Aeolian Relief Research Articles

The dynamics of Pilkosios Dunes relief during 2010–2022, based on the digital elevation model analysis

To assess aeolian relief dynamics in Pilkosios Dunes, 6 digital elevation models (DEMs) were prepared from the year 2010, for January, May and October of 2018, for May of 2019, and for November of 2022. These DEMs were then compared with each other to obtain elevation difference rasters through time. The obtained results indicated that elevation changes were directional through time, and their highest intensity coincided with the bare-sand surface class, where active blowout landforms were located. In these locations, the average negative elevation change rate was determined to be approximately 2 cm/year. To analyse the driving forces of these elevation changes, the relationships between a measure of elevation change and the tested factor characteristics were evaluated. The strongest relationship amongst all tested factors was found with the distance to the edge of grassland/bare sand. Locations that were farther away from this edge experienced a four times larger decrease in elevation, compared to areas closer to the edge. The distance to the shoreline, which is related to the absolute altitude, was also an important factor. This relationship can be summarized as follows: the lowest areas, which were further from the lagoon, were inactive; while the highest locations, which were closer to the shoreline, had the highest intensity of elevation change (averaging 0.5–0.7 m for adjacent to the shoreline locations and -1.7 m for locations ~ 300 m away from the shoreline). The slope factor described a trend of how the steepest slopes were decreasing in height by 2 m on average, while gentler slopes were mostly stable.

Пространственное распределение естественного и антропогенного эолового рельефа на севере Западной Сибири

The authors show the differentiation of the modern aeolian landforms spatial distribution (natural and anthropogenic origin) for the northern part of the West Siberian Plain (an area of about 800 thousand km2) based on the analytical processing of Sentinel-2 satellite images (resolution 10 m/px). A deciphering technique was developed; it includes the use of unsupervised ISODATA classification algorithms, visual editing, verification of results based on high-resolution satellite images, and standard spatial analysis procedures. In total, 404,675 aeolian relief objects with a total area of 2228,18 km2 were identified. The average area of natural forms was 0,44 ha (the largest share in the Yamal district of the Yamalo-Nenets Autonomous Okrug – 1,02 %), the average area of anthropogenic forms – 2,84 ha (the largest share in the Purovsky district of the same region – 0,19 %). It was revealed that in the territories of oil and gas production, the maximum area of both natural and anthropogenic aeolian forms corresponds to the boundaries of the Urengoy field (19,14 and 34,58 km2, respectively). It was established that in the Yamal Peninsula, the modern aeolian relief is confined mainly to marine and hydroglacial deposits, while in that of Gydan Peninsula, a connection can be traced with glacial or marine ones that have experienced direct mechanical action of cover ice. It was revealed that the mentioned relief is often formed in areas with increased drainage, facing towards the direction of the prevailing winds in the spring-autumn period (terraces and the watershed of the Pur and Nadym rivers). The results of the study can be used at monitoring the reclamation of disturbed areas and the natural dynamics of vegetation as an indicator of global climate change in the north of Western Siberia.

Study of Holocene aeolian morpholithogenesis of the Eastern coast of the White Sea using georadiolocation and palaeolimnological methods

Abstract. Holocene aeolian topography and sediments were investigated at two key sites on the Zimny Coast and one key site on the Kaninsky Coast of the White Sea. Field work included ground penetration radar profiling, paleolimnological and geomorphological study, as well as aerial imagery and topography surveys. Analytical studies including grain-size, geochemical and diatom analyses and radiocarbon dating of lake sediment cores were performed. Accumulative aeolian relief was formed in areas with a positive coastal-marine sediment balance. The sands are brought in by a longshore drift or river discharge. The aeolian topography and the number of stages of aeolian activation vary across the key areas. The present-time coastal dunes have been forming since the late or middle Holocene, when relative sea level became close to contemporary levels.

