Hasil untuk "Harbors and coast protective works. Coastal engineering. Lighthouses"

Xuan Zhang, Jian Luo, Ruihong Yu et al.

River runoff and suspended sediments exhibit high dynamic and multiscale variability, particularly during rainstorm-driven floods in arid and semiarid regions. Despite the widespread use of the hysteresis loop model, flood-event-scale hysteresis patterns and their controls remain poorly quantified in these environments. This study investigated the hysteresis patterns between runoff and sediment and identified the dominant factors affecting the hysteresis index (HI) in a typical semiarid catchment in northern China. Forty-eight flood events were classified by K-means clustering using the runoff depth (H), flood duration (T), and peak flood flow (Qp) into three types: A (low-intensity, medium-duration floods), B (medium-variability, long-duration floods), and C (high-intensity, short-duration floods). The monthly runoff and sediment load were decomposed via multivariate empirical mode decomposition (MEMD) to extract scale-specific dynamics, whereas event-scale hysteresis patterns were quantified separately to assess sediment transport mechanisms during floods. Figure-eight loops occurred most frequently (31.3 %), followed by counterclockwise (29.2 %), complex (22.9 %), and clockwise (16.7 %) loops. HI is governed by distinct hydrological factors for each loop type: flood peak timing skewness (FT) for clockwise loops; Qp, suspended sediment yield (SSY), mean suspended sediment concentration (Sm), and peak suspended sediment concentration (Sp) for counterclockwise loops; T and high traffic duration (HT) for figure-eight loops; and flood variability (FV) for complex loops. By combining MEMD-based scale decomposition with objective K-means event classification and HI quantification, we provide a transferable, scale-aware framework for diagnosing sediment transport regimes in semiarid basins.

Breno Carvalho da Silva, Lucas Garcia Martins, João Hemerson de Sousa et al.

Incidental capture (bycatch) is a major threat to all seven marine turtle species worldwide. This systematic review assessed (i) research trends over the past 20 years; (ii) relationships between fishery types, gear, and species caught; (iii) post-capture outcomes; and (iv) challenges in bycatch mitigation. A systematic search of Web of Science and Scopus up to April 2024 identified 236 studies, comprising 336,616 global bycatch records. Publications on turtle bycatch increased significantly (<i>p</i> < 0.001), peaking in 2020. Reported captures also rose (ρ = 0.45; <i>p</i> = 0.026), with <i>Caretta caretta</i> most frequently documented (74.8%). Methodology influenced outcomes: aerial monitoring and direct observation underestimated captures of <i>Chelonia mydas</i>, <i>Lepidochelys kempii</i>, and <i>Eretmochelys imbricata</i> compared with mixed methods; interviews only affected the latter. Regarding fishery interactions, <i>Dermochelys coriacea</i> was more susceptible to hook-and-line fishing (<i>p</i> = 0.0079), while <i>C. mydas</i> was more associated with small-scale fisheries (<i>p</i> = 0.0115). Most turtles were released after capture (60.6%), with no significant temporal variation in outcomes (<i>p</i> > 0.05). Despite growing monitoring, knowledge gaps remain in standardized reporting, regional and species coverage, and methodological integration. Addressing these issues is essential to guide effective, collaborative conservation strategies.

Yiping Wang, Yongjun Lu, Huaixiang Liu et al.

The estuarine reach of the Yellow River (YRE), located within the core zone of the Yellow River Delta Reserve, serves as a critical zone where the conservation and restoration of fish biodiversity constitute essential elements for achieving high-quality development in the Yellow River Basin. However, the fish population in this area is subject to multiple disturbances (especially water‒sediment regime changes), and because of the year-round fishing ban, relevant data are lacking. By integrating historical fish species records with water‒sediment phases classified via Bayesian mutation analysis and key drivers identified via principal component analysis, this study elucidates the reasons for the evolution of fish biodiversity. The results revealed mutation points of the annual runoff (2001) and sediment load (2004) in the YRE during 1950–2023, with a marked declining trend preceding these shifts (P < 0.05), accompanied by fluctuations in fish taxonomic diversity and obvious changes in the dominant fish ecological types. Moreover, the key water–sediment factors influencing fish biodiversity were associated primarily with fish reproduction and migration during the investigation periods, including the proportion of monthly mean discharge relative to the natural baseline phase, minimum daily ecological flow guarantee rate, and annual flow cessation days in zero-flow years. We emphasize that these findings are based on empirical observations from implemented water regulations, but the causal relationship requires rigorous testing via process-based models or controlled experimental studies. Nevertheless, this study still provides the necessary empirical data and initial hypotheses for subsequent research, which can serve as a reference for optimizing protection measures for the YRE.

