-5-year flood event. We quantified the sensitivity of LSPIV to varied parametrizations when retrieving surface velocity, and validated LSPIV velocities against 2D hydrodynamic model simulations. Discharge was computed using classical velocity-area techniques. Our results demonstrate accurate inference of discharge (Q ) with deviations ranging from 0.3 – 15% from gauging station observations. Precision of Q is influenced by the choice of a surface velocity depth-averaging coefficient (α ), used in LSPIV. Satellite video presents a compelling advance for space-based flow velocity and discharge measurement, especially during flood events, and at ungauged locations.