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A Siltation Simulation and Desiltation Measurement Study Downstream of the Suzhou Creek Sluice, China 被引量:3
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作者 季永兴 杨绯 +1 位作者 张汉云 卢永金 《China Ocean Engineering》 SCIE EI CSCD 2013年第6期781-793,共13页
The Suzhou Creek Sluice is currently the largest underwater plain gate in the world, with a single span of 100 m. It is located in a tidal estuary at the junction of the Huangpu River and Suzhou Creek in Shanghai, Chi... The Suzhou Creek Sluice is currently the largest underwater plain gate in the world, with a single span of 100 m. It is located in a tidal estuary at the junction of the Huangpu River and Suzhou Creek in Shanghai, China. In this study, physical and 2D vertical mathematical models were used to investigate and distinguish the mechanism of siltation downstream of an underwater plain gate from that of other gates types. According to quantitative data obtained by site investigation and the application of the physical hydrodynamic models, it was found that the characteristics of the tidal estuary as well as the fact that the sluice span is equal to the creek width are the major reasons contributing to siltation. A possible desiltation treatment system is proposed for the underwater plain gate. The system includes selection of a suitable location that allows the determination of a reasonable top elevation of the sluice floor, reserving sufficient space under the gate to accommodate siltation, setting up a mechanical desiltation system, and flushing silt along with overflow over the top of the gate. Furthermore, on-site hydraulic silt flushing experiments and a topography survey were conducted. These results showed that the measurement system is effective, and by maintaining this scheduled operation once a month, the downstream riverbed has been maintained in a good condition. 展开更多
关键词 tidal estuary underwater plain gate siltation SLUICE Suzhou Creek
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Prediction of Siltation in the Downstream Approach Channel of Tidal Locks 被引量:3
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作者 张幸农 杨红 孙波 《China Ocean Engineering》 SCIE EI 1999年第3期317-326,共10页
Silt deposition occurs in the downstream approach channel of the tidal lock as in a closed channel or excavated dock basin. It is often difficult to calculate or predict siltation because of complex flow and sediment ... Silt deposition occurs in the downstream approach channel of the tidal lock as in a closed channel or excavated dock basin. It is often difficult to calculate or predict siltation because of complex flow and sediment conditions and many other affecting factors. In this paper, the characteristics of flow movement in the approach channel (including its mouth) of the tidal lock are analyzed, the basic laws of sediment movement and siltation mechanism are investigated, the conditions for three types of siltation (circumfluence siltation, density flow siltation and slow flow siltation) are discussed, and corresponding calculating formulas are proposed. A practical example shows that the difference between measured and calculated results is small, indicating that the present calculating methods could be used in design and management of practical engineering projects. 展开更多
关键词 tidal reach tidal lock approach channel siltation
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Mechanism of back siltation in navigation channel in Dinh An Estuary, Vietnam 被引量:2
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作者 Viet-Thanh NGUYEN Jin-hai ZHENG Ji-sheng ZHANG 《Water Science and Engineering》 EI CAS CSCD 2013年第2期178-188,共11页
The Dinh An Estuary is one of the Nine Dragon estuaries of the Mekong River. An international navigation channel was built in the estuary for vessels traveling from the South China Sea to the southwestern area of Viet... The Dinh An Estuary is one of the Nine Dragon estuaries of the Mekong River. An international navigation channel was built in the estuary for vessels traveling from the South China Sea to the southwestern area of Vietnam and then to Phnom Penh, Cambodia. The morphological evolution of the navigation channel is complicated and unstable. The back siltation intensity in the navigation channel has largely increased and been concentrated in the curvature segments of the channel since 1980. In this study, based on simulation results and measured data, five key factors that influence the back siltation in the navigation channel were systematically analyzed. These factors included the increasing elevation gap between the channel and the nearby seabed, the disadvantageous hydrodynamic conditions, sediment transport, mixing of saltwater and freshwater, and wave effects in the navigation channel. It is shown that the back siltation to a large extent results from the low current velocity of the secondary ocean circulation, which often occurs in the curvature segments of the channel. Suspended sediment also settles in the channel due to the decrease of the current velocity and the sediment transport capacity when flow passes through the channel. The changes of hydrodynamic conditions are responsible for the majority of the severe siltation in the curvature segments of the navigation channel. 展开更多
