Application of Image Technique to Obtain Surface Velocity and Bed Elevation in Open-Channel Flow

The frequency of droughts and floods is increasing due to the extreme climate. Therefore, water resource planning, allocation, disaster prevention have become increasingly important. One most important kinds hydrological data in resources planning management discharge. general way measure depth discharge use Acoustic Doppler Current Profiler (ADCP), a semi-intrusive instrument. This method would involve many human pose severe hazards by events. In recent years, it has mainstream with nonintrusive methods such as Large-Scale Particle Image Velocimetry (LSPIV), which used surface velocity rivers estimate However, unknown an obstacle for this technique. study, combined LSPIV bathymetry was proposed. experiments combining technique continuity equation obtain bed elevation were conducted 27 m long 1 wide flume. flow conditions ensured be within uniform subcritical flow, thermoplastic rubber particles tracking measurement. two-dimensional estimated from depth-averaged leapfrog scheme predefined grid under constraints Courant–Friedrichs–Lewy (CFL). results verified using (ADV) measurements, study conventional point gauge measurements. indicate that proposed effectively variation elevation, especially shallow level, average accuracy 90.8%. experimental also showed feasible combine imaging numerical calculation solving elevation.