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This study investigates the impact of straight groynes of varying lengths on flow velocity distribution at the edges of a 180° bend canal. Using HEC-RAS 2D (version 6.5), the canal was modeled with a rectangular cross-section featuring a bottom width of 0.8 meters and a horizontal bed (zero slope). The topography included a 180-degree bend with an inner radius of 0.4 meters. Model validation was conducted by comparing the numerical flow velocity results with experimental data from a 180-degree bend canal without groynes. The comparison showed excellent agreement, with a root mean squared error (RMSE) of 0.1. This study examines the impact of varying groyne lengths (1/4 W, 1/5 W, 1/6 W, and 1/8 W, where W is the canal width) on flow dynamics, vortex formation, and bank stability. The results revealed that shorter groynes (1/8 W) significantly reduce flow velocity at the outer edge of the bend, providing effective protection against bank erosion. In contrast, longer groynes increase vortex intensity, leading to higher shear stresses and a greater risk of scour. The study emphasizes the importance of optimizing groyne length to balance flow velocity reduction and vortex control, offering valuable insights for riverbank protection and sediment management in curved channels.

Numerous groynes had been constructed on the Dwarkeswar River to improve bank protection. Among them, groynes adjacent to the village Rautara of Khandaghosh Block, West Bengal have been studied which were constructed in the year of 2009. This study investigates the alteration of channel morphology, sedimentology and flow characteristics influenced by emerged groynes through micro-level field study. An extensive field survey has been made with a dumpy level and fifty-nine sediment samples were collected from the field. Different channel parameters such as degradation aggradation ratio, braided index, channel instability and bar occupied area indices have been used from 2003 to 2018. The simulation of channel flow has been done using HEC RAS. It has been found that width/depth (w/d) ratio, bankfull channel width, channel area and sand-bed length of the river decrease due to groyne construction. On the other hand, channel maximum bankfull channel depth, depositional rate, the difference between average depth, maximum depth and braided index drastically increased. Increasing flow velocity, flow deflection with coarse and poorly sorted multimodal sediments near the tip of the groynes as well as decreasing flow velocity, curve flow path, accelerated sedimentation with elevating river bed have been observed. Altogether result indicates that the emerged groynes are effective in protecting the river banks at the cost of channel degradation.

Existing riverbank riprap could face the risk of failure if the flood regime changes in future. Additionally, changed sediment transport in rivers, as a possible result of climate change, impacts the failure risk of flood protection measures. Evaluation of this potential failure is the primary issue of riprap stability and safety assessment. The consequences of the bank failure are probably uncontrolled erosion and flooding with disastrous consequences in residential areas or damage to infrastructures. Thus, a probabilistic analysis of riprap failure considering different mechanisms due to the flood and sediment transport uncertainties is required to assess embankment stability. In this article, the concept of a probabilistic assessment model based on Monte Carlo simulation method, moment analysis methods, and Rosenblueth point estimation method are presented to define the failure risk of riprap as the river bank protection. The probability of failure in different modes, namely direct block erosion, toe scouring and overtopping, has been defined by taking into account the river bed level variation based on bedload transport described with a probabilistic function of the peak discharge. The result of three models comparison revealed a good agreement (the average deviation of less than 2%) in estimation of riprap failure probability. This model is a strategical tool to search the critical river reaches and helps to evaluate the risk maps. So that, the model could cover the engineering aspect of environmental stability in the rivers with riprap as the bank protections.

The Gandak River originates in Nepal and merges with the Ganga River in India. The Gandak River is experiencing significant geomorphological alterations due to climate change and anthropogenic causes. In this study, an attempt has done to examine river bank erosion & accretion, shifting of the river bank, sinuosity, and braiding index of the Gandak River between Sahibganj and the confluence with the Ganga River, covering a length of 92.4 km from 1989 to 2022 (33 years) using remote sensing and geospatial technologies. The delineation of the river bank line for different periods, along with the quantification of erosion and accretion of the river’s right and left banks, were analysed using GIS, including the sinuosity and braiding patterns. The overall sinuosity value ranged from 1.16 to 1.01 and did not follow any specific pattern in significant reaches. The sinuosity value was almost constant over the most d/s reach of 30.74 km. The braiding index of the River was found to be the maximum between Ismailpur and Baijalpur and the minimum value between Munja and Chakia in 2015 and 1995 respectively. This study revealed that the river is shifting to the right, and bank protection measures were needed. Finally, the proposed investigation revealed the braiding phenomenon, river shifting in the transverse direction, and shifting of the meander bend was primarily responsible for the erosion and accretion of the river banks. This study will benefit local government agencies, concerned authorities, and people residing along the banks of the Gandak River by providing insights into the river’s migration patterns. Further, this knowledge aids in better planning of riverbank protection measures and developing a navigation system.

Many alluvial rivers worldwide are plagued with significant geomorphology changes due to severe riverbank collapse. This study developed an approach for quantifying riverbank erosion and outlined a structure for riverbank preservation based on insights gained from field investigations conducted in the lower Yellow River. Using the erosional forces, the newly introduced assessment method enables convenient measurement of riverbank erosion at various locations, even without cross-sectional profiles or channel-specific data. Abundant evidence highlights the severe riverbank collapses in the lower Yellow River, exemplified in the Jiyang Reach, where the left riverbank retreated at 26.0 m/yr from March 31, 2016 to May 10, 2018. The presence of weak soil erosion resistance is an inherent cause of riverbank collapse, with the critical shear stress of the soil being only 0.1 N/m 2 , significantly lower than that of the flow of 3.1 N/m 2 . Climate change and human activities, such as increased heavy rainfall frequency, reduced incoming water-sediment conditions and changes in riverbank boundary conditions, have triggered riverbank collapse. To prevent the occurrence of riverbank collapse, this study proposes a theoretical framework for a riverbank protection structure that simultaneously addresses the need for flood control and ecological conservation.