关键词 back siltation hydrodynamics navigation channel sediment transport Dinh An Estuary
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Simulation and Analysis of Back Siltation in a Navigation Channel Using MIKE 21 被引量:2
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作者 ZHANG Kuncheng LI Qingjie +4 位作者 ZHANG Jing SHI Hongyuan YU Jing GUO Xinchang DU Yonggang 《Journal of Ocean University of China》 SCIE CAS CSCD 2022年第4期893-902,共10页
The channel back-siltation problem has been restricting the development of channels,and its monitoring is limited by funds and natural conditions.Moreover,predicting the channel back-siltation situation in a timely an... The channel back-siltation problem has been restricting the development of channels,and its monitoring is limited by funds and natural conditions.Moreover,predicting the channel back-siltation situation in a timely and accurate manner is difficult.Hence,a numerical simulation of the back-siltation problem in the sea area near the channel is of great significance to the maintenance of a channel.In this study,the back siltation of a deep-water channel in the Lanshan Port area of the Port of Rizhao after dredging is predicted.This paper relies on the MIKE 21 software to establish the wave,tidal current,and sediment numerical models and uses measured data from two observation stations in the study area for verification.On this basis,taking one month as an example,the entire project channel was divided into five sections,and three observation points were set on each section.The results show that the area with offshore siltation is located in the northerly direction of the artificial anti-wave building.Siltation occurred on the northern seabed in the sea a little farther from the shore.Siltation occurred on the seabed surface far away from the shoreline,and with the increase in the distance from the shoreline,the amount of siltation in the south,center,and north became gradually closed,and the results can be used to guide actual engineering practices.This study will play a positive role in promoting the dredging project of Rizhao Lanshan Port. 展开更多
关键词 channel back siltation numerical simulation back silting analysis and prediction
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The influences of the tectonic subsidence and the siltation on the situation of preventing flood disasters in the Dongting Lake area 被引量:1
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作者 LAIHongzhou MODuowen 《Journal of Geographical Sciences》 SCIE CSCD 2004年第2期226-234,共9页
With the long-term data of the geodetic sea level measurements undertaken in the Dongting Basin and the recent sediment data of Dongting Lake, we analyze the tectonic subsidence rate of the Dongting Basin and the sedi... With the long-term data of the geodetic sea level measurements undertaken in the Dongting Basin and the recent sediment data of Dongting Lake, we analyze the tectonic subsidence rate of the Dongting Basin and the sedimentary rate of Dongting Lake. From the point of view of geomorphology and hydrogeology, we distinguish the two different spatial concepts between 'the basin of Dongting Lake' and 'the Dongting Basin'. Then, we discuss the influences of the tectonic subsidence and the siltation on the levees and the space of storing flood. The better quality of levees is required due to the tectonic subsidence and the siltation, and the difficulties of preventing flood disasters are increasing. The space of storing flood is not affected by the tectonic subsidence, but by the siltation. At present, the sedimentary rate of Dongting Lake is higher than the tectonic subsidence rate of the Dongting Basin. The tectonic subsidence capacity of the Dongting Basin counteracts a part of sedimentary capacity, and the shrinking tendency of Dongting Lake is restrained to a certain extent, but the tectonic subsidence is harmful to the situation of preventing flood disasters in the Dongting Lake area. 展开更多
关键词 Dongting Lake tectonic subsidence siltation flood disasters
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Grey Prediction of Siltation in North Channel of Yangtze Estuary 被引量:1
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作者 Yu Cimei Shanghai Waterways Design & Research Institute, Shanghai 200120 《China Ocean Engineering》 SCIE EI 1994年第2期207-216,共10页
