UAVs for Hydrologic Scopes: Application of a Low-Cost UAV to Estimate Surface Water Velocity by Using Three Different Image-Based Methods

摘要

Stream velocity and flow are very important parameters that must be measured accuratelyto develop effective water resource management plans. There are various methods and tools tomeasure the velocity but, nowadays, image-based methods are a promising alternative that doesnot require physical contact with the water body. The current study describes the application of alow cost unmanned aerial vehicle that was selected in order to capture a video over a specific reachof Aggitis River in Greece. The captured frames were analyzed by three different software (PIVlab,PTVlab, and KU-STIV) in order to estimate accurately the surface water velocity. These three softwarealso represent three different image-based methodologies. Although there are differences amongthese three methods, the analysis produced similar trends for all. The velocity ranged between 0.02and 3.98 m/s for PIVlab, 0.12 and 3.44 m/s for PTVlab, and 0.04 and 3.99 m/s for KU-STIV software.There were parts, especially in the existing vegetation, where differences were observed. Furtherapplications will be examined in the same or different reaches, to study the parameters affecting theanalysis. Finally, the image-based methods will be coupled with verification measurements by acurrent meter to produce more rigorous results.