The regularities of technogenic eutrophication of rivers under the impact of mining facilities are studied. The main specific features of succession during anthropogenic eutrophication were analyzed. Methods of quantitative bioindication and risk-analysis of these successions for the river ecosystems are developed. This takes into account a variety of alternatives for the possible development of environmentally dangerous events. As a result, the most likely environmental damage is estimated and given its cost equivalent. This opens up the possibility of forecasting and managing the situation on a quantitative basis. Developments allow forecasting the level of technogenic impact on the ecosystem, to determine and regulate the most likely technogenic ecological damage.
Methods for quantitative study, assessment, rationing and selection of measures for regulation of multifactorial anthropogenic impacts on ecosystems of freshwater reservoirs and watercourses have been developed. Reaction of biota to influence is estimated by a condition of macrozoobenthos as the most sensitive bioindicator, and the influence itself is estimated by the special indicator taking into account effect of interaction of factors. The regulation of multifactorial impact is based on identifying its maximum permissible level, which does not cause irreversible changes in macrozoobenthos. Regulation of the impact is aimed at reducing it to the maximum permissible combinations of interacting factors to achieve a safe level of their joint biotic effect.
The analysis of the modern normative-methodological basis for determining anthropogenic damage to hydro-ecosystems, which has many significant drawbacks, is given. An alternative method of quantitative assessment of anthropogenic successions of hydro-ecosystems and the damage caused to them, based on the analysis of environmental risk, is proposed. The main characteristics of ecosystems were studied, the background values of environmental risk and the size of environmental risk in value terms were determined, scenarios of probable damage from construction and operation of the object and the model of the tree of dangerous events and their consequences were developed. The zone of potential influence of the object on the water areas - the zone where the risk values exceed the background level was singled out; the comparative analysis of the expected damage in the presence of several design solutions was carried out. The optimal solution is the one leading to the minimum damage.
The impact of the mining enterprise OAO Phosphorit on the ecosystem of the Luga River and its tributaries has been fully assessed. It turned out that a significant contribution to the total technogenic load of the hydro-ecosystem is made not only by wastewater discharge, but also by the transfer of pollutants into the atmosphere. A considerable increase in the impact of the enterprise on the Luga and its nearest tributaries, including those located upstream, has been recorded. Not only clear changes in various abiotic indicators of exceeding the maximum allowable concentrations of biogenic elements - mineral and organic phosphorus, nitrates, ammonium, fluoride ions, sulfate, combination of oil products, but also the main biotic parameters (structural and functional characteristics of microphytobenthos, phito- and zooplankton, zoobenthos, ichthyofauna) were established. In the area of influence of OAO Phosphorit, the overall level of anthropogenic impact on the hydro-ecosystem is 2-3 times higher than the stability of the ecosystem, which is significantly (40%) higher than the background indicator. According to research results, negative changes in the Luga ecosystem are still reversible at present. However, even a relatively small (30% or more) increase in anthropogenic load can lead to rapid and irreversible biotic degradation of rivers in the entire zone of influence of Phosphorit. This defines high requirements for the development and implementation of a system of environmental protection measures for Phosphorit, especially taking into account the volume of production growth.
