scholarly journals CONTROL AND METHODOLOGY OF MODELING HYDROLOGICAL PROCESSES IN THE DESIGN OF HYDRAULIC STRUCTURES IN THE ESTUARIES OF RIVERS

Author(s):  
D. A. Antonenkov ◽  
◽  
A. E. Shchodro ◽  

The article presents the methodology of hydrological modeling of water flows for constructing flow plans in the design of hydraulic structures. On the basis of these calculations, both the specific costs of bottom and suspended sediments in each flow stream and the deformation of the riverbed at various points in time can be determined. The results of experiments with spatial models of river sections are considered. The developed technique makes it possible to calculate the deformation of the bottom and shores and form a flow organization scheme, which, due to an increase in velocities in some section of the channel, ensures sediment transport to more remote areas of the seashore, up to the open sea.

2020 ◽  
Vol 175 ◽  
pp. 12002 ◽  
Author(s):  
Issam Boukhanef ◽  
Anna Khadzhidi ◽  
Lyudmila Kravchenko ◽  
Zeroual Ayoub ◽  
Kastali Abdennour

In Algeria, the problems of erosion and sediment transport are critical, since they have the most dramatic consequences of the degradation of agricultural soils on the one hand and the siltation of the dam on the other .The sediment transport in the Algerian basins is very important especially during the periods of floods, It is in this sense that this study, which consists of estimating the sediment transport in suspension and determining the models of relation linking the liquid discharge and the sediment discharge in order to estimate the solid transport in the absence of suspended sediments concentration data at the Sidi Akkacha station at the outlet of the basin of Oued Allala which is subject to a high water erosion, it degrades from one year to the other under the effect of this phenomenon especially during the floods which drain high amounts of fine particles exceeding in general, the concentration of 150 g/l, the results obtained from the application of the models are very encouraging since the correlation between liquid and solid discharge exceeds 80 %.


2012 ◽  
Vol 106 ◽  
pp. 1-15 ◽  
Author(s):  
A. Palanques ◽  
P. Puig ◽  
X. Durrieu de Madron ◽  
A. Sanchez-Vidal ◽  
C. Pasqual ◽  
...  

2021 ◽  
Vol 233 ◽  
pp. 03035
Author(s):  
Zhuzhu Yu ◽  
Zhiguo He ◽  
Li Li ◽  
Taoyan Ye ◽  
Yuezhang Xia

Based on FVCOM hydrodynamic numerical model and coastline topographic data in 2013, a three-dimensional numerical model of fine sediment transport in Hangzhou Bay has been established to explore the water and sediment exchange mechanism between Hangzhou Bay and the open sea at different typical sections. The results of validation with measured and satellite retrieved data show that the model can well simulate the process of water and sediment movement in Hangzhou Bay. Compared with the calculation results of the coastline topographic data of Hangzhou Bay in 1974 and 2020, the influence mechanism of shoreline change on the water and sediment exchange mechanism between Hangzhou Bay and the open sea has been studied. The results show that the sediment transport inside and outside the Hangzhou Bay is generally in the pattern of north-inflow and south-discharge. Compared with the coastline in 1974, the sediment transport from Yangshan port in the north of Hangzhou Bay and Zhoushan Islands in the middle of Hangzhou Bay increases when the coastline is pushed into the bay in 2020, while the outward sediment transport from Jintang Channel in the South decreases. The overall trend features that the sediment transport into the bay increases, with the bay mouth silting. In the three sections extending from Hangzhou Bay to the open sea, the inflowing water and sediment of the horizontal section on the north side is decreasing, while the discharged sediment from the south side and the inflowing water and discharged sediment from the vertical section at the east side are increasing.


Geografie ◽  
1997 ◽  
Vol 102 (2) ◽  
pp. 130-138
Author(s):  
Zdeněk Kliment ◽  
Jan Kopp

The article examines suspended sediment transport in Mže, Radbuza, and Úhlava Rivers over the period 1989-95. Data on suspended sediments was collected at five observing sites. The research has been carried out in collaboration with Czech Hydrometeorological Institute, Plzeň. Apart from the suspended load characteristics also the seasonal variation of suspended sediments, siltation of Hracholusky and České Údolí Lakes, and the share of inorganic material in suspended sediments have been examined.


