Peculiarities of ecological risk assessment in oil technobiogeochemical provinces

PECULIARITIES OF ECOLOGICAL RISK ASSESSMENT IN OIL TECHNOBIOGEOCHEMICAL PROVINCES 

Oil exploration and transport are accompanied by degradation of natural ecosystems due to huge amounts of various pollutants, from salt solutions up to crude oil leakages. Furthermore, as usual the oil fields are being explored very intensively, for instance, the predominant region of oil exploration in the north of west Siberia includes about 100,000 boring wells. 

High mobility of oil and oil products leads to permanent redistribution of pollutants between different blocks of soils and grounds, and it continues until all of the oil leans away. This is accompanied by a variable distribution of oil in the soil, sometimes differing among contrasting blocks by 2 1 orders of magnitude (Table 1). 

The vertical distribution of oil products in a soil profile depends on the fluxes and ground level of soil-ground waters, which both temporally and spatially are very dynamic. In spite of being restricted due to low water solubility, migration of oil products with natural waters in the areas of oil pollution may significantly increase the distance of lateral pollutant transport with surface and sub-surface waters. 

Lateral migration of oil pollutants depends on the relief of the site where oil leakage took place. The distance of oil migration is determined by a combination of soil and ground characteristics, or in other words, by soil structure in the path of oil migration. 

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