Temporal Variability of River Inflow to the Lake Baikal and Reservoirs of the Angara Cascade of HPS

Main properties of long-term and seasonal fluctuations of runoff are studied based on the prolonged observation of the inflow to reservoirs of the Angarsk cascade of HPS. Statistical characteristics (parameters of distributions) of seasonal and annual inflow are estimated. The analysis of sequence of annual inflow to the Lake Baikal led to the conclusion about heterogeneity of the long-term fluctuations. It is shown that spatial variability of runoff value in the studied region, which is high, is defined by differences in conditions of the hydrological regime formation. This variability is expressed as the matrix of pair correlations characterized by small values. With the inflow to the Lake Baikal as an example, the parameters of a seasonal inflow for two uniform periods providing a possibility of stochastic modeling of the inflow with a discretization interval one month are estimated. For the months with negative values of an inflow, the application of the IV-type distribution of Pearson is recommended. The results received in the work are intended for the solution of the optimum control of the Angarsk reservoir cascade problems.