The article is based on review of published and archived materials related to the history of the mapping the Arctic Relief in the XIX–XXI centuries. The first attempts to represent relief and geomorphological zoning in the map format in Russia and Europe goes back to 1880–1910. In the Arctic, the first geomorphological works and the first maps were produced by R. Koettlitz, A. Armitage, M.N. Ivanychuk, geologists of the mining and geological department of GUSMP. Scientific foundations of mapping techniques developed by K.K Markov, A.I. Spiridonov, Z.A. Svarichevskaya, Leningrad school of geomorphological mapping, using the experience M.M. Tetyaeva, I.N. Gladcin and Ya.S. Edelstein. Unfortunately, many pioneers of geomorphological mapping in the Arctic were repressed in the 1930–1950s. It is shown that geomorphological mapping in the north of the USSR was always closely connected with geological survey. Its “golden age” falls into 1950–1970s. – State geological survey. Although geomorphological map was excluded from the compilation of the State Geolmap-1000 third-generation kit, but the analysis of relief remains one of the main method of investigation in supporting different concepts of relief formation in the Arctic. Principles of geomorphological mapping, different concepts of origin of the relief and unconsolidated deposits, discussion of many geological and geomorphological issues significantly enrich the general theory of terrestrial and marine geomorphology of the Polar regions. Because of the contribution of hundreds of participants of geological and geomorphological surveys, Russia has a series of high-quality geomorphological maps that are not only accurately illustrate the land surface, but also shows the deep fundamental geomorphological knowledge. The advancement of geomorphological mapping in the Arctic would be based on traditional approach of geomorphology, walking across unknown land, which still remains plenty the Arctic has so far, and complemented with new digital and space bases research. That further development could not even be imagined by the first arctic geomorphologists.

Large paleochannels are considered to be a geomorphological phenomena. The review of landscape-geomorphological traces of large paleochannels on the floodplains of the Volga Rivers basin is carried out, the regularities of their distribution are considered, the improvement of the method of analyzing the topography of river floodplains based on remote sensing data is proposed. Based on the analysis of high-resolution satellite images and digital elevation models of the Volga basin river valleys, more than 1700 sites with large paleochannels have been mapped. The morphology of paleochannels reflects the landscape and climatic differences between the northern and southern parts of the basin. The distribution of large paleochannels in the Volga basin apparently indicates that the duration and severity of paleoclimatic episodes of high river runoff on the East European Plain was maximum in the area that occupied by modern steppes and forest-steppe. To the north and south of this area there were fewer episodes of high runoff and therefore not too many geomorphological traces have been left in the river valleys.

Work with published and stock materials on the geomorphology of the Volga River valley within the Upper Volga Lowland made it possible to divide the history of research into three stages. The first stage includes the works of the 1930s–1960s, in which researchers present the results of geomorphological observations in different parts of the valley and offer the first versions of the valley’s evolution. We separate the results of largescale geological surveys of the 1950s–1980s into a separate stage – the time of obtaining detailed geological information about the valley’s structure. Since the end of the second half of the twentieth century, a gradual transition has been made to the third stage of research – the compilation of generalizations, the correlation of available materials, and the formulation of the main hypotheses about the Volga River valley evolution within the Upper Volga Lowland. We established that by the beginning of the XXI century there was no common understanding of either the morphology or the age of the Volga River valley in the Upper Volga Lowland. Nevertheless, based on a significant amount of factual material, we suggest our view of the river valley geomorphological structure. The Volga River valley in the Upper Volga Lowland has a floodplain and a staircase of three terraces. The floodplain should include the surfaces of narrow fragments along the channel up to 6 m high above the shoreline before flooding. The low (first) terrace is expressed at an altitude of 8–10 m above the shoreline. The middle (second) terrace has an extremely uneven downstream height: we refer to it levels from 10 to 15 m above the Volga River’s edge before flooding. We suggest that a wide terrace at a height of 15–17 m above the Volga River’s edge is the highest one, the third above the floodplain. The features of the geological structure of higher terrace-like surfaces do not allow them to be considered as terraces above the floodplain. We attribute them to the interfluve complex. There is also no single idea regarding the age of the Volga River valley within the Upper Volga Lowland – the beginning of its formation is attributed to the Late Moscow, and to the Early Valdai, and the Late Valdai (LGM). None of the known reconstructions have been supported by numerical dating of the terrace alluvium. To understand the features of the development of the Volga River valley needs a convincing chronological justification.

