Application of close-range remote sensing for automatic identification of ice jams in rivers in the area of the inlet to the fishway

Ice phenomena in watercourses and channels pose a threat to flow continuity and hydrotechnical devices. The organoleptic method, relying on human observation, has limitations such as a narrow range, subjective assessment, and high effort, leading to its decline in use. This article presents a number of modern techniques, i.e., the interpretation of RGB images, using unmanned aerial vehicles. Drone imagery offers a bird’s-eye view of areas that would otherwise be difficult to survey. It can improve the detection of frazil ice jams and, thus, contribute to the monitoring and spread of frazil ice. The authors performed research in the area of the Wrocław Water Junction on the Odra River in the area of the inlet near the fish pass at the Opatowice Weir during the flow of frazil ice on the water surface. To observe the phenomenon, a UAV with an RGB camera was used to record video in an orthogonal perspective in order to reduce geometric distortions of the optical system. The center of the frame was used for the analysis. The presented research results and the recognition of the literature indicate the possibility of using the presented technique for early detection of a potential threat from emerging ice phenomena. The results of the conducted analyses are objectively compared to the observational technique used at observation stations and allow for a reliable comparison of the intensity of ice phenomena in selected periods.

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Opracowanie rekordu ze środków MNiSW, umowa nr SONP/SP/546092/2022 w ramach programu "Społeczna odpowiedzialność nauki" - moduł: Popularyzacja nauki i promocja sportu (2024).