Intense Erosion Research Articles

Urban Erosion in The Amazon Region: Mitigation and Control Strategies in The Municipality of Buriticupu (MA)

Purpose: this work aims to analyze the factors that contributed to the intensification of erosion in the Amazon region of Buriticupu (MA) and discuss possible forms of mitigation and control. Methods: urban area of the municipality was characterized and data on soil, pedology, relief, slope, use and occupation, economic activities developed, as well as satellite images, were collected. This information was used to analyze indicators of natural erosion processes, as well as the influence of human activities. Possible mitigation and control solutions were discussed. Results and discussion: it was found that several aspects contribute to the development of erosion phenomena in the region, such as soil type, slope and hydrology. In the case of the municipality under study, geoenvironmental factors favor the development of gullies. However, the main force has been the action of man in modifying the landscape and weakening the soil. It is understood that it is necessary to implement articulated biogeoengineering strategies, such as controlling the slope and stability of slopes, the water flow regime, plant restoration and environmental education strategies. With this, we can be successful in mitigating the phenomenon and preserving the landscape. Implications of the research: it is urgent to develop shared management measures between federated entities, organized civil society and the local population to map and regulate sustainable development, especially in Amazonian regions. Originality/value: in some Amazonian regions, as in the case of the municipality of Buriticupu (MA), the advancement of agricultural activities and urban development, associated with climate change, have significantly influenced the emergence and advancement of gullies, which can promote the disappearance of the built environment. These gullies are treated as more advanced soil erosion phenomena, serious and difficult to control and remediate. Although erosion is a problem that affects many regions in Brazil, there are still few studies that aim to investigate the causes of its appearance and the discussion about possible solutions applied to gullies in the Amazon region is unprecedented. Agricultural development has accelerated soil degradation and is an urgent problem to be debated.

Soil erosion resistance of gully system under different plant communities on the Loess Plateau of China

AbstractGully erosion, considered as a type of intensive erosion, is the dominant source of sediment at small watershed scales in certain environments. Variation of vegetation may result in the changes in near soil surface characteristics, which likely further affect the resistance of gully systems to erosion. However, the potential effects of near soil surface characteristics of plant communities on resistance to erosion are still unclear in gully systems. This study was performed to investigate the variations in resistance of gully systems to erosion under different plant communities and to identify the dominant influencing factors leading to these variations on the Loess Plateau. Five typical plant communities (two grasses, two shrubs and one forest) that distributed on different gully systems were selected. Six hundred undisturbed soil samples collected from different sites of gully systems were subjected to detach by overland flow under six different shear stresses (6.66 to 15.02 Pa). The results showed that the mean soil detachment capacity of gully systems covered by grass and shrub communities was 0.15 and 0.37 times to that of gully system covered by forest. Compared to forest gully systems, rill erodibility reduced by 29.8% to 85.6% for the other four plant communities. The relative rill erodibility of different vegetation communities generally increased from grass to shrub and forest communities. The critical shear stress of forest gully system was 58.7% and 63.8% of gully systems covered by grass (6.22 Pa) and shrub (5.73 Pa) communities. Bulk density, soil cohesion, water stable aggregate, root mass density, and the thickness of biological soil crust were the dominant factors affecting the resistance of gully systems to soil erosion. Rill erodibility decreased logarithmically with increasing soil cohesion, water stable aggregate and root mass density. Critical shear stress increased with the increase of soil cohesion and root mass density as a power function, and linearly with the increase of water stable aggregate. These results show how vegetation can mitigate against the erosion induced by concentrated flow in relatively stable gully systems.

