Differentiation of the Southern Transbaikalia territory in the thermo-freezing regime of soils

Abstract

Broad variations in the soil temperature are characteristic of the southern Transbaikalia. The soil temperature varies in the ranges of -2,5 ÷ -19, -0,5 ÷ -12,5 and 2,8 ÷ -3,2 °C at the depths of 0.2, 0.8 and 3.2 m respectively. The mass of data is classified into four groups that are characterized as moderately cold, cold, very cold and severe based on qualitative characteristics of their thermal conditions. The moderately cold conditions of soils (A) occur at the south-eastern shore of Baikal lake. Cold conditions of soils (B) are scattered over all the territory and usually occur at near-river descents and valleys of hollow type. The very cold conditions of soils (C) are most widely spread in the Southern Transbaikalia. They can be considered as the background conditions of the territory considered. The severe conditions (D) are met in the form of small dispersed patches only. Based on the method of conjugate analysis of mutually related landscape components, a cartographic model is developed that can be pertained to the ecological direction in cartography. Analysis of annual temperature variations at the soil profile depths and of its vertical distribution in all months of a year revealed some new regularities. Firstly, the periods of near-zero temperatures and their durations in different soil layers were determined and, secondly, annual temperature amplitudes were fixed in soil profiles of various cooling and freezing conditions.