Biogenic transformation is one of the leading factors responsible for the state of the modern sea bottom. The goal of marine biogeomprphology is to understand all of the processes responsible for biological modification of the sea bottom. This review includes description, classification and quantitative analysis of the influence of biota on the sea bottom landscapes. The living organisms create biogenic structures and marine sediments, change bottom landscape, and physical and chemical properties of sediments and bedrock. They participate in biological weathering, redistribution of sediments at the sea bottom and within the near-bottom layer, convert dissolved calcium and silica into stable carbonates and silicates. Examples of marine biogenic forms include coral and polycaetes reefs, mussel and oyster banks. The organisms create both, positive and negative marine landform that may reach 10 and more meters in size. Borrows, holes, ditches, funnels created by walruses, turtles, whales, scouts etc. may persist on the bottom from weeks to months. Micro and macro organisms create notches at the sea level (bio-karst). Mangroves, algae and seagrass protect sea bottom from erosion and trap fine grain sediments. Fish transport sediments from reefs to lagoons. Macrophyte algae are capable to move cobbles and pebble size material to long distances (rafting). Many bivalve mollusks and other filter feeder organisms sieve mineralogic fraction filtering large volumes of water. Bioturbation performed by borrowing worms change physical and chemical properties, stabilize and compact marine sediments. The same species of organisms may both, increase and decrease strength properties of marine sediments. Diversity and variability of biological processes obstruct the understanding and quantitative assessment of the role of biota in geomorphological processes. With rare exceptions, the impact of single organisms on marine landscape is limited to a few cm, but integrated activities of organisms within the same habitat are causing noticeable changes. Practical applications of biogeomorphology are particularly useful in developing measures to protect coast from erosion.

The paper presents a review of the Holocene landscape and climate reconstructions for the forest zone of Central and Eastern Europe revealed from various proxies and comparison of the data obtained with the main stages of relief development and sedimentation during the Holocene. Projections of expected climate change are discussed according to IPCC scenarios (Coupled Model Intercomparison Project, Phase 5; Representative Concentration Pathways for possible range of radiative forcing). Analysis of the data showed that in the Early Holocene (11.7–8.2 ka BP), a rapid climate warming led to crucial transformation when all of landscape components were transformed, and relief-forming processes underwent significant changes. In the Middle Holocene, the time interval of 8.2–5.7 ka BP was characterized by the maximum heat supply in comparison with the whole Holocene and the weakening of the temperature gradient in the direction from west to east. At this time, a continuous zone of broad-leaved forests occupied the mid-latitude regions of Europe. Starting from 5.7 ka BP, the climatic cooling led to the sectoral differentiation of vegetation cover. In the western regions, the expansion of beech and hornbeam began, in the east, and the role of spruce in forest communities increased. Climate reconstructions for the Late Holocene (4.2 ka BP – present) have shown that against the background of the general climate trend towards a decrease in heat supply, periods of warming and cooling are distinguished. During the late Holocene the modern landscape cover was formed, the influence of the anthropogenic factor increased. According to paleobotanical, isotope-geochemical and paleohydrological studies in various regions of Central and Eastern Europe, the climate was drier than at present during periods of warming, mainly due to changes in the precipitation/evaporation balance, and climate cooling was accompanied by an increase in moisture. Bearing in mind the Holocene climate reconstructions as a possible scenario of climate changes during the current century, one can expect that an increase in temperatures, especially in the summer period, will cause the increase in the frequency of droughts and natural disasters, associated with irregular rainfall.

Braided river channels are very diverse both morphologically (in terms of the number and water content of channel branches, size and shape of islands, their position, ratios, evolution, etc.), and in the mode of channel changes. Nevertheless, both in Russian and foreign literature, when describing them, there are different points of view on terms and classifications that define them, which make it difficult to analyze types of braided channels and regimes of channel changes, possible reactions of channels to changes in factors due to too much generalization. The classification of Moscow State University is considered to be an exception. It is constantly being improved as new data are obtained based on scientific research. Braided channel reaches are formed at several structural levels – point, midchannel bars, channel (island), floodplain-channel and floodplain (split channels). Each higher level of braided channels includes channel types of the previous levels. The main channel patterns that determine channel regime of braided rivers are island-braided channels, along which there are distinguished morphological homogeneous reaches or single patterns of channels or certain channel branches. In turn, in island-braided channels each of their types has several varieties depending on the number and morphology of islands, channel stability, water content of channel branches and peculiarities of water and sediment runoff dispersion along them. Braided channel types and their varieties are characterized by certain values of the flow quasi-uniformity indicator of I.F. Karasev and special coefficients in hydrological and morphological relationships linking morphological parameters of channels with characteristics of determining factors. The article provides a detailed, most complete classification of braided channels and substantiates the use of terms and concepts that characterize each type or braided channel reaches and their elements.

