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Introduction: This study investigates the characteristics of sediment disturbance caused by impeller rotation in reservoirs of inland rivers with high sediment content in China. A scaled experimental model, reflecting typical environmental conditions of inland water reservoirs in Northwest China, was established in Lanzhou, Gansu Province, following the principle of similarity. Methods: The study integrates numerical simulations using Ansys Fluent software and corroborates the findings through hydraulic experiments. Computational Fluid Dynamics (CFD) and the κ-ε Realizable model were employed to simulate the solid-liquid mixing process, which was verified against the experimental model. Results: The results indicate that increasing the impeller velocity from 2 rad/s to 8 rad/s, while submerged at a depth of 1000 mm in the flow field, enhances the rate of bottom sediment suspension. Furthermore, the rate of suspended sediment discharge from the model outlet increased with inflow velocity ranging from 0.1 m/s to 0.8 m/s. A decrease in the impeller's submersion depth from 600 mm to 1200 mm was found to reduce the maximum disturbance radius affecting the bottom sediment. Discussion: The reliability of the simulation was confirmed by comparing the software results with experimental data. This study provides insights into the mechanisms of sediment-laden flow disturbance in the reservoir areas of inland rivers in China and lays the groundwork for more comprehensive investigations into sediment discharge in these environments. [ABSTRACT FROM AUTHOR]

Sorting out the requirements for intelligent functions is the prerequisite and foundation of the top-level design for the development of intelligent ships. In light of the development of inland intelligent ships for 2030, 2035, and 2050, based on the analysis of the division of intelligent ship functional modules by international representative classification societies and relevant research institutions, eight necessary functional modules have been proposed: intelligent navigation, intelligent hull, intelligent engine room, intelligent energy efficiency management, intelligent cargo management, intelligent integration platform, remote control, and autonomous operation. Taking the technical realization of each functional module as the goal, this paper analyzes the status quo and development trend of related intelligent technologies and their feasibility and applicability when applied to each functional module. At the same time, it clarifies the composition of specific functional elements of each functional module, puts forward the stage goals of China's inland intelligent ship development and the specific functional requirements of different modules under each stage, and provides reference for the Chinese government to subsequently formulate the top-level design development planning and implementation path of inland waterway intelligent ships. [ABSTRACT FROM AUTHOR]

China has a vast territory and a long history of inland navigation. This paper is based on the Shaying River Shenqiu hub project, and a normal physical model with a geometric scale of 65 was established to simulate the characteristics of water and sediment in the entrance area of the project. By setting different working conditions and measuring and analyzing the velocity flow pattern of the wharf area, planning suggestions for the artificial channel with straight cut-off can be given. Simultaneously, the study simulates the natural sediment deposition state in typical years, observing changes in terrain and evaluating their impact on navigation, thereby validating the rationality of scouring and desilting processes. The research findings indicate that in the reconstructed river wharf's entrance area, the flow velocity is low, and the flow pattern is stable, ensuring that the transverse flow velocities along the recommended route meet the requirements for vessel navigation. Post-scouring from the regulating gate discharge, downstream deposition decreases, with a sediment flushing efficiency reaching 68.5%. Under the specified conditions, the thickness of sediment deposition after scouring does not negatively affect the water level for ships entering or departing the wharf. The results of this study may offer valuable reference insights for the planning of artificial rivers in similar terrains. [ABSTRACT FROM AUTHOR]

The cargo volume handled by China's inland waterway transport (IWT) system increased from 358 million tons in 1978 to 3.74 billion tons in 2018, far exceeding the total cargo volume on all rivers in the world except China. The container throughput of ports along the Yangtze River increased from 106,000 Twenty Equivalent Unit (TEU) in 1990 to 19.6 million TEU in 2018. The remarkable growth rate of IWT volume over 40 years is much higher than that of all land transport modes, ranging from 3.2% to 8.3% during the same period. This study examines the causes of such remarkable growth of volume in the IWT sector and draws lessons and experiences for China, which will help shape emerging economies desiring to develop their IWT system. This study applies documentary analysis of the Chinese government with historical data over 40 years. This study has defined four distinctive developmental stages: take-off, adjustment, breakthrough, and high growth. This study reveals that China's remarkable growth of IWT is attributable to institutional reform, infrastructure development, fleet modernization and standardization, financing diversification, and human resources development and education under central government's consistent interventionism over past 40 years. • China's inland waterway transport (IWT) has four growth stages, i.e., take-off stage, adjustment stage, breakthrough stage and high growth stage in 1978–2018. • China's growth of IWT is attributable to institutional reform, infrastructure development, fleet standardization, financing diversification and human resources development. • The above attributors have been generated by China's central government's consistent, sustained and adaptable policy in 1978–2018. [ABSTRACT FROM AUTHOR]

