Savichev O.G., Guseva N.V, Abdullaev B.D. Water balance of the Shira Itkul lake system (Khakassia)

Written by Erkin Turdibaev

Thursday, 17 March 2016

Shira and Itkul lakes (the lake water surface areas are 35.90 and 23.25 km 2 respectively) are located in the steppe zone in Kha-kassia (Russian Federation). The distance between lakes is 3 to 4 km. The conditions of water resource formation for both reservoirs are similar. However, the salinity of Shira Lake is 12-30 g/kg, the salinity of Itkul Lake is less than 1 g/kg. The mathematical model of lake water balance formation on the average for the long-term period was developed for an explanation of these differences. The evaporation from the catchment surfaces at the snow cover presence was calculated using the P.P. Kuzin method. The M.I.Budyko method was used in case of snow cover absence. The evaporation from water surfaces was estimated using the turbulent diffusion method (depending on the wind velocity and humidity deficit). The catchment moistening was calculated as the sum of liquid atmospheric precipitation and snow melt. The annual water redistribution is considered due to the formation and melting of the seasonal ice cover. The Son River flow into Shira Lake was determined using long-term observation data delivered by the Russian Federal Hydrometeorology and Environmental Monitoring Service (Roshydromet). The Karysh River flow into Itkul Lake was estimated according to the annual mean discharge, which is 1.6 L/(sDkm 2). The annual mean discharge was calculated as the mean value of the Son River flow (at the point near village Spirinskaya Zaimka) and the Tuim River flow (at the point near village Tuim). The ground-water inflow to the lakes corresponds to the groundwater discharge into rivers (the Son River for Lake Shira and the Karysh River for Lake Itkul). The groundwater discharge corresponds to the river flows from December to February. From March till November it is defined by linear interpolation between the values for February and December. Wastewater dump in Shira Lake corresponds to the water drawoff from Itkul Lake. The annual change of the volume of waters of Shira Lake is calculated according to the Roshydromet data about average monthly lake water levels. The difference between water inflow and outflow in Shira Lake is determined. This difference as a whole for one year can be considered as groundwater inflow. Its average volume is 6791,000 m 3/year (the calculation error is 5433,000-8149,000 m 3/year). The groundwater inflow is possible from Itkul Lake, the water level in which is 100 m higher than that in Shira Lake. Thus the average groundwater velocity is 0.041 m/day, and the value of hydraulic conductivity is 1.391 m/day. Thus, these lakes are connected (hydraulic connection). Itkul Lake can be considered as the drainage lake. Only Shira Lake can be considered as a reservoir without a water flow. The mechanism of its water salinity formation is determined, first of all, by evaporation of water. Itkul Lake is characterized by more active water exchange in comparison with Shira Lake. Therefore, evaporation from its water surface in June-July does not result in the high salinity like in Shira Lake. Besides, little time of water-sediment interaction is observed. Download (in Russian) (pdf, 434 kB) Source: http://cyberleninka.ru/

 

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