The paper investigates channel deformations at the Belaya River – a piedmont river in the Western Caucasus with low-stability channel crossing accumulative piedmont plain. The goal of this paper is to assess lateral channel migrations and vertical channel deformations and their main drivers: runoff fluctuations and sediment load using a quantitative analysis. The research is based on comparison of remote sensing data, in-situ observations and drone imagery collected in 2001–2020. We determined the relations between bank erosion rate and runoff fluctuations. The rate of bank erosion is closely related to the number and duration of bankfull discharge floods. The rate of bank erosion along meandering part of the Belays River is high, mean rate is more than 20 m per year whereas maximum rate is up to 70–80 m per year. The maximum rate of bank erosion is observed during high floods, when water level is varied from the tops of large ripples to floodplain edges. During rare extreme floods, when water inundates the floodplain, the mechanism of channel deformations that modifies and radically changes the channel is taking place. During such episodes the main stream moves to the floodplain channels, and bends get straightenedmations that modifies and radically changes the channel is taking place. During such episodes the main stream moves to the floodplain channels, and bends get straightened.

Using the Izborsko-Malskaya valley (Pskov region) as an example was considered the issues of the origin of glaciolacustrine terraces in overdeepened valleys widespread in the Late Valdai (Ostashkov, Weichselian) glaciations areas. Fragments of the one-levelled terrace in the northern part of the Izborsko-Malskaya valley, composed of fine-laminated sands, are adjacent to the lower parts of the valley slopes. This terrace could be determined as alluvial or kame terrace. Detail field and lab investigations allowed us to establish the formation of fine-laminated sands. They accumulated in the proglacial lake during the Izborsko-Malskayay valley’s deglaciation. Then the sandy thickness was divided by the water flow. The formation of the erosional incision should not be associated with the modern r. Obdekh. It tooks a more significant water flow then in the modern river. Perhaps the dissection of the primary glaciolacustrine surface and the initiation of an erosion cut in the bottom of the valley occurred during the proglacial lake discharge ~ 13.3 ka. The ice-dammed drainage happened rather quickly. That is why there is no variability in the composition and facies in the upper part of the glaciolacustrine deposits. Furthermore, the additional terraces are absent in the erosion incision. Thus, the surfaces of terrace fragments have an accumulative glaciolacustrine origin and their scarps - erosional genesis. The new data on the mechanism formation of terraces in the northwest of the East European Plain differ from current concepts. Along with the previously described mechanisms of glaciolacustrine terraces formation (abrasion activity of former proglacial lakes, gradual cutting of rivers, or the formation of slopes of glacial contact in kame terraces), one should bear in mind the possibility of cutting powerful water flows during catastrophic discharges of proglacial lakes. The investigation results indicate the necessity for detailed studies in valleys on the northwest of the East European Plain.

