№ 5 (2023)

The task of soil moisture assessing by remote (satellite) methods remains relevant up to the present time. Regression models based on the correlation of radar data with ground measurements of soil moisture are constructed to assess soil moisture in the work. Ground-based measurements were taken at two stations in Germany (Falkenberg and Gevenich), which are part of the ISMN (International Soil Moisture Network) worldwide soil moisture data network. Sentinel-1 satellite data is used as radar data. Multiple regressions with a determination coefficient up to 0.91 are constructed. It is proposed to use not only radar, but also meteorological data in regressions, which allows increasing the coefficient of determination and reducing the standard error of regression. For the possible spread of regressions obtained for one territory to another territory, two criteria are selected: the proximity of the values of the Selyaninov hydrothermal coefficient and the similarity of the soil texture. According to these conditions, two stations in the Ryazan region and in Kalmykia were chosen, whose archival information on soil moisture is contained in the ISMN database up to 1998. Each of the selected stations satisfies only one of the criteria.

The duration of polar ozone depletion events depends on the phase of the quasi-biennial oscillation (QBO). The QBO determines the location of the subtropical critical wind line that influences the propagation of planetary waves into the stratosphere. As a result, the polar vortex intensifies during the western phase of the QBO and weakens during the eastern phase, which manifests itself in the timing, duration, and intensity of stratospheric ozone depletion. Polar ozone depletion occurs inside the strong polar vortex from late winter to spring due to the occurrence of heterogeneous and photochemical ozone destruction reactions in the presence of solar radiation. We studied the effect of QBO phases at different isobaric levels on the dynamics of the stratospheric polar vortices based on satellite data from the Goddard Space Flight Center NASA. It is shown that the QBO at the 30 hPa pressure level has a predominant effect on the dynamics of the polar vortices. This is observed from September to December, especially in October and November, in the dynamics of the Antarctic polar vortex, and throughout the entire period of its existence in the dynamics of the Arctic polar vortex.

The work is aimed at the practical application of satellite imagery data for the selection of promising areas for geological exploration in conditions of medium-low mountain relief and a sharply continental climate. The results of processing and analysis of WorldView-2 data within the Talmanskaya area are presented in order to identify zones of hydrothermal-metasomatic changes in rocks that are promising for the identification of gold-polymetallic mineralization. The choice of the study area is due to sufficient geological knowledge and the absence of technogenic formations that affect the result of processing satellite imagery materials. To increase the spectral information content of the WorldView-2 data, the spectral channel ratio method was used, as a result of which a pseudo-color RGB composite was created that displays the spectral characteristics of objects on the Earth’s day surface, in particular, minerals of the oxide/hydroxide group containing transitional iron ions (Fe³⁺ and Fe³⁺/Fe²⁺). Comparison of the results of processing satellite data along with geological information made it possible to identify spectral anomalies as indicators of the presence of near-ore changes, which are an important search criterion for hydrothermal deposits.

Currently, more and more attention is being paid to the development of technologies for satellite monitoring of land use and the state of agricultural landscapes. The lack of up-to-date information about the boundaries of individual agricultural fields does not allow us to fully assess the state of arable land and take them into account. The available statistical sources have discrepancies and do not have information about the spatial distribution of used and unused agricultural fields. The purpose of this work is to establish the spatial distribution of cultivated and uncultivated arable lands of the Volgograd region according to remote sensing data. The paper presents the results of mapping the actual boundaries of arable lands of the Volgograd region as of 2021. High-resolution Sentinel-2 and Google Earth PRO data in the geographic information program QGIS3 were used to decrypt arable land. As a result, 6.05 million hectares of arable land were mapped. The data obtained were compared with official statistics for 2021, as a result of which, an excess of 12% was noted in comparison with the results of decryption. It is noted that over the past 20 years, according to statistical data, the areas of arable land and deposits have practically not changed. When comparing the decryption results with the data on arable lands of the Vega service, a difference of 4% was noted, which is quite high accuracy. According to the All-Russian Agricultural Census of 2016, the area of arable land used was exceeded by 8%. According to the SRTM digital terrain model, morphometric parameters of arable land were calculated throughout the region. It is determined that agricultural fields are located mainly on the slopes of the western exposure (37%), which is due to the predominance of the general slope of the relief to the west. Most (78%) of the field areas are on slopes with a steepness of up to 1°, and about 2% occupy areas of more than 3°. Water erosion is noted on steep slopes. The smoothest relief in the Volga region is on the territory of the Caspian lowland. Using remote methods, the assessment of the areas of fallow lands was carried out: about 960 thousand hectares. According to various sources, from 4.8 to 891 thousand hectares of unused arable land are noted. The resulting geoinformation basis will allow to fully account for and assess the condition of cultivated and uncultivated arable lands, as well as to develop projects for the rational use of land resources to increase yields and prevent degradation of agricultural landscapes.