CHANNEL PROCESSES OF THE CHEREMOSH RIVER WITHIN THE UKRAINIAN CARPATHIANS UNDER NATURAL CONDITIONS

Abstract

This article presents the results of a comprehensive study of natural channel processes of the Cheremosh River within the mountainous part of the Ukrainian Carpathians. The relevance of the study stems from the insufficient understanding of channel processes in this river, as well as the need to generalize patterns governing the functioning of mountain river systems. The aim of the research is to identify the key parameters of the flow–channel system of the Cheremosh River under its active state and to establish the main regularities of its natural channel processes. The methodological framework is based on hydromorphological analysis, which involves tracing spatial changes in the structure and functioning of the flow–channel system, taking into account valley morphology, hydrological characteristics, and flood impacts. The study is based on cartographic materials from different periods, remote sensing data, field observations, and hydrological records, including data related to the catastrophic flood of 2008. The results indicate that the most characteristic features of the Cheremosh River channel processes are channel branching with the formation of anabranches and mid-channel bars, as well as forced meanders associated with valley constrictions. These forms alternate along the river course, forming a regular spatial pattern controlled by geomorphological and tectonic factors. Flow parameters during flood events, including velocity, depth, discharge, and water level amplitude, were analyzed to assess the intensity of channel processes. The calculation of dimensionless hydraulic indices (Froude and Glushkov numbers, and the sediment mobility parameter) indicates the predominance of supercritical flow conditions and a high degree of channel dynamics. The river channel in the mountainous section is classified as a structural-alluvial type, specifically as a bedrock-controlled structural-alluvial channel. It is shown that the formation of major channel features occurs mainly during the falling stage of floods or during smaller flood events. The findings contribute to a better understanding of channel processes in mountain rivers of the Ukrainian Carpathians and can be applied in further hydromorphological research, as well as in addressing practical issues of sustainable river management and environmental management.