Changes in the underlying surface and vegetation in the Chornobyl Exclusion Zone during 1986−2017

The analysis results of the type surface and vegetation changes in the Exclusion Zone of Chornobyl Nuclear Power Plant, for the period after accident in 1986 until 2017 are presented. In the article it is shown that after the Chornobyl accident in 1986, the largest changes occurred with vegetation on agricultural lands. Analysis of the current state of vegetation showed that the area of restored forest plantations on uncultivated lands amounted to –31% of the Chornobyl NPP Exclusion Zone. Studies have shown that fires cause great damage to the forest ecosystems. Forests and woody vegetation of natural regeneration damaged by the fire in the Chornobyl NPP Exclusion Zone as of 2017 amounted to 41.3 km2, which is about 4% of the area of forest vegetation. It is noted that the movement of certain volumes of radioactive waste from temporary storage points affect changes in the levels of pollution of environmental components in the Chornobyl NPP Exclusion Zone. Cartographic calculations showed that the areas allocated for the enterprises of the main and auxiliary cycle in the Chornobyl NPP Exclusion Zone occupy an area of about 56 km2 , of which 42% is covered with woody vegetation. The condition of such forested areas affects fire safety on stationary and temporary areas intended for localization of radioactive waste. It is stated about the expediency of organizing mineralized strips, conducting timely measures to care for plantations around such areas. Such measures are — felling of damaged stands, clearing the area of dead parts of trees, planting forests on burned areas. Maps obtained after the analysis and assessment of spatial heterogeneity of the territory are presented in the article. The maps show the location of areas of enterprises that may be sources of radioactive contamination and natural complexes that was changed. It created a set of digital raster and vector maps which reflect the structure of the study area for different periods. Vector maps were developed based on remote sensing data and fairly accurately reflect the modern structure of the territory, capture processes occurring within the territory. It concluded that the cartographic classification of objects on the ground surface and types of vegetation may be used for analyzing changes in the Exclusion Zone and unconditional resettlement of Chornobyl NPP, as well as parameterization of the type of underlying surface for assessment of environmental pollution. It is noted that the combination of the created cartographic material with the data of actual surveys of forest ecosystems makes it possible to more accurately determine the amount of bioresources of the Exclusion Zone in areas with high levels of pollution. The obtained cartographic materials make it possible to determine and display the modern spatial structure and characteristics on the Earth’s underlying surface and to calculate the areas in the changed territory.