The study of the dynamics of the deltas of the northern rivers is complicated by a number of circumstances: a) the slowed rates of the processes occurring in the cryolithozone condition determine the small variability of the deltas; b) the shortness of the season of possible observations after the completion of the spring flood and before the formation of snow cover limits the choice of suitable shooting dates by the end of July–August–September; c) cloudiness shielding, weather conditions drastically reduce the choice of images. Remote studies of the dynamics of the northern deltas over the past half century are based on images from the Landsat satellite; to assess the current state of the deltas, images from the Sentinel satellite with the best resolution and frequency of shooting are used. To ensure the comparability of images obtained by different imaging systems, they are mutually geometrical (transformed) and brightness (brought to a common division by brightness levels) matching, selection of comparable spectral channels is performed. Based on the analysis of the spectral brightness curves of the main objects studied, the survey channels that are most informative for the study of delta dynamics are determined. To select the optimal method of automated isolation of coastlines, several methods of computer separation of water and land objects were tested: clustering into two levels using the entire set of spectral channels; the same for the most informative channels in the near and middle infrared spectrum; creating index images (water index options). Due to the complexity of eliminating the errors that remain with these methods, the luminance quantization of images in the near infrared zone is considered optimal, allowing the use of best-resolution images and sequentially refining the brightness level chosen for dividing based on comparing the quantization results with the original synthesized images. The Landsat-7 images of 1999 and Sentinel-2B 2017 in the near infrared zone, quantized to brightness levels «water»–«land», obtained a raster image of the Yenisei delta with contours of water appearing at the land (erosion of the coast) and land formation at the water location (accumulation of sediments). On its basis, maps of the delta dynamics are compiled. Three types of maps of different scales and contents reflecting the dynamics of the Yenisei delta are proposed.

Kravtsova Valentina Ivanovna, doctor of geographical sciences, leading researcher of Faculty of Geography Lomonosov Moscow State University, 119991, Moscow, Leninskie Gory, 1, MSU, Faculty of Geography. E-mail: valentinamsu@yandex.ru.

Vachnina Olga Vasilyevna, research scientist of Faculty of Geography Lomonosov Moscow State University, 119991, Moscow, Leninskie Gory, 1, MSU, Faculty of Geography. E-mail: vachnina-ov@yandex.ru.

Kharkovetz Evgeniy Georgievich, Senior research scientist of Faculty of Geography Lomonosov Moscow State University, 119991, Moscow, Leninskie Gory, 1, MSU, Faculty of Geography. E-mail: e_x@lakm.geogr.msu.su.

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