A series of cartographic models was created basing on the conjoint analysis of quantitative indicators of the air and sols temperature regime, obtained by automated ground and satellite temperature sensors. It reflects the characteristics of temperature fields of typological units of soil-bioclimatic zonality for the Altai-Sayan region. Key worlds: cartographic modeling; temperature fields; automated ground monitoring; satellite data.
Testing of the methodological provisions for identifying the boundaries of temperature fields was carried out on the example of typological units of the soil cover of the Altai-Sayan region, including a variety of steppes of the Chulym-Yenisei and Minusinsk troughs, the Chuy, Kurai, Turan-Uyuk, Central Tuva, Ubsu-Nur basins and tundrasteppe complexes Ukok Plateau. The key areas were selected taking into account the principles of landscape zoning, which allows one to recognize, classify, and map landscape differentiating factors, landscape components, the regional landscape structure as a whole, and its dynamic features. The method is based on a coupled analysis of regional structures objectively reflected in satellite images and recorded on landscape-typological maps. Landsat 8/9 satellite images were used as information sources. Thematic soil and climate maps were used as auxiliary maps for decoding satellite images. The intermountain basins of Khakassia and Tuva are located in the eastern sector of the Altai-Sayan mountain region in the following sequence from north to south - SeveroMinusinskaya, South Minusinskaya, Turano-Uyuk, Central Tuva and Ubsu-Nurskaya. The elevations of the bottoms of the basins increase southward from 300 to 500 m above sea level in the basins of Khakassia and from 700 to 900 m above sea level in the basins of Tuva. In the same direction, climate continentality increases – from the mildest climatic conditions in the North Minusinsk to the most severe type of thermal regime in the Ubsu-Nur basin. Distribution features and conditions for the formation of thermal conditions in the steppes of the left bank of the Yenisei-Minusinsk depression (Khakassia) are associated with their location between the mountain structures of the Kuznetsk Ala-Tau, East and West Sayan.
On the territory of Tuva, the Turano-Uyuk, Central Tuva and Ubsu-Nur steppe basins are clearly distinguished by climate-forming factors and thermal conditions of soil formation. Within the boundaries of the Ukok highlands, tundra-steppe complexes with a contrasting combination of mountain-steppe and mountain-tundra soils and quantitative indicators of the soil climate stand out. The contrast of the climatic regimes of air and soils in the basins of Khakassia is formed depending on the severity of the direction of moisture transfer, which in the eastern sector of the Altai-Sayan mountain region has a western, alternating with a northwestern orientation (Table 1).
Climatic conditions, as a set of environmental factors, have a direct impact on the formation of the diversity of the soil cover in the hollow steppes of Khakassia. In the regions of the Uzhuro-Kopiev and Shirin steppes, in which the average annual air temperature is 1,3 °C, the frost-free period is 168 days and ∘ > 10∘ = 1573∘ southern and ordinary chernozems prevail, occupying from 14 to 34% of the area.
In the Uybat steppe, located in close proximity to the eastern foothills of the Kuznetsk Ala-Tau, the average annual air temperature is -1,1 °C, the frost-free period is 170 days and ∘ > 10∘ = 1630∘. Therefore, the most xerophilous core of the steppe vegetation is located here and low-fertile solonetzic soils are formed. In the Tuva basins clearly differing in physical and geographical environmental conditions, annual and daily climate cycles, temperature fields are distinguished, which can be considered as indicators of differences in the complex of climatic conditions and the structural organization and functioning of the soil cover (Table 2). >10° >5° >0° <0° avteemrapgeeraantunrueal 1,1 1,0 0,9 1,2 1,2 * the denominator is the number of days
Table 2. Air and soil temperature regime indicators by the soil profile depths (cm) for Tuva steppe basins.
indicators, Т°С >10° >5°
temperature on the soil 10 20 30 Т°С surface
Turan-Uyuk basin, Turan (N52°08'18,8"; E93°49'25") 1572,8/95* 1754,1/96 1470,3/88 1284,9/82 908,9/70 1768,5/121 1951,4/124 1726/124 1536,5/116 1210,3/112 50 >10° >5° >0° <0° average annual
temperature * the denominator is the number of days
The Turano-Uyuk Basin, located at an altitude of 700-900 m above sea level according to the main indicators of the climatic regime – the average annual air temperature (-2.3°), the duration of the frost-free period (160 days) and ∘ > 10∘ = 1573∘, it approaches the conditions of the arid steppe zone. Thermal conditions of the UlugKhem and Khemchik hollows, the bottoms of which are 600-800 m above sea level, characterized by a higher average annual air temperature (-0.4°), a longer frost-free period (180 days) and ∘ > 10∘ = 2043∘. The Ubsu-Nur basin is distinguished by a low atmospheric humidification and high heat resources of summer: average annual air temperature (-1.9°), frost-free period – 169 days and ∘ > 10∘ = 2034∘, which create a regime semi-desert zone with chestnut soils and psammozems.