Strong Climate Control on the Millennial‐Scale Dust Variability and Sediment Provenances in the Equatorial Indian Ocean Inferred From Sr‐Nd Isotopes

AbstractHigh‐resolution Sr and Nd isotope compositions along with major and trace element abundances have been analyzed in silicate fraction of sediments core, SSD004‐GC03, from the Equatorial Indian Ocean (7.2°N and 77.9°E) at 1,540 m water depth with a depositional history of ∼38 ka to determine source variabilities and their controlling factors. 87Sr/86Sr (0.71978–0.72491), ƐNd (−14.8 to −21.9), and a couple of source diagnostic elements display profound variability over the depositional time scale and point toward major sediment contribution from the Peninsular Gneissic Complex (PGC) and the Deccan Basalts along with aeolian dust flux, their relative proportions being determined by climate variability. The cold/arid periods are characterized by an enhanced proportion of aeolian dust and the Deccan Basalts, whereas the sediment contribution from the PGC is augmented during the warm/humid periods. The sediment provenance variations at the Equatorial Indian Ocean coincide very well with known cold/arid (Heinrich Stadial events: HS 1–4, LGM, Younger Dryas, 8.2 ka, 5.2 ka, and 1.1 ka) and warm/humid (Early Deglacial, Holocene Intensified Monsoon) climatic events reported in the tropical region and sea‐level change which are strongly captured by the Sr‐Nd isotope and elemental composition of sediments. The present investigation underscores the significant role of climate, mainly the aridity, in modulating the dust fluxes and erosion intensity and the strong coupling between Indian monsoon and North Atlantic climatic oscillations and further demonstrates minimal time delay between the production and transport of sediment from source to sink.

Analysis of soil erosion changes and influencing factors based on the CSLE model and GeoDector in Dongjiang River Basin of China

AbstractSoil and water conservation and protection are of great importance to China, as the source of the Pearl and Xiang Rivers, and the main rare earth mining area, the ecology of Dongjiang River Basin, is very fragile. In this paper, the Chinese soil loss equation and the Geodetector method are used to analyze the spatial and temporal patterns and the impact factors of soil erosion in this area from 2016 to 2020. The results show that (1) Soil erosion intensity in the Dongjiang River Basin from 2016 to 2020 is mainly mild, with the soil erosion intensity in the Dongjiang River Basin in 2016 being the largest in five years. (2) The erosion modulus shows an increasing trend with the increase of slope. In terms of vegetation, when the vegetation cover is <30%, the soil erosion modulus is the largest, which is easy to induce soil erosion. When the vegetation cover is >60%, the soil erosion modulus is the smallest, which effectively slows down the occurrence of soil erosion. Rainfall is proportional to the soil erosion modulus and soil erosion. (3) The results of Geodetector indicate that the single factor sizes are land use > vegetation > slope > precipitation, and interaction factors all show a nonlinear enhancement. (4) The proper allocation of land use types, the prohibition of steep slopes for cultivation, and the restoration of forestry can effectively prevent and control soil erosion in the area.

Rock and ice avalanche-generated catastrophic debris flow at Chamoli, 7 February 2021: New insights from the geomorphic perspective

Within mountainous landscapes neighboring glaciers, slope instabilities and consequent catastrophic mass flows are vital processes on Earth's surface, which have been of increasing interest for decades. These events commonly exhibit large volume, high velocity, and high mobility. Recently, a catastrophic debris flow occurred in India on 7 February 2021, which unfortunately claimed 70 lives and left 134 people missing. The failed mass comprises 80 % rock debris and 20 % glacier ice. Our remote sedimentological investigation of remnant deposition shows clear evidence of wet granular flow in upper Ronti Gad valley, which doesn't support the previous interpretation of immediate melting of the failed 20 % ice mass during the falling and impacting process. We further utilized the superelevation phenomenon to back-calculate the velocity downstream of the impact zone, and estimated the peak discharge, which is verified by field-documented data. Our results revealed an initial waning trend of rock and ice mass flow. As it entered the narrow valley of the lower Ronti Gad River, the extensive material erosion resulted in three-fold flow enlargement, which gave rise to a maximal peak discharge of up to 48–54 × 104 m3/s. The transition from granular flow to debris flow occurred in the 2-km-long channel downstream of the Ronti Gad-Rishigangga confluence. The sediment deposition of 4.8 × 104 m3 and the incorporation of stream water in this zone have dominated the rheologic transition. We inferred that the intense erosion of erodible sediment due to topographic constraint plays an essential role in maintaining the mobility of the flow. Therefore, the effect of glacier ice meltwater on high mobility may be overestimated. As long as the granular flow can access the stream water in major rivers, flow transformation can easily happen because of sufficient water supply in the channel. The valley morphology in the proglacial region is commonly featured by the shift from an upstream U-shaped valley carved by glacier erosion into a downstream fluvial-erosion-dominated V-shaped valley. This geomorphic setting of glaciated tributary favors the long-distance run-out of rock and ice avalanche.