Features of aeolian relief formation of the sandy massif Suvinskii Kuitun in the Barguzin Depression

The principal objective of the article is the determination of the main features of the aeolian relief formation of the Suvinskii Kuitun sand massif, one of the regions of active modern aeolian morphogenesis in the Barguzinskaya Depression. A brief description of the morphology of the aeolian relief, characterized by the predominance of deflationary forms over accumulative ones, is given. Among the forms of active deflation, deflation basins dominate here, separated by elongated deflation inselbergs, composed of sands of lacustrine, alluvial, deluvial-proluvial, and aeolian genesis. The mineralogical and granulometric composition of sandy deposits in the southern part of the Suvinskii Kuitun, characterized by poor roundness of sandy grains, has been analysed. A distinct northeastward eolomotion was revealed towards the foothills of the Ikat Range and its accumulation there. The age of the aeolian sands, mainly related to the formation of the Tagar culture (the end of the Bronze Age) was determined. The phytomelioration carried out in the second half of the 20th century led only to a partial fixation of sands, without affecting their overall deflation in most areas of the Suvinskii Kuitun.

Modeling of near-surface flows over an aeolian relief

As a result of interaction of an air flow with the elements of an aeolian relief, the character of the flow changes. It affects both the conditions of dust blowing from the surface and the surface shape itself. A model is developed for the formation of the windward slope under the influence of wind. It makes it possible to estimate the dynamic speed when moving up the windward slope on the basis of data on height and movement of the dunes. The coefficient of linear change in the dynamic velocity and its decrease with increasing structure are obtained. This property is probably due to a change in the nature of the flow and circulation at the surface. To study such problems, dome methods are applied to simulate the air flow near a complex 3D surface using the open OpenFOAM package with a 4-level spatial grid. A technology is also proposed for converting the digital terrain data into a format understandable to mathematical packages for modelling of air flow around a 3D object. Based on the simulation results, the coefficient of linear change in the dynamic velocity for aeolian structures with a height of about 100 m has been calculated, which generally corresponds to values obtained from theoretical estimates and real data on changes in height and movement of dunes.

Risk assessment of dangerous Aeolian processes within the Baikal rift zone

Among dangerous natural processes in the Baikal region we emphasize aeolian processes of high intensity which is due to dust storms caused by hurricane winds. The factors of the process development were studied, and special attention was paid to the wind regime and seismic activity, as well as to the catastrophic consequences and damage. We analyzed the number and duration of dust storms, calculated the deflation potential of the wind and the energy of the air flows. The morphology of aeolian relief forms, both deflationary and accumulative was studied. We forecasted sand dune drifts based on the analysis of the charted sand rose. Differences in structure, mechanism, and intensity of the processes are revealed depending on the hydroclimatic conditions during the monitoring period. In connection with global climate change, which is manifested in the Baikal region by an increase in the number of arid years of observations (35%), and the frequency of emergency situations associated with natural processes increases. It is necessary to continue the monitoring of aeolian processes in order to create long-term and short-term forecasts to avoid catastrophic consequences.

Model of the windward slope formation of the eolian relief form

The model for establishing the windward slope upon exposure to the air flow is based on the analysis of the state of the layer composed of sandy incoherent particles. It is assumed that the wind removal of individual particles of this layer leads to a change in its length due to rolling and immobility of larger particles. Accounting for precipitating saltating particles gives an idea of the reasons for the alternation of layers of large particles with layers of smaller ones involved in wind-sand transport. Assuming a linear dependence of the dynamic velocity on the height of the location on the windward slope, the forms of the windward slope, which are close to the observed ones, are obtained. An algorithm for determining the linear coefficient of change of dynamic velocity is proposed. The calculation of the relative change at different levels of the windward slope of the values of the roughness parameter and the scale of the laminar layer made it possible to estimate the coefficient of surface resistance.

