Modelling summer water temperature on the Yenisei River

Abstract

A summertime hydrothermal regime of the Yenisei River downstream of the Krasnoyarsk hydroelectric power plant is modeled based on a deterministic approach. To that end, the Fourier equation is used and the following physical processes contributing to the heat exchange between water and the surroundings are taken into consideration: absorption of direct and scattered solar radiation by water, absorption of downwelling thermal infrared radiation from the atmosphere by water surface, thermal infrared radiation back from the water surface, convection of heat and heat loss due to evaporation of water. A clear-skies river thermal regime under no wind is studied in a 124-km stream reach below the power plant and the obtained results are compared against temperatures recorded at gauging stations.