Lithodynamic Processes Research Articles

Influence of lithodynamics of coastal area on the safety of railway operation on the Tuapse-Adler section of the North Caucasus Railway

The present paper considers the railroad bed on the Tuapse-Adler section of the North Caucasus Railway (Black Sea coast) in terms of its protection from wave scouring. Aim. To evaluate the influence of coastal lithodynamics on the safety of the railway operation on the section under consideration. The paper describes lithodynamic processes in the sea coastal zone and demonstrates the influence of coastal protection structures produced on lithodynamics in general and on adjacent sections, as exemplified by a specific section of the coast (1907–1910 km). The study involves a retrospective analysis of the step-by-step construction of trapping structures, and sea groins without full-fledged dumping of beach-forming material into the inter-groin compartments. The investigation and analysis of satellite images of 1907–1910 km coast within the Vodopadny-Lazarevskoye section indicate that lithodynamic processes remained unconsidered during the intensive construction of bank protection structures, which led to the beach erosion and the emergency condition of the seawalls along 1909–1910 km section. The paper provides recommendations for considering lithodynamic processes in the construction of railway protection structures, thereby increasing the safety of the railway operation.

ХАРАКТЕРИСТИКА ПРИЛИВНЫХ ОСУШЕК В МЕЗОПРИЛИВНЫХ ЭСТУАРИЯХ РЕК БЕЛОГО МОРЯ НА ПРИМЕРЕ УСТЬЯ РЕКИ ПИЛЬЕМА В ОНЕЖСКОМ ЗАЛИВЕ

The biogeochemical characteristics of tidal drying in the estuary of the small Pilema River in the Onega Bay of the White Sea are considered based on observations made in October 2023. Here, mesotidal conditions are observed with a mean tidal range of 2.4 m at the entrance to the river mouth. Along the eastern shore of the estuary, anomalously high suspended sediment loads (356–692 mg/L) were observed due to stormy weather, but the estuarine section of the river, which is closed to developed wind disturbance, had relatively low suspended sediment loads (6–21 mg/L). The upper tidal drying zone was characterized by low values of benthic abundance, biomass and biodiversity, low projective cover of the bottom by algae, and insignificant concentrations of heavy metals such as cadmium, copper, lead and zinc. This situation is mainly due to active lithodynamic processes observed in this zone.

On certain issues related to the place of lithodynamic processes in the general classification of geologic hazards and phenomena

The article addresses issues related to the study of lithodynamic processes on the shelf as dangerous phenomena. On the example of the coastal zones of South Sakhalin where hazardous exogenous processes on the shelf are state-monitored, it is shown that an annual redistribution of bottom sediment accumulation and erosion zones occurs within the identified key areas. Other examples from the practice of similar works in the Gulf of Finland of the Baltic Sea indicate that lithodynamic processes in the coastal zone lead to a significant disturbance of the coast, which poses a specific danger to the population. It is concluded that lithodynamic processes should be studied via standard lithological and geophysical methods used in marine geological work.

Forecast of the Dynamics of a Sandy Beach in Complexed Hydrodynamic Conditions

Changes in the coastal zone under the influence of currents of different nature and wind waves are being investigated. A sandy beach located in the water area of the “Park of the 300th Anniversary of St. Petersburg”, the Neva Bay of the Gulf of Finland of the Baltic Sea, is considered as an object. The beach is actively affected by wind waves and eventually washes away with the intensity of the retreat of the shore of about 4 m per year. For numerical modeling, a set of models is used: SWAN–wind-wave model and COASTOX-UN–a two-dimensional model of currents, sediment transport and bottom reformation. It was developed a model of the Neva Bay and the mouth of the Neva River from the Flood Prevention Facility Complex in the west to the river Neva near the Liteiny Bridge in the east. Based on the reanalysis of wind data, 36 strong storms were selected for a five-year period from 2014 to 2018, for the sequence of which numerical modeling of waves, currents and lithodynamic processes was carried out. It was obtained balances of alluvial and washouts after a ten-years simulated period for beach sectors. To verify the results, satellite images of the modeling area are used, it was found that the model adequately describes the main observed trends in the development of the beach.

Modeling of Hydrodynamic and Lithodynamic Coastal Processes in the Harbour Area

One of the problems in the design of ports is the assessment of coastal sediment movements near structures. The article presents materials for assessing the impact of port facilities on the processes of coastal erosion/accumulations in the area of Gelendzhik Bay (Black Sea). All the main processes of interaction of waves, currents and sediment movement occur in the coastal zone, therefore, the study presents the possibilities of complex application of hydrodynamic and lithodynamic models. In this work, the wind wave models Wave Watch III and SWAN were used. As the initial data, the data of the NCEP/NCAR reanalysis of wind fields in the period from 1989 to 2012 were used. To simulate currents, sediment transport and lithodynamic processes, a model of two-dimensional COASTOX–CUR currents generated by waves and wind, COASTOX-SED sediment transport together with the COASTOX–MORPHO bottom reshaping model was used. In the simulation scenario, a sequence of the 5 strongest storms from the period under consideration was considered. Analysis of washout zones/accumulations have shown that areas of intensive bottom reshaping are associated with the most intense currents. It is shown that the construction of the port facilities will not have a significant impact on the lithodynamic processes in the Gelendjik bay.