-The North Channel in the Yangtze Estuary is one of sea-leading waterways of Shanghai Harbour, in which yearly dredging volume reaches over ten million cubic meters, and it tends to increase year by year. Based on the... -The North Channel in the Yangtze Estuary is one of sea-leading waterways of Shanghai Harbour, in which yearly dredging volume reaches over ten million cubic meters, and it tends to increase year by year. Based on the channel regime similarity and through the relational grade, a GM (2, 1) is set up. It reveals the course of development of channel regime similarity under the action of various factors, and predicts the siltation volume in the nearest future which is the basis of dredging planning for relevant dredging departments. 展开更多
关键词 Grey prediction siltation Yangtze Estuary DREDGE
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The siltation of debris flow behind check dam in the midstream of Bailong River 被引量:4
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作者 YUAN Dong LIU Jin-feng +4 位作者 YOU Yong LIU Dao-chuan SUN Hao ZHANG Li ZHOU Wen-bing 《Journal of Mountain Science》 SCIE CSCD 2018年第1期100-113,共14页
Siltation gradient and siltation length are important parameters for designing gravity check dams for debris flows,which directly affect the accuracy of estimates of interception capacity.At present,siltation gradient... Siltation gradient and siltation length are important parameters for designing gravity check dams for debris flows,which directly affect the accuracy of estimates of interception capacity.At present,siltation gradient calculations are based primarily on empirical values,and range from 0.4 to 0.95 times the channel slope coefficient.The middle reaches of the Bailong River are one of the four areas in China that are most severely affected by debris flow hazards.Gravity dams are widely employed in this mountainous area.However,field studies of their capacity are lacking.In this paper,the operations of check dams were investigated.Based on field investigation results and theoretical analysis,calculations for siltation gradient,siltation length,and dam storage capacity are established.The impact of debris flow density,channel slope,and particle size weight percentages are discussed.The calculations show that the theoretical values for siltation gradient are consistent with measured values with 83.6% accuracy;and theoretical values of siltation length are consistent with measured values with 91.6% accuracy.The results of this research are an important reference for optimal height and spacing of dams,estimation of dam storage capacity,and disaster prevention. 展开更多
关键词 Debris flow Check dam siltation gradient siltation length Disaster prevention engineering
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Characteristics of gully bed scour and siltation between check dams 被引量:1
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作者 LYU Xiao-bo YOU Yong +3 位作者 WANG Zhuang LIU Jin-feng SUN Hao ZHAO Wan-yu 《Journal of Mountain Science》 SCIE CSCD 2023年第1期49-64,共16页
Check dams are the most commonly used engineering measure for debris flow control worldwide.The scour and siltation characteristics between dams are important factors affecting dam design.In this study,classical dimen... Check dams are the most commonly used engineering measure for debris flow control worldwide.The scour and siltation characteristics between dams are important factors affecting dam design.In this study,classical dimensional analysis of the variables that influence the development of gully bed scour and siltation was carried out.Flume experiments were conducted to examine the influence characteristics of opening width,flume slope,debris flow density,and opening rate on the characteristics of gully bed scour and siltation.The influential characteristics of variables on the dimensionless scour depth,scour length,siltation length,scour volume and siltation volume were obtained.The experiments showed that,with an increase in the relative opening from 1.5 to 2.5,scour depth increased by 7.4%,scour length decreased by 11.2%,siltation length increased by 22.0%,scour volume decreased by 4.7%and siltation volume increased by 22.0%.With an increase in flume gradient from 0.105 to 0.213,scour depth,siltation length and siltation volume increased by 40.0%,65.9%and 65.9%,respectively,and scour length decreased by 20.1%.With an increase in sediment concentration from 0.303 to 0.545,siltation length and siltation volume increased by 15.4%and 15.4%,respectively,and scour depth,scour length and scour volume decreased by 9.6%,9.1%and 17.8%,respectively.As opening rate increased from 0.08 to 0.32,siltation length and siltation volume increased by 33.3%and 33.3%,respectively,and scour depth,scour length and scour volume decreased by 5.4%,13.7%and 18.4%,respectively.The results showed that the flume gradient was the most influential factor on scour depth,scour length,siltation length and siltation volume,and the sediment concentration was the most influential factor on scour volume.Then,according to the experimental data,some empirical formulas predicting scour depth,scour length,siltation length,scour volume and siltation volume were obtained.The error between the computed values according to the formulas in this paper and the observed values was within±10%.These research results may provide a technological basis for window dam design in debris flow disaster prevention and mitigation. 展开更多