Anirban Mandal, Zulfequar Ahmad, Erik Mosselman

Submerged vanes are an effective approach to sediment management in river systems. Nowadays, submerged vanes are increasingly utilized in contemporary river engineering due to their convenient and cost-effective installation, which distinguishes them from traditional approaches. However, this structure induces localized scour, which can potentially destabilize and compromise its integrity. The performance and effectiveness of a submerged vane in controlling scour and managing sediment depends on its shape and dimensions. The primary aim of this study is to refine the design of submerged vanes to assess the maximum scour depth in their vicinity and changes in bed morphology downstream of the vane. We carried out 95 experimental runs in clear-water conditions to investigate the influence of vane height, bevel angle, angle of flow attack, and flow regime on the maximum scour depth in the vicinity and downstream of the vane. Results show that the maximum scour depth increases with the increase in the angle of attack, vane height-to-depth ratio, and densimetric Froude number. The depth of scour around the vane and downstream in the channel decreases as the bevel angle increases. We propose empirical equations for calculating the maximum scour depth near the vane and downstream at equilibrium condition. The densimetric Froude number of the flow and the angle of flow attack are found to have the largest influence on maximum scour depth and downstream extension. The findings indicate that the bevel shape is effective method to reduces the maximum scour depth around the vane.

Dawei Guan, Xuefen Zhang, Hao Meng et al.

This review focuses on the mechanisms and scour resistance of various soil solidification methods used in civil and coastal engineering. Traditional chemical methods, such as ordinary Portland cement (OPC) and lime, enhance scour resistance primarily through pozzolanic reactions and cementitious bonding, which increase cohesion and shear strength. The laboratory results revealed that OPC-solidified soil can resist flows of up to 4 m/s after one day of curing, whereas lime-treated soils can withstand flows of up to 8.5 m/s after 14 days. Polymer-based treatments work by forming a surface-binding network that improves soil aggregate stability; optimal dosages can reduce rainfall-induced erosion rates to as low as 0.3 % compared with those of untreated soil, although their limited strength restricts their use to nonhydrodynamic environments. Ionic soil stabilizers (ISSs), a class of chemical agents, function by replacing exchangeable ions in clay minerals, leading to reduced plasticity, improved particle alignment, and increased soil density. While widely applied in subgrades and slope stabilization, their application in hydraulic environments is still in its infancy. Current evidence of scour resistance remains limited because of insufficient laboratory and field data. Biological methods, including microbial and enzyme-induced calcium carbonate precipitation (MICP/EICP), function by precipitating calcium carbonate that binds particles and fills pores; these methods can reduce sand erosion by up to 80 %–98 %, although the cost and nonuniform distribution of enzymes present challenges. Combined methods leverage complementary mechanisms—for example, carbonate precipitation and cement hydration—to improve microstructure and strength synergistically, with reported increases in critical shear stress up to 971.6 Pa. This review provides a comparative analysis of the methods, focusing primarily on their underlying mechanisms and ability to enhance scour resistance, with additional discussion on costs, environmental impact, and operational complexity. Future research is needed to address how these methods could be optimized for better performance and cost efficiency, especially for large-scale prototype applications.

Andrea Lammer, Rolf Rindler, Michael Tritthart et al.

Temporal and spatial variability and a wide range of measured transport rates at comparable flow rates are well-known characteristics of the bedload transport process but represent substantial difficulties in practice and for load calculation. The possibility of measuring the bedload transport process has increased in recent years through the use of technically advanced methods. Since 2011, an integrative bedload monitoring system has been operating on the Urslau River in Austria and has been continuously observing the transport process. This long-term integrative dataset provides the basis for comparing calculation results from commonly used bedload transport formulae with measured data. On the basis of 27 high sediment transport efficiency events, as well as 75 events with reduced sediment availability and 34 events with low sediment availability, this study compares the measured and calculated bedload volumes. In addition, a wide range of measured bedload transport rates are presented for comparable discharges, and values in this range are represented by the formulae shown. The performance of the transport equations is improved by considering measured data from integrative bedload monitoring and by classifying bedload events. The results presented here indicate that, depending on the question considered and by selecting the appropriate formula, it is possible to achieve improved calculation results for practice that are comparable to the measured values.