Morphological characteristics of gullies affected by the soil type of artificial slopes in the Dry‐hot Valley Region, Southwest China

AbstractGully erosion is widely recognized as a significant form of land degradation globally, posing threats to ecological security and human societal development because of its ability to generate substantial amount of sediment. Artificial slopes are commonly disturbed landforms that are susceptible to intensive gully erosion. Morphological characteristics play a crucial role in assessing the intensity of gully erosion and can be utilized to predict sediment yield. Notably, soil type has been identified as a key factor influencing the morphological characteristics of gullies. Consequently, a comprehensive analysis was conducted based on meticulous field investigations to examine the impact of soil type on the morphological characteristics of gullies on artificial slopes in the Dry‐hot Valley Region of Southwest China. The results showed that the gully cross‐sectional area (Ac), curvature (Cc), and shape index (Si) exhibited a decrease along the downslope direction of the artificial slopes for all three studied soil types, following power functions. Additionally, the soil type of the artificial slope significantly influenced the mean values of the gully cross‐sectional morphological characteristics. Regarding the longitudinal morphological characteristics of the gullies, the largest longitudinal concavity (Ca), longitudinal curvature (Cl), and length‐gradient index (Gl) values were observed for the Vertisol, Entisol, and Ferrasol, respectively. These findings suggested that gullies developed on different soil types exhibit significant variations, particularly in terms of longitudinal morphological characteristics. Furthermore, strong correlations were detected between the gully cross‐sectional and longitudinal profile morphological characteristics, and the gully cross‐sectional shape index (Si) was correlated with all the longitudinal profile morphological characteristics. This study offers valuable insights into the morphological characteristics of gullies on artificial slopes with different soil types. Such knowledge is of paramount importance for effectively preventing and controlling gully erosion in contemporary society.

Numerical prediction of cavitation nuisance on hydrofoils: Combined analysis of cavity dynamics and the aggressiveness of collapsing cavitating structures

The unsteady cavitating flow past a three-dimensional twisted hydrofoil is numerically investigated by a large eddy simulation to obtain in-depth insight into the bubble dynamics near the cavitation erosion region. Macroscopic cavity evolution is captured by a multiphase flow computing frame, while the bubble oscillations in the cavitating flow are computed by solving the Gilmore bubble dynamic model, in which the driving force for the bubble movement is exported through the application of a discrete phase model. The cavitation erosion potential is then computed by a robust indicator developed based on the energy balance hypothesis. The relevance between the dynamics and the destructive essence of a cavitation bubble and the erosion intensity is thoroughly analyzed. The results show that the unsteadiness involved in the turbulent cloud cavitation is well reproduced, and the main cavitation erosion risk in the middle region of the hydrofoil is also accurately predicted comparing with the painting test results. A localized high-pressure region is identified near the rear part of the attached cavity where the mainstream encounters the primary reentrant jet flows. The peak bubble internal pressure can reach 487 MPa near the middle plane of the hydrofoil, during the stage when the surrounding liquid pressure is continuously increased. The bubbles with the smallest radius, ranging from 23.1 to 26.3 μm after compressing from their initial sizes (R0 = 100–700 μm) in the near wall region, are associated with the extremely high internal pressure, and they are responsible for the cavitation erosion damage on the hydrofoil surface.