ფოთის პორტის ახალი მოლოს გავლენა სანაპირო ზოლის ლითოდინამიკურ პროცესებზე

In the city of Poti and its maritime region, for several decades there have been of environmental and geomorphological problems, which have been caused by anthropogenic interventions in this region. The impact of the breakwater of the new port of Poti on lithodynamic processes in the coastal zone is discussed in the paper. The sediment mass constancy equation is used in numerical experiments to determine the velocities of overbank and bank-driven sediment transport. To solve this equation, we use the finite element method and Crank–Nicolson schemes. According to calculations, 1,500,000 m3 of sediment migrates along the Nabada delta's banks, 850,000 m3 south of the delta to the harbor, and 65,000 m3 north of the delta to Khobiskal. The remaining 2,500,000 m3 is moved along the shore in a westerly direction before being dumped on the sea's underwater slope. After the new breakwater is built, all fine sediment movement in that direction will be stopped, and solid sediment will start to settle to the north of the new breakwater. Eventually, this will cause the southern branch of the Nabada Canal to become blocked. The total flow of water from the Nabada canal will be transferred to the northern branch, and the formation of a new delta will begin there.

Analytical and numerical studies on the scouring of a pile foundation of a marine terminal

Introduction. The purpose of the work is to assess potential scouring of the bottom soil of a designed marine terminal resting on a pile foundation to prevent the bottom erosion caused by wind waves and currents.
 Materials and methods. The authors have analyzed those effective regulatory documents that could be potentially used to study erosion near pile foundations of marine terminal structures. Numerical modelling of lithodynamic processes was conducted in the mooring basin area in extreme weather conditions, like severe storms, to study soil erosion near the hydraulic structures of the marine terminal.
 Results. Having analyzed the method used to assess local erosion pursuant to VSP 33-03-07 (Industry-wide set of rules 33-03-07), the authors concluded that it had major fundamental drawbacks and, therefore, it could not be applied to a multi-row pile structure. Therefore, it could not guarantee the required accuracy of projections. The authors presented the numerical modelling of wind waves, currents and lithodynamic processes to study the wave erosion on the bottom of the mooring basin of the marine terminal. Towards this end, a three-level system of interconnected models was designed. It had a model of wind waves, a model of currents and changes in sea levels and a lithodynamic model.
 Conclusions. Having considered a method for assessing local erosion, described in VSP 33-03-07 (Industry-wide set of rules 33-03-07), engineering and geological conditions near the NZMU marine terminal, as well as the structural solutions contributed to the project, the authors believe that this method cannot be applied to reliably analyze local erosion near the pile supports of a sea terminal. Simulated lithodynamic processes, that are underway near the pile supports of designed mooring structures, suggest that anticipated erosion, caused by severe storms, did not exceed 25 cm and no complete erosion funnel was formed around the pile. Sediment accumulation zones appeared on the windward side of the piles. They were larger than the zones of erosion. Therefore, the authors assume that the influence of lithodynamic processes on the stability of pile supports is insignificant during the operation of hydraulic structures of the marine terminal.

Creation of a system of comprehensive monitoring of the aquatic environment state of the black sea by its mathematical modeling

Modeling and forecasting of hydrodynamic processes in the Black Sea with high resolution are important for coastal and shelf zones, because of the biggest anthropogenic pressures. Here are the processes of distribution and transformation of pollutants that emerged in the sea in different ways, the transfer and sedimentation of solid river alluvium, lithodynamic and biochemical processes and more. The peculiarities of such processes are directly related to the dynamic processes that develop in coastal areas. Development of a regional operational system for forecasting the state of the Black Sea northwestern part has to be undoubtedly considered as a significant step forward for oceanography in this area. Creation of the integrated monitoring system of the Black Sea aquatic environment as well as its separate areas by means of mathematical modeling, in conjunction with further forecasting instruments meets the modern needs of society. It will help to prevent and respond in a timely manner to crises caused by natural and man-made risks. The created system will contribute to ensuring national security, improving the quality of life of people, the development of new knowledge-intensive industries.