Transformation of aeolian relief forms under wind influence

The interaction of the air flow with the surface consisting of sandy disjoint particles is considered. Taking into account their mobility on the surface in the calculations allows us to describe the reasons for increasing the stability of the layer of particles bordering the air environment. The value of the threshold wind speed required for the removal of the particle increases due to the change in the pressure difference above and below the particle relative to the same value at a stationary state. The number of surface particles to be torn off when the wind reaches the threshold values increases. This circumstance allows to explain one of the possible reasons for the appearance of the known effective change of gravity acting on the layer, with the growth of eolian forms of relief. For inclined surfaces, the balance for the flows of falling and torn off by the wind particles is disturbed due to the difference in resistance to the effects of air flow. The differentiation of the eolian form of relief on the area with different intensities of wind removal makes it possible to estimate the relative increase in mass, which determines the optimal distance between the two structures for sustainable growth.

Lake water and talik groundwater interaction in continuous permafrost, Central Yakutia

Structural features of a lake talik associated with eolian relief are discussed. Analysis of hydrochemical and hydrological data for 2010-2017 showed that talik groundwater feeds lake and maintains perennial outflow from the lake. Variations in the chemical composition of the lake and outflowing creek are characterized on an annual and interannual basis. Seasonal comparison of hydrochemical data indicates a downward trend in dissolved-solids content of the lake water over the last six years, suggesting an increasing contribution of suprapermafrost groundwater to the lake and lake talik. Probable reason of enhanced suprapermafrost flow is increase of its duration due to observed rise of winter air temperature.

Przemiany wybranych form rzeźby terenu województwa łódzkiego w ostatnim stuleciu

The paper presents changes in the relief of the Łodź Voivodeship over the past 100 years. In view of a shortage of data, only a few cases of changes to aeolian landforms and to selected forms appearing on the slopes of gullies and other young erosional cuts were described. The transformation of aeolian relief in the last 100 years was associated with the formation of small, initial aeolian hillocks and with the transformation by wind of older late-glacial dunes. The changes to gullies involved rapid transformation of their slope profiles under the influence of soil cultivation and comprised from 2.18 to 51.4% of the gullies’ slopes. As in the case of the dunes, the transformation of the relief both of former Neoholocene gullies, and of young, small, but permanent erosional forms originated on the slopes took place. Relief analysis of aeolian landforms and features occurring on the slopes was preceded by consideration of the vulnerability of the Łodź Voivodeship area to aeolian activity and slope processes.

Exogenous processes and problems of rational nature management in the Selenga river transboundary basin

The problem of soil degradation as a result of deflation remains particularly relevant for the territory of the Selenga midland. Based on historical data, it led to huge losses in agriculture, the dust storms, sand filling of settlements and roads. The problem of desertification is closely connected with the processes of aeolian relief formation. Therefore, the development of effective policies and practices to prevent desertification requires investigations of geomorphological systems response to climate change and anthropogenic impact. The necessary data can only be obtained in the course of interdisciplinary research involving geography and geology methods and historical materials. This paper presents the data on the dynamics of aeolian relief formation during the Holocene and historical era in the central part of the Selenga midland. Based on the study of soil-sedimentary sections and its radiocarbon dating the stages of soil formation corresponds with an relatively favorable climatic conditions were distinguished. Arid phases correspond to activation of aeolian processes and manifest themselves as horizons of loess and sand deposits overlying the buried soils. The most intense, they were proceeded at the Late Glacial – Holocene border (12.9 – 11.7 kyr BP) and Early Holocene (10.5 – 9.4 kyr BP), in the Atlantic (8.6 – 6.9 kyr BP), beginning (∼ 5.4 – 4.8 kyr BP) and the end (∼ 3.4 – 2.9 kyr BP) of Subboreal period of Holocene. Analysis of historical and literature data revealed the process of farmland degradation into desert landscape, unsuitable for further agricultural use. For this territory results of investigation of the morphological structure, the rate of aeolian landforms formation and particle size distribution of the constituent of sand are presented.

