Altitudinal zonation of landscapes on the local testing area in the southern Baikal region

Abstract

Today identification of altitudinal zones of landscapes in local areas, especially in mountainous areas, is inextricably linked with the creation of digital terrain models and their geoinformation interpretation. We have considered the altitudinal zonation of landscapes on the Mamai model testing area, located on the Northern macroslope of the Khamar-Daban Ridge and in the Tankhoi coastal plain of the Baikal Lake. The special geoinformation software, partially modernized during the works, was used. Landscapes were studied by their main components: relief and geomorphological processes, soils and soil-forming processes, vegetation. The landscapes of the testing area are represented by three main groups: 1) goltsy altitudinal and mountain-taiga landscapes of the Khamar-Daban Ridge on the crystalline metamorphic rocks of the khungurul series of the lower Proterozoic age and granites of the Khamar-Daban and Sayan intrusive complexes of the upper Proterozoic and lower Paleozoic, respectively; 2) taiga and meadow-marsh landscapes of the Tankhoi plain on loose sediments of the Late Pliocene and Quaternary ages; 3) intrazonal landscapes within transverse mountain river valleys on the Late Pleistocene and Neo-Pleistocene and modern loose sediments. The base of the identification of altitudinal zones of the landscape is layers of a relief. But the relief is a fairly static component of the landscape, its invariant structure change for tens or hundreds of thousands of years. To determine a more detailed and dynamic structure of the altitudinal zonation, we use other components: soils and vegetation. Changes in the invariant structure of the soil cover occur for thousands or tens of thousands of years, and of the vegetation cover – for hundreds or thousands of years. Features of the landscapes structure and characteristics of their main components allowed us to allocate six altitudinal zones in the testing area: goltsy altitudinal, subgoltsy altitudinal, low-mountain, foothill, foothill-plain, and coastal-plain. The intrazonal landscapes of transverse mountain river valleys, which violate the normal structure of the altitudinal zonation, are singled out as a separate type.