Changes in local climate in the neighbourhood of the Ust-Ilimsk water reservoir on the Angara, Russia

Abstract

The paper presents results of investigations on microclimate over one of the largest artificial water reservoirs in the world - Ust-Ilimsk on the Angara in Russia. It is located in the western edge of the Central Siberian Upland in the northern part of Irkutsk Oblast. The area of reservoir at a normal level of water damming (296 m a.s.l.) amounts to 1873 km2, the capacity of stored water - 59,4 km3, and the shoreline length is equal to 2384 km. The evaluation of the influence of the water reservoir on local climate was based on the analysis of data collected over many years measurements of a series of particular elements of the climate and carried out in the direct neighbourhood of the reservoir before (1936-1975) and after its construction in 1977. From the research the results show that the Ust-Ilimsk water reservoir distinctly influences the local climate of adjacent areas. The differences are mostly connected with the increase in total radiation and changes in the radiation balance of the reservoir, and the larger heat capacity of the water mass in comparison to land. As data from meteorological stations indicate, the climate in the neighbourhood of this water reservoir gains many new features and generally becomes milder. The average annual increase in air temperature over the reservoir shores reached 1.3°C, whereas with in land it was only 0.4°C. At every meteorological station (inshore and continental), in the summer period and during the whole year as well, the average sum precipitation decreased by 7-14%. In the winter, when polynya exist, the number of days with fogs increases over the reservoir. Fogs in the shore zone of the Ust-Ilimsk reservoir delay the coming of frosts by 1-2 weeks.

Examining the Effects of Hydropower Station Construction on the Surface Temperature of the Jinsha River Dry-Hot Valley at Different Seasons

“…Tashlykova et al presented the results of a microclimate survey of the Us-Ilimsk reservoir in Angara, Russia, one of the largest man-made reservoirs in the world. The results showed that the reservoir could affect the temperature in the surrounding area, making the neighboring weather more temperate [47]. As temperatures in the neighboring areas approached the reservoir temperature, the temperature became more moderate.…”

The influence of water level fluctuations in the Ust-Ilimsk water reservoir in Russia on the action of some geological processes

“…The total area of the reservoir up to the height of its normal damming level (296 m a.s.l. in the Baltic system) amounts to 1873 km 2 , the water capacity is equal to 59.4 km 3 (TASHLYKOVA, 2013a). The mаximum depth of the reservoir at the dam in Ust-Ilimsk exceeds 90 m; water damming is observed on the Angara river up to the dam of hydroelectric power station in Bratsk and reaches up to 304 km, whereas on the Ilim river -302 km (UST-ILIMSKOYE VODOKHRANILISHCHE, 1975;SAVEL'YEV, 2000).…”

“…The Ust-Ilimsk water reservoir is an anthropogenic object with comprehensive functions, but its formation disturbed the balance in the nature, which has resulted in the modification of the microclimatic and geological-engineering conditions, and also the underground water regime of flooding and soil swamping occurring in the zone of its influence (TASHLYKOVA, 2007c(TASHLYKOVA, , 2013a. The formation of the reservoir caused the development of new relief-shaping processes.…”

“…The building of anthropogenic water reservoirs, especially the largest ones, causes a significant interference in their environment (VICULINA & SELJUK, 1966;BARDACH & DUSSART, 1973;DIXON ET AL., 1989;MCCARTNEY ET AL., 2001; DEGU TASHLYKOVA, 2007aTASHLYKOVA, , 2013a. Man-made water reservoirs are natural-technical water objects, which despite being controlled by man, develop as natural water reservoirs.…”

Comparative Study on Temperature Response of Hydropower Development in the Dry‐Hot Valley

“…Previous studies indicate that the influence of dams on the temperatures of the areas surrounding the reservoir depend on the study area and the dam specifications. (Tashlykova, 2013;Wang, W. et al, 2012;Xiong et al, 2020). Song et al (2017) analyzed the temperatures in the downstream area of the Three Gorges Reservoir and found that the surface temperatures decreased during the day in the summer and increased at night in the winter.…”