2011 ◽  
Vol 1 (6) ◽  
pp. 20 ◽  
Author(s):  
G. E. Vincent

With a view to explaining the phenomena of sediment transport in the open sea, outside the wave breaking area, the author carried out a laboratory investigation of wave action on a horizontal bed. He puts forward a number of new results regarding : 1 - The state of turbulence near the bed and the stability of the oscillatory laminar boundary layer. 2 - The setting in notion of materials under the influence of wave alone. 3 - The entrapment current caused by wave action close to the bed. 4 - The transport of material under wave action only. 5 - The indirect action of wave on the bed. The main conclusions reached are as follows : 1/ - The results given by Kuon Li regarding the onset of turbulence within the oscillatory boundary layer overestimate the range of laminar conditions. Vo (maximum orbital velocity) and e (roughness) are the principle factors governing the transition. Test waves are either generally laminar, or are only slightly turbulent within the body of liquid, but they are, however, more often turbulent in the immediate neighbourhood of the bed. 2/ - The Investigation of conditions for the onset of grain movement of the bed material shows that the action of wave can be appreciable, even at depths of several tens of metres. A wave of 6 metres amplitude, with a total length of 120 metres, would be capable of putting a 0.3 mm sand grain into motion at a depth of 60 metres. 3/ - The experimental investigation, as well as the viscous fluid theory, shows the existence, close to the bed, of an entrainment current of liquid particles which always works In the direction of wave propagation. 4/ - In test flumes, this entrainment current forms part of a mass transport within the liquid, the vertical distribution of which varies with the characteristics of the fluid motion. On a horizontal bed, It generally gives rise to an effective sediment transport, in the direction of wave propagation, as the preponderant part of the liquid velocity component, near the bed. is in this direction. 5/ - Owing to the existence of the pass transport current and the onset of suspension of material above the bed, some sediment transport can exist out to sea. These results give an explanation of why, under the action of long and regular wave . material tends to be carried in the direction of the waves and build up on the beach whereas, under storm conditions, a strong resultant turbulence produces suspension and favours erosion of the beach. 6/ - On a sloping bed, transport towards the shore is counterbalanced by the effect of gravity, currents caused by winds from seaward and density currents set up in the wave break area so that finally material eroded from land surfaces are, In part, gradually carried away towards the open sea.


Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2189
Author(s):  
Zekun Song ◽  
Weiyong Shi ◽  
Junbiao Zhang ◽  
Hao Hu ◽  
Feng Zhang ◽  
...  

Based on the 2013 field survey data of hydrology, suspended sediments and bottom sediments in the Central Hangzhou Bay, this paper explores the dynamic mechanism of suspended sediments in Hangzhou Bay by employing material flux decomposition. Meanwhile, the migration trends of bed sediments are also investigated by analyzing grain size trends. The results show that during an ebb or flood tide, the hydrograph of suspended sediment concentration of Hangzhou Bay is dominated by an M shape (bimodal), which is attributed primarily to the generation of a soft mud layer and a separate fluid mud layer. Laterally, the distribution of suspended sediment concentration is high in the south and low in the north. From a macroscopic perspective, the net sediment transport in the study area displays a “north-landward and south-seaward” trend, presenting a “C”-shaped transport mode. That is, the sediments are transported from the bay mouth to the bay head on the north side and from the bay head to the bay mouth on the south side. The sediment transports by advection and tidal pumping are predominant, while the sediment transport by vertical circulation makes little contribution to the total sediment transport. Moreover, the sediment transport in the center of the reach area is dominated by advection, whereas that near both sides of the banks is controlled by tidal pumping. The asymmetry of the tides, i.e., flood-dominance in the north and ebb-dominance in the south, is the primary cause of the dynamic mechanism for the overall “C”-shaped transport mode in Hangzhou Bay. Additionally, coupled with the narrow-head wide-mouth geomorphology, Hangzhou Bay remains evolving by south shore silting and north shore scouring.


2020 ◽  
Vol 12 (19) ◽  
pp. 3133
Author(s):  
Lu Zhang ◽  
Zhuohang Xin ◽  
Huicheng Zhou

Recent developments of satellite precipitation products provide an unprecedented opportunity for better precipitation estimation, and thus broaden hydrological application. However, due to the errors and uncertainties of satellite products, a thorough validation is usually required before putting into the real hydrological application. As such, this study aims to provide a comprehensive evaluation on the performances of Tropical Rainfall Measuring Mission Multi-satellite Precipitation Analysis (TMPA) 3B42V7 and Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks-Climate Data Record (PERSIANN-CDR), as well as their adequacies in simulating hydrological processes in a semi-humid region in the northeastern China. It was found that TMPA 3B42V7 showed a superior performance at the daily and monthly time scales, and had a favorable capture of the rainfall-intensity distribution. Intra-annual comparisons indicated a better representation of TMPA 3B42V7 from January to September, whereas PERSIANN-CDR was more reliable from October to December. The Soil and Water Assessment Tool (SWAT) driven by gauge precipitation data performed excellently with NSE > 0.9, while the performances of TMPA 3B42V7- and PERSIANN-CDR-based models are satisfactory with NSE > 0.5. The performances varied under different flow levels and hydrological years. Water balance analysis indicated a better performance of TMPA 3B42V7 in simulating the hydrological processes, including evapotranspiration, groundwater recharge and total runoff. The runoff compositions (i.e., base flow, subsurface flow, and surface flow) driven by TMPA 3B42V7 were more accordant with the actual hydrological features. This study will not only help recognize the potential satellite precipitation products for local water resources management, but also be a reference for the poor-gauged regions with similar hydrologic and climatic conditions around the world, especially the northeastern China and western Russia.


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