Suchergebnisse

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.

In 1958 V.F. Perov, staff member of the Khibiny Research and Training Station of the MSU Faculty of Geography, described four snow-ice formations in the Khibiny Mountains and classified them as very small glaciers. Until our research began in 2005, these glaciers were not studied in detail. We used field observations, drilling, GIS and remote sensing methods to study the structure of the glaciers and evaluate changes in their geometry during 60 years. The snow-ice formations were drilled through for the first time and the ice cores underwent geochemical and isotope-oxygen analyses. The thickness of ice kernels varies from 0,2 to 1,6 m. Our investigations showed that despite a slight degradation, the glaciers` area remains relatively stable since 1958. This fact may be caused by the increase in solid precipitation in recent years. According to the analysis of climatic changes, in the early 2000s a decrease in snowfall was observed in the Khibiny Mountains. The maximum snow thickness at the meteorological site of the Khibiny station in 2002-2003 winter period was 55 cm. This could be a factor of more than 2 times decrease of glacier areas during 2000-2010. After 2007 there has been an increase in snow precipitation, and the maximum snow depth of 180 cm was observed in 2020, the absolute maximum for the whole period of observations (1984-2020). According to published data the increase in mean annual temperature at the plains of the Kola Peninsula is 2,3 ± 1°C during the last 50 years. However, mean monthly temperatures of the summer do not rise. We consider that, along with recently increasing snow precipitation, this is exactly what determine rather stable state of snow-ice formations in the Khibiny Mountains, which appeared to be more resistant to climate warming than mountain glaciers.