Traditional multimodal transportation dispatching of roads, railways, and maritime has been studied for years. This study investigates a bulk cargo distribution problem in a multimodal transportation network considering both the transportation modes of inland waterways and containerization technology. First, we qualitatively discuss the advantages and challenges of transportation using cargo containerization technology from the aspects of transportation cost, time-saving, pollutant emission reduction, and customer preference. Second, a mixed-integer linear programming model is developed, wherein the influence of bridge heights on transportation is considered. The model is validated based on near-practice numerical experiments, and we can obtain the optimal transportation scenario by solving the model, including transportation mode selection, vehicle routing, depot selection, and cargo quantity for containerization. Third, we conduct numerical experiments based on the multimodal transportation network of the Yangtze River in China to discuss the performance of multimodal transportation with containerization technology considerations. The results show that containerization transportation can decrease the total transportation costs for logistics companies under certain parameter configurations. The model and experiments are then extended by considering pollutant emission reductions and time savings, respectively. We uncover the performance of containerization technology by analyzing the Pareto fronts of this technology and traditional bulk cargo transportation. This study elucidates the decision making of logistics companies and government policymaking. [ABSTRACT FROM AUTHOR]

When the government decides to use the public-private partnership (PPP) in projects, such as infrastructure construction, selecting a private-sector partner that meets the project's needs is one of the key factors for successful implementation, but this is ignored in existing research. On this basis, this paper proposes a GRA-VIKOR method based on the combined weight of the improved CRITIC-entropy weight method (EWM). The traditional CRITIC method is improved by combining it with EWM. The combined weights are measured, which reduces the limitations of the single weight. Considering the inherent correlation of evaluation indicators, the VIKOR method is combined with the grey relational analysis (GRA), which makes the results of the selection assessment more reasonable. This paper carries out a case study of the first inland navigation PPP project in China. Through preliminary tracking studies, it tests the effectiveness of the proposed method, the superiority of which is demonstrated by comparing the evaluation results with those of the traditional GRA methods, VIKOR, and TOPSIS. [ABSTRACT FROM AUTHOR]

China's extensive inland navigable water system determines that inland navigation must be an important part of China's shipping industry. The collision process of ship striking the anti-collision pier is analyzed through simulation experiment in this paper. The results show that the collision process usually lasts less than 2 seconds, and the peak value of the collision force, friction and resultant force appears 0.5 after the start of the collision. [ABSTRACT FROM AUTHOR]

The multi-functional buoy is an important facility for assisting the navigation of inland waterway ships. Therefore, real-time tracking of its position is an essential process to ensure the safety of ship navigation. Aiming at the problem of the low accuracy of multi-functional buoy drift prediction, an integrated deep learning model incorporating the attention mechanism and ResNet-GRU (RGA) to predict short-term drift values of buoys is proposed. The model has the strong feature expression capability of ResNet and the temporal memory capability of GRU, and the attention mechanism can capture important information adaptively, which can solve the nonlinear time series drift prediction problem well. In this paper, the data collected from multi-functional buoy #4 at Nantong anchorage No. 2 in the Yangtze River waters in China were studied as an example, and first linear interpolation was used for filling in missing values; then, input variables were selected based on Pearson correlation analysis, and finally, the model structure was designed for training and testing. The experimental results show that the mean square error, mean absolute error, root mean square error and mean percentage error of the RGA model on the test set are 5.113036, 1.609969, 2.261202 and 15.575886, respectively, which are significantly better than other models. This study provides a new idea for predicting the short-term drift of multi-functional buoys, which is helpful for their tracking and management. [ABSTRACT FROM AUTHOR]