MODERN CHANGES COUNTOUR OF COASTLINE SPITS OF THE SEA OF AZOV

Problem Statement and Purpose. At present the studying of the shores and their dynamics configuration and especially the most active parts – the heads of the Azov spits, is caused by both reasons dynamic and geopolitical changes as well. A large number of spits is a characteristic feature of the shores of the Azov Sea. There are spits all over the coast of the Azov Sea. However, spits oriented deep into the Azov Sea shore line there are just on the northern sea area. The reason of intense lithodynamic processes in the coastal zone of the Azov is the high velocities of currents in the bottom layer as a result of storm winds. In the coastal zone of the sea the cycle of abrasion rate from 1 to 4 m per year (sometimes up to 15m per year) was established. Fluctuations in the level of the Azov Sea are provides by many natural factors acting simultaneously and input to abrasion processes. The largest range of fluctuations is associated with wind activity phenomena. Data & Methods. In the paper takes into account the regular field studies of the position of the coastline of the distal parts – the streamer heads using of satellite radio navigation systems – GPS receivers. The radio navigation equipment recorded the exact route along the interaction zone. The sampling was carried out in a calm period on the sea surface. The data in situ (recorded routes) were compared with retrospective data of GIS systems. Cartographic materials, various specialized sources of information and satellite images were also used for the further analysis. Results. In fact, this paper is an attempt for the first time analysis of the available retrospective, modern and satellite monitoring data for the comparing of the dynamics of the Azov spits in frame of Ukraine area. As an example the dynamics of the coast line of the spits: Biryuchiy Island, Obitochnaya, Berdyanskaya and Belosaraiskaya were done. The study of the modern state of the Ukrainian coast line in the Azov Sea, the possible degradation of the coastal part of the sea and the reasons causes of it isessential for the sustainable development of the economy, the recreational potential of the region, the social level of the population and the geopolitical situation in the event of delimitation in the Azov Sea.

Impact of the Revetment on the Seashore in the Region of Babie Doły (KM 93.6–93.9), Poland

The present paper addresses the litho-dynamic and morpho-dynamic processes in the coastal zone of Babie Doły (KM 93.6–93.9), Poland. As a background, the history of coastal engineering measures in this area is described. The impact of post-war structures on the seashore is analysed on the basis of historical maps, supported by results of the sediment transport modelling. Shore regression is caused by the so-called downstream erosion behind the headland with remains of rock palisade structures. The possible consequences for the seashore resulting from the removal of the analysed revetment are discussed. The paper also presents recommendations to the relevant authorities for the future.

Forecasting the development of the sea coastal area based on analysis of the clif-beach dynamic system

The paper is devoted to the study of the dynamics and stability of the coast. The seaside territories are an active geodynamic system, which,being at the junction of the land and sea systems, has a high rate of change(transformation) processes. Relevance of the topic due to the economic value of the shores and a huge in-crease in anthropogenic load on them. A dynamic simulation model is presented to calculate the optimal amount of beachforming material to be maintained on the beach. The studies carried out made it possible to significantly clarify the ideas about the hydro- and lithodynamic processes occurring in the coastal zone of the beach. The influence of the parameters of waves and sediments that make up the beaches on such morphometric characteristics of the surf zone, which are important for the practice of marine coastal protection, such as the length and height of the wave run-up, the depth at the point of their collapse, is shown.

Lithodynamic Processes along the Seashore in the Area of Planned Nuclear Power Plant Construction: A Case Study on Lubiatowo at Poland

The Polish government has made a decision to build a nuclear power plant (NPP) in the South Baltic coastal zone. This means that three major types of structures will be located in the nearshore: (1) breakwaters and a wharf where ships may dock to load and unload cargo (harbor), (2) seawalls protecting the shore against erosion and storm surge floods, and (3) an underwater piping system for cold water intake and heated water discharge. This study determines the dominant directions and rate of sediment transport for the coastline section in the vicinity of the projected Polish NPP (ca. 100,000 m3/year), as well as assesses current changes at this coastline location on the basis of field measurements and mathematical modeling.

INFLUENCE OF SEASONAL DISTRIBUTION OF WAVE ENERGY AND STRUCTURE OF LOCAL STORM EVENTS ON SEDIMENT TRANSPORT

The structure of storm events means the character of the wave energy distribution in time over the storm period. The storm includes three principal phases: increase, stabilization and waning. The main idea that resulting morphological effect of storm depends on both quantity of wave energy within every phases and distribution of different storm phases over the time. The post-storm relief in the coastal zone depends heavily on the particularity of hydro- and lithodynamic processes during the storm waning phase. The main objectives of the study include estimation of seasonal distribution of wave energy and character of structure of separate storm events for different seasons.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/mgDDF-oQg94

Mathematical modeling of lithodynamic processes

A mathematical model for beach reshaping in the vicinity of transverse hydraulic structures has been developed on the basis of the developed unified approach for determining the alongshore transport of heterogeneous sediments as applied to the conditions of pebble and sandy beaches.