关键词 Debris flow Gully bed scour Gully bed siltation Window dam
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Impact of PhaseⅢProject of Maji Mountain Port on sediment siltation in adjacent sea area 被引量:1
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作者 JIN Zuowen ZUO Changsheng WANG Zhizu 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2017年第12期111-118,共8页
Based on a 3-D Finite Volume Coastal Ocean Model(FVCOM), tidal dynamics has been studied in the sea area around the Phase III Project of Maji Mountain Port(MMP). Furthermore, taking typhoon "Canhong" as an examp... Based on a 3-D Finite Volume Coastal Ocean Model(FVCOM), tidal dynamics has been studied in the sea area around the Phase III Project of Maji Mountain Port(MMP). Furthermore, taking typhoon "Canhong" as an example, a storm surge and sediment model has also been established to study the impact of the Phase III Project on current flows and siltation during extreme weather. Tidal currents before and after the project have been compared. Model results show that the changes of tidal current mainly occur in the engineering areas with a magnitude change of 0.3–0.4 m/s during maximum flood and ebb tides. The flow condition for the port has been improved as the flow direction is changed to parallel to the wharf after the completion of the project. There is little siltation in the adjacent area, which will not affect the safety of ship navigation. Besides, the sudden siltation during typhoon period is relatively weak. The back silting in two days is less than 5 cm indicating no sudden siltation occurs. 展开更多
关键词 Maji Mountain Port FVCOM tidal current siltation storm
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A Novel Method for Real-Time Monitoring of Channel Siltation Based on Bistatic Scattering Theory
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作者 侯朋 许文海 +1 位作者 王俊生 李瑛 《China Ocean Engineering》 SCIE EI 2010年第1期105-115,共11页
Monitoring the thickness changes of channel siltation is paramount in safeguarding navigation and guiding dredging, This paper presents a novel method for realizing the field monitoring of channel siltation in real ti... Monitoring the thickness changes of channel siltation is paramount in safeguarding navigation and guiding dredging, This paper presents a novel method for realizing the field monitoring of channel siltation in real time. The method is based on the bistatic scattering theory and concerned more with the receiving and processing of multipath signal at high-frequency and small grazing angle. By use of the multipath propagation structure of underwater acoustic channel, the method obtains the silt thickness by calculating the relative time delay of acoustic signals between the direct and the shortest bottom reflected paths. Bistatic transducer pairs are employed to transmit and receive the acoustic signals, and the GPS time synchronization technology is introduced to synchronize the transmitter and receiver, The WRELAX (Weighted Fourier transforul and RELAX) algorithm is used to obtain the high resolution estimation of muhipath time delay. To examine the feasibility of the presented method and the accuracy and precision of the developed system, a series of sea trials are conducted in the southwest coast area of Dalian City, north of the Yellow Sea. The experimental results are compared with that using high-resolution dual echo sounder HydroBoxTM, and the uncertainty is smaller than + 0.06 m. Compared with the existing means for measuring the silt thickness, the present method is innovative, and the system is stable, efficient and provides a better real-time performance. It especially suits monitoring the narrow channel with rapid changes of siltation. 展开更多
关键词 channel siltation real-time monitoring bistatic bottom scattering relative time delay WREIAX multipath signal
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Change of Back Siltation in Lianyungang Harbor before and after Completion of the West Breakwater
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作者 张华 虞志英 金鏐 《China Ocean Engineering》 SCIE EI 1999年第3期359-364,共6页
