ANTHROPOGENIC TRANSFORMATION OF TERRAIN IN THE NORILSK INDUSTRIAL DISTRICT

The scale of anthropogenic terrain transformation within the Norilsk industrial region was quantified and a classification of its consequences has been elaborated. The work is based on the results of 2021 expeditionary geomorphologic studies, interpretation and analysis of remote sensing materials and digital elevation models. It has been established that the total area of direct terrain transformation during the territory development was about 122,4 km2, and that of indirect transformation - 23,6 km2. The volume of anthropogenic landforms is at least 1,8 billion m3; accumulative forms account for 93% of the area and 72,6% of the volume of direct landform transformations. The types of anthropogenic landforms were identified, it was found that the largest area is occupied by embankments for industrial development and tailings, and the largest volume is characteristic of slope dumps. Indirect terrain transformation is mainly activation of gravitational processes, linear erosion, suffusion, thermokarst, heaving and deflation. The mass displacement of slope dumps by landslides or stone glaciers are the most dangerous for infrastructure facilities. Separate areas of indirect transformations are mainly limited to the lacustrine-alluvial lowlands and the bottoms of river valleys. Among them, the largest area (up to 20 km2) is occupied by segments of river valleys affected by spills of oil products and tailings. It has been established that the accumulation of pollutants in river valleys of the Norilsk industrial region occurs within the internal deltas and ice glades where the longitudinal slope decreases. Three stages of anthropogenic development of the territory are distinguished (I - 1920-1953; II - 1953-1986; III - 1986-2021); the most significant increment in the area of anthropogenic terrain occurred from 1953 to 1986. The average rate of anthropogenic terrain area increment over the past 36 years amounted to 0,81 km2/year. The highest rates of area growth are characteristic of the Kayerkan and Talnakh regions, which is associated with ongoing mining.