Building inland waterways affects the natural structure, formation, and extent of the riverbed and riparian zone. It alters the hydrology and sediment deposition conditions and hence damages the aquatic ecosystem. To address the effects of the construction of inland waterways on the riverine biome, benthic macroinvertebrate communities were compared at different building stages of inland waterways along a gradient of shipping traffic density at two montane rivers in China. The Shannon–Wiener diversity index of the benthic macroinvertebrate communities ranged from 0.4 to 1.6; the lowest value was recorded in the completed inland waterway, while the highest value was recorded in the unaffected stretch. Principal component analysis and canonical correlation analysis showed the communities in the inland waterways to be distinct from those in the natural riparian habitats. Our results suggest that benthic macroinvertebrate communities can reflect the damage done by the hydromorphological modifications caused by building inland waterways. Benthic macroinvertebrate diversity and abundance should therefore be included when assessing the impact of building and operating inland waterways. [ABSTRACT FROM AUTHOR]

Bubble dissolution during the flood discharge creates high total dissolved gas (TDG) concentration zones downstream of the dams. The dissipation of supersaturated TDG is a very slow process. Thus, the elevated TDG may remain through the water body for hundreds of kilometers downstream and lead to gas bubble disease (GBD) and even mortality in fish. To improve the navigation conditions of waterways, dikes (i.e., a solid structure) of varied sizes and shapes are commonly constructed. However, this would affect the dissipation and transportation of the supersaturated TDG. It would significantly change the turbulence intensity and hydropressure of the flow, which dominates the dissipation of TDG. Therefore, TDG distribution in the waterway differs from that in the natural river. In this study, a numerical simulation of the TDG at the Yangtze River's upper reaches (one of the inland waterways in China) was conducted with the establishment of a two-dimensional TDG dissipation model. The effect of the dikes' size and shape was analyzed to assess the influence of the regulation structures on the dissipation and transportation of the supersaturated TDG. Meanwhile, simulation in the study area with the natural topography was also set as blank control. Based on that, impact evaluation of TDG supersaturation on fish under different simulation scenarios was made. This study can provide a scientific basis for reducing the adverse effect of supersaturated TDG in fish and the construction of ecological waterway therefore. [ABSTRACT FROM AUTHOR]

A considerable literature has recently grown up on the theme of ship wireless communications. However, much of the research up to now has been descriptive in the offshore area. There has been little quantitative analysis of wireless communication in inland waterways, which has received considerable attention lately. Until now, only the effects on inland river environment are examined. What is less clear is the nature of channel change caused by the antenna movement. Here we explore the moving ship-to-fixed-ship fading characteristics at 5.9 GHz for an inland waterway in the city center of China. The ship motion trajectory is designed in order to determine the effect of changes in the antenna position. We evaluate the channel fading characteristics of inland waterway, which are highly correlated with the distance between transmitter and receiver. We demonstrate that the line-of-sight component, as well as the components from multipath with obstruction reflections, contributes largely to the mean power gap. Our findings reveal critical ship-toship characteristics in inland waterway, which definitely contribute to the field of ship wireless communications. [ABSTRACT FROM AUTHOR]