On the basis of a comparison of the field hydrological, sediment and topographic data observed before and after the completion of the West Breakwater in Lianyungang Harbor, which has led to the change of topography fr... On the basis of a comparison of the field hydrological, sediment and topographic data observed before and after the completion of the West Breakwater in Lianyungang Harbor, which has led to the change of topography from a strait to a bay, a synthetical analysis is conducted on the change of back siltation. The results show that it is the change of coast line and the consequent change of hydrological condition and sediment movement that has led to the change of back siltation in the harbor. This phenomenon is caused by the lag effects of water current, sediment movement and local adjustment of topography after the construction, and it tends to be stable. The results of analysis provide not only a basis for extension of Lianyungang Harbor into a deep water harbor, but also propose a case for the study of the change of back siltation in a harbor on muddy coast. 展开更多
关键词 Lianyungang Harbor West Breakwater artificial bay back siltation
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Second sea-entering approach of Changjiang River: Tongl Canal-planning of control dimensions, analysis of erosion and siltation and selection of outlet
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作者 Lu Wujiang and Jin Jianxin(Research Institute of Coastal and Ocean Engineering, Hobal University, Nangjing 210024, China) 《Acta Oceanologica Sinica》 SCIE CAS CSCD 1995年第1期113-125,共13页
Assume that the Tonglu Canal would be widened and deepened in which a water lock is constructed atthe river side, and made open to the sea side. The canal's planned control dimensions are determined, and the erosi... Assume that the Tonglu Canal would be widened and deepened in which a water lock is constructed atthe river side, and made open to the sea side. The canal's planned control dimensions are determined, and the erosionand siltation characteristics along the river (totally 81. 8 km) are analyzed by the numerical calculation of one-dimen-sional unsteady flow and the relative standards. According to the data of the evolution, hydrology and sediment inthe Xiaomiaohong Waterway, it is found reasonable to select the channel near the Xingang Gate as the second sea-entering approach. This paper is helpful in planning and designing the approach. 展开更多
关键词 Sea-entering approach Tongl■ Canal erosion and siltation analysis planning scale
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Predicting Siltation in Entrance Channel Based on Wind Conditions
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作者 蒋学炼 曹祖德 李炎保 《Transactions of Tianjin University》 EI CAS 2007年第5期349-353,共5页
The siltation induced by wind waves in an entrance channel is one of the prime factors influencing the operation efficiency of a port. It is necessary to predict the siltation accurately for dredging and ship operatio... The siltation induced by wind waves in an entrance channel is one of the prime factors influencing the operation efficiency of a port. It is necessary to predict the siltation accurately for dredging and ship operation passing through the entrance of the port. However, it is difficult to apply the traditional method to predicting entrance siltation because of its complex computational procedure and lacking the data of ocean dynamic elements in the specified sea area. From the view of energy conservation, a direct relationship between wind conditions and sediment deposition can be founded. On the basis of the above methodology, an empirical formula expressed by wind conditions for forecasting the siltation in the entrance channel is set up. The wind conditions are easily obtained from the local meteorological stations or weather maps, so the formula established in this paper is more convenient and practical than the traditional method. A case study is provided, in which the emopirical formula is calibrated and verified utilizing the measured wind and siltation conditions in the entrance channel of the port. Comparisons between computed values and measured data show satisfactory aqreement. 展开更多
关键词 wind conditions entrance channel siltation
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Siltation Prediction for Navigation Channels and Harbour Basins on Muddy Beach (II)
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作者 Liu Jiaju and Zhang Jingchao Professor, Senior Engineer, Nanjing Hydraulic Research Institute, 210029 Nanjing Senior Engineer, Nanjing Hydraulic Research Institute, 210029 Nanjing 《China Ocean Engineering》 SCIE EI 1992年第3期297-316,共20页