Fateme Sedaghatkish, Safoora Asadi Kapourchal, Misagh Parhizkar

Biochar, as a viable substrate and soil amendment, has the potential to improve the physical and chemical properties of soils, consequently affecting soil erosion. However, few studies have explored the impacts of different types of biochar on soil detachment rates in the hillslope rill erosion process due to overland flow in deforested areas. To fill this knowledge gap, this study evaluated the soil detachment capacity (Dc) and rill erodibility (Kr) of soil samples amended with four different biochars (wood, rice, olive, and almond shells) collected from deforested hillslopes in northern Iran. Dc was measured via a hydraulic flume at three-bed slopes (8.5%, 16.9%, and 25.4%) and five flow discharges (0.21, 0.32, 0.43, 0.55, and 0.63 L/(m·s)). Moreover, key properties of the amended soils and the control soil, including organic matter (OM), aggregate stability (MWD), bulk density (BD), and cation exchange capacity (CEC), were measured. Compared with the control treatment, the application of the four types of biochar significantly (p < 0.01) decreased the Dc (with at least a 41% reduction). The application of almond shell and rice biochars significantly increased the OM and MWD, thus effectively decreasing Dc (−76% compared with that of wood biochar) and (−47% compared with that of olive biochar). The correlation analysis revealed significant associations between OM, MWD, and BD on the one hand and Dc on the other hand. Overall, the soils treated with almond shell and rice biochars could be distinguished from the other soils into distinct groups via principal component analysis. The linear relationship between Dc and shear stress was used to reflect the relationship between the dependent and independent variables (coefficient of determination, R2 > 0.71). The multiple regression equation developed to estimate Dc from the OM, MWD, and BD data was also accurate (R2 > 0.83). This study demonstrated that almond shells and rice biochars can be effective factors in controlling and reducing Dc and Kr on deforested and steep hillslopes. The findings of this study can help land managers select the most effective organic substrate for soil conservation purposes as well as hydrologists to support the estimation of rill erosion on steep hillslopes.

Mark R. Jury

Coastal climate processes that affect landscape hydrology and beach dynamics are studied using local and remote data sets near Cape Vidal (28.12° S, 32.55° E). The sporadic intra-seasonal pulsing of coastal runoff, vegetation, and winds is analyzed to understand sediment inputs and transport by near-shore wind-waves and currents. River-borne sediments, eroded coral substrates, and reworked beach sand are mobilized by frequent storms. Surf-zone currents ~0.4 m/s instill the northward transport of ~6 10⁵ kg/yr/m. An analysis of the mean annual cycle over the period of 1997–2024 indicates a crest of rainfall over the Umfolozi catchment during summer (Oct–Mar), whereas coastal suspended sediment, based on satellite red-band reflectivity, rises in winter (Apr–Sep) due to a deeper mixed layer and larger northward wave heights. Sediment input to the beaches near Cape Vidal exhibit a 3–6-year cycle of southeasterly waves and rainy weather associated with cool La Nina tropical sea temperatures. Beachfront sand dunes are wind-swept and release sediment at ~10³ m³/yr/m, which builds tall back-dunes and helps replenish the shoreline, especially during anticyclonic dry spells. A wind event in Nov 2018 is analyzed to quantify aeolian transport, and a flood in Jan–Feb 2025 is studied for river plumes that meet with stormy seas. Management efforts to limit development and recreational access have contributed to a sustainable coastal environment despite rising tides and inland temperatures.

Athanasios A. Kallianiotis, Chryssa Anastasiadou, Ioannis E. Batjakas

The marine ecosystem’s balance is crucial for sustaining biodiversity and supporting fisheries. Marine protected areas have been increasingly used to enhance marine habitats, yet their impact on fish populations remains a topic of debate. This study focuses on a marine protected area in Kitros, Pieria, in Greece, where an artificial reef was constructed, to understand its influence on coastal fish populations. The objectives were to investigate the changes in fish biomass and abundance, comparing the data from periods before and after the construction of an artificial reef. This research compares the data between 2007 and 2008 with the data between 2016 and 2017, collected with bottom trawl surveys strategically executed prior to and after the artificial reef’s installation. Fish species captured were identified, with their lengths and masses measured. The findings indicate an increase in the biomass and abundance of certain fish species after artificial reef deployment, notably the commercially significant <i>Mullus barbatus</i> and <i>Pagellus erythrinus</i>. The artificial reef in Kitros, Pieria, with its surrounding marine protected area appears to have had a positive impact on the local fish populations over the years, suggesting that it can contribute to marine conservation and fishery enhancement. These results underscore the potential of artificial reefs as tools for marine ecosystem management, offering insights for policymakers and environmentalists into coastal resource management.