Megaflood Erosion on Mars—How Lava‐Filled Craters Became Mesas (With Insights From Lava Physics, Stream Power, and Rock Mechanics)

AbstractRound mesas up to 500 m high occur in Martian outflow channels. Mesas in Ravi and Elaver Valles occur in deepest parts of the channels where the most intense megaflood erosion occurred. I theorize that Noachian basalts poured into craters which acted as lava traps, similar to Kilauean lava lakes. Subsequent flood basalts buried the infilled craters. Hesperian megafloods stripped away hundreds of meters of basalts, exhuming erosion‐resistant strata. Lava solidification theory is explored to assess the role of cooling in governing the structure and strength of the Martian basalts. The postulated lava lakes that formed the Ravi Vallis mesas would have needed millennia to cool. The larger Elaver Vallis mesa may have needed up to 20,000 years to solidify. Long cooling times led to coarse, doleritic mineral textures and reduced numbers of cooling joints, greatly increasing bulk rock strength and resistance to hydrodynamic erosion. Using rock mechanics theory, cores of exhumed lava‐filled craters would have bulk rock strengths at least 5 to 30 times greater than more highly fractured basalts. Discharge hydrographs for the Morella Crater breach flood that carved Elaver Vallis peak at ∼2.1 × 107 m3 s−1. Stream power per unit streambed area ranged up to >150,000 W m−2 as the breach grew in size. The calculations provide an envelope of power sufficient to erode hundreds of meters of basalts, but not great enough to remove the large mesa. Thus the legacy of an ancient, lava‐filled crater is a high mesa on the floor of Elaver Vallis.

Assessment of the Erosion and Outflow Intensity in the Rif Region under Different Land Use and Land Cover Scenarios

The port of Tangier Med is essential due to its strategic location, as it is an important trading center linking Europe, North America, and Africa. However, the increased rates of downstream sediment transportation put pressure on the sustainable future of the port. Thus, assessing the existing erosion rates and future improvement scenarios is imperative for planning sustainable management at the catchment level. We utilize the Erosion Potential Model (EPM) combined with the Intensity of Erosion and Outflow (IntErO) algorithm to assess the erosion and outflow intensity and to distinguish the sediment-producing areas in the R’mel watershed. The port’s proximity at the bottom of the slope opposite the R’mel Dam is relevant in this context. Initial results show an average erosion rate of 13 t/ha/year. Quarry operations were identified as the primary sediment source, as indicated by the factors contributing to erosion. The qualitative PAP/RAC (Priority Actions Program/Regional Activity Center) model was used to assess the development trends in the watershed, confirming a clear tendency toward irreversible degradation in the quarry areas. Considering that the mined carbonate lithology represents 23.77% of the total area of the catchment, the situation in the region could deteriorate if quarry operations continue. The simulation of quarry rehabilitation scenarios through land use and land cover change (LULC) with IntErO shows that reforestation of quarries can significantly reduce erosion rates (4.78 t/ha/year) compared to their conversion to agricultural land. This study underlines the effectiveness of IntErO, based on the EPM model, in quickly and effectively mapping and quantifying water erosion.

Determining the Dependence of a Landscape’s Ecological Stability and the Intensity of Erosion during 1990–2018

Among the main elements that contribute to climate change are degradation processes and the ecological level of a landscape. These two topics have been discussed and researched for many years, and many studies have been conducted. The idea behind this article is to determine the correlation between the ecological stability of a territory and the intensity of degradation processes and find out how ecological stability affects the intensity of soil erosion and vice versa. The ecological stability was calculated based on various methods during the years analyzed, i.e., 1990, 2006, 2012, and 2018. The soil water erosion measurements were performed for the same period in order to identify the relationship between ecological stability and the intensity of soil erosion. The investigated area is located in the Slovak Republic, and each year reflects different types of management of the territory, reflecting the current situation in the catchment according to the year evaluated. The intensity of the erosion process was measured using a physically based EROSION-3D model based on the precipitation levels derived using the Community Land Model (the CLM). In addition to identifying the relationship between the level of ecological stability and the intensity of erosion, this study also describes the development of ecological stability during the evaluated period together with changes in soil erosion processes. The results show a dependence between the intensity of ecological stability and soil erosion. First of all, it determines whether such a dependence exists at all and also its extent.