5. Application and Popularization of Computational Methods for Siltation The above mentioned computational method covers siltation in navigation channels andharbour basins on muddy beach. This part mainly deals with t... 5. Application and Popularization of Computational Methods for Siltation The above mentioned computational method covers siltation in navigation channels andharbour basins on muddy beach. This part mainly deals with the possibility of its application tosilty beach and sandy beach and the computation of scouring. The following discussion involvestwo aspects, and then some computational examples are given. 展开更多
关键词 siltation Prediction for Navigation Channels and Harbour Basins on Muddy Beach II
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Integrated Evaluation of Soil Erosion Hazard and Risk Management in the Oued Beht Watershed Using Remote Sensing and GIS Techniques: Impacts on El Kansra Dam Siltation (Morocco)
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作者 Rabii El Gaatib Abdelkader Larabi 《Journal of Geographic Information System》 2014年第6期677-689,共13页
The initial state of the Oued Beht watershed (430,728 ha) is characterized by a socio-ecological vulnerability associated to the water erosion risk. Especially, the consequences are chained and the soil loss alters it... The initial state of the Oued Beht watershed (430,728 ha) is characterized by a socio-ecological vulnerability associated to the water erosion risk. Especially, the consequences are chained and the soil loss alters its hydrological behavior and its ability to protect functional and structural challenges (good land, El Kansra dam, agricultural activities). In this perspective, this study suggests a methodology, reproducible and generalizable, to assess the natural water erosion risk (R). The approach used is based on spatial processing technology of information to develop a spatial database and geographic information system (GIS) concerning biophysical and?topoclimatic parameters in the Oued Beht watershed. Thus, the risk analysis is obtained by combining thematic maps of Susceptibility (S) and potential Consequences (C). Although, the spatial analysis of maps obtained reveals the extent of susceptibility involving land degradation, with the potential risks, which generated a decrease in the storage capacity of El Kansra dam (?3.03 Mm3/year). The results show that erosion is active on more than three quarters (3/4) of the watershed, and a considerable loss of land with 8.36 Million tonnes per year. In this way, flood analysis and study of?hydrometeorological events identified the vulnerability of flood sites (hot-spot) contributing at 77%?of El Kansra siltation dam. Therefore, the consequence assessment is obtained by identifying risk elements and estimating potential damage coefficient, which represents the financial gap flow affecting the socio-economic context due to the erosion impacts. 展开更多
关键词 Risk Susceptibility VULNERABILITY Erosion Flood siltation DAM
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Comprehensive analysis on the sediment siltation in the upper reach of the deepwater navigation channel in the Yangtze Estuary 被引量:6
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作者 匡翠萍 陈维 +1 位作者 顾杰 贺露露 《Journal of Hydrodynamics》 SCIE EI CSCD 2014年第2期299-308,共10页
The results from both the field measurements and numerical simulation were reported to comprehensively analyze the sediment siltation in the upper reach of the Deepwater Navigation Channel Project in the Yangtze Estua... The results from both the field measurements and numerical simulation were reported to comprehensively analyze the sediment siltation in the upper reach of the Deepwater Navigation Channel Project in the Yangtze Estuary after the project has been implemented. In this research, firstly some basic information about the river evolution in the Yangtze Estuary is analyzed, including the variations of water depths in the Hengsha Passage and the inlet cross-sections of the North Passage and the South Passage, and changes of diversion ratios of ebb flow and sediment flux in the North Passage and the South Passage, Then the Delfl3D-FLOW model is applied to simulate the hydrodynamics and sediment transport in the Yangtze Estuary. This model has been calibrated and the simulated results agree well with the measured data of the tidal levels, flow velocities and suspended sediment concentration (SSC), indicating that the model can well simulate the hydrodynamics and sediment transport of the Yangtze Estuary caused by the Deepwater Navigation Channel Project. The research results show that the development of the Hengsha Passage and decrease of diversion ratio of ebb flow and sediment flux in the North Passage are the main reasons of sediment siltation in the upper reach of the Deepwater Navigation Channel in the Yangtze Estuary. 展开更多
关键词 Yangtze Estuary Hengsha Passage deepwater navigation channel numerical simulation sediment siltation
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PROMOTING SILTATION EFFECTS AND IMPACTS OF HENGSHA EAST SHOAL ON THE YANGTZE RIVER ESTUARY 被引量:4
