DYNAMICS OF THE NEARSHORE ZONE OF KALAMITSKIY GULF (BLACK SEA) UNDER INFLUENCE OF WIND WAVES

2017 ◽  
Author(s):  
Vladimir Fomin ◽  
Vladimir Fomin ◽  
Konstantin Gurov ◽  
Konstantin Gurov ◽  
Vladimir Udovik ◽  
...  
Keyword(s):  
Coastal Zone ◽  
Bottom Sediments ◽  
Wind Waves ◽  
Bottom Topography ◽  
Fast Response ◽  
Nearshore Zone ◽  
Qualitative And Quantitative ◽  
Waves And Currents ◽  
Quantitative Assessments ◽  
Sedimentation Processes

Coastal zone dynamics is especially interesting for interdisciplinary researchers. This is due to general retreat of the coast of the Western Crimea and the fast response in the beach ar-ea. This justifies the need for monitoring of morphodynamic processes in the coastal zone of Crimea with the aim of qualitative and quantitative assessments of modern coastal trans-formation, as well as forecasts of possible changes. XBeach model has been used to simulate dynamics of waves and currents, sediment transport and changes in bottom topography, as well as the processes of drying and flooding of coastal areas. Erosion and sedimentation processes for the bottom sediments of the coastal zone of the Western Crimea have been numerically studied. The bottom profile has been reconstructed on the basis of bathymetric investigations in the coastal zone of the Western Crimea. Numerical simulations have been performed for various parameters of the bed composition and wind waves. Two fractions of bottom sediments have been considered for numerical experiments. The obtained results show that XBeach model can be successfully applied to simulate the bed profile evolution and changes in bottom sediment fractionation.

DYNAMICS OF THE NEARSHORE ZONE OF KALAMITSKIY GULF (BLACK SEA) UNDER INFLUENCE OF WIND WAVES

2017 ◽  
Author(s):  
Vladimir Fomin ◽  
Vladimir Fomin ◽  
Konstantin Gurov ◽  
Konstantin Gurov ◽  
Vladimir Udovik ◽  
...  
Keyword(s):  
Coastal Zone ◽  
Bottom Sediments ◽  
Wind Waves ◽  
Bottom Topography ◽  
Fast Response ◽  
Nearshore Zone ◽  
Qualitative And Quantitative ◽  
Waves And Currents ◽  
Quantitative Assessments ◽  
Sedimentation Processes

Coastal zone dynamics is especially interesting for interdisciplinary researchers. This is due to general retreat of the coast of the Western Crimea and the fast response in the beach ar-ea. This justifies the need for monitoring of morphodynamic processes in the coastal zone of Crimea with the aim of qualitative and quantitative assessments of modern coastal trans-formation, as well as forecasts of possible changes. XBeach model has been used to simulate dynamics of waves and currents, sediment transport and changes in bottom topography, as well as the processes of drying and flooding of coastal areas. Erosion and sedimentation processes for the bottom sediments of the coastal zone of the Western Crimea have been numerically studied. The bottom profile has been reconstructed on the basis of bathymetric investigations in the coastal zone of the Western Crimea. Numerical simulations have been performed for various parameters of the bed composition and wind waves. Two fractions of bottom sediments have been considered for numerical experiments. The obtained results show that XBeach model can be successfully applied to simulate the bed profile evolution and changes in bottom sediment fractionation.

Experimental Evaluation of an Autonomous Surface Craft for Shallow-Water Bathymetry

2017 ◽  
Vol 51 (4) ◽  
pp. 59-67 ◽  
Author(s):  
Rubén Raygosa-Barahona ◽  
Miguel Ángel Garcia-Terán ◽  
Cecilia Enriquez ◽  
Ernesto Olguín-Díaz
Keyword(s):  
Pid Control ◽  
High Spatial Resolution ◽  
Wind Waves ◽  
Bottom Topography ◽  
Small Surface ◽  
Experimental Procedure ◽  
Exchange Processes ◽  
Waves And Currents ◽  
Displacement Speed ◽  
Aquatic Vehicles