Modelirovanie shtormovykh izmeneniy rel'efa beregovoy zony i granulometricheskogo sostava nanosov v rayone peresypi oz. Bogayly (Zapadnyy Krym)

Introduction . A series of numerical experiments was carried out to study the mechanism of storm deformations of the coastal zone relief and the redistribution of different sediment fractions after the parameters of the wind waves directed almost normally to the coastline, are changed. Data and methods . The lithodynamic processes taking place at the Western Crimea coastal zone in the region of the Lake Bogaily bay-bar were investigated using the XBeach mathematical model. The in-situ data on the bottom relief and the sediments granulometric composition obtained during monitoring observations in the Western Crimea coastal zone performed by the Marine Hydrophysical Institute of RAS was used as the model input parameters. The granulometric composition was preset as a mixture of three components distributed along the profile of the underwater coastal slope; at that the ratios of volume concentrations were different. Results . It is shown that influence of the storm waves results in intensive beach erosion, strong alteration of the profile of the underwater coastal slope upper part and formation of an accumulative body. Main changes of the initial profile and redistribution of the sediment fractions are observed during the first 3–6 hours and depend on the wave period. The rate of the water edge retreat and the values of the coastal zone relief deformation were quantitatively assessed for various time periods of the wave action. Position of the marine boundary of the site within which significant motion of sediments and their accumulation during a storm took place was calculated. Discussion and conclusion . Possibility of the bay-bar crest erosion is analyzed for the wind wave’ different periods. It is shown that the volume concentrations of different components of the mixture change mainly after the fine fractions are rapidly removed to the seaward part of the bottom profile and the coarser fractions are redistributed in the upper part of the underwater coastal slope. The obtained results provide a possibility of indirect determining the conditions for blocking the alongshore sediments transport in case of building a hydraulic structure.

Engineering-geological investigation in the coastal zone of St. Anastasia Island

The Engineering-geological research relates to the development of concepts for the reconstruction and extension of an existing harbor for small vessels on St. Anastasia Island in order to protect the water area from dangerous geological and meteorological conditions. It is confirmed that in connection with the construction of future hydrotechnical facilities, the studied area is presented of Upper Cretaceous volcanic rocks and Quaternary marine sediments, subjected to the active impact of lithodynamic processes in Burgas Gulf. The performed Engineering geological studies included sampling, sample analysis, strength-deformation and physico-mechanical characteristics of lithological varieties and foundation conditions. The conditions for the foundation of the designed pier with a fenced mall are favorable for two types of hydrotechnical constructions: gravity and pilot.

Analysis of Gravitational Deposits at the Continental Slope of the Northeastern Part of the Black Sea

Analysis of new 3D and 2D seismic data made it possible to describe the continental slope relief of the northeastern Black Sea in detail, and to reveal a large number of gravitational processes of various types. It was found that the final phase of active development of lithodynamic processes was caused by the New Euxinian regression associated with the last glaciation; this ended more than 10 000 years ago. Irregularities that formed as a result of late Holocene landslides also occur; however, their contribution is insignificant, with an amplitude rarely exceeding 1 m.

Analysis of the continental slope gravitational deposits (the north-eastern part of the Black Sea)

Analysis of new 3D and 2D seismic data made it possible to describe in detail the continental slope relief of the northeastern part of the Black Sea, and a large number of gravitational processes of various types. It is established that the final phase of the active lithodynamic processes development is due to the NovoEvksin regression of the basin associated with the last glaciation and completed its development more than ten thousand years ago. The irregularities formed as a result of late Holocene landslides also occur, but their contribution is insignificant, and the amplitude rarely exceeds 1 m.

Transport of Fine Sediments in MarineWaterbodies Near River Mouths: Preliminary Results

Abstract Transport of fine sediments depends mainly on the efficiency of flocculation. Flocculation, understood as the result of simultaneous processes of aggregation of particles and floc break-up, is a common phenomenon in marine environments. It is typical of fine sediments. This study presents a mathematical model of fine sediment transport. A model of flocculation is an important part of this model. Its main assumption is that flocculation is governed by turbulence. The model was qualitatively tested in a simplified theoretical waterbody. Such factors as the wind direction, wind speed, river discharge and concentration of suspension in the river were investigated. The results show that the proposed model describes reasonably well the lithodynamic processes characteristic of fine flocculating sediments. Thus it seems possible to apply it for description of fine sediment transport under real wave–current conditions that occur in many marine waterbodies near river mouths.

Hydrological Regime and Lithodynamic Processes in the Mezen River Estuary

In the Mezen River estuary, morpholithodynamic processes are regulated by tidal currents, river runoff, wind waves, and alongshore sediment flows. Due to the movement of a huge mass of sediments in the Mezen River estuary, intense deformations of silty sand banks occur, reforming the bottoms of channel grooves and displacing navigable waterways. On the whole, the Mezen River estuary is gradually being filled with river and marine sediments. Various sandy ridges form in the channel grooves of the estuary.