The main goal of this investigation is to establish the relationships between linear and areal expansion of gullyes based on their morphology, dimensions and hydrometeorological conditions. Instrumental methods for studying linear and areal growth of gullyes on agricultural land for the period from the early 2000s to 2017 are considered. The instrumental methods of the study included a planned geodetic survey of the top part of the gullyes, including the edges, talweg and transverse profiles using an electronic total station. Records from the three nearest meteostations and stream gages were used in the analysis. The objects of the study include 6 gullyes of various types (at the watershed, near-valley, top and bottom), developing within 6 key areas, where their catchment areas are arable land used for crops of legumes and forage crops. The main purpose of the research is to identify the relationship between the linear and areal growth of ravines, depending on their morphological and morphometric features and hydrometeorological conditions. For two of the gullyes under consideration, the maximum erosion was observed in 2001, when the linear headcuts retreat varied from 2.3–21.8 m, and the areal ones, respectively, from 23.1 to 436.7 m². It is established that in most cases there is a clear relationship between the considered indicators, which is most typical for a bottom single-top gully and at the watershed growing with three headcuts (r = 0.832). A fairly high correlation was also found in the nearvalley single-top gully on the right slope of the Vyatka river valley (r = 0.790), which erodes periglacial alluvium within the locality. The average relationship was observed in the single-top (r = 0.569) and technogenic three-top gullyes (r = 0.567) developing in different key areas of the right bank of the Kama river. No connection was found only in one top gully growing in the upper part of the Holocene gulch bottom with three headcuts (r = 0.269), which is explained by the technogenic redistribution of runoff in the plowed catchment of the gully. A smooth change in the area growth over the years and a rather sharp fluctuation in the values of the linear growth of the headcuts of gullyes, regardless of the type and their morphological and morphometric features, were revealed. The dependence of their annual growth on the conditions of land use in the catchment area and their morphological and morphometric features has not been revealed. The analysis of hydrometeorological indicators for 1998–2016 and the linear growth of the considered gullyes did not reveal a close relationship with any of the analyzed factors. A significant relationship between the area growth in 2000–2016 was found only in two gullyes with the intensity of snowmelt and the annual amount of precipitation, and, accordingly, a moderate relationship with the intensity of flood runoff in the line of the nearest small river. The research has shown that the spring flood runoff has ceased to play a dominant role in the linear and areal growth of gullyes during the period under review.

This paper presents results of comparative analysis of the sediment budgets of the Ob’ and the Yenisei, base on universal erosion equations, RUSLE using 250 m resolution DEM GMTED 2010. Cumulative volumes of sediments accumulated in the stream catchments were estimated calculating the difference between erosion and sediments runoff of the studied basins. Thus, the difference between total erosion (watershed erosion + bank erosion) is (1250 MT/year + 35 MT/year) for the Ob and (315 MT/year + 21.9 MT/year) for the Yenisei. Sediment runoff in the mouths of both rivers estimated based on MSU data is 63.5 MT/year for the Ob and 32.5 MT/year for the Yenisei; Sediment runoff in the mouths estimated based on Roshydromet data is 16 MT/year for the Ob and 2.4 MT/year for the Yenisei. Sediment runoff was used to calculate the total deposition of matter in the catchment area during the transport of sediments from sources to sinks, for the Ob total deposition is 1270 MT/year, for the Yenisei is 335 MT/year. For the unregulated part of the Ob’ catchment, the accumulation was 56.5 MT/year, and for the unregulated part of the Yenisei catchment was 43 MT/year. The coefficient of reduction of sediment runoff (1/SDR) downstream, based on new samplings of sediment runoff in 2018–2019 in the mouths of both, Ob and Yenisei, was 2.3, and for the entire catchment area 20 and 30 respectively. Volume of sediments moved by denudation processes in the basin ends up being redeposited within the same fluvial systems. Thus, under the current hydro-meteorological regime, the large drainage basins in Russia and elsewhere are major depositional systems.

Glacial degradation of Pamir, growth of alpine lakes area, of stream discharges, frequency and risk of natural disasters are all results of increasing summer temperatures. The influence of climate change on the growth of the potential risk of outburst floods and debris flows in the Western Pamirs has been proved, using the example of a typical glacial basin of the Varshedzdara River (the Gunt River tributary). Detailed field studies of the basin, including bathymetric and aerial surveys, revealed the instability of the unconsolidated moraine impounding Lake Lower Varshedzkul, the presence of an ice core in it, and the presence of active rock stream, a large amount of material potentially involved in debris flow, in the river valley. Estimated volume of water contained in lakes Lower Varshezkul and Higher Varshezkul are 1.94 million m³ and 3.57 million m³ respectively. The area of glacial lakes in the Varshedzdara river basin has increased 3 times over the past 40 years (from 51.7 tsd m² to 173 tsd m²), and the area of the Varshedz glacier has decreased by 11% (from 7 mln m²  to 6.2 mln m²). The maximum volume of a debris flow in the valley was estimated at 5.73 mln m³, the debris flow discharge was 1000 m³/s. If both lakes are to breach simultaneously, an estimated discharge would reach 3.725 mln m³. That includes half of the volume of Higher Varshezkul and the entire volume of Lower Varshezkul lakes. According to the results of mathematical modeling, it was found that the lag time for the stream reaching the settlements is only 0.1 h, the buildings and the highway located on the debris cone will be inundated up to 3–4 meters with flow velocity of 3 m/sec. and destroyed. The results can be interpolated to other glacial basins of the western Pamirs, in which growing glacial lakes are located, and the potential hazard will increase.