Marcan Graffin, Mohsen Taherkhani, Meredith Leung et al.

Antonio Oliva, Jorge Olcina, Alfredo Ollero

Coastal retreat processes are usually associated with many anthropogenic actions, such as the regulation of river basins, the construction of hydraulic storm defence works in coastal areas and the building of housing on the beach. To all of this, we should also add the increase in sea levels due to the effect of climate change. The chosen area of study corresponds to the coastal area of the municipality of Guardamar del Segura, belonging to the Segura River Basin. The methodology applied in this study comprised the gathering of historical information, the extraction of data using GIS, the compiling of data using official organisations and the analysis of all these data from a geographical perspective. The obtained results show the chronology of the regulation works in the Segura Basin and their relationship with the reduction and negative trend in average ordinary flows (1940–2023) and the extraordinary, swelled flows recorded in the period 1994–2023. Furthermore, the coastlines from 1923 to 2023 were mapped, enabling us to determine the evolution of the coastline retreat processes experienced in the dune ridge of Guardamar del Segura and the increase in the frequency of impacts due to storms on Babilonia Beach. Finally, data on wind, waves and marine currents recorded at a gauging station were incorporated, enabling us to understand their impact on this coastal sector. The results obtained are discussed, and they indicate the need to incorporate data on sediment into the study in order to complete it. The conclusions reveal the existence of a relationship between all these anthropogenic elements in the beach erosion processes experienced in the village of Guardamar del Segura.

Elina Apine, Tim Stojanovic

Climate change-induced sea level rise has exacerbated coastal change putting millions of people at risk from coastal hazards, such as flooding and coastal erosion. Nature-based solutions have been recognised as an opportunity to simultaneously address the coastal hazard risks and achieve biodiversity goals. While such solutions are included in climate adaptation strategies, “hard” engineered solutions are still often preferred by those implementing the schemes. We sought to explore the diverse perspectives on UK coastal flood risk management among interested and/or affected groups by utilising the Q-methodology. We identified five perspectives: (1) The Pro-Green Practitioners; (2) The Future-Planning Relocators; (3) The Case-by-Case Thinkers; (4) The Cautious Practitioners and (5) The Climate Change Concerned. All five perspectives strongly valued the co-benefits of nature-based solutions and their role in coastal risk reduction. None of the perspectives prioritised hard-engineered solutions as the primary flood protection strategy in the UK, though they recognised their role in protecting essential infrastructure. The main disagreements between perspectives were (1) on the need for relocation strategies, and (2) whether nature-based solutions could cause social inequalities. The Q-methodology does not identify how prevalent such perspectives are, thus further research is needed to assess the social acceptance of nature-based solutions.

Bashiru Turay, Sheku Gbetuwa, Alieu Turay

Flooding is a well-known extreme climate event affecting coastal settlements around the world. It is the principal climate-related disaster encountered by residents of Portee and Rukupa, coastal slums in Freetown, Sierra Leone. The impacts of floods in these slums have been exacerbated by the lack of effective control measures to address the disaster. One reason for this ineffectiveness is a lack of information about how households are ready to manage floods and the roles of community-based organisations (CBOs) in these events. Given this concern, this study examines household readiness and CBOs’ roles in flood management in Portee and Rokupa using observation, purposive, and snowball sampling techniques to study 204 households and 12 CBOs. The results show that flood-related information in the community is mostly shared verbally among residents. In addition, most households claimed not to have received support amidst flood events, whereas CBOs within the area claimed the opposite. As such, we recommend that future studies look at household perceptions of vulnerability and willingness to take risk-reduction actions. This study encourages community members to strengthen inter-community and organisational learning, feedback, and support systems and adopt a “no wait on the government principle” for flood management.

Raquel A. F. Neves, Luciano N. Santos, Gisela M. Figueiredo et al.

