Experience in Studying the Urbanization of Valley Geomorphosystems at the Local Level (on the Example of Irkutsk)

Abstract

Urbanisation processes affect all components of the natural environment, often causing ecological tensions, leading to negative consequences for humans and their economic activities. Upper Angara region is an old-developed which experienced an upsurge of urbanization after the construction of the Angara HPP cascade HPP cascade on the Angara River in the period of 1950-1980. In this context it is important to have an idea of the structure and dynamics of the natural complexes and population of the territory against the background of urbanization processes. The article is devoted to the complex analysis of the relief and population dynamics in the key area of the downstream bank of the Angara river in Irkutsk. The main attention is paid to the time interval from the beginning of the Irkutsk hydro power station construction till now (1950-2022). Based on the comparison of multi-temporal aerial photographs (AFS), satellite images and topographic maps, the dynamics of morphology, changes in the structure of exogenous processes. Certain quantitative indicators (change in the area of relief elements, volumes of the displaced soil) allowed to estimate high adaptive properties and stability of the geomorphosystem. Five stages of the formation of the urban area, reflecting the development of the space of the study area. The dependence of the population density distribution on morphotypes of building-up of the territory, determining a degree of the anthropogenic loading and geomorphologic risks. It is determined that the maximum anthropogenic impact has shifted from the floodplain-channel complex to the terrace complex since construction of the HPP. Results of researches, can be applied at large-scale zoning on a degree of anthropogenic impact of territories.