Eolation dynamics in the shore of artificially impounded bodies (by the example of Bratsk water reservoir, Russia)

The process of eolation in the near-shore area of the Bratsk water reservoir results in the landscape changes and may lead to abrasion process activation. The eolation dynamics factors are water level and wind conditions. The eolation shows a cyclical pattern that is primarily related to the duration of low stand of level. The eolation processes that differ in sedimentation rate, water level and morphology of eolian relief forms ranging from mere sand blowing to travelling dunes have been phased in studies of the sections of dune sand deposits. The topography model of index plot Rassvet that makes it possible to scale the process of eolation and to know some regular trends and mechanisms of its development has been constructed as result of eolation dynamics research.

Формирование и развитие эоловых форм рельефа на территории национального парка «Бузулукский бор» по материалам космических снимков высокого разрешения

Формирование и развитие эоловых форм рельефа на территории национального парка «Бузулукский бор» по материалам космических снимков высокого разрешения

Растительность песчаных степей Оренбургской области

Растительность песчаных степей Оренбургской области

Intensity of geodynamic processes in the Lithuanian part of the Curonian Spit

Abstract. The paper considers conditions and intensity of aeolian and dune slope transformation processes occurring in the wind-blown sand strips of the dunes of the Curonian Spit. An assessment of the intensity of aeolian processes was made based on the analysis of climatic factors and in situ observations. Transformations in aeolian relief forms were investigated based on the comparison of geodetic measurements and measurements of aerial photographs. Changes in micro-terraces of dune slopes were investigated through comparison of the results of repeated levelling and measurements of aerial photographs. The periods of weak, medium, and strong winds were distinguished, and sand moisture fluctuations affecting the beginning of aeolian processes were investigated. The wind-blown sand movements were found to start when sand moisture decreased by 2 % in the surface sand layer and by up to 5 % at a depth of 10 cm. In 2004–2016, the wind-blown sand movements affected the size of reference deflation relief forms: scarp length by 8 %, scarp width by 35 %, pothole length by 80 %, pothole width by 80 %, roll length by 17 %, roll width by 18 %, hollow length by 17 %, and hollow width by 39 %. The elementary relief forms in the leeward eastern slopes of the dunes experienced the strongest transformations. During a period of 5 months, the height of micro-terraces of the eastern slope of the Parnidis Dune changed from 0.05 to 0.64 cm. The change was related to fluctuations in precipitation intensity: in July–August 2016 the amount of precipitation increased 1.6-fold compared with the multiannual average, thus causing the change in the position of terrace ledges by 21 %.

TO THE 150 ANNIVERSARY OF OUTSTANDING RUSSIAN DESERTOLOGIST V.A. OBRUCHEV

V.A. Obruchev studied relief of deserts and eolian relief forming under new tectonics development. Up to him new tectonics corresponded with those earth crust structures which formed under very young movements took place in the end of Tertiary and first part of Quaternary period. Last researches in various countries found out that these movements greatly spread and play significant role in present-day relief forming. In his opinion, separating them from Alpine tectogenesis cycle is necessary because in some cases they appear more or less hard in those Earth’s regions where structures were formed by more early cycles – Hercynian or even Caledonian, and Alpine cycle were absent or poor.

Растительность развеваемых песков и песчаных степей нижней части бассейна р. Селенги (Республика Бурятия)

Modern aeolian relief is widespread in the forest-steppe landscapes of Transbaikalia. Valleys of the Selenga River and its inflows are the areas covered by ancient sandy deposits. Human impact in dry climatic conditions causes intensive wind erosion and formation of open and moving sands covered with sparse plants. The flora and vegetation of such landscapes notably differ from surrounding territories. It’s particularity is caused by presence and domination of plant species usually seen on open sands. Despite of numerous publications describing the sandy dunes of Transbaikalia, the psammophyte vegetation and natural dynamics of sandy landscapes are poorly documented. This study presents the analysis of 398 relevés describing psammophyte vegetation from the South-West Transbaikalia (Selenginsky, Dzhidinsky, Kyakhtinsky and Bichursky administrative disticts of the Republic of Buryatia).