AbstractVast coastal water bodies such as mangroves and wetlands, despite their enormous importance, are inaccessible to even the smallest aquatic vehicles, which are not capable of navigating the extremely shallow environments. To understand their behavior and the transport and exchange processes with both sea and land, it is crucial to study local hydrodynamics, which are highly dependent on bathymetric configuration. In order to obtain accurate and high spatial resolution bathymetric samples, an existing small surface vehicle instrumented with GPS and echosounder was implemented with an autopilot system to achieve autonomy. A description of the autonomous system together with the evaluation of the whole vehicle's performance in a natural coastal environment (e.g., affected by the wind, waves, and currents that exist in coastal regions) is presented. The navigation system is based on an autopilot system, which follows a set of user-selected waypoints to drive the vehicle through a previously designed path. The trajectory is self-corrected to achieve sufficient accuracy (the limits are also defined by the user) using real-time kinematics. The tracking is performed by two independent proportional-integral-derivative (PID) control systems: the boat's displacement speed and the bearing control. A simple experimental procedure to tune the low-level PID control parameters is presented. Comparisons between the bathymetric maps obtained with the system and with other standard bathymetric surveys from a selected coastal site (ship-towed echosounder) are presented to test both the precision of the boat's navigation and the fine structure of the bottom topography. The results confirm the system's capability as a valuable tool for surveying large and very shallow environments.

scholarly journals PROBLEMS OF SEDIMENTS TRANSPORT MODELING IN THE COASTAL AREA

2021 ◽  
Vol 49 (1) ◽  
pp. 93-141
Author(s):  
R. D. Kosyan ◽  
B. V. Divinsky
Keyword(s):  
Sediment Transport ◽  
Surface Waves ◽  
Wave Field ◽  
Frequency Distribution ◽  
Coastal Zone ◽  
Bottom Sediments ◽  
Wave Energy ◽  
Laboratory Experiments ◽  
Wind Waves ◽  
Wave Spectrum

Due to the development of measuring instruments, a more detailed analysis of the wave field and the field of suspended sediments spatio-temporal characteristics has become possible. Through the efforts of Russian specialists over the past decades: A unique database of observations of the sediment movement in storm situations in different physical and geographical areas of the coastal zone of the Black, Baltic, North, Mediterranean, South China Seas has been collected, supplemented by extensive data of laboratory experiments in the best laboratory in Europe (Hannover, Germany). New experimental material has been obtained to determine the physical features of sediment transport by wave flow. The main mechanisms controlling the amplitude and phase relationships of the concentration fluctuations and discharge of suspended sediment on time scales less than the period of the peak of the wind wave spectrum are considered. The presence of low-frequency fluctuations in sediment concentration with a period of the order of several periods of wind waves and an amplitude several times higher than the average value of concentration is noted. The previously unexplored problem of the wave energy frequency distribution in the spectrum of surface waves influence on the sediment transport has been analyzed. Differences in the response of the washed-out bottom to an external disturbance, represented by irregular surface waves with constant integral characteristics (significant wave height and period of the spectrum peak) and variable wave energy frequency distribution, were revealed. The influence of swell waves on the redistribution of bottom sediments in the sea coastal zone was investigated. It is shown that dividing the wave field into separate components allows a more correct description of the spatiotemporal structure of surface waves, as well as a significant refinement of the bottom sediment transport schemes in the coastal zone. Using the example of the Anapa bay bar, it is shown that situations are possible in which the alongshore flow of bottom sediments is almost completely determined by swell waves. The results of field and laboratory experiments make it possible to determine the directions for further research on the creation of physically based models of sediment transport by waves and wave currents.

scholarly journals Influence of Storm Conditions on Changes in the Granulometric Composition of Bottom Sediments in the Coastal Zone of the Western Crimea

2021 ◽  
Author(s):  
K. I. Gurov ◽  
V. V. Fomin ◽  
◽  
Keyword(s):  
Coastal Zone ◽  
Bottom Sediments ◽  
Wind Waves ◽  
Initial Distribution ◽  
Computational Domain ◽  
Model Calculations ◽  
Coastal Slope ◽  
Sediment Volume ◽  
Median Diameter ◽  
Sandy Material

