Author(s): Donatella Termini; Peyman Peykani
Linked Author(s): Donatella Termini
Keywords: DCP measurements; Flow velocity distribution; Image-based technique; River monitoring
Abstract: In the context of climate change, the knowledge of flow discharge is of crucial importance. Flow discharge is not a direct measurement but is estimated on the basis of information of flow velocity and cross-sectional flow area. Thus, accurate flow velocity measurement is critical for defining early warning systems for flood management and for quick decision-making for emergency actions. In recent years, the acoustic Doppler current profiler (ADCP) has been especially used to measure flow velocity profiles and to estimate flow discharge, in natural and man-made waterways. But, during flood events, the operating conditions are not safe due to continuously changing velocities, water depths, and the presence of high sediment concentrations. As consequence, in high flow conditions, measurement equipments like current meters and/or more advanced instruments such as ADCP cannot be used. For this reason, in the last decade, an alternative approach based on image-based techniques has been increasingly used to obtain the spatial distribution of the surface velocity, from which the flow discharge might be estimated. Several software tools have been also implemented for the image-based technique application. In comparison to the traditional measurement methods, the image-based technique presents the advantage to be non-intrusive allowing the safe estimation of surface velocity distribution also during floods. One of challenges in the application of image techniques is determining the error in estimating surface velocity, whose quantification depends on many factors characterizing not only the measurement conditions but also the processing method used. In this study, the efficiency of the digital image-technique for remote monitoring of surface velocity is analyzed. The analysis is conducted by using accurate ADCP flow velocity measurements in selected Sicilian (Italy) river reaches.
DOI: https://doi.org/10.3850/iahr-hic2483430201-252
Year: 2024