Vol 25, No 4 (2025)

Using the example of several districts of the Middle Angara region, the changes in the system of rural settlements in the taiga zone of the Irkutsk region in the period from the first All-Russian Population Census in 2002 after the collapse of the Soviet Union to the last one in 2021 are revealed. The system-dynamic analysis also touched upon the period of formation of regional settlement systems, which fell during the Soviet period and played a major role in their genesis. Geoinformation mapping and analysis of settlement systems were carried out at different levels: regional, inter-municipal, local, elementary. The results of the study revealed that functional changes affected the majority of rural settlements and occurred due to the loss of agricultural and forestry specialization of settlements, especially in the Bratsk region. The loss of production functions by rural settlements, combined with long-term depopulation, is changing the established settlement systems. Mainly the grassroots settlement systems (elementary and local) are disappearing. Only the centers of these former systems remain, the viability of which is ensured by the relatively high population of settlements, the safety of social infrastructure facilities, and the possibility of employment. In the future, changes in the structure of settlement systems will require administrative reform within municipalities under a reactive problem response scenario, which can be seen in the example of the Chunsky district, which has transformed into a district. For proactive actions by the authorities, it is necessary to stimulate the development of small and medium-sized businesses, covering the fields of specialization of the research areas, and the formation of new industries.

The increase in illumination levels in populated areas, including as a result of the implementation of several federal projects, has raised concerns about light pollution caused by artificial lighting. This has led to questions about identifying areas and cities where artificial lighting levels have significantly increased, as well as evaluating the impact of this increase on the environment. Light pollution is considered one of the types of physical pollution, and within this framework, it has been analyzed in the context of the Saratov region. Based on data from the region, the absolute and relative (per street meter and per inhabitant) values of illumination from artificial lighting were analyzed over the period 2007 to 2022. Districts and cities with advanced and lagging development in terms of lighting were identified, and attempts were made to analyze the causes and factors behind the observed dynamics. The territory of Saratov was zoned to assess the current situation regarding light pollution. The analysis of the dynamics in the period 2012–2024 showed a decrease in the level of light pollution in the old districts of Saratov, but its increase in the new Gagarin district and on the outskirts. The territories of the city with a critical situation have also been identified. This study focuses on the effects of artificial lighting in the Kumysnaya Polyana Nature Park.

The article discusses the content and distribution of natural radioactive elements (uranium, thorium, and potassium) in the Upper Jurassic deposits of the Kogalym-Pokachevsky region, based on data from nine wells. Through comprehensive studies, eight stages of deposition have been identified, including deposits from shelf silts to the prefrontal zone of the beach. Certain patterns of migration and accumulation of these radioactive elements have been observed for each stage, and their limiting values have been determined. These results can serve as reliable indicators of sedimentation conditions, and can be useful for both stratigraphic analysis and correlation of sediments from different time periods. Additionally, they can contribute to paleogeographic research.