Hydrobioid gastropods are abundant in coastal systems and ecologically important for ecosystem functioning. We aimed to unravel the relationship between usual and stress-related population attributes of the dominant macrofaunal species <i>Heleobia australis</i> with indicators of environmental quality and coastal pollution. Using Guanabara Bay (GB, Brazil) as a model of a multi-impacted coastal system, our hypothesis is that increased amounts of rainfall during the warm season reduce the bay’s environmental quality and induce shifts in snail population attributes. A suite of environmental variables, population attributes, and sediment quality descriptors was assessed by combining field and laboratory evaluations with literature compilation. Results indicate high organic pollution levels with environmental degradation and reinforce GB status as a severely contaminated system. Some environmental conditions can be applied as seasonal predictors of changes in warm-rainy (rainfall and salinity), intermediate (silicate), and cold-dry seasons (nitrite and nitrate). Three selected usual population attributes (snail density, fecundity, and recruitment) were not affected by changes in environmental conditions, but significant effects were detected on two stress-related attributes (relative penis length index and shell deformity). For the first time, shell deformity was recorded in <i>H. australis</i> snails. Low variation in usual population attributes highlight the high tolerance of <i>H. australis</i> to shifts in environmental conditions.

Carla Edworthy, Paul-Pierre Steyn, Nicola C. James

Ocean acidification (OA) refers to a global decline in the average pH of seawater driven by the absorption of atmospheric carbon dioxide (CO2). Marine macroalgae, while affected by this pH change, are also able to modify seawater pH through their own interaction with inorganic carbon in the carbonate system. Through this action, macroalgae-dominated habitats are potential refugia from OA for associated marine species. This review summarises the most prominent literature on the role of macroalgae in OA mitigation and the potential of macroalgal habitats to serve as OA refugia. It includes a brief overview of macroalgal distribution in an effort to illustrate where such refugia might be most prevalent. Macroalgae influence seawater carbonate chemistry through the absorption of CO2 and HCO3− during photosynthesis, raising surrounding seawater pH in the process. This transient effect on seawater chemistry could provide some respite from the negative effects of OA for many marine species. This refuge role varies over a range of scales along with macroalgal architecture, which varies in size from low-growing turfs to large canopy-forming stands. The associated pH changes can range over various temporal (daily and seasonal) and spatial (from centimetre to kilometre) scales. Areas of high macroalgal biomass are likely to play an important role as significant OA refugia. Such communities are distributed widely throughout the globe. Large brown macroalgae (Laminariales) dominated communities are common in temperate regions, while members of the Fucales are responsible for substantial macroalgal stands in warmer tropical regions. These marine fields and forests have great potential to serve as localised refuges from OA. While more work needs to be done to clarify the effect of macroalgal communities on seawater pH on a large scale, such refuge areas could become important considerations for the management of marine resources and in protected area selection.

José Amorim Reis-Filho, Tommaso Giarrizzo

Generating accurate estimates of the number of vessels in fishing ports using traditional methods (i.e., ground- and boat-based) can be challenging as observations are distorted by an horizontal perspective. Automated inspection using drones is an emerging research alternative for this type of investigation. However, the drone-based and ground- and boat-based survey methods have not been quantitatively compared for small-scale and commercial fishing fleets in their ports. The objective of this study was to determine the number of fishing vessels and detect onboard fishing gear using three independent sources of data along 41 ports across the Brazilian coastline. Proved by statistical significance, the drone-derived vessel counts revealed 17.9% and 26.6% more fishing vessels than ground- and boat-based surveys, respectively. These differences were further highlighted during the assessment of ports without a ground walkway, causing difficulty, especially for ground-based surveys. Considerable numbers and types of onboard fishing gear were detected using the drone survey, that could not be detected using the ground- and boat-based methods. Although the ground-based survey was associated with a lower cost in comparison with other methods, the drone-based survey required the least time to record fishing fleet features in study ports. Our findings demonstrate that drone surveys can improve the detection and precision of counts for fishing vessels and fishing gear in ports. Further, the magnitude of the discrepancies among the three methods highlights the need for employing drone surveys as a considerable time-reducing approach, and a cost-effective technique for fishery studies.

