Horizontal Channel Erosion on the Rivers of Udmurtia

The results of a study of channel displacement for 2000–2022 in 55 key areas located on rivers of different orders, flowing in different landscapes of Udmurtia, are presented. The erosion rates were determined using benchmarks and tacheometric survey. To analyze the obtained results, the rivers were divided into 4 groups according to the magnitude of their orders (according to the method of A. Scheidegger). Maximum erosion is typical for rivers with an order higher than 14 (up to 15 m/year), for medium rivers with an order of 9–14 these values are 6–8 m/year. For small rivers with an order of 6–9, the maximum erosion reached 5.5 m/year, and for very small rivers (of order 6 or less), respectively, up to 4.2 m/ year under natural conditions and up to 8.1 m/year at man-made intervention. Statistical indicators of the average annual and maximum erosion in the reference areas for the period under consideration were obtained. Correlation analysis showed a high significant relationship between the erosion rate and the order of the river and, accordingly, the average annual and maximum discharges. An analysis of erosion over a 23-year time interval is given with the definition of the trend equation for the selected groups of rivers.