To generate autonomous collision avoidance encounter scenarios for inland waterway vessels, according to the characteristics of inland waterways, this paper presents a method for parametric modeling of encounter scenarios for ship avoidance testing in inland waterways, which is employed to automatically generate inland waterway ship encounter scenarios. Starting from the utilization of AIS and radar data acquisition and fusion methods, a ship navigation data acquisition and fusion system was established. Taking the waterway between Three Gorges dam and Gezhouba Dams waterway segment in China as an example, the ship navigation data was collected and analyzed to identify key factors for collision avoidance scenarios. A parameterized modeling approach for generating encounter scenarios in inland waterway ship collision avoidance testing was proposed, enabling the automated generation of collision encounter scenarios by setting relevant parameters. By testing encounter scenarios between two or more ships, a series of test scenarios were generated. The simulation demonstrated the effectiveness of this parameterized scenario generation method in supporting the testing of autonomous collision avoidance algorithms for inland ships. • This paper constructed a ship navigation data collection system based on AIS (Automatic Identification System) and maritime radar. Methods for AIS data reception and restoration, radar data processing, and fusion of AIS and radar targets is proposed. This system enables automatic data collection and fusion of ship navigation data between the Three Gorges Dam and the Gezhouba Dam in the Yangtze River. • A motion control model based on inland waterway bulk carriers is established, and a three-degree-of-freedom MMG hydrodynamic model is used to better fit the motion characteristics of inland waterway ships for the characteristics of more curves and larger drift angles. • Key elements in the autonomous collision avoidance test scenarios for inland waterways were identified. A parameterized modeling method for autonomous collision avoidance scenarios in inland waterways was proposed. Test results demonstrated that the proposed method can rapidly generate a large number of simulation collision avoidance testing scenarios that comply with actual ship traffic flow characteristics. These scenarios can be used to test the reasonableness and reliability of the decision-making algorithm for autonomous collision avoidance of ships in the future research. [ABSTRACT FROM AUTHOR]

Most scientific attention on port studies centers on deep sea ports, especially container ports. In this paper, in contrast, attention is focused on the spatial–temporal development of inland waterway ports on the Midstream Yangtze River from 2001 to 2013. The aim of this study is to assess two relevant and complementary questions of the hinterland evolution: its geographical extent and the coordination relationship with the inland port. To conduct the study, it was necessary to first identify the boundaries of the ports' hinterlands within the given timeframe. Then, the coupling coordination degree model was introduced to explore the underlying relationship between the port service and hinterland economy. Furthermore, to better depict the intricate economic characteristics of the hinterland, the development stage theory was applied in the models. The results highlight the emergence of a discontinuous hinterland at Wuhan Port and its reinforcement of primacy with respect to fierce hinterland rivalry. It also demonstrates that an interplay between major ports and their corresponding hinterlands evolves from the transitional stage, characterized by lagging port service, to the multi‐stage, wherein the supply of ports partly outstrips hinterland demand. [ABSTRACT FROM AUTHOR]

Maritime safety and emergency operation management are critical to preventing maritime accidents and mitigating risks. In this study, we propose a novel method to optimize maritime emergency resource allocation to improve emergency management efficiency. We combine the analytic hierarchy process (AHP) and coefficient of variation (CV) to develop an inverse comprehensive weight (CW) - data envelopment analysis (DEA) model. We apply this model to evaluate the efficiency of allocating emergency resources among ten Maritime Safety Administrations (MSAs) in the Jiangsu section of the Yangtze River in China. Our results indicate that five MSAs have low emergency management benefits, and we propose emergency resource allocation optimization options to improve their emergency management benefits. This study provides policymakers with valuable insights and guidelines for optimizing maritime emergency resource allocation in inland waterways. • A novel method is proposed for optimizing maritime emergency resource allocation. • The proposed method is based on the inverse CW-DEA model. • Maritime emergency resource allocation schemes are optimized accounting for inputs and outputs. • A detailed optimization scheme could be formulated for the allocation of various emergency resources. • The method has the potential to promote the improvement of maritime emergency policy. [ABSTRACT FROM AUTHOR]

Navigation pharos is the symbol of safe navigation of ships. In order to overcome the puzzles of being poor in management real time and being more in security hidden dangers in the maintenance of manual tour-inspection of navigation channel pharos maintenance, the paper explored a kind of remote sensing monitoring system of navigation pharos in bridge area for inland waterway. In this paper, it pointed out the challenges of navigation management in the current inland waterway bridge area, explored the system architecture and workflow, designed the system of navigation pharos information management, video monitoring and its corresponding other modules, developed and implemented a remote sensing monitoring and management system of navigation channel in bridge area based on B/S pattern. Good operation results after the system runs verify the feasibility and availability of the designed remote sensing monitoring system. [ABSTRACT FROM AUTHOR]

