编号 5 (2024)

According to satellite data from Landsat 8, 9 and Sentinel-1,2 for the period 2017–2024, the spatiotemporal variability of the Kuban River plume distribution was studied. The features of plume manifestation on radar images, as well as in the visible and infrared range, were studied. It is shown that the Kuban plume is formed from two main jets, as well as the waters of the Kurchansky estuary near the river mouth. Based on the analysis of long-term optical data, 4 types of plume propagation were identified: “western,” “eastern,” “northern,” and “alongshore.” The most extensive spread of the plume occurs during the “northern” type, when the plume spread to a distance of up to 15.5 km from the coastline. The main reason for changes in plume distribution is variability in wind conditions. The seasonal and interannual variability of the distribution of Kuban waters has been studied. For the period 2019–2023 in most cases, plumes of a “western” direction were recorded (2019 – 45%, 2020 – 49%, 2022 – 35% and 2023 – 45% of cases), except for 2021, when more often plumes spread to the east (in 37% of cases) under the influence abnormal wind conditions.

For the Tuukansky ore cluster area, located in Russia in the Mamsko-Chuysky district of the Irkutsk region and identified as promising for the discovery of new uranium, gold, and iron ore objects, an original approach was applied based on geoinformation technologies and processing of Earth remote sensing data, including structural-geomorphological, spatial-geometric, spatial-density, and tectonophysical methods for identifying specific stages of development of the fault framework defining the location of ore mineralization. The possibility of using the morphological features of the terrain for reliable reconstruction of both neotectonic and ancient fault networks using a special lineament analysis technique based on analysis of a digital elevation model created using SRTM data has been proven. It has been shown that zones of the dynamic influence of northeast and northwest faults act a crucial role in mineral localization. Based on the tectonophysical approach, the orientations of the main axes of compression and tension in the regional stress-strain field, as well as the kinematics of the major types of formed faults, have been reconstructed. Taking into account the established orientation of the main axes of the regional stress field when calculating the shear trend made it possible to identify the most hydraulically active segments of fault structures. Within the zones of dynamic influence of identified faults, the parameters of local stress-strain fields, as well as the formation stages of these structures, have been reconstructed. The obtained information should be taken into account when compiling a metallogenic essay and predicting minerals in the area.

The paper examines one of the consequences of a change in the normal operating mode of the Russian microwave scanner/sounder MTVZA-GYa – a significant decrease in the accuracy of georeferencing of this device measurements data, which took place in April 2022. Deterioration in accuracy was discovered during retrospective thematic processing of MTVZA-GYa data, at the stage of visual analysis of the input data quality. The detected displacement of radio thermal portraits relative to the real coastline was about 70 km. The analysis of the described changes was carried out in two stages. At the first of them, during manual review of measurement data from each half-orbit, it was possible to determine the failure’s time frame (from April 10 to May 25), and also to identify the main cause of the observed displacements - change in the yaw angle of the MTVZA-GYa. At the second stage, as a result of end-to-end machine processing of the daily composites, formed by the device, an accurate value of the changed angle was determined, amounted to (–2.64 ± 0.23)° (instead of that used in normal mode (–0.84 ± 0.15)°). The conducted studies demonstrated the possibility of using the algorithm for determining MTVZA-GYa georeference-correcting angles as an indicator of failures in the operation of individual systems of this instrument. The potential possibility of adjusting the georeferencing of MTVZA-GYa measurements in the event of such failures was also demonstrated. In particular, for the case considered in this work, it was possible to reduce the georeferencing error by almost 6 times.

This review analyzed studies of flooding areas (F_tot) and water balance in the Volga delta (WB) during flood periods. The review represents a basis of accumulated knowledge about the characteristics of F_tot and WB during flood periods and methods for their study. We have analyzed the advantages and disadvantages of these methods. We have revealed that studies of F_tot and WB during flood periods have not been completed; only rough daily F_tot and rough daily WB parameters have been obtained for a number of flood periods. Therefore, peculiar features of F_tot and WB during flood periods of different water contents have not been fully understood. Research methods have been continuously changing and improving, thus the accuracy of the estimated daily F_tot and daily WB parameters obtained by different methods for different flood periods varies significantly. Therefore, the results of such calculations cannot be analyzed in combination. The results of such calculations cannot supplement highly accurate data bases which are going to be obtained in future studies. However, thanks to new technologies and a large amount of satellite data, the previously developed methods can be used in the modern researches to obtain highly accurate results. As a result, we propose the following objectives for future researches: to calculate with high accuracy the daily F_tot and daily WB parameters for flood periods of different water contents, using high-technological methods and a large number of satellite images; to identify spatiotemporal patterns and distinctive features of flood periods of different water contents based on daily F_tot and daily WB parameters.