The purpose of the study was to study the general regularities of radon emanations and the deviation of physical and chemical characteristics in the underground waters of the Southern Baikal region. Measurements of volumetric activity of radon were made on the radiometer PPA-01M-03, physical and chemical characteristics, which were measured on Hanna HI 98129 Combo express analyzer. In addition to Q parameters and physical and chemical characteristics, seismic and meteorological data also analized for sampling days on the studied area. Reconnaissance testing of several dozens of groundwater sources located within the Southern Baikal region, to allows to organize the monitoring investigations on a series of water points. The sampling network consists of 8 ground water sources in Irkutsk and on the right (northern) bank of the Irkutsk reservoir. For which site every two weeks physical and chemical parameters of groundwater (including radon concentration) were determined, as well as meteorological and seismic activity in the region. Analysis of the database, including measurements of a set of parameters for six years (2012–2018), allows to make the following conclusions. 1. According to radioactivity, the ground water sources studied in the Southern Baikal region are divided into three groups (the 1-st mean radon concentration is about 15 Bq / l, the second one has the average radon concentration of about 30 Bq / l and the third group has the average radon concentration ≈ 60 Bq / l), which, apparently, is determined with the conditions of recharge and groundwater formation. The change of Q during the monitoring period is 30-60 % of the average value of this parameter in the tested source. 2. According to physical characteristics, groundwaters studied in monitoring period are generally classified as cold and neutral with rigidity varying from «soft» to «very hard» in different sources. Absolute limits of changes in the parameters variations are characterized by the following values: water temperature from 1,7 to 12 °C, i. е. Δ ≈ 42,88 % of the average water temperature in the source; hydrogen index from 7 to 9,9, Δ ≈ 10 % of the average value; conductivity index from 43 to 412 μS / cm, Δ ≈ 18,52 % of the average value; hardness from 85 to 833 Ppm, Δ ≈ 14,08 % of the average value; the flow rate from total absence of flow to 140 l / min, Δ ≈ 87,82 % of the average value. 3. Comparison of the monitoring schedules of the complex of the parameters showed showed that the radioactivity of groundwater, like most of the indicators studied, is largely determined by the climatic conditions of the Southern Baikal region. In this respect, the analyzed indicators are divided into three groups. For one of them the values are maximal in the cold months of the year (the amount of dissolved radon, the hydrogen index of water and atmospheric pressure). The parameters of the other group have the opposite view (water temperature and flow rate of water sources, temperature and humidity of air). A feature of the parameters from the third group (hardness and electric conductivity of water, as well as the index of seismic activity) is that their fluctuations do not show significant dependence on the period of the year, but they differ by good intragroup convergence.

Seminsky Aleksandr Konstantinovich, Postgraduate, Senior Laboratory Assistant, Institute of the Earth's Crust SB RAS, 128, Lermontov st., Irkutsk, 664033, Russian Federation, tel.: (3952) 42-30-27, e-mail: zzzsancheszzz@gmail.com 

Seminsky Konstantin Zhanovich, Doctor of Sciences (Geology and Mineralogy), Head, Laboratories of Tectonophysics, Institute of the Earth's Crust SB RAS, 128, Lermontov st., Irkutsk, 664033, Russian Federation, tel.: (3952) 42-30-27, Scientific Center SB RAS, 134, Lermontov st., Irkutsk, 664033, Russian Federation, e-mail: seminsky@crust.irk.ru

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