Due to the unique role of inland waterway transport in reducing carbon emissions, the demand for inland vessel transportation has greatly increased recent years in China. More and more vessels in the inland waterway have gradually formed a non-free following queue, rather than the free traffic flow of the past. To provide a theoretical basis for organizing the vessel traffic under a crowded state, it is necessary to understand accurately the microscopic characteristics of inland waterway vessel traffic flow, such as vessel-following behavior. This research carried out three vessel-following experiments to obtain valuable microscopic data of vessel-following behavior in different inland restricted waterways in Yangtze Delta, China. Considering the uniformity of traffic flow, six typical car-following models were tried to verify their applicability to inland vessel-following behavior. The parameters of the car-following models were recalibrated based on the experimental data. The simulation results of different models were evaluated, and the improved General Motor (GM) model was proposed to avoid vessel collision during the simulation process in GM model. The results show that the improved GM model, Newell model, Intelligent Driver model (IDM) and Longitudinal Control model (LCM) were confirmed to be suitable to describe the vessel-following behavior in the inland restricted waterway. These models may help professionals understand deeply the inland vessel traffic characteristics. • Three vessel-following experiments were carried out and presented in different inland restricted waterways. • Six typical car-following models were tried to verify their applicability to inland vessel-following behavior. • An improved GM model was proposed to avoid vessel collision during the simulation process in GM model. • The improved GM model, Newell model, IDM and LCM were confirmed to be suitable to describe the vessel-following behavior in the inland restricted waterway. [ABSTRACT FROM AUTHOR]

The inland waterway transportation is generally recognized to be the environmentally friendly transportation mode. However, it is relatively weak resilience to the service disruptions. In the post-pandemic era, the regular epidemic prevention is still one of the main considerations for waterway transportation since it undertakes the vast majority of global trade and faces more risk of epidemic spreading. This paper considers a multi-modal transportation system consisted in road network and inland waterway network. The epidemics occur in one or several regions, which would increase the monetary and time cost in the transportation process. We propose the flexible freight consolidation strategy to guide the cargos to be concentrated among the ports via the multi-modal transportation system. The proposed strategy can be built a non-linear mathematical programming model, which can discretized to a 0–1 Knapsack problem by the finite element method and calculated with branch-and-bound algorithm. The Yangtze River Economic Belt is adopted to illustrate validity of the proposed strategy and algorithm. • Consider the inland waterway transportation problem with the effect of COVID-19. • Propose a flexible freight consolidation strategy to improve the resilience of transportation system. • Conduct a numerical example based on the Yangtze River Economic Belt in China. • Determine the optimal flexible freight consolidation strategy according to the configuration of regions with COVID-19. [ABSTRACT FROM AUTHOR]

A distinct feature of Wuhan is that almost a quarter of the total area of this city is covered with water, leading to its unique hot and humid climate characteristics in summer. However, according to records, water area in built-up zone of Wuhan has been reduced by 130.5 km2 from 1965 to 2008, while the annual average air temperature has been increased by more than 3℃. To investigate the quantitative connection between the water area reduction and air temperature increase, three scenarios were simulated in a summer; to evaluate the impact of water reduction on the local thermal environment in different water areas; and to study the impact of water reduction on the urban heat island (UHI) phenomenon. Meso-scale meteorological models of Weather Research and Forecasting model were applied in this study for quantitative assessment and prediction. With the predictions, this study reveals that the decreased water area could affect air temperature, wind velocity and wind flow direction, energy balance and the UHI intensity. The simulations show that areas with significant wind velocity, wind direction and air temperature differences are distributed among the downwind zones. Moreover, the areas with high UHI intensity are wider and farther from the boundary of urban areas because of the reduction of water areas. [ABSTRACT FROM AUTHOR]

