Aeolian-accumulative complex Sarykum is one of the highest isolated (i.e. formed away from the deserts) sandy landforms in Eurasia, located within the Terek-Sulak lowland plain at the north-eastern foothill of the Caucasus Mountains, 16–17 km towards WNW of the Makhachkala City port of Caspian Sea (Republic of Dagestan, Russia). On the basis of particle size distribution and mineralogical analysis of 59 sandy samples, the heterogeneous structure of the complex is defined. The coarsest sandy material (modal values are 352 micron and more) composes the central dune-ridge segment of Sarykum (of so-called Great (or West) Sarykum). The further from the dune constructions to the periphery, the thinner the average dimension of the sand particles and smaller the modal values (249 micron and less) of their granulometric spectra. This grain size distribution can be explained not only by windy sorting of the sands and further aeolian recast of dune-ridge segment, but also by spatial features of the facial changes during the period of initial sandy accumulation, and also by the differences in composition of rocks, which were the sources of denudation. In the vertical structure of Sarykum the heterogeneity is also expressed. It is associated with temporary changes of sandy sedimentation conditions in the region. So, the dune-ridge segment of Great Sarykum can be represented as a system of consistently accumulated sandy layers (lenses?) (which includes the gravelly sands), which differ in composition and age, having apparently the coarsest content in the middle part of its vertical geological cross-section.

The material of overwhelming majority of the selected samples belongs to mineral group of quartz sands (quartz content is over 90%) and subgroup of quartz subarkose (quartz content is 80–90%). Moreover, the aeolian (defl ated) sands of the dune-ridge segment and its underlying cross-bedded sands of Great Sarykum entirely belong to the first group; the hilly and peripheral sands, which characterized by fine granulometry, refer to the second mineral subgroup.

The Sarykum’s structure is due to the combination of gravelly sands, formed by the river Shura-Ozen’ deltaic accumulation in the Late Quaternary, and sandy (with gravels and pebbees) deposits proluvially and deluvially dislocated to the recent Sarykum massif territory from the slopes of the nearby Narat-Tube mountain range. The mixing of originally and compositionally different sediments that formed the Sarykum complex, likely have the complicated history, following by the staged changes of the periglacial landscape-climatic conditions in the Late Quaternary.

Observations in various volcanic regions revealed the features of the interaction of lava covers and river flows. The specific structure of the lava flows – the presence of lava tubes considerable length – leads to the fact that waterways can use these voids within the lava flow and in some cases watercourse continues under lava that filled his valley. As a result sometimes younger alluvium may lie not only above, but under more ancient lavas, as well as in their cavities. So it’s necessary to be careful to define the age of lavas and alluvium on their mutual bedding. New incisions on the surface of lava covers are formed not only in their marginal parts – on contact with the less resistant rocks that has been well studied, but also: 1) in embryonic valleys – downhill oriented fallings between lava flows, 2) above lava tubes in places of their roofs collapse and 3) in the cracks, which contribute to the concentration of underground waters.

The Hamrin reservoir, located on the Diyala River (left tributary of the Tiger River), differ for its unusual shape, large surface area and small depth, a significant level fl uctuations in the long-term dynamics and great depth of drawdown, and intense siltation. Intensive siltation of the reservoir caused by the arrival of material from solid river fl ow and from hollow (basin) slopes in which bottom reservoir is located. In rainy season the material moved through the temporary streams channels and deposited on alluvial fans at the foot of the slopes. In winter and spring seasons of reservoir’s full filling, at high water-level and under the process of wave increasing the various forms of underwater and above-water coastal forms of relief are developed. In dry summer season part of water area is dry out. Accumulative processes develop under low level of wave action; at that a big role belongs to soaking of sandy-clay material which composes the lower parts of the underwater coastal slopes. Drained part is involved in agricultural productivity. Annual renewal of the coastal relief induce the activity and abrasion-accumulation, anthropogenic double quick erosion and natural slope processes, so the rate of banks retreat is not reduced. Anthropogenicnatural reservoir system is still on the stage of activation, when stable relations between elements of new relief and environmental factors not yet formed, so the intensity of banks re-formation is not reduced, and siltation of the reservoir will be continued.

The identifying of characteristics of the landscape with regard to their belonging to various elements of the relief, the determination of the changes in time and space, the consequences forecast of natural-anthropogenic and anthropogenic impacts on geoecosystem are conducted as a result of the mathematical and geomorphological modeling of the landscapes subjected to erosion and the use geographic information for analysis of degradation. GIS modeling and mapping are carried out taking into account many-sided information from distributed and concentrated databases, high-resolution satellite imagery, space map and DEM. The authors developed a modified model of the system “Height – Shape slope – Length” in view of its reference to the center of mass. It was found that most of the slopes profile has the view of an S-shaped curve, which is described by the logistic function provided in normalized values with a high correlation coefficient (more than 0.995)

h(l) = (100 – 5t)/(1 + 69.7 · exp((0.434 – 0.033t) · l + (2.59t – 35))) + 5t.

where: h(l) – current height of a profile, %; 69.7 – coefficient determining the position of the mass center system “Height – Length – Shape slope”; 0.434 and 0.033 – factors that determine the shape and incline of the curve; l – the width of the profile section,%; t – the period of normalized time.

At that, digital models of status and dynamics of relief in connection with the geocoded information, and the space images of the studied surface of allow to determine the spatial disposition, shape and topology of geoecosystems. Modeling of landscapes is the basis for identifying the existing erosion relief, as it refl ects already established, for some time, situation, as well as when identifying stable relationships allows predicting the erosion state of such landscapes.

