The north of Sakhalin Island is characterized by frequent earthquakes and many disjunctive dislocations. One of the catastrophic earthquakes occurred in the settlement of Neftegorsk. The level of modern technologies makes it possible to track the change in environmental parameters accompanying dangerous natural processes with a high degree of certainty. The article proposes an interpretating technology for disjunctive dislocations detecting, which differs from the existing ones with the complex use and summation of satellite image data using image processing methods widely applied in “computer vision”. The study aims to compile and describe a map of discontinuous faults of the village of Neftegorsk, located in the northern part of Sakhalin Island, using the developed decoding technology and geophysical data. Methods: Identification methods used in the work: 1) methods of primary image processing (correction, transformation, resolution change, cropping, visualization); 2) a set of “contextual” and “autonomous” methods of lineament analysis, with the help of which a series of images is processed (canny, erosion, Hough’s algorithm); 3) methods for constructing maps of discontinuous faults (summation, sequential linking). Results. Using the developed technology, a map of discontinuous faults in the area of the Neftegorsk earthquake was constructed. The implementation of the technology makes it possible to provide the monitoring data on discontinuous faults to organizations that are engaged in seismic zoning, construction and operation of objects for various purposes, including mineral deposits.

Link for citation: Kuptsova O.V., Melkiy V.A., Verkhoturov A.A., Dolgopolov D.V. Fault mapping by data of aerospace surveys to ensure the safety of main pipelines (by the example of the section Chayvo–De-Kastri oil pipeline). Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 6, рр.92-102.In Rus. The relevance of the research is caused by the need to identify the hazardous geological processes during the construction and operation of pipelines. The Russian Federation ranks second in the world in terms of the total length of main pipelines, where accidents sometimes occur as result of the negative impact of natural and man-made factors. The main hazardous geological processes affecting pipelines are displacements in zones of active faults in the earth's crust. Diagnostics of the presence of fault zones in the territory planned for the construction of linear structures makes it possible to identify potentially dangerous areas that should be paid close attention, and to organize constant monitoring in places of possible movements of soil masses. Based on economic considerations, it is advisable to conduct research using Earth remote sensing data, and use modern geoinformation products for data processing. Monitoring using remote sensing allows you to quickly assess the changing engineering and geological conditions in the areas where the pipeline is laid, as well as detect signs of the occurrence of natural processes that pose danger to infrastructure facilities. Monitoring of corridors of main pipeline routes must be carried out by all available means during construction and operation. The use of ArcGIS, QGIS and LEFA software in combination with geophysical data provided by the Unified Geophysical Service of the Russian Academy of Sciences makes it possible to assess seismic activity, its intensity and the nature of the relationship with faults. The main aim of the research is to identify and show on the map the most dangerous areas with active fault zones, that pose a potential threat of negative impact on the pipeline during operation. Objects: space images of the corridor of the main pipeline route to identify ruptures of a seismogenic nature, maps of earthquake epicenters previously identified near the pipeline route. Methods: interpretation of satellite images, methods of geoinformation modeling, mapping, statistical methods, methods of automated lineament analysis, methods for changing the resolution, size and visibility of images without loss of information quality, such as interpolation and aggregation methods, spatial analysis of the interdependence of fault zones and earthquakes, compilation of geoinformation. Results. The analysis of geological, geophysical and satellite information about the territory where the pipeline was laid was carried out in order to identify fault zones. Automated lineament analysis of images in different spectral ranges and with different spatial resolution made it possible to identify the most probable fault zones. The seismic activity of the study area was estimated on the basis of geophysical data. Potentially dangerous sections of the study area, along which the main pipeline is laid, are identified and presented on the map, characterized by the presence of fault zones and increased seismic activity.