Roles of changes in land weathering intensity in the Nd cycle of the South China Sea during the past 30 kyr as inferred from neodymium isotopic composition in foraminifera

Neodymium isotopic compositions (εNd) in the marginal sea is influenced by the ocean circulations as well as the lithogenic input from continents, but their relative contributions and the impact of detrital sediments are not well constrained. In this study, Nd isotopic compositions of mixed planktonic foraminifera species and carbonate-free fraction of sediment from two cores collected at 1250–1350 m water depth in the southwestern (core MD01–2393) and northeastern (core MD18–3569) South China Sea (SCS) have been investigated in order to constrain the relative contributions of lithogenic Nd inputs from large Asian rivers and hydrological variations at intermediate depth in the SCS. The foraminiferal εNd values of both cores (−7.3 ± 0.2 to −5.8 ± 0.2 for core MD18–3569 and − 8.1 ± 0.2 to −7.2 ± 0.2 for core MD01–2393) indicate strong modifications of the initial εNd of the North Pacific Intermediate Water (NPIW) (εNd of −4) flowing into the SCS by unradiogenic sediments (−13 to −11) from large Asian rivers. The foraminiferal εNd record of core MD01–2393 displays significantly unradiogenic values from 18 to 8 cal kyr BP which are associated with intensification of monsoon rainfall and river input of detrital material characterized by strongly altered minerals (high illite chemical index and kaolinite/illite ratio) deriving from tropical plain soils of the Mekong River basin. We suggest here that pedogenetic minerals from tropical plain soils are more efficient in terms of Nd exchange with the seawater than primary minerals produced by intense physical erosion during the glacial period. In contrast, the foraminiferal εNd record for the northern core MD18–3569 is characterized by radiogenic εNd values from 18 to 12 cal kyr BP; these values have been linked to an increased intrusion of radiogenic glacial NPIW to the northern SCS and greater ventilation of water masses (deduced from Δ14C) in the northern deep basin of the SCS compared to the southern one. This time interval is associated with newly formed NPIW in the subarctic Pacific Ocean beginning at about 18 cal kyr BP. Overall, our results indicate that the state of chemical weathering of sediment delivered by rivers is the main factor controlling the detrital modification of past seawater εNd distributions in the marginal sea of the SCS.

Rapid evolution of salt glacier caves on a mountain diapir in a semiarid climate

Salt caves occur mostly in hyperarid and arid climates and are typically a few thousand years old. There is little data on the evolution of salt caves in semiarid climates, and no data on caves developed in salt glaciers, i.e., salt masses spreading under their own weight, similar to ice glaciers. The age of salt caves and the incision rates of cave streams were studied on a salt glacier of the Jahani diapir in a semiarid climate, Zagros Mts., Iran. Wood fragments from 3 caves sampled 0–11.3 m above the present streambed were dated by AMS 14C. The cave passages accessible today were developed during the last ~600 years at the Jahani. The cave level 5–6 m above the present streambed was formed 1520–1660 CE or slightly earlier, then the stream incised upward and reached its highest level between 1690 and 1920 CE or slightly earlier. Then, the downward incision started. This indicates that caves in semiarid climates evolve extremely rapidly. The maximum vertical incision rate of the cave stream on the semiarid Jahani diapir is 20–110 mm/yr, which is faster than 0.4–25 mm/yr in caves in hyperarid climates. The incision rate of the cave stream at the Jahani exceeds the denudation rate of the thick cap soil surface, being comparable to the denudation rate of salt exposures. The persistence of the steep longitudinal profiles of the integrated salt caves at the Jahani is probably caused by the transport of very coarse sediment. Aggradation was probably caused either by blocking of cave passages by earthquakes or by more intense erosion of the cap soil. The salt glacier at the Jahani is moving slowly (<10 mm/yr); claims that this glacier is the fastest on Earth (velocity in the range of m/yr) are based on a study that did not follow geodetic standards and are in strong disagreement with the age of the caves and other lines of evidence.

