ASSESSMENT OF EVAPORATION IMPACT ON RESERVOIR OPERATION REGIME

Abstract

The article presents a review of studies into the process of evaporation from a reservoir bowl and its calculation, which is considered as one of the elements that greatly affects water balance in reservoirs. Reservoirs play an important role in water resource management, however losses of water from a reservoir create uncertainties in water accounting. Therefore, effective management of water resources as well as accurate calculation of the amount of water lost through evaporation, taking into account parameters of the object and climatic conditions, is deemed to be one of the urgent tasks nowadays. It is known that evaporation in reservoirs depends on several factors: maximum volume of water and its area, air temperature, wind speed in a given area and the number of plants in the reservoir bowl. Taking into account a sharp increase in the air temperature and the effects of wind, the evaporation process was subject for studies in April, May and June in 2018 and 2022. The research made use of the data retrieved from field observations and measurements, as well as of empirical formulas proposed by scientists B.D. Zaikov, A.Z. Braslavsky and P.A. Vikulina.
According to calculations made with B.D. Zaikov’s formula, in April, at high water levels, the average amount of evaporation increased from E0 = 159.7 mm to E0= 168 mm. According to findings achieved with formulas by A.Z. Braslavsky and P.A. Vikulina, this indicator increased from Ev = 225.8 mm to Ev = 243.6 mm.
Analyzes have shown that the amount of evaporation in reservoirs keeps growing from year to year, which causes a change in the hydrological regime of reservoirs.
The research concluded that increased evaporation is being caused by changing climatic conditions and rising air temperatures