The aim of this work is to study the dynamics of bottom sediments granulometric fractions in the Kalamitsky Gulf coastal zone near the Lake Sakskoe bay-bar under influence of storm surge based on the XBeach numerical morphodynamic model. A series of numerical experiments has been carried out, in which the parameters of waves at the seaward boundary of the computational domain changed in time, simulating the passage of a cyclonic atmospheric anomaly over the investigated region. The initial distribution of the sediment volume concentrations in different parts of the underwater coastal slope profile was set based on the results of field observations. The duration of model calculations was 24 h. The quantitative characteristics of the spatial distribution of various bottom sediments fractions, sediments median diameter and values of bottom deformations were obtained. It has been established that the main morphodynamic changes occurs in the area 0–120 m from the shoreline and are limited by the 3.5 m isobath. It was noted that the maximum changes in the relief of the coastal zone and the upper section of the underwater coastal slope occur during the development and attenuation phases of a storm. In the same time intervals an intensive redistribution of sandy material is observed. It has been established that, with a change in the parameters of wind waves in time at the seaward boundary, the scales of sand material redistribution and deformations of the coastal zone are higher than in the experiment when the direction of the waves does not change with time at the seaward boundary of the computational domain.

Wind-Induced Waves and Currents in a Nearshore Zone

1997 ◽  
Author(s):  
Nobuhiro Matsunaga ◽  
Misao Hashida ◽  
Hiroshi Kawakami
Keyword(s):  
Nearshore Zone ◽  
Waves And Currents

scholarly journals Ultrasound examination of gastric contents: are qualitative and quantitative assessments complementary? A reply

Anaesthesia ◽  
2017 ◽  
Vol 72 (10) ◽  
pp. 1281-1282 ◽  
Author(s):  
V. Yuen ◽  
C. Chen ◽  
L. Liu ◽  
C. Y. Wang ◽  
S-W Choi
Keyword(s):  
Ultrasound Examination ◽  
Qualitative And Quantitative ◽  
Gastric Contents ◽  
Quantitative Assessments

Qualitative and quantitative assessments of HAART adherence of substance-abusing women

AIDS Care ◽  
2003 ◽  
Vol 15 (2) ◽  
pp. 239-249 ◽  
Author(s):  
G. M. Powell-Cope ◽  
J. White ◽  
E. J. Henkelman ◽  
B. J. Turner
Keyword(s):  
Substance Abusing ◽  
Qualitative And Quantitative ◽  
Haart Adherence ◽  
Quantitative Assessments

Anthropogenic Impact on the Lithodynamics of the Coastal Zone of the Southern and Western Black Sea Coast (Review)

2021 ◽  
Author(s):  
T. V. Efremova ◽  
Yu. N. Goryachkin ◽  
◽  
Keyword(s):  
Coastal Zone ◽  
Black Sea ◽  
Bottom Sediments ◽  
Anthropogenic Impact ◽  
River Flow ◽  
The Black Sea ◽  
Negative Consequences ◽  
Coastal Zones ◽  
Natural Dynamics ◽  
The Impact

Anthropogenic impact on lithodynamics of the coastal zone changes the natural dynamics of bottom sediments, which leads to increased abrasion and swelling of beaches, activation of landslide processes creating a threat of destruction of the coastal infrastructure. The article aims at providing an overview of the scientific literature on the anthropogenic impact on lithodynamics of the coastal zone of the southern and western coasts of the Black Sea (shores of Romania, Bulgaria and Turkey). The work shows that with all the differences in the natural conditions of the coastal zones of these countries the types of anthropogenic effects they undergo are almost the same. These include: hydrotechnical construction without regard to the impact on the neighbouring coast sections; reduction of solid river flow due to river regulation by reservoirs; construction of capital facilities directly on the beaches; illegal extraction of sand from beaches and river beds; dredging with sale of the extracted material to construction companies; covering of cliffs by various structures; destruction of coastal dunes, etc. The main negative consequences of these actions are reflected in disruption of natural dynamics and shortages of bottom sediments, changes in the coastline, reduced aesthetic attractiveness and accessibility of shores, destruction of coastal ecosystems. The article also provides information on the legislation of these countries regarding environmental management in the coastal zone

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