Late Pleistocene reconstruction of the lower part of the Moksha River valley (between the mouth of the Tsna River and the mouth of the Moksha River) was completed using mechanical coring and radiocarbon (AMS) dating of alluvium in the river valley bottom. Results revealed that between 40–30 ka BP, the river incised deeper than the present level, due to the increase of the river runoff associated with climatic changes. Later the incision was replaced by the valley infill caused by the drying up of the climate and a lowering of the river runoff, that was more significant during the last glacial maximum (LGM, 23–20 ka BP). Sediments derived from scarcely vegetated slopes activated by cryogenic processes from drainage area caused changes of river’s longitudinal profile due to sediment accumulation. In the Late Glacial time starting from 18.5 ka BP a significant increase in river runoff led to the formation of macromeanders and widening of the valley bottom. The Holocene was characterized by a decrease in runoff and channel parameters, and narrowing of the meander belt of the river. During interglacial, sediment accumulation in the channel was negligible because of decreased sediment supply from the eroding basin.

The analysis of a large complex of materials – satellite images, UAV surveys, meteorological observations of polar stations, and archival data made it possible to establish the shoreline retreat rates of Ushakov Island. The island is entirely coved by the glacial dome formed above the late Cretaceous and Quaternary rock formations. The ice/rock interface is partially located below sea level. lying on the Ushakov island is located in the northern part of the Central Kara Upland and was discovered in 1935 by Soviet sea expedition visited by scientific expeditions extremely rare. For a long time, Ushakov Island was maintained by slightly negative (up to 1% volume annually) ice balance, a short ice-free period, and protected from storm waves by fast ice. At the beginning of the XXI century, the situation changed – the air temperature began to increase noticeably, the area of sea ice decreased, and the wave activity increased during the warm season. The edges of Ushakov ice dome began to break off and float into the sea as icebergs evenly around the perimeter with an increasing rate: from 10.9 m/year in 1954–2011, up to 27.3 m/year in 2011–2019. The area of the island decreased in 2002–2019 by 230.8 ha/year, in 2015–2019 – up to 294 ha/year. The glacier surface around the polar station has decreased by 15 m in 65 years. A monument of science and technology - the polar station (built in 1954, 800 m from the edge of the glacier) was washed away to the sea in 2018. The subtype of ice shores has changed from ice barriers up to 3 m high (low cliffs of floating ice) to ice walls up to 45 m and more.

Investigation of the 8–10 m high river terrace structure and composition was completed at the archaeological site in the lower Khoito-Aga river. Absolute age of the terrace was estimated using radiocarbon dates of alluvium and buried soils. The results were compared with regional studies of low terraces in the Zabaikalie. The terrace deposits formation stages during the second half of Late Pleistocene and Holocene were identified. The covering genetic complex sediments (2 m) include the Hobdori draw colluvial fan deposits, aeolian, aeolian– deluvial sands and sandy loams, soils. The Сhernozem soil (0.2 m) is recorded in the excavation top. According to archaeological data, it formed during the last ~4.5 kyr. At depths of 100–200 cm, an Early MIS 2 pedocomplex with two humic soil horizons (were dated ~23.4–21.3 kyr BP) was excavated. Soils formed during warm and moist climate stages when rates of exogenous processes were decreased. The completion of alluvium accumulation and terrace escarpment formation were dated ~30–29 kyr BP (MIS 3 and 2 boundary). Interlayed fine–grained and different–grained sands with grus, rubble, gravel alluvial (1.5 m) sediments separated by Late MIS 3 cultural horizons (0.15–0.25 m) with an age of ~ 32.5–31.7 kyr. Within archaeological site Sakhyurta–1 five cultural horizons (CH) were identified with 494 artifacts in total. The cultural horizons 1 and 2 associated with modern soil. The collection of artifacts corresponds to the archaeological sites of the Late Neolithic–Bronze age for Transbaikalia area (4.5–2 kyr BP). Cultural horizon 3 corresponds to the Early MIS 2 pedocomplex (23.4–21.3). СH 4 correlates with terrace alluvium top (31.7–30). СH 5 is associated with alluvial buried soil was dated ~32.5–31.7 kyr BP.