Zaštita prirode life and nature primena GIS-a i ERM modela u proceni intenziteta erozije zemljišta u slivu reke Lugomir

An adequate land management is one of the greatest challenges in the field of environment. In this paper, the assessment of the intensity of soil erosion in the Lugomir river basin (central Serbia), which has an area of 451 km2, was investigated. The first step in this study is related to the collection of geospatial data and their application in geographic information systems (GIS). The second step is the evaluation of all the criteria required for the calculation of the intensity of erosion (Z) using the Gavrilović method: geological base, land use method, state of vegetation and slope of the topographic surface. The third and final step is obtaining a synthesis map, i.e. a map of erosion intensity and interpretation of the obtained results. Based on the EPM model and calculations in GIS, it was established that 41.4% of the territory of the basin is subject to medium and strong erosion. The average erosion coefficient is 0.409, that is, it belongs to the weak erosion class. The study offers a description of the application of modern technologies in determining the degree of erosion in the territory of the Lugomir basin, and the obtained results can be applied for more adequate management of water resources and soil, as well as for nature protection and sustainable planning of forest ecosystems.

Effects of Soil Erosion on the Tillage-Layer Quality and Limiting Factors of Sloping Farmland

Soil erosion is the key factor leading to the degradation of tillage-layer quality, which directly threatens regional food and ecological security. To study the characteristics of soil structure, water retention capacity, and nutrient changes in the tillage layer of purple soil sloping farmland under different erosion conditions, a shovel soil erosion test was performed to distinguish the factors that hinder the tillage-layer quality of sloping farmland under different erosion degrees. The degradation of soil structure showed that with the intensification of erosion, soil bulk density, soil capillary porosity, and sand content displayed an overall increasing trend; the soil water retention degradation was expressed by the average increase in the soil water holding capacity and the average decrease in the infiltration rate; soil nutrient degradation was derived from the average decrease in soil nutrient content. At the initial stage of erosion, the soil nutrient degradation was extremely sensitive to soil erosion, which was the limiting factor of the tillage layer; when the erosion reached stage E-15 (erosion 15 cm), the soil nutrients, soil permeability, and soil capillary porosity became the limiting factors; for E-20 (erosion 20 cm), the limiting factors added an index on the basis of stage E-15, namely, soil total porosity. When soil erosion continued for 53 years, the tillage-layer quality index was lower than the threshold value (0.46). Reconstructing soil profile of the tillage layer is an effective way to break the limitations of the barrier factors and improve the tillage-layer quality.

MODIFICATION OF TI-6AL-4V TITANIUM ALLOY SURFACE RELIEF BY COMPRESSION PLASMA FLOWS IMPACT

Investigation of compression plasma flows impact on surface relief of Ti-6Al-4V titanium alloy was carried out in this work. Profilometry, x-ray diffraction, scanning electron microscopy, and sample weight measurements were used as investigation techniques. The findings showed that plasma impact led to the formation of developed surface relief (R&lt;sub&gt;a&lt;/sub&gt; parameter was changed in the range of 0.7-2.7 &amp;mu;m) due to the action of hydrodynamic instabilities at the melt-plasma border. Increase in the number of pulses resulted in the growth of R&lt;sub&gt;a&lt;/sub&gt; value. Numerical simulation of surface evolution under plasma impact was carried out on the basis of the model of incompressible fluid potential flow. Simulation data correlated with experimental data set. The hydrodynamic flow of the melt during plasma impact led to another process: surface erosion. Increase in both the absorbed energy density and the number of pulses resulted in erosion intensity increase. Formation of titanium nitride on the surface was observed as a result of the interaction of nitrogen (as a plasma generating gas) with the surface heated under plasma impact. Titanium nitride film prevented the development of the surface relief formed by the action of hydrodynamic instabilities.

