Criteria for ecological estimation of the geological environment under the influence of oil products
The purpose of this work is to choose the main criteria for the estimation of sustainability of the geological environment to pollution by oil products. The purpose of this work is very important because the territory of Tomsk (for 2013) has 119 oil-stations and, as a result, we have a problem of estimation of the conditions of the geological environment change under the influence of oil products. A complex review of this problem, including identification and study of the factors defining the nature of pollution of the geological environment by oil products, is represented as very important. To estimate sustainability of the geological environment, the following algorithm was used: initially we classify types of the structure of the geological environment of the territory, and then identify, estimate and make forecast of changes in this system. As a result, we classify soils of the territory of Tomsk, which was subsequently used as a basis for territory division into districts by the degree of sustainability of the geological environment to oil product pollution. The main criteria for classifying soil with a thickness of ~20 m are the petrographic structure of soils and type of oil product distribution in them. The mapping of types of soil thicknesses is executed on the basis of the analysis of engineering-geological maps of Tomsk conditions of scales 1:25000 and 1:10000, geological data of a large number of wells and results of allocation of oil products in soil. The territory of Tomsk has seven types of soil thickness by the analysis of its structure and permeability. The analysis of the structure of technogenic deposits with thickness up to 3 meters was not considered in the classification of types. To estimate the stability of the geological environment of Tomsk to oil product pollution and its degree, we use an approach based on the total accounting of the estimated values of factors offered by G.K. Bondarik and V.T. Trofimov. We offer to understand "stability of geological environment" as the ability of components of the geological environment to resist external influences without transition to a new quality. Also we offer to use permeability of soil concerning oil products; sorption ability of soil; the scale of the change of structure, condition and properties of soil at interaction with oil products; hydrogeological and geomorphological conditions as major factors for estimation of the stability of the geological environment. Thus, on basis of the considered factors, we define three types of the geological environment for the territory of Tomsk with high, average and low degrees of stability to pollution by oil products. On the basis of the developed classification the schematic map was made. The content of this map reflects the distribution of types of natural and technical systems with various degrees of stability to pollution by oil products.