Based on the traffic situation, vessel type and atmospheric condition, an inland waterway traffic noise prediction model was developed for environmental assessment in China. This model was developed from the Germany Richtlinien für den Lärmschutz an Straßen (RLS 90) model by adding the water surface condition, absorption and gradient along vessel travel direction correction terms to the governing equations. The re-described parameters, including traffic flow and composition, vessel speed, air absorption, and water surface, ground and atmospheric conditions, etc., were chosen as inputs into the calculating equations. The verification results showed that the absolute error between the predicted and measured noise levels within the range of ± 1.4 dBA was 82.9%. The mean difference between the predicted and measured noise levels was 0.02 ± 1.25 dBA. The comparison results with the RLS 90 model and the modified Federal Highway Administration (FHWA) model also showed that the developed model in this study had better precision and accuracy. [ABSTRACT FROM AUTHOR]

Based on the local environmental standards, vessels types and traffic conditions, an inland waterway traffic noise prediction model was developed for use in China. This model was modified from the US FHWA model by adding the ground absorption and water surface attenuation correction terms to the governing equations. The parameters that were input into the equations, including traffic flow, vessel speed, distance from the center of the inland waterway to the receiver, position and height of the barriers and buildings, location of the receiver, type of ground, percentage of soft ground cover within the segment, and water surface conditions were re-defined. The model was validated by comparing the measured noise levels obtained at 33 sampling sites from Shugang Channel, Yanhe Channel and Danjinlicaohe Channel in China with the predicted values. The deviation between the predicted and measured noise levels within the range of ±1.5dB(A) was 81.8%. The mean difference between the predicted and measured noise levels was 0.15±1.75dB(A). However, the noise levels predicted developed model are generally higher than the measured levels. Overall, the comparison has proved that the developed method is of a high precision, and that it can be applied to estimate the traffic noise exposure level on inland waterway in China. [ABSTRACT FROM AUTHOR]

As the inland waterway transportation developed rapidly in China, the frequency of hazardous chemical leakage accidents is increasing every year. Such pollution to inland river environment has become a world-wide issue. Montmorillonite (Mont) is typical 2:1 layer type silicate clay and due to their special structure, it has been used in organic pollution removal process. In order to improve their ability in pollution adsorption, the pillared Mont was made in this work. Since the common toxic structure in most chemical pollutants is the halogen atom-benzene ring part, we select a typical compound Monochlorobenzene (MCB) as the aim contaminant. In this research, the original Mont, -Mont, and -Mont were prepared and used in MCB degradation experiment as catalysts. The influence of catalyst amount, promoter () amount, MCB concentration and reaction time to MCB removal rate were studied, respectively in detail. [ABSTRACT FROM AUTHOR]

The article discusses the maritime law of China, and its limitation of liability with respect to applicable ships, limitation funds, and the right to revoke. It presents information on the limitation of liability for oil pollution and nuclear damages, and reflects various trading areas where the limits of liability for general maritime laws vary which includes international, coastal and inland waterways. Several court cases concerning the issue of Chinese Maritime Code (CMC) are discussed.

The article presents information on the $62.5 billion Chinese civil engineering project called "South-North Water Transfer Scheme." This project is among one of the biggest engineering projects the Chinese government has undertaken and it is an effort to shift water from three southern river basins to its populous and thirsty northern provinces. The South-North Water Transfer Scheme involves the construction and excavation of a series of canals, pumping stations, reservoirs, and dams that would supply water to the north for drinking and for irrigation.

The need to balance inland waterway engineering with river ecological integrity has attracted increasing attention from waterway engineers. Quantitative tools for evaluating the effects of waterway engineering on fish habitat serve as an effective basis for engineering design assessment and improvement. A tourism waterway construction project along the Upper Yellow River (UYR) is located within a core area of the National Aquatic Germplasm Resources Conservation Area. The evaluation of the habitat design performance of waterway training works (which is similar to the term of Inland navigation channel training works, it involves structures and measures that reshape a river channel to create reliable depths and widths for safe and dependable vessel transit.), however, are rare in China. To evaluate the effects of waterway engineering on fish habitats and improve engineering design, we evaluated the influence of waterway training works on habitats for endangered adult Platypharodon extremus (Han et al., 2016) by applying a 2D hydrodynamic model to three scenarios: with and without training works and with improved training works. The simulations reproduced changes in flow velocity and water depth within the navigation discharges range. The size and distribution of suitability indexes of water depth and flow velocity and their combined habitat suitability index were employed to assess available habitats for adult Platypharodon extremus to evaluate the influence of engineering actions. The simulations show that the habitat losses due to waterway training works in the study reach can be restored by introducing eco-friendly concepts into training structures and dredging design. Habitat availability for adult Platypharodon extremus has been reduced after waterway training works, especially at low and moderate discharges (the percentage of available area decreased from 13.48% to 11.69% at designed lowest navigation discharge). Habitat availability is much less sensitive to training works at high discharge than at moderate levels. The available habitat can be restored to at least 97% of its original level through the introduction of eco-friendly conceptual designs (the percentage of available area at designed lowest navigation discharge can be recovered to 13.41%). • To balance fish habitat protection and waterway engineering in a fish conservation area on Upper Yellow River was studied. • A quantitative tool was used to evaluate the effects of waterway engineering on fish habitats. • Eco-friendly concept design was introduced into traditional waterway training works for habitat restoration. [ABSTRACT FROM AUTHOR]

