A Deterministic-Stochastic Modeling of Mass Transfer in the Catchment-Reservoir System

Kondratyev S. A., Shmakova M. V

A deterministic-stochastic modeling system describing mass transfer in the catchment-reservoir system is developed. The components of the system are a stochastic weather model, a runoff model in the catchment area, a model for the removal of dissolved impurities in catchment that form an external load on the reservoir, a model for assessment the annual solid flow of rivers, and a hydrodynamic model of flows and impurity transport in the reservoir. Currently, the modeling system is effectively used in solving problems of assessment of abiotic processes in the catchment- reservoir system in the conditions of a lack of field observations, as well as forecasting the impact of possible climate changes on the studied water bodies. In the lack of field observations data, the stochastic weather model is used as a generator of long series of meteorological parameters (precipitation and air temperature). The obtained series are entered in deterministic models, and the result of the simulation is not only the values of required quantities, but also the parameters of their distribution function. Also, the distribution functions of the solid runoff and the characteristics of mass transfer in the water area are calculated for different situations formed by extreme weather conditions. In task of assessing the impact of possible climate changes on the studied processes, predicted values of precipitation and air temperature are determined at the end of the forecast. These values are entered in the stochastic weather model instead of the current values, and the predicted series of input data for deterministic models are generated. The result of modelling is a distribution functions of required quantities at the end of the climate forecast.

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