Assessment of soil erosion in the Boussellam watershed, Algeria: Integrated approach using the Erosion Potential Method (EPM) and GIS

Land degradation is a growing concern, exacerbated by recent climate change. Water erosion emerges as a crucial tool to address this issue. This study focuses on estimating soil loss from water erosion in the Boussellam valley watershed, a part of the ex-pansive Soummam basin in northeastern Algeria, characterized by a semi-humid to humid climate. Covering an expanse of 4,301 km2 with a perimeter of 420 Km, the basin's assessment incorporates often-overlooked factors such as temperature. Utilizing Geographic In-formation System (GIS) in conjunction with GAVRILOVIC's EPM (Erosion Potential Method) model, erosion projections for the year 2022 have been generated. The findings reveal that the entire Boussellam watershed experiences an average erosion rate of 8.50 tonnes per hectare annually. However, it is evident that the current protective measures implemented by decision-makers are suboptimal. To pinpoint the most vulnerable areas, GIS was employed to map and subsequently categorize them into five levels of erosion intensity: low, moderate, medium, high, and very high. These detailed maps will enable more precise and tailored interventions by decision-makers to effectively safeguard the regions most impacted by erosion.

Экзогенные процессы формирования современной геоэкологичеcкой ситуации в Белгородской области

According to the “Fundamentals of state policy in the field of environmental development of the Russian Federation for the period up to 2030”, it is the anthropogenic factor that has a greater impact on the environmental situation in our country. In such conditions, the risk of dangerous geological processes increases significantly. The authors found that exogenous geological processes in combination with anthropogenic factors make a significant negative contribution to the ecological situation in the region. The object of the study is exogenous geological processes occurring on the territory of the Belgorod region. The subject of the study is exogenous geological processes, anthropogenic processes, and their contribution to the current state of the ecological situation in the Belgorod region. The purpose and objectives of the study are as follows: to study the characteristics and patterns of development of exogenous geological processes in the Belgorod region; methods and technologies for the rapid detection and prediction of the occurrence of exogenous geological processes, as well as preventive measures to reduce them in the region are developed. The authors have come to the following conclusions: On the territory of the region, the development of erosive, landslide, karst, Aeolian and suffusion processes has a significant impact on the environmental situation, the manifestation of which is primarily due to the geological structure of its parts, physical and geographical conditions, the deve­lopment and condition of the mining industry and agriculture. The dominant exogenous geological process that makes the greatest contribution to the formation of the ecological situation of the Belgorod region is linear erosion. The degree of damage to the territory of the region by erosion processes is quite high. Intensive erosion dismemberment is one of the main indicators of the unfavorable ecological and geomorphological condition of the territory. The influence of the anthropogenic factor on exogenous processes is expressed, first of all, in environmental pollution, landscape transformation and changes in the hydrological regime. The possibility of neutralizing exogenous geological processes in order to ensure the safety of the population of the Belgorod region should be justified by knowledge of the engineering and geomorphological conditions of the territory. To do this, it is necessary to create a strict modern system for monitoring exogenous geological processes, which will reduce the risks associated with them, more accurately predict their occurrence and obtain more reliable data. The solution of this problem is possible within the framework of the regional monitoring center for exogenous geological processes.