Buildings aerating features are one of important characteristics of urban environment. The CFD method (realized in the UrbaWind software) was used for quantitative assessment of relief (topographic) infl uence on the aeration of urban residential zones. The necessary stage of CFD-modeling is creating of geometrically correct image of real landscape. The model must include Earth surface, buildings and main groups of trees. Modeling need such input data as digital elevation model (DEM), digital buildings model and field anemometrical data (for verification of computer simulation results). Then these results analyzed by methods of mathematical statistics. The assessment of topography infl uence on the aeration of two residential areas was implemented: 1) for group of urban square with different number of storeys to north from historical center of Kursk including the part of Kur River’s valley; 2) for one urban square on leveled surface of Tuskar’ River’s fl oodplain. The infl uence of topography on the aeration of residential sites is possible to define by comparison of wind field characteristics by different directions for two conditions: ideal fl at topography and real topography. The comparison is convenient to realize by Pearson-correlation (R-coefficient) of pairs of mean speed values in the same points of model. On the whole, the minimal values of R are inherent to the more topographical dissected area (site №1). By some directions the minimal values of R are inherent 1) to general aspect of Earth surface on the site; 2) to aspect of the most sloped area – fragment of erosional scarp of Kur River valley in the shape of cirque. The morphology of Earth surface even in plain environment infl uences on the urban area aeration.

Based on the analysis of cartographic documents and hydrological data, as well as detailed studies of fl uvial processes in the Upper Oka, carried out in 1990-ies and continued in 2010–2015, it was found that the longitudinal profile of the river was significantly infl uenced by anthropogenic river bed disturbances – exploitation of in-stream mines of alluvial construction materials, concentrated in the middle reaches of the river within 400–800 km from the source. Changes in river bed morphology and sediment deficiency has resulted in the deep erosion. To determine the role of anthropogenic disturbance in the longitudinal profile formation, in accordance with the N.I. Makkaveyev’s approach, the calculation of graded longitudinal profile and its comparison with real one were performed. By calculating the stream-gradient index proposed by J. Hack, the uneven gradient distribution was revealed along the entire river and on separate typical sections. The highest values of the stream-gradient index observed at the site where mechanical modifications are the most – between Kaluga and Kolomna Cities. On this stretch of the river in the late 1930s, the longitudinal profile in most aspects practically coincides with the calculated graded profile. However, mechanical changes of the river bed and the accompanying river bed degradation has led to the fact that along with general elevation decrease, profile became ungraded, and one can expect some deformations aimed at its restoration. As a result, the difficulties in using the resources of the river, which emerged in the early 1990-ies, have increased.

Reconfiguratings of the Lena river bed near Yakutsk city (one of the most complex part of the river concerning channel deformations) have directional character, and it caused gradual river drift away from the city. Development of the right-hand tributaries system mostly occurred near Yakutsk, meanwhile the left-handed ones (where the city is situated) grow shallow, and it leads to troubles in operation of municipal water intakes, water accesses to the city, complication of navigability etc. Nowadays the Lena river development is defined by: 1) transforming of the adjacent tributaries into parallel-channeled ones near Yakutsk, upfront not-forks in upper reaches and alternate one-sided forks in the lower reaches; 2) multidirectional river channel shift near Yakutsk – towards right with the right branch development, and towards left with development of shallow bend – on the adjacent section in upper reaches; 3) transgressive shift of the fl ood-plain island massives – its washaway from the heads and extension of the downstream ends, which lead to the shallowing of left branch (Adamovsky channel) near Yakutsk and development of the right-hand channel here.

General regularities of the river bed reconfiguratings allowed to elaborate the trial scheme of recommendations to castigation of the present negative situation on the Lena river near Yakutsk city based on the river processes management and formation of conditions for its development in right direction, as well as to validate the program of detailed researches for the mathematic modelling of the river bed reconfigurations and engineering of hydrotechnical measures.

The article is dedicated to the peculiarities of the dynamics of thermoabrasional coasts of the Kara Sea in the area of the gas main pipeline “Bovanenkovo-Ukhta” crossing of the Baydaratskaya Bay. The coasts in Yamal and Ural key sites differ signifi cantly both in wind wave conditions and in criolithologic structure. The study was based on the results of the coastal retreat fi eld monitoring, carried on since 1988. Spatial and temporal variability of the thermoabrasional coasts dynamics have been estimated. The effect of wind-wave and thermal factors on the temporal variability of the coastal dynamics has been determined. We have found out that average coastal retreat rates in natural conditions vary from 0.3 and 1.2 m/year at the Yamal key site and from 0.5 to 2.4 m/year at the Ural key site. Spatial variability of coastal retreat rates in the Baydaratskaya Bay is determined by the geomorphological structure of the shore. It is more considerable in the Ural key site than in the Yamal key site because of more complex geocryological structure and the presence of ground ice bodies. Temporal variability of coastal retreat rates of the Baydaratskaya Bay in natural conditions is mainly determined by the wind-wave factor at the Yamal key site and by the combination of wind-wave and thermal factors at the Ural key site. It is better expressed at the Ural key site than at the Yamal key site, along with spatial variability. In 2009–2012, the main factor determining the coastal dynamics at both Yamal and Ural coasts was the technogenic factor.

Nikolay S. Blagovolin (1927–2006) – scientific researcher of Institute of Geography AS USSR (RAS), talented geomorphologist which creative career during more than 40 years was associated with the Crimean Peninsula. His academic interest was focused on the Crimean Mountains morphostructure, history of relief development, including the stage of modern tectonic movements. He was one of the authors of unique approach of complex field and an office study which was optimized in 1960–1970 years within the territories of the geodynamic field test sides including Crimean one. N.S. Blagovolin is the author of more than 60 scientific papers on the Crimean geomorphology.