Exogenous geological processes of the Republic of Bashkortostan and activitty of their development in the last decade (2013-2023)

Abstract

Exogenous geological processes refer to a series of discrete alterations occurring within the near-surface geological environment due to the exchange of energy and mass at the interface of the lithosphere with the atmosphere and hydrosphere. These processes result in irreversible transformations in the state of the subsurface. The principal categories of exogenous geological processes encompass phenomena primarily influenced by: gravitational forces, surface water, groundwater, wind, and anthropogenic activities. Within each group, prominent processes, types of exogenous geological processes, manifestations, and geographical distributions are delineated to provide comprehensive insight. Studies have shown that among all exogenous geological processes observed in the territory of the Republic of Bashkortostan, processes driven by surface and groundwater activity are the most pronounced. Particularly impactful on residential areas of the republic are lateral erosion of rivers, karst formations, and landslides in the Southern Urals. Information regarding the ongoing development of these processes serves as crucial indicators for informing managerial decisions aimed at mitigating their adverse effects on economic assets and ensuring the safety of the population’s livelihoods. The contemporary activity of river lateral erosion development was assessed by comparing aerial photo interpretation materials from 1953-1955 with modern satellite imagery. The results of this comparison are corroborated by monitoring data on the condition of water body banks at 29 observation sites, conducted by sectoral organizations under state contracts with the Ministry of Nature Management and Ecology of Republic of Bashkortostan. It was determined that the rate of river lateral erosion development over the past 10 years has been lower than the average annual rate. The current activity of karst development is assessed based on the frequency of new karst sinkhole formations, utilizing a database of sinkholes of various origins with documented time of formation. It has been determined that on the territory of the republic, the average frequency of large karst sinkholes (with cross-section and depth exceeding 3 meters) over the past 100 years was two sinkholes per year, while in the last 10 years, it increased to 3-6 sinkholes per year. In accordance with current regulatory documents, the activity of sinkhole formation due to karst development over the last decade in Bashkortostan is generally estimated as high, and in 2023 specifically, as very high. Current activity of landslide process development is assessed as low. Other types of modern exogenous geological processes have limited distribution, the activity of development and their impact on socio-economic objects of the republic are episodic.