Архив метки: humidity

ON THE QUESTION OF MATHEMATICAL MODELING OF THE EVAPORATION PROCESS

Arid Ecosystems

UDC 632.125;910.1;531.3

Salugin A.N. ON THE QUESTION OF MATHEMATICAL MODELING OF THE EVAPORATION PROCESS // Arid Ecosystems. 2023. Vol. 29. № 2 (95). P. 12-19. | PDF

Mathematical methods for describing the processes of evaporation from the soil surface in the conditions of the southern Russia subarid zone are discussed. The analysis of theoretical works in this field and the results of their practical application are made. Mathematical modeling was used to explain the field observations. Mathematical models of evaporation from the soil surface are divided into two types: physico-mathematical models based on the interaction of water with the soil framework and phenomenological models based on balance ratios. The data on evaporation from the surfaces of light soils were analyzed taking into account the diffusion and film transfer of moisture in the pore space. In the analysis of cumulative evaporation from extended territories, a semi-empirical model was used, linking the intensity of evaporation with precipitation and the hydrophysical state of soil moisture aeration. The theory of capillary movement is in good agreement with the data on evaporation from the surface of open sandy soils. A nonlinear relationship between the evaporation rate and the thickness of the underlying surface and humidity has been revealed. The amount of annual precipitation in the south of Russia and cumulative evaporation are connected by power dependence, indicating the capillary-sorption nature of evaporation.

Keywords: evaporation, porosity, aeration zone, pressure gradient, humidity, capillary radius, mathematical modeling, water regime of soils.

Funding. The work was carried out for the state task No. 122020100450-9 “Development of a New Methodology for Optimal Management of Bio Resources in Agrolandscapes of the Arid Zone of the Russian Federation Using System-dynamic Modeling of Soil-hydrological Processes, a Comprehensive Assessment of the Impact of Climate Change and Anthropogenic Loads on Agrobiological Potential and Forest Conditions”.

DOI: 10.24412/1993-3916-2023-2-12-19

EDN: DCKJSF

TRENDS IN HYDROTHERMAL INDICATORS OF THE STEPPES OF SOUTH-EASTERN TRANSBAIKALIA IN THE CONTEXT OF CLIMATE WARMING

Arid Ecosystems

Davydova N.D. TRENDS IN HYDROTHERMAL INDICATORS OF THE STEPPES OF SOUTH-EASTERN TRANSBAIKALIA IN THE CONTEXT OF CLIMATE WARMING // Arid ecosystems. 2022. V.28. № 1 (90). P. 3-10 . | PDF

One of the problems of the development of society on Earth was climate change due to the increase in the temperature of the surface layer of air, which for different regions was and remains not equal. The analysis of long-term data on air temperature, atmospheric precipitation and humidity of deep-frozen powdery-carbonate chernozems of the Onon-Argun steppe of South-Eastern Transbaikalia is carried out. It is shown that the next dry period of 1999-2020 differs from the previous one by a significant increase in temperature and an ambiguous annual amount of precipitation. According to these indicators, it is divided into two parts: very dry warm and wet very warm. In the driest period (2001-2011), the moisture reserves in the soils were mostly at the level of withering humidity and below. In nature, there were such catastrophic phenomena as the widespread drying of stands of trees, the disappearance of lakes, including a large one-Barun-Torey. Since 2012, the amount of precipitation has increased, but has had little effect on the soil moisture reserves and the replenishment of the water volume in the lakes. As a result, by 2018, the water area of another large lake of the Torey depression – Zun-Torey-disappeared. The bottoms of the dried-up lakes turned into soda-sulfate sodium and soda- chloride-sulfate sodium salt marshes. In the terrestrial grassland of the steppes, the introduction of xerophilic species into the communities was observed, as well as a decrease in its height and density. The amount of aboveground plant mass decreased by 1.5-2.0 times.

Keywords: global warming, Onon-Argun steppe, atmospheric precipitation, air temperature, humidity, soil, lake drying, vegetation, xerophilic species, stand of trees.

Acknowledgement. The author is grateful to the head of the Borzya meteorological station, L.I. Karpikova, hydrologist O.V. Perminova and all the employees who worked in different years for their long-term assistance in the selection of materials, consultations, understanding and warm friendly attitude, as well as Ph.D. L.V. Dudareva, who took a direct part in the formation of the Chemical Analytical Center of the Institute of Geography of the SB RAS and its accreditation, the development of the instrument base and the receipt of KHA data.

Financing. The work was carried out at the expense of the state assignment of the IG SB RAS, state registration No. AAAA17-117041910171-7, “Spatial and temporal patterns of the material state of the landscapes of Siberia in changing environmental conditions”.

DOI: 10.24412/1993-3916-2022-1-3-10