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作者 XIE Jun YAN Yi-xin 《Journal of Hydrodynamics》 SCIE EI CSCD 2011年第5期649-659,共11页
For the Hengsha East Shoal Promoting Siltation Project in the Yangtze River Estuary, this work developed a formula for calculating sediment carrying capacity based on variable coefficients and a mathematical model for... For the Hengsha East Shoal Promoting Siltation Project in the Yangtze River Estuary, this work developed a formula for calculating sediment carrying capacity based on variable coefficients and a mathematical model for suspended sedimentation using variable saturation recovery coefficients. Not only does the model yield good verification, preferably give the hydrodynamics and the sediment concentration, but also reach a good agreement between the simulation results andlux by tide for studying the effect the measured topographical changes in the promoting siltation zone of the Hengsha East Shoal. Moreover, this article proposes a method for examing the net sediment tran- sportation fs of the project of promoting siltation and comparatively analyzes the current siltation of the Hengsha East Shoal and siltation mouth layouts, entrance widths, entrance bottom elevations, and the impact of the South Main Dike on promoting siltation through calculating the net sediment transportation flux by tide over the fixed bed and the direct movable bed numerical simulations. The results are in good agreement with each other, indicating that the method for calculating the net sedi- ment transportation flux by the tide is also useful for assessing the project in promoting siltation. Finally, we use the modeling results to analyze the water and sediment diversion ratios and the changes in silting and scouting in riverbeds and draw the conclusion that the completion of the Hengsha East Shoal Promoting Siltation Project would not adversely affect the Yangtze River Estuary Deepwater Channel Project. 展开更多
关键词 Hengsha East Shoal promoting siltation effects mathematical simulation sediment diversion ratio net sediment transportation flux
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Efficient Identification of water conveyance tunnels siltation based on ensemble deep learning 被引量:1
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作者 Xinbin WU Junjie LI Linlin WANG 《Frontiers of Structural and Civil Engineering》 SCIE EI CSCD 2022年第5期564-575,共12页
The inspection of water conveyance tunnels plays an important role in water diversion projects.Siltation is an essential factor threatening the safety of water conveyance tunnels.Accurate and efficient identification ... The inspection of water conveyance tunnels plays an important role in water diversion projects.Siltation is an essential factor threatening the safety of water conveyance tunnels.Accurate and efficient identification of such siltation can reduce risks and enhance safety and reliability of these projects.The remotely operated vehicle(ROV)can detect such siltation.However,it needs to improve its intelligent recognition of image data it obtains.This paper introduces the idea of ensemble deep learning.Based on the VGG16 network,a compact convolutional neural network(CNN)is designed as a primary learner,called Silt-net,which is used to identify the siltation images.At the same time,the fully-connected network is applied as the meta-learner,and stacking ensemble learning is combined with the outputs of the primary classifiers to obtain satisfactory classification results.Finally,several evaluation metrics are used to measure the performance of the proposed method.The experimental results on the siltation dataset show that the classification accuracy of the proposed method reaches 97.2%,which is far better than the accuracy of other classifiers.Furthermore,the proposed method can weigh the accuracy and model complexity on a platform with limited computing resources. 展开更多
关键词 water conveyance tunnels siltation images remotely operated vehicles deep learning ensemble learning computer vision
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On the siltation of the middle Yangtze River
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作者 YIN Hongfu1, CHEN Guojin2, LI Chang抋n1 & WEI Yuan3 1. School of Earth Sciences, China University of Geosciences, Wuhan 430074, China 2. Hydrogeological Team, Hubei Bureau of Geology and Mineral Resources, Jingzhou 434100, China 3. Geological Survey of Jiangxi Province, Nanchang 330201, China 《Science China Earth Sciences》 SCIE EI CAS 2004年第5期463-480,共18页
