ОЦІНКА ЗАРЕГУЛЬОВАНОСТІ СТОКУ РІЧКИ СЕРЕТ

Abstract

The Seret River is a 242 km long left tributary of the Dniester, flowing within the Ternopil region. The basin covers an area of 3900 km2, a river slope of 0,9 and a river network density of 2,44 km2/km. The average long-term water discharge in the river is 12,1 m3/s, the water turbidity is 100-200 g/m3 and the salinity is 350-550 mg/dm3. There are 8 small hydropower plants on the river with a total capacity of 21,57 MW. The aim of the study is to assess the regulated flow of the Seret River and determine the amount of siltation in the reservoirs in its channel. The study found that 8 reservoirs have been created on the Seret River, with a total water surface area of 21 km2 and a total volume of 57,4 million m3. The Seret River is one of the most heavily regulated rivers in the Western Podillia. The Seret River basin contains 30% of all reservoirs in the Ternopil region. The upper reaches of the river are the most regulated, with 5 reservoirs with a total volume of about 33 million m3 and a usable volume of 25 million m3. According to the results of the calculations, it was found that the coefficient of flow regulation of the Seret River is 0,17; the degree of flow regulation is 0,25. The volume weight of sediment in the Seret River is 0,79 t/m3. It was found that the river transports about 57 thousand tonnes of sediment per year. Over the estimated period of operation (40 years), 3 million m3 of sediment will accumulate in the Seret River reservoirs. The siltation of Ternopil reservoir is 3,5 %, Vertelivske – 5 %, Zalozhtsivske – 10 %, Verkhnya Ivachyvka – 58 %, Bilche-Zolotetske – 65 %, Skorodynske – 75 %. Based on the results obtained, it can be concluded that the Seret River is undergoing significant anthropogenic pressure, and there are risks of degradation of the watercourse and a decrease in the energy potential of the reservoirs in the middle and lower reaches of the river. Therefore, there is a need to develop scientifically based measures to optimise nature management and renaturalise the Seret River basin and valley.