Characteristics of surface waters condition in the rivers of Lake Baikal basin according to specified parameters

Observations were carried out in twenty-five rivers: Rel, Tyya, Kichera, V. Angara, Tompuda, B. Sukhaya, Manturikha, Mysovka, Mishikha, Pereyemnaya, Snezhnaya, Vydrinaya, Khara-Murin, B. Osinovka, Solzan, Kharlakhta, Utulik, Bezymyannaya, Pokhabikha, Slyudyanka, Kultuchnaya, Goloustnaya, Buguldeyka, Anga and Sarma during the period from March to September. In the following rivers: Rel, Tyya, V. Angara, Kichera and Tompuda samples were taken once, while in the remaining rivers - from four to six times.

The average annual concentration of phenols exceeded the permissible limit by 1.5 – 2.0 times in the water of the following rivers: Goloustnaya, Buguldeyka, Sarma, Manturikha, Kultuchnaya; by 3.0 times – in Anga River. Maximum concentrations of phenols exceeded MPC by 2 to 4 times in the water of the following rivers: B. Sukhaya, Vydrinaya, Snezhnaya, Khara-Murin, Utulik, Mishikha, Pereyemnaya and Kultuchnaya. B. Osinovka, Pokhabikha, Slyudyanka, Bezymyannaya, Kharlakhta, Solzan, Anga; by 5 times - in water of Manturikha, Goloustnaya, Buguldeyka and Sarma rivers.

The content of organic substances as per COD in annual average values exceeded the permissible limit by 1.7 times in the water of Goloustnaya River; maximum excessive values were found in rivers: Goloustnaya – by 3.9 times, Kultuchnaya and Kharlakhta – by 3.0 times. The maximum content of organic substances as per BOD₅ exceeded MPC by 1.2 times in the water of Manturikha River.

Annual average concentration of nitrite nitrogen in the water of Mysovka River exceeded MPC by 1.4 times; maximum was equal to 6.1 MPC. The maximum content of oil products in the water of Anga River exceeded MPC by 1.6 times. Both average and maximum concentrations of other surveyed indicators (minerals, phosphates, sulphates, chlorides, nitrogen nitrate and ammonia) did not exceed MPC.

Compared to the previous year, the average content of phenols in the water of the following rivers: Goloustnaya, Buguldeyka, Sarma, Anga and Manturikha increased by 1.5-2.0 times; in the water of the rivers: B. Sukhaya, Mysovka, Utulik, Pereyemnaya, Kultuchnaya and Kharlakhta - decreased by 2.0 times. Compared to the previous year, the average concentration of organic substances as per COD in the water of rivers: Buguldeyka and Sarma increased 5.1 and 1.9 times respectively; it decreased in the rivers: Kultuchnaya and Anga by 1.1 and 2.6 times respectively. The average annual content of organic substances according to BOD₅ decreased in the water of rivers: Rel, Kichera, B. Sukhaya, Manturikha, Vydrinaya, Khara-Murin, Bezymyannaya and Solzan by 1.1-2.3 times. The average content of nitrite nitrogen increased in the water of Mysovka River by 27.0 times.

In 2015, the degree of water contamination according to the universal integrated water impurity index (UIWII) was evaluated in ten rivers. The water of Goloustnaya and Mysovka rivers was characterised as “slightly polluted” class 2, while water of the following rivers: Buguldeyka, Sarma, Sukhaya, Manturikha, Snezhnaya, Vydrinaya, Khara-Murin and Utulik was classified as “conditionally clean” and was estimated as 1 class. Compared to the previous year, the water quality in Buguldeyka River improved with the transition from the category “slightly polluted” to the category of “conditionally clean”, deteriorated in the Mysovka River with the transition from the category of “conditionally clean” to the category “slightly polluted”. Hydrochemical condition of water in Goloustnaya, Sarma, Sukhaya, Manturikha, Snezhnaya, Vydrinaya, Khara-Murin and Utulik rivers remained at the same level. 

Statistical data on quality of surface waters of Selenga River for 2012-2015 at the main-stream station, (mg/dm3)*

Note: * - FSBI «Buryatsky Center for hydrometeorology and environmental monitoring» branch of FSBI «Zabaikalsky Territorial Administration for Hydrometeorology and Environmental Monitoring» of Roshydromet.

red colour - excess of MPC.

Statistical data on quality of surface waters of Verkhnyaya Angara River for 2012-2015 at the main-stream station, (mg/dm3)*

Note: * - FSBI «Buryatsky Center for hydrometeorology and environmental monitoring» branch of FSBI «Zabaikalsky Territorial Administration for Hydrometeorology and Environmental Monitoring» of Roshydromet.

red colour - excess of MPC.

Statistical data on quality of surface waters of Tyya River for 2012-2015 at the main-stream station, (mg/dm3)*

Note: * - FSBI «Buryatsky Center for hydrometeorology and environmental monitoring» branch of FSBI «Zabaikalsky Territorial Administration for Hydrometeorology and Environmental Monitoring» of Roshydromet. 

red colour - excess of MPC.

Annual aqueous runoff received by Lake Baikal

The annual water inflow received by Lake Baikal in 2015 amounted to 15,756 m³/s (41,393 km³), estimated according to operational data.