Presented at NZ Hydrological Society Technical Workshop 17-20 March 2020
Aerial image velocimetry with drones provides exciting capabilities for discharge gauging and physical habitat assessments in New Zealand rivers. AIV is well suited for braided river systems at low or high flows, where ADCPs can struggle due to blanking distances, or air entrainment and flow separation under the transducer. This talk covers techniques for drone deployments and data processing for single camera Large Scale Particle Image Velocimetry (LSPIV) that are suitable for flows with visible fixed reference points [i.e. low flows]. It then presents recent progress with the development of a stereoscopic camera system, which has been designed for flows with no visible reference points [i.e. large floods]. Finally, the talk presents progress with the development of a theoretical basis for surface velocity to depth averaged velocity conversions.
Hamish is an Ecohydraulics Scientist at NIWA. His research focuses on the development of novel remote sensing techniques and measurement systems. His areas of expertise include: aerial surveying with drones, sediment transport, remote sensing of vegetation, turbulence and flow vegetation interactions, programming and data analysis. His current projects are:
1. The ‘drone flow project’ which is developing new systems for remote sensing of flow in rivers and assessment of physical habitat;
2. The ‘rolling stones project’ which is investigating the transport of sediment in rivers during floods using in-situ ‘smart-stone’ sensors;
3. The ‘cyanobacteria aerial monitoring project’ which is investigating remote sensing of toxic cyanobacteria with multispectral and hyperspectral camera systems.