Mohammad Arian, Hassan Akbari, Seyed Mojtaba Hoseini Chavoshi

Construction of a new coastal structure changes the stable shape of the shoreline. This issue generally leads to sedimentation and erosion around adjacent structures due to changes in Littoral Sediment Transport (LST). This mechanism is considerably more complicated in crenulate-shaped bays than in straight shorelines. Therefore, special theories have been introduced for these bays. In addition to the above-mentioned difficulties, using two-dimensional long-term morphological models with considerable run times is not practical in most real cases. Instability and numerical errors may also be occurred due to the complicated forms of shorelines. The aim of this research is to introduce a proper morphological model for South-Eastern shorelines of Iran. Long term morphological simulation has been done for three important bays in the Mokran coasts using numerical and empirical models. The results show that these models are appropriate for understanding the behavior of crenulate-shaped bays. Their responses to natural changes like climate changes as well as human interventions can also be simulated properly.

Atiyeh Kamyab, Masoud Torabi Azad, Mahdi Sadeghi et al.

The nuclear disasters in Chernobyl and Fukushima have shown that such nuclear incidents are causing serious and undesirable long-term damage to the environment and the health of living beings, including humans. So that they should be taken very seriously. Considering the importance of the subject, in this paper, the simulation of the transmission and emission of cesium 137 nuclear abandoned from the contingency incident of Bushehr Power Plant in the Persian Gulf using the CROM (Código de cRiba para evaluaciÓn de iMpacto) code has been discussed. We assumed that the incident took place on July 1, 2018, and the most dangerous and an important nucleus of the abandoned is cesium 137. The simulation results show that the Cs-137 released from the incident is moved to the west and northwest of Persian Gulf and approach the head of the Persian Gulf after fifteen days. Then driven by the discharge of the Arvandrood River to the south coast and center of the Gulf moves forward and leads to the bottom. About two months later (late August) it will leave the Strait of Hormuz and will advance the Oman Sea and the Indian Ocean. Now, if this happens on January 1, after about 30 days, cesium 137 reaches the head of the Persian Gulf, and four months later (late March) will leave the Strait of Hormuz. The results of this study can be used under the same conditions in the nuclear emergency of Bushehr Power Plant.

Alireza Sadat Hosseini, Mohammad Reza Bahaari, Mohammad Lesani

This research is dedicated to study the relative stress concentration factors (SCF) at FRP strengthened tubular T-joint subjected to brace in-plane and out-of-plane bending moments using Finite Element Analyses performed by ABAQUS software package. Validation analysis for the finite element model of the unstiffened joint is performed against the experimental results together with the Lloyd’s Register and API equations. The effectiveness of using three different types of FRP materials such as Glass/Vinyl ester, Glass/Epoxy (Scotch ply 1002) and Carbon/Epoxy (T300-5208) on enhancing the fatigue life of tubular T-joints through computing the SCFs was investigated in three schemes. At first the chord alone was strengthened in order to investigate the effects of strengthening the chord member on SCFs. In the second phase, FRP was applied only on the brace member to study the brace strengthening effects, and in the third phase, both of the chord and brace members were strengthened. Promising results derived from analysis which show that FRP strengthening method can effectively decrease the SCF values at T-joints.

mojtaba zoljoodi, afshin mohseni arasteh, mozhgan ghazi mirsaeid

The internal waves complicate the propagation process of sound in the water. These waves are considered the main cause of disturbances in sound speed, and now it is known that the internal waves are the dominant parameter in the change process of sea frequency spectrum, as these changes range from many hourly cycles (floating frequency) to almost one daily cycle (inertia frequency).    The profile of mass sound speed in shallow waters depends on salinity and temperature gradients in turbulence internal waves. Here, the assumption is that the only probability function source is the turbulence internal waves in a water column. This investigation aims to use the mathematical models to study the internal wave effects on propagation of sound waves in shallow waters and that the waves how affect the sound propagation and depend on what parameters? We used the data gathered from Persian Gulf to calculate the parameters such as: sound speed, floating frequency, the ratio of resulted turbulences in sound propagation by vertical movement, phase functions and internal wave domain. Meantime, based on a given wave length (in the study area: 235m.), the shape of first mode has been compared to the other modes. The probability density functions have been calculated for two different modes. Comparing the ratio of generated turbulences in sound propagation by vertical movement and horizontal speed of particle, showed the horizontal movement is considerably less than the vertical one and also by increasing the depth (consequently decreasing the floating frequency), vertical movement is raised highly.  The highest floating frequency and turbulences generated in sound propagation by vertical movement are found on the places near the water level and this is due to thermocline existence and on the other hand in the same places we have the lowest range of vertical movement.