Modern dynamics of water levels and their flood rises in the upper reaches of the Prut River within the Chornohora Landscape (Ukrainian Carpathian)

Abstract

This article presents the results of the analysis of modern water levels of the upper reaches of the largest river named Prut in the mountain landscape of Chornohora for the period from 2010 to 2019, based on data from own long-term hydro-meteorological observations on the basis of Landscape Monitoring Laboratory of Ivan Franko National University. The studied river is characterized by a dense river network, a peculiar hydrological regime and periodic formation of heavy floods, as well as the presence in its basin of valuable landscape complexes and environmental facilities, high landscape diversity and recreational and tourist potential, which determines the relevance of this study. As a result of the study, the peculiarities of the formation and modern features of the hydro network of the Prut river basin were established, its heterogeneity in the mid-mountain and high-mountain landscape tiers was characterized. It is established that during the period 2010-2019 in the upper reaches of the Prut River there was an increase in river water levels, as well as identified the main factors and their impact on current changes in the hydrological regime of the river. The annual changes in the water level in the upper reaches of the Prut River for the period 2010-2019 were also analyzed and it was found that its mountainous nature causes high dynamics of river water levels at different times of the year and in certain months. It was important to identify the relationships between their indicators and the characteristics of the annual distribution of precipitation and snowmelt during studying the annual cycles of water level fluctuations. Particular attention is paid to the study of the formation and spread of floods as the most dangerous hydrological phenomenon of the upper reaches of the Prut River, characterized by a sharp rise in water levels, high erosion capacity, etc. The study found that more than 75 % of floods occur during the spring snowmelt in April and May where the average daily river water levels usually do not exceed 60-70 cm. The analysis of flood rises in terms of years and months shows that the most severe catastrophic floods are formed in November-December due to heavy rains, which cause the formation of powerful destructive water flows and catastrophic growth of river water levels over 90-100 cm. The total annual number of flood rises in the Prut River was also analyzed according to certain categories of indicators (over 60 cm, 70 cm, etc.) and it was found that the total number of floods in the upper reaches of the river is increasing.