Unsteady flow induced by hydropower stations exerts a significant impact on the water level in multi-approach channels, which directly threatens the safe passage of ships. In this study, a one-dimensional and a two-dimensional hydrodynamic model are adopted to simulate the water level fluctuations at the entrance of multi-approach channels and the lower lock head of a ship lift with consideration of initial water surface elevation, base flow, flow amplitude, regulation time, and locations of hydropower stations, unfavorable conditions are successfully identified; and the fluctuations at the approach channel entrance and the lower lock head of a ship lift under single-peak and double-peak regulating mode are analyzed considering the flow regulating of the Gezhouba Hydropower Station (GHS), thus, the water level oscillation process in the multi-approach channels is presented. Results show that the largest wave amplitude in the multi-approach channels manifests under unfavorable conditions including lower initial water surface elevation, smaller base flow, larger flow variation, and shorter regulation time; and water level fluctuation in the multi-approach channel is primarily induced by flow amplitude and net flow between the Three Gorges Hydropower Station (TGHS) and the GHS, with consideration of the counter-regulation process of the GHS. This research contributes to providing a reference for a similar large-scale cascade hydropower station regarding regulation and control of navigation conditions. [ABSTRACT FROM AUTHOR]

The impact of extreme weather events on the navigation environment in the inland waterways of the Yangtze River is an interdisciplinary hotspot in subjects of maritime traffic safety and maritime meteorology, and it is also a difficult point for the implementation of decision-making and management by maritime and meteorological departments in China. The objective of this study is to review the variation trends and distribution patterns in the periods of adverse and extreme weather events that are expected to impact on inland waterways transport (IWT) on the Yangtze River. The frequency of severe weather events, together with the changes in their spatial extension and intensity, is analyzed based on the ERA-Interim datasets (1979–2017) and the GHCNDEX dataset (1979–2017), as well as the research progresses and important events (2004–2016) affecting the navigation environment. The impacts of extreme weather events on IWT accidents and phenomena of extreme weather (e.g., thunderstorms, lightning, hail, and tornadoes) that affect the navigation environment are also analyzed and discussed. The results show that: (1) the sections located in the plain climate zone is affected by extreme weather in every season, especially strong winds and heat waves; (2) the sections located in the hilly mountain climate zone is affected particularly by spring extreme phenomena, especially heat waves; (3) the sections located in the Sichuan Basin climate zone is dominated by the extreme weather phenomena in autumn, except cold waves; (4) the occurrence frequency of potential flood risk events is relatively high under rainstorm conditions and wind gusts almost affect the navigation environment of the Jiangsu and Shanghai sections in every year; (5) the heat wave indices (TXx, TR, and WSDI) tend to increase and the temperature of the coldest day of the year gradually increases; (6) the high occurrences of IWT accidents need to be emphasized by relevant departments, caused by extreme weather during the dry season; and (7) the trends and the degree of attention of extreme weather events affecting IWT are ranked as: heat wave > heavy rainfall > wind gust > cold spell > storm. Understanding the seasonal and annual frequency of occurrence of extreme weather events has reference significance for regional management of the Yangtze River. [ABSTRACT FROM AUTHOR]