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Processes of distribution and deposition of hexavalent chrome,manganese and copper oxide in Southern Baikal were studied with a non-stationary spatial Eulerian model taking into account the influence of the relief.Industrial enterprises and complexes situated in valleys of the Angara and Selenga Rivers,on Lakes Baikal and Gusinoye coasts were emission sources.Meteorological information was obtained by statistical treatment of measurement data from hydrometeorological stations.Numerical experiments were carried out at the site with area of 500 ?250 km2 and 5 km high over Lake Baikal.Intervals within time and horizontal line were 150 sec and 5 km,respectively.The vertical interval was determined as follows: it was 50 m up to the height of 300 m above Baikal level and then 200,1000,1500 and 2000 m.Coefficients of turbulent diffusion were calculated with ratio of semi-empirical theory of turbulence.The density of deposition of these toxicants in the region under observation was estimated at each time interval from each source separately and during their joint action.The amount of studied heavy metals deposited onto the surface of Southern Baikal with the area of 9000 km2 per year was determined.The highest values of heavy metal fluxes were detected in the vicinity of the main emission sources located in valleys of the Angara and Selenga River.There were carried out two series of numerical experiments on estimation of relief impact on the deposition of heavy metals in Southern Baikal.Mountainous ridges(Primorsky,Baikalsky,Khamar-Daban and others)surrounding the lake appeared to significantly influence the transfer of heavy metals.The amount of these toxicants would precipitate onto Southern Baikal by 30%more without the relief than with the relief.Calculations and estimations showed that Irkutsk enterprises were the main source of pollution of Southern Baikal by Cr and Mn: 74 and 60%,respectively,while by Shelekhov enterprises – 17 and 21%,respectively.Emission sources of Shelekhov contributed the highest amount of CuO to the pollution of Southern Baikal – 72%.The Irkutsk impact is rather less(20%).