About 5.2×108 t/a of silts from the upper reach of the Yangtze River are transported through Yichang into the middle Yangtze River. The middle Yangtze itself and its tributaries yield ca. 0.8×108 t silts ann... About 5.2×108 t/a of silts from the upper reach of the Yangtze River are transported through Yichang into the middle Yangtze River. The middle Yangtze itself and its tributaries yield ca. 0.8×108 t silts annually. Of this total 6×108 t/a input of silts, ca. 1.2×108 t/a are deposited within the river artery and lakes, while ca 4.83×108 t/a are at first transported into the lower reach through Datong, and then either deposited along the river and the Yangtze Delta, or output into the sea. Along the middle Yangtze River silting generally exceeds scouring, but the spatial and temporal distributions of scour-and-fill, as well as its distribution in the river valley transections, are uneven. Along the Yichang-Chenglingji and Jiujiang-Datong Segments of the middle Yangtze, scouring exceeds or equals silting. Silting mainly occurs along the Luoshan-Wuhan-Huangshi Segments with Wuhan as the pivotal point, as well as in the Dongting and Poyang Lakes. Even in these silting-dominated areas, there are times and parts of segments that scouring prevails. As to the transections, generally the river channel of main stream is scouring-dominated, forming V-shaped sections to a depth of 2030 m or more, whereas the floodplains and bar islands are silting-dominated, forming wide and relatively high flats, which are often artificially transformed into protected embankments. Because the Jingjiang Levee separates the Jianghan Plain from Yangtze to the south, little has been deposited in that plain except a few sediments from the Han River—a tributary of the middle Yangtze. This factor plus the tectonic sag of that plain has made the altitude of plain surface several meters lower than that of the levee in most of the areas. Sil-tation along the Luoshan-Wuhan-Huangshi Segments has resulted in the elevation of flood level in this and upstream segments. River channel scouring plus floodplain silting have caused the transections of the middle Yangtze valley typically with deep channel and heightening flat bank, separated from the descending Jianghan Plain only by the Jingjiang Levee. Such a transection explains why the flood level becomes higher and higher with the same water flowage. High water level has to be prevented only by the elevation of the levee, which in turn increases hydraulic pressure to the levee and to the protected low plain, thus making it easier to cause leakage and related disasters. The increasing height difference between the low plain and the heightening floodplain and flood level is a serious and long-term Achilles’ heel of the middle Yangtze. 展开更多
关键词 the MIDDLE Yangtze scour-and-fill siltation SILT utilization.
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Siltation and radiocesium pollution of small lakes in different catchment types far from the Fukushima Daiichi nuclear power plant accident site
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作者 Mikhail Komissarov Shin-ichiro Ogura 《International Soil and Water Conservation Research》 SCIE CSCD 2020年第1期56-65,共10页
The Fukushima Daiichi nuclear power plant accident caused radioactive pollution in northeastern Honshu Island,Japan.This study examined the influence of snowmelt and rainfall on soil erosion pro-cesses and siltation o... The Fukushima Daiichi nuclear power plant accident caused radioactive pollution in northeastern Honshu Island,Japan.This study examined the influence of snowmelt and rainfall on soil erosion pro-cesses and siltation of small lakes in Miyagi Prefecture(150 km northwest of the power plant).Two sets of slopes and lakes,respectively in pasture and forest catchments,were examined.Snowpack thickness,soil infiltration,surface runoff volume,soil and sediment physicochemical properties,Cs concentration of precipitation,meltwater,and rainwater,and lake siltation rates were determined.The total radioactive Cs content in precipitation was 0.7-7.4 Bq·L^-1 and was below the Japanese standard(10 Bq·L^-1).Total radioactive Cs was at the allowable level in water flowing down the pasture catchment slope(0.1-9.2 Bq·L^-1)during snowmelt and rainfall,as well as in pasture(0.9-8.8 Bq·L^-1)and forest(0.7-5.2 Bq·L^-1)catchment lake water.There was no soil erosion(surface runoff)in the forest catchment.Soil losses in the pasture catchment were 23 due to rainfall and 9 kg ha^-1 yr^-1 following spring snowmelt.After snow-melt,a 0.5 and 0.2 mm thick layer of silt was deposited in pasture and forest catchment lakes,respec-tively,and 1.4 and 0.6 mm were deposited during the rainfall period.Average siltation rates were 1.9 and 0.8 mm·yr^-1 for pasture and forest catchment lakes,respectively.The upper layer of lake bottom sedi-ments is represented mainly by silt fractions(2-50μm),with high organic matter(4.0-5.7%)and radiocesium(1100-1600 kg·ha^-1)contents. 展开更多
关键词 Fukushima Daiichi RADIOCESIUM siltation Suspended sediment Waterbodies Water turbidity
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