One major floods problem in Miu River is huge amount of sediment which transported along the river channel. The decreasing of river capacity has been analysed and some channel courses changes also detected. These problems caused river morphological change and it is necessary to find comprehensive solution which not only decreasing the flood damage but also consider appropriate approach to natural environment. The complexity of these problems and possible solutions to overcome flood and sedimentation problem were investigated. Increasing of river capacity by channel excavation, protecting riverbank with revetment and construction of sediment control facilities were proposed as main solution. However, it is necessary to evaluate the effectiveness of these efforts by analysed sediment control facilities location and dimension of the structures. Some alternatives were investigated in order to find most effective solution to solve flood and sedimentation problem in Miu River.

In the river system, the deployment of impermeable dikes often leads to significant morphological changes, including scouring due to strong momentum exchanges between the dike field and the main flow. This presents a challenge in managing riverbank erosion effectively. This study aims to analyze the impact of alternative length layouts of dikes on flow dynamics in an open channel, with the focus on minimizing the scour responsible factors around dikes. Employing a Computational Fluid Dynamic approach, this research investigates flow behavior around a series of emerged and a protective dike with varying lengths. The study utilizes the Reynolds Stress Model (RSM) to capture detailed flow characteristics such as velocity, turbulence, and recirculation eye displacement both upstream and downstream of the protective dike. The results showed that employing a protective dike with 0.5 L -0.6 L (where L represents the dike length) can significantly reduce depth averaged velocity and turbulent kinetic energy near the first dike head by 35% and 41%, respectively. The study recommends constructing protective dikes with optimized dimensions to mitigate the adverse impacts of momentum exchanges, thereby enhancing riverbank protection and reducing erosion risks.

In power systems, capacitor banks play a significant role in improving voltage profiles, reducing losses, and adjusting power factors. Security measures must be implemented quickly and reliably to protect them from a wide range of threats. As a consequence of capacitor bank failures, finding and fixing the damaged units/elements is more difficult, which may lead to voltage control difficulties or the loss of any of these benefits. The paper shows the application of system-based testing methods for protection systems using RelaySimTest software, which works with OMICRON injection test sets. System-based testing methods are applied to test voltage differential protection for center-tapped shunt capacitor banks. The use of system-based testing methods has many advantages over conventional testing methods, which include distributed testing, transient state conditions testing, etc., which in turn result in cost savings during the commissioning and testing phase. The impact of external faults on bank installation has been tested successfully.

Protecting river banks from turbulent flow is crucial for sustainable development. This study aims to evaluate the performance of submerged hockey groynes on river flow characteristics. This study employs numerical simulations were conducted using ANSYS Fluent, a computational fluid dynamics (CFD) software, to examine flow patterns, mean streamlines, mean velocity profiles, bed shear stresses, and vortex kinetic energy around the groynes. The simulations utilized a laboratory flume with a hockey groyne model at three orientation angles (60°, 90°, and 120°) and three submergence ratios (75, 100, and 125%) at varying discharges (0.0057, 0.0087, and 0.0119 m 3 /sec). This research contributes to the understanding of submerged hockey groynes' effectiveness in riverbank protection, highlighting specific configurations that align with field requirements and offering a basis for future studies on sustainable river management strategies. The findings suggest that a submergence ratio between 75 and 100% optimizes flow characteristics, and an orientation angle of 90° provides the most effective configuration for reducing shear stress and enhancing flow stability. The validation results demonstrated that the simulations effectively modeled the flow dynamics around the groynes. A single hockey groyne exhibited a minimum scour depth, with maximum shear stresses significantly lower than those observed for a series of elliptic groynes. A direct correlation was found between bed shear stress and maximum scour across all submergence ratios and orientation angles. While the study provides valuable insights into groyne performance, the laboratory conditions may not fully replicate real-world scenarios, which could affect the generalizability of the results.

Riverbank protection is essential in areas vulnerable to erosion that could lead to economic and environmental losses. Baffles are one of the riverbank protection techniques in river engineering. The presence of baffles significantly reduces riverbank erosion, but their effects on flow patterns is not thoroughly examined. Therefore, an experimental investigation on the flow patterns and morphological changes due to presence of baffles in a meandering channel was conducted in the Hydraulics Laboratory, Faculty of Civil Engineering, UTM Johor Bahru. Two discharge rates of 0.19 L/s and 0.36 L/s, and two angled baffles, set at 20° and 40° were investigated. Hydraulic parameters such as Manning’s n , velocity distribution, and morphological changes in the channel were examined. The findings revealed that the baffles induced an additional flow resistance in the channel up to 67%. Additionally, the presence of baffles significantly altered the velocity distribution, erosion and deposition processes. The baffles effectively protected riverbanks only when placed at optimum angle under specific discharges. This study enhances understanding of flow characteristics and highlights the effectiveness of baffles in riverbank protection.