The value of precipitation intensity factor (R-factor) in determining soil loss (based on the example of the Akkanburlyk river basin)

Currently, it is important to calculate the soil flushing, optimize it and organize preventive measures. Soil leaching is one of the most intense trends, which has a significant negative impact on land resources and the national economy. Soil erosion is divided into two parts depending on the main formation: wind erosion and water erosion. One of the main factors influencing the formation of water erosion is intense and abundant precipitation. Calculation of precipitation intensity (coefficient R) using the interpolation method in the presented work. GIS technologies were used for this purpose and, accordingly, algorithms were considered. The Akkanbulik River basin is 131 km long from east to west and 99 km wide from north to south. There are low mountains to the east of the basin, and to the west, due to its location on the plain, precipitation decreases as you move from east to West. As a result, the average value in the eastern region is 639 mm, and in the western region -572 mm. Fine-grained soils are more prone to soil erosion, for example, in areas with high rainfall and winds. Intensive erosion processes lead to a decrease in soil fertility, deterioration of the quality of sown seeds and pastures. All this causes huge damage to agriculture. This article is devoted to this issue and uses the interpolation method in GIS technology to determine the intensity of precipitation (factor R). The results of the study showed that in the agricultural lands of the Akkanburlyk river basin, the maximum R-factor values corresponded to the eastern part of the basin 280-290, and the minimum values corresponded to the western part of the basin in the range of values 253-260.

Bottom sediments of Lake Peyungda as a natural archive of climatic and catastrophic events in the past

Using scanning micro-XRF using synchrotron radiation, profiles of changes in the section depth of the elemental composition of the banded clays of Lake Peyungda (Krasnoyarsk region), located 33 km southwest of the epicenter of the Tunguska disaster of 1908, were obtained. The age model is confirmed by the presence of a dated layer of anomalous thickness associated with the fall and explosion of the Tunguska cosmic body (TCB). Changes in element contents in dated core layers are compared with instrumental meteorological observation data over the last century, and a relationship is found between the average annual temperature of the region and the elemental composition of coeval layers of bottom sediments (transfer function). According to scanning electron microscope and Raman spectroscopy, the 1908 layer is characterized by increased concentrations of Ti-containing minerals (anatase). The appearance of anatase is probably associated with the explosion of the TCB and the subsequent intense erosion of dolerite bodies, which are widely represented in the catchment area.

Geochemistry of Miocene sediments of the Middle and South Caspian basins (within Azerbaijan): climate, chemical maturity and provenance

Geochemical and petrographic characteristics of the Miocene rocks of the Shamakhi-Gobustan trough (South Caspian basin) and the North Absheron uplift zone (Middle Caspian basin) indicate that these sediments contain products of erosion of the magmatic rocks of the Eurasian continent’s active margin - the volcanic arc of the Lesser Caucasus, as well as granitic basement of the Garabogaz High and Mesozoic-Eocene sedimentary strata of the Middle Caspian basin and the Greater Caucasus. The uplift of the Greater Caucasus, which began in the Middle Eocene as a result of the collision of the Afro-Arabian and Eurasian plates, brought to the exposure of the Mesozoic-Eocene sedimentary rocks of the Tethys Ocean that were deposited from the detrital material of the disintegrated igneous rocks of the Lesser Caucasus and the granitic basement of the Russian platform. The clastic material of these eroded Cretaceous-Eocene sedimentary rocks was accumulated in the Miocene basin that caused the geochemical characteristics of the Miocene sediments demonstrating the occurrence of igneous rocks of active margins or products of their erosion in the sources area. The accumulation of thick quartz-containing sand beds in the Chokrakian time (analogous to the Langhian stage) in a number of fields of the Shamakhi-Gobustan trough was the result of the exposure removal to the surface of quartz-rich Cretaceous rocks of the Greater Caucasus because of collisional processes, and their intensive erosion due to humidization of the climate during the Middle Miocene climatic optimum. Judging by the geochemical characteristics, during deposition of shale mudrocks the arid conditions prevailed. Keywords: Miocene; South Caspian and Middle Caspian basins; geochemistry; provenance; climate; geodynamic setting.