DischargeProcessing Non-intrusive and safe optical flow measurement for rivers, overland flows and flooding events • • • • Camera-based measurement of water level, surface velocity and discharge on demand Analysis of movie material acquired with smartphones, cameras or drones Detailed hydrodynamic study of surface velocity A posteriori analysis of videos recorded during overland flows or flood events C13_DischargeProcessing_e_S1_4 29.06

DischargeProcessing With the use of image processing technology, detailed analyses and reports about water level detection, surface flow velocities, vertical velocity calculations and discharge are possible. This allows to post-process flood events if video footage obtained by smartphones, surveillance cameras or drones is available or to address specific hydrodynamic questions for which exact water level or surface velocity measurements are important (e.g. scouring processes, flow in fish ladders, calibration of existing water level sensors). 1. Detailed surface velocity in meters per second...

References B. Post-processing of a flood event recorded by a surveillance camera Analysis of video footage acquired with a surveillance camera mounted on a pole near to a bridge. The water level is detected on a pillar of the bridge, the velocity is measured on the upstream portion of the bridge. Flow rate calculations are then performed combining this information. Surface velocity field measured during a flood event. Water level detected optically under night conditions. Water level detected under day light conditions, during a flood event. C. Surface velocity analysis for a fish behaviour study...

References D. Water level and surface velocity measurements with images acquired by drones Measured surface velocity field Drone during the video recording. Recommendation for the movie recordings • Do not move during the movie recording. HD resolution and at least 25 fps are required. An optimal measurement quality can be obtained when the water course stretches over as much of the field of view as possible. Any recording can be processed after the event, if the place of recording can be visited to measure: - 6 ground control points - the approximate camera position while recording The right...