The article presents the results of the research of the fault zones of earth’s crust within the North Sakhalin plain using the lineament analysis of the SRTM model. The faults be identified in order to increase the information content of the maps of geological content. SRTM data was used as input. The analysis performed using the functionality of the LEFA software package. The use of SRTM data made it possible to assess disjunctive disorders in territory of the north of Sakhalin Island. The images of surface were analyzed using the binary-morphological erosion operation or using Canny mathematical algorithms with further digital processing by means of Hough Transform. The paper reveals the position of linear elements in different parts of the North Sakhalin plain. Excellent test of the quality of performed definitions was the results of earlier studies of the eastern part of the North Sakhalin Plain, which were carried out in connection with the development of hydrocarbon deposits and after the strong Neftegorsk earthquake. The data obtained served as the basis for drawing up a map of disjunctive disturbances of Sakhalin Island at scale of 1:500,000. Depending from scale, spatial resolution, and level of generalization of image, disjunctive disturbances of different lengths (transregional, regional, sub-regional, local) and ranks (1 rank from a few to hundred meters, 2 rank from a hundred meters to a kilometer, 3 rank from 1 km to 35 km, 4 rank from 35 to 100 km, 5 rank more than 100 km). The analysis of the SRTM model with the help of the LEFA toolkit allowed us to identify the zones where the earth’s crust fractures are located. The analysis of the SRTM model with the help of the LEFA toolkit allowed us to identify the zones where the earth’s crust fractures are located. As aresult of the analysis, the West Sakhalin, Central Sakhalin, Hokkaido-Sakhalin (Upper Piltun segment), Piltun, Garomai, Val-Langri, Gyrgylany-Daginsky, South Baikal, Udyl and many other faults of less than rank 2 were identified. The main results of the work will be useful in choosing places for the construction of economic and industrial facilities, as well as in the search and exploration of mineral deposits.

The network of fault zones caused by vertical and horizontal tectonic displacements blocks of Earth’s crust relative to each other is clearly visible on the Earth’s surface in images obtained from satellite surveys. Many researchers distinguish linear and annular structures among the faults. Lineaments in satellite images are detected as rectilinear objects with a certain spectral brightness. The initial data for the experimental research includes images from the Landsat-8 satellite and SRTM data. The lineament analysis of satellite images and SRTM data of the Central-Kamyshovy meganticlinorium of the West Sakhalin Mountains was carried out using the functionality of the LEFA software package using the developed decryption technology. The obtained results were processed using the QGIS program tools. Statistical processing of Sakhalin lineaments was carried out on the basis of researching distribution directions of linear segments set of vector strokes data and lineaments data. The map of disjunctive disturbances of the Central-Kamyshovy meganticlinorium of Western Sakhalin Mountains on a scale 1:500 000 was compiled by basis of data obtained. The analysis of SRTM model with the help of LEFA toolkit made it possible to identify zones where discontinuous disturbances of the Earth’s crust are located. As a result of analysis, West Sakhalin fault and many other faults of a rank below 2 were identified. Fault zones are mapped on scale of 1:500 000. It was revealed that 15.3 % of all earthquakes in this area were timed to the Krasnopolsky fault, including in the zone within 1 km from the fault—70 %, 1–2 km—19 %, 2–3 km—9 %, more than 3 km—2 %. The results of work will be useful in choosing places for construction of industrial facilities, as well as for seismic zoning of territory.

Fault zones on the territory of Nature Sanctuary “Dolinsky” (Sakhalin Island), which are characterized by high geodynamic activity, are generally well distinguished when analyzing satellite imagery materials. In any territory, it is not difficult to identify the various plant communities that occupy it, as well as to determine their state by the content of phytomass determined by the vegetation index NDVI. The aim of the study is to test the validity of the hypothesis about the formation of abundant vegetation cover within the fault zones by analyzing the state of various plant communities by the volume of phytomass. Methods: decryption and analysis of Earth remote sensing data from Sentinel, Landsat and SRTM generation, geoinformation mapping on the ArcGIS platform. Results. In the course of the study, the state of the Nature Sanctuary “Dolinsky” analyzed by Landsat-8, Sentinel-2A satellite sur-veys, as well as SRTM data. Fault zones identified using the software systems ArcGIS, QGIS, and PyLEFA by lineament analysis, vegetation was classified by the maximum likelihood method, and its condition was determined by the values of the NDVI index, which reflects the content of phytomass in the study area. As result of the work carried out, an increase in phytomass revealed, and, consequently, good conditions for the growth of plant communities confined to the zones of distribution of faults of the earth's crust, and the reliability of the working hypothesis confirmed.