Ivan Kirvel, Alexander Volchak and Sergey Parfomuk
As a result of the conducted investigations of the level fluctuations in lake naroch the initial data are divided into 3 components: a polynomial regression that makes it possible to find out an independent on time law of trajectory, a periodic component of sinusoidal type and a residual sequence of independent random quantities. Modeling of the trajectory fluctuations is based on the deterministic part, consisting of the regression of the 8th order and periodic component, and also the random part, consisting of independent equally distributed quantities. Using this model it can be modeled the trajectory of the level fluctuations in lake naroch. The modeled trajectory by 200 years long demonstrated the probability of exceeding of maximum annual level, equal 1 per cent.
The research results of runoff changes in the River Viliya at 3 stations (Steshitsy Village, Vileyka Town and Mihalishki village) during the period 1946–2014 for the average annual, maximum, minimum summer-autumn and winter runoff are presented. It has been concluded that heterogeneity in the time series of the river runoff is caused by natural-climatic and anthropogenic factors. At Mihalishki Village the average annual runoff is about 59.7 m3 s–1, the maximum 1570 m3 s–1, minimum summer–autumn is 22.0 m3 s–1, the minimum winter runoff is 17.3 m3 s–1, and the environmental runoff is 21.1 m3 s–1. A forecast of runoff changes for the River Viliya, depending on forecasted climate change using the “Atlas of Global and Regional Climate Projections” was made on the basis of four scenarios RCP8.5, RCP6.0, RCP4.5, RCP2.6. The results of research indicate that significant changes in runoff will not occur as the forecasted climatic parameters did not change significantly. A forecasted decrease in spring runoff was investigated, thus reducing the minimum runoff is not essential. In the event of possible low water periods the Vileyka reservoir resources, involving the Olkhovskoye and the Snigyanskoye water reservoirs, can be used for compensation measures, which may be considered as the most reliable backup source of industrial water supply for the Belarusian Nuclear Power Plant.
Alexander A. Volchek, Ivan Kirvel, Sergey Parfomuk and Roza Makhambetova
The optimal number of hydrological monitoring stations for the annual values, the maximum spring, the minimum summerautumn and the minimum winter river runoff in Belarus is determined. The research on optimization of the hydrological network of Belarus led to a conclusion about the optimum number of hydrological stations in the country, but in the case of observing the values of the annual runoff, the number of the existing plants is the minimum necessary, and reducing their number is inadmissible. On the basis of trends in air temperature changes, precipitation and humidity deficits from 1985 to 2009, the forecasts of these parameters are prepared until 2020. Taking into account the models of climatic parameter change, a possible change in the water regime of the rivers in the future is investigated.