Ground-based automated monitoring of air and soil was organized using a specialized temperature recorder
DS1921G “Thermochron” taking into account indicators reflecting the genetic unity of the climate types of the
AltaiSayan region. To fix the air temperature, an autonomous recorder was installed at a height of 2 m from the soil
surface under conditions excluding direct radiation exposure. The dynamics of temperature changes on the soil
surface and horizons of the soil profile was recorded during the year with an interval of 4 hours. As a result of the
observations, a large amount of evidence was obtained, which was used as the basis for calculating the thermal
resources of temperature fields and identifying their time trends [
Thematic processing of satellite images was carried out using the original nonparametric methods and
technologies for satellite images segmentation proposed by the authors, which allow taking into account both spectral
and spatial features, as well as ground-based observations [
For retrospective analysis, statistical processing and visualization of MODIS data were used the original software
and algorithmic tools created at ICT SB RAS, based on a new technology for access to the satellite data archive
implemented using the PostgreSQL DBMS with an additional module [
An interpretation of typological units of structural and functional organization for soil cover of steppe basins is presented on the basis of a statistical analysis of the combination of boundaries and the information content of the soil cover contours and the temperature field contours obtained from the analysis of satellite data of day and night temperatures and the temperature difference of subtraction of two compiled series calculated for 16 year period (2001-2016).
The possibility of cartographic modeling of the structural organization and functioning of the soil cover was revealed using steppe basins of the Middle Siberian transect and tundra-steppe complexes of the high mountains of the Altai-Sayan region as an example. The interpretation of typological units of the structural and functional organization of the soil cover of the steppe basins of Khakassia is presented on the basis of a statistical analysis of the combination of boundaries and the information content of the soil cover contours and temperature fields obtained by analyzing satellite data of daytime, nighttime temperatures and temperature differences obtained by subtracting two compiled series (Figure 1).
The obtained cartographic models give a clear idea of the boundaries of the temperature field contours of typological units of the soil cover of Khakassia, the functioning of which is carried out in a wide range of temperatures. They make it possible to get an idea of the thermal conditions of both large units of soil cover, such as the Shirinskaya or Uybatskaya hollows, and occupying small areas – Koibalskaya or Sorokaozernaya, but having independent environmental significance. Noteworthy are the significant difference in the allocation of areas of soil contours and their temperature fields in the basins of dry (deserted) steppes, obtained on the basis of the analysis of satellite data, both day and night temperatures. The spatial distribution of temperature fields, taking into account current trends in thermal resources, can be used to adjust the contour boundaries of the structural units of the soil cover.
The spatial distribution of temperature fields in the steppe basins of Tuva has a southwestern direction and is due to the peculiarities of the macro relief. In the basins of Tuva, characterized by a high degree of diversity of characteristics of the soil geographical space and aridization of the climate, the obtained cartographic models of temperature fields can be used to identify spatial and temporal gradients of thermal resources at the scale of large and local soil cover units (Figure 2).
Cartographic models of temperature fields are also informative for identifying the conditions of heat supply for the formation and functioning of the tundra-steppe complexes of the Ukok highlands, for the soil cover of which combinations of mountain-steppe and mountain-tundra soils are typical (Figure 3).
Temperature field models can be used to obtain additional information about natural complexes, the formation and functioning of which is carried out under conditions of ultra-high or ultra-low temperatures.
In general, cartographic models of temperature fields obtained as a result of a joint analysis of terrestrial and satellite data are sufficiently informative with respect to the energy of soil-forming processes and can be used to assess the thermal conditions of soils in insufficiently studied and inaccessible territories of the Altai-Sayan region.
The novelty of the approach lies in the fact that cartographic models of soil temperature fields, created on the basis of quantitative indicators of the temperature regime, have sufficient information content to establish relationships with other characteristics of environmental objects and to solve the problem of distinguishing the boundaries of temperature fields of typological units of soil cover.
Acknowledgements. The authors are grateful for the financial support of the No 18-04-00633-a. project