Human activity and aeolian relief of Starczynów “Desert”, Poland

Abstract Starczynów „Desert” is located in the eastern part of the Silesian Upland (southern Poland) and makes a compact area with the occurrence of aeolian sands, which till the 1960s. were intensively blown. Its flat surface is diversified by many dunes of different shapes and sizes. Aeolian coversands are formed here as a cover of changing thickness. The „desert” is not a typical dry climatic area. The term Starczynów „Desert” refers to the area of occurrence of bare sands and aeolian processes and makes a geographical name that can be found on topographic maps. Its development was conditioned by human activity, where since the Middle Ages dense forest areas have been cut to obtain timber for the needs of contemporary mining and metallurgy of lead and silver ores causing the activation of aeolian processes at sandy substratum, built from the Vistulian proluvial-deluvial deposits. In the formation of the aeolian relief of Starczynów „Desert” it is possible to distinguish some stages of intensive wind activity: the 13th-15th centuries, the 16th-17th centuries, the turn of 18th and 19th centuries, the turn of 20th and 21st centuries. In present times human interference in the environment of Starczynów „Desert” consists of fixing sandy areas to protect them from deflation. Human damage exists here in the aeolian relief through terrain levelling and building fire escape roads. In the north-eastern part of the „desert” sand was exploited, therefore a sandpit appeared. This area was subject to the activity of mining for Zn-Pb ores, which caused numerous collapsed cones. In the last few years this part of the „desert” was properly reclaimed.

Eolian relief of southeast Banatian

During the Quaternary, eolian processes had dominantly morphological importance in shaping of southeastern Banat. In morphology of this region, therefore, dominates loess plains, Zagajica's ridge and Deliblato and Banatian dune field. About the genesis of loess plains, Zagajica's ridge and Deliblato dune field are different, very often opposite opinions. Meanwhile, during the geomorphologic mapping of Vojvodina, at the end of nineties years of last century and at the beginning of 21st century, the author of this paper came to new conclusions, so he explains his opinion about relief of southeastern Banat. Special attention was paid on morphology and morphogenesis of Deliblato dunes field and Zagajica's ridge.

Symmetrical Cone-Shaped Hills, Abaco Island, Bahamas: Karst or Pseudokarst?

2 Abstract: Abaco Island, Bahamas, contains a large number of conical hills that strongly resemble cone karst, a dissolutional landform associated with karst processes in tropical carbonate localities around the world. Field investigation demonstrated that the conical hills are roughly symmetrical in shape and consist of mid to late Pleistocene eolian calcarenites (carbonate sand dunes) partly mantled by talus. The original hummocky depositional topography of the eolian ridges has been dissected by a variety of processes including dissolution pit formation that enhances slope failure, vegetative disruption of the rock surface, and fire-induced exfoliation of the bedrock. The original asymmetrical shape of continuous dune ridges has thus been modified into a series of hills with a symmetrical cone shape, in which the steeper leeward depositional slopes of the dunes have been masked by talus to create a lesser slope that approximates the dip of the exposed bedrock slope of the more gentle windward depositional faces of the dunes. The conical hills are primarily constructional in nature, modified by mass-wasting slope processes only partly influenced by dissolution; therefore these conical hills are not true cone karst, but pseudokarst, despite their cone shape and their development in soluble carbonate rock. Abaco is the only island in the Bahamian Archipelago with both high eolian relief and a significant positive water budget; that water budget supports the degree of dissolution and forest growth necessary to create the root wedging and fire- induced exfoliation that most modify the steep leeward slopes of the dunes. As the eolian calcarenites were deposited only during the brief glacioeustatic sea-level highstands of the last few hundred thousand years, the development of cone-shaped hills in these eogenetic rocks has been geologically very rapid.