Within the valleys of streams of geothermal zones, where manifestations of gas-hydrothermal activity are noted, the processes of relief formation are accompanied by chemical and thermal effects. It has been established that in the valleys of the rivers under consideration: 1) the formation of specific accumulative forms of micro- and mesorelief both in the channels and on slopes occurs, 2) there is a processing of alluvial deposits and bedrocks by hydrothermal solutions, which leads to a radical change in both their properties, and the features of fluvial processes; 3) the activation of slope processes with the formation of landslide bodies and rockslide masses is observed due to which in the bottoms there is an accumulation of displaced slope’s material, including redeposited by mudflows. Typification of accumulative relief forms, the formation of which is associated with gas-hydrothermal activity, within the river valleys of 4 volcanic massifs on the Kuril Islands (volcanoes Mendeleeva on Kunashir Is. and Baranskogo on Iturup Is.) and Kamchatka (volcanoes Mutnovsky and Uzon-Geysernaya caldera) was carried out. The main forms of accumulative micro- and mesorelief associated with various manifestations of gas-hydrothermal activity are highlighted; their characteristics are given, morphometric parameters are described. Typical processes in the valleys of geothermal zones are not only the formation of various sinter forms and the cementation of floodplain and terrace deposits in places where mineralized thermal springs emerge, but also are forming of rather large landslide terraces and blocking of watercourses with dams composed of slope’s and mudflow’s material. Under the influence of acidic solutions, active weathering of bedrocks and boulder-pebble material to clays can also occur. Often, the sediments that make up floodplains and terraces, morphologically looking like typical pebble alluvium, are in fact a clay mass and are easily washed away by surface waters. With the attenuation of gas-hydrothermal activity, landslide bodies and drip forms overgrow and morphologically look like ordinary river terraces.

August 2021 marked the 100th anniversary of the birth of Yuri Alexandrovich Meshcheryakov, an outstanding scientist with an international name, inspirer and organizer of structural, geomorphological and morphostructural studies, the study of modern tectonic movements of the earth’s crust and many other scientific projects. In the last years of his short life, Yu.A. Meshcheryakov laid the foundation for another new and most daring scientific direction – satellite geography. The purpose of pioneering research was to study the possibilities of using space images in geomorphology and geography. The results obtained for the first time showed the high informativeness of space photographs in the study of morphostructures and morphosculpture of different genesis, the detection of a lineament in length 2500 km in the Sahara; for the first time, real transitional boundaries of landscape latitudinal zones of Africa were established. Yu.A. Meshcheryakov, assessing the significant prospects opening up for geographical science, proposed to create a Laboratory of Satellite Geography at the Institute of the IG as USSR Academy of Sciences, developed a program of comprehensive research on application of space images. After the death of 1970 Yu.A. Meshcheryakov, research on satellite geography using aerospace sounding and cartographic modeling methods has been successfully continued to the present day. The findings were confirmed in further domestic and foreign research in the field of aerospace sounding.

In 2021, we marked the 100th birth anniversary of Yuri Meshcheryakov, outstanding Russian geodesist and geomorphologist. The vast contribution of this progressively minded scientist of the postwar generation of Soviet geomorphologists to science made during his short life cannot but amaze. With no higher education in geography (he graduated with honors from the Moscow State Institute of Geodesy and Cartography) he promptly assessed, assimilated and accepted the main achievements of geomorphology in the Soviet Union and abroad; he organized large-scale collective studies of structural morphology and modern tectonic movements, developed the methods of geomorphological cartography and studies of exogenic processes of morphogenesis. A successful explorer and theoretician he had several new methods of structural geomorphological studies to his name; he organized large-scale collective efforts and supervised the studies and theses of his pupils. He took part in geological and geomorphological expeditions in the central and south-eastern parts of the Russian Plain, Bashkiria, the Volga and the Caspian areas, West Siberia and the Eastern Sayan Mountains which inspired him to elaborate and improve the use of certain geodesic and geographic methods in the studies of modern and ancient reliefs. He generalized and formulated the basic theoretical ideas about modern tectonic processes, methods of their studies and enriched geomorphology with qualitative methods of studies and geophysical approaches. As a scientific advisor he was personally involved in drawing, in the shortest time possible, of the first maps of the modern movements of the Earth’s crust in the European part of the Soviet Union and East European countries. He was the recognized leader of studies of the modern movements of the Earth’s crust. The Geomorphological Commission at the USSR Academy of Sciences set up in 1958 and the Geomorfologiya (Geomorphology RAS) journal, another unique project started in 1970 are indisputable evidence of his organizational talents; both have survived the ups and downs of our history. He was born at the right time in the right country. We should cherish his memory.