Based on the characteristics of waves, tidal currents, sediment and seabed evolution in the Caofeidian sea area in the Bohai Bay, a 2D sediment mathematical model of waves and tidal currents is employed to study the d...Based on the characteristics of waves, tidal currents, sediment and seabed evolution in the Caofeidian sea area in the Bohai Bay, a 2D sediment mathematical model of waves and tidal currents is employed to study the development schemes of the harbor. Verification of spring and neap tidal currents and sediment in the winter and summer of 2006 shows that the calculated values of tidal stages as well as flow velocities, flow directions and sediment concentration of 15 synchronous vertical lines are in good agreement with the measured data. Also, deposition and erosion of the sea area in front of Caofeidian ore terminal induced by suspended load under tidal currents and waves are verified; it shows that the calculated values of depth of deposition and erosion as well as their distribution are close to the measured data. Furthermore, effects of reclamation scheme of island in front of the land behind Caofeidian harbor on the hydrodynamic environment are studied, including changes of flow velocities in the deep channels at the south side of Caofeidian foreland and Laolonggou and in various harbor basins, as well as changes of deposition and erosion of seabed induced by the project.展开更多
In order to study the mechanism of flow-sediment movement, it is essential to obtain measured data of water hydrodynamic and sediment concentration process with high spatial and temporal resolution in the bottom bound...In order to study the mechanism of flow-sediment movement, it is essential to obtain measured data of water hydrodynamic and sediment concentration process with high spatial and temporal resolution in the bottom boundary layer （BBL）. Field observations were carried out in the northwest Caofeidian sea area in the Bohai Bay. Near 2 m isobath （under the lowest tidal level）, a tripod system was installed with AWAC （Acoustic Wave And Current）, ADCP （Acoustic Doppler Current Profilers）, OBS-3A （Optical Backscatter Point Sensor）, ADV （Acoustic Doppler Velocimeters）, etc. The accurate measurement of the bottom boundary layer during a single tidal period was carried out, together with a long-term sediment concentration measurement under different hydrological conditions. All the measured data were used to analyze the characteristics of wave-current-sediment movement and the BBL. Analysis was performed on flow structure, shear stress, roughness, eddy viscosity and other parameters of the BBL. Two major findings were made. Firstly, from the measured data, the three-layer distribution model of the velocity profiles and eddy viscosities in the wave-current BBL are proposed in the observed sea area; secondly, the sediment movement is related closely to wind-waves in the muddy coast area where sediment is clayey silt： 1） The observed suspended sediment concentration under light wind conditions is very low, with the peak value generally smaller than 0.1 kg/m^3 and the average value being 0.03 kg/m^3; 2） The sediment concentration increases continuously under the gales over 6-7 in Beaufort scale, under a sustained wind action. The measured peak sediment concentration at 0.4 m above the seabed is 0.15-0.32 kg/m^3, and the average sediment concentration during wind-wave action is 0.08-0.18 kg/m^3, which is about 3-6 times the value under light wind conditions. The critical wave height signaling remarkable changes of sediment concentration is 0.5 m. The results show that the suspended load sediment concentration is mainly influenced by wave-induced sediment suspension.展开更多
In this paper, by studying bathymetric survey and shallow seismic detection data over multiple periods of history, the authors outline the geomorphic features of the Caofeidian Channel. The results of our studies indi...In this paper, by studying bathymetric survey and shallow seismic detection data over multiple periods of history, the authors outline the geomorphic features of the Caofeidian Channel. The results of our studies indicate that the channel at the front end is dominated by erosion. The maximum water depth reaches 42.2 m, which sets the highest record for the water depth in Bohai Bay;the authors preliminarily conclude that the formation of the early channel occurred because the subsidence rate of the deep structure is slightly smaller than the deposition rate of the upper strata, and the Caofeidian Channel has existed for a long time, over 20 ka. The trending of the channel experienced a transition from the NS to the NE and then NW direction;the authors conclude that endogenic and exogenic processes, such as geological structures, the evolution of the ancient Luanhe River Delta, marine hydrodynamics, and human activity, jointly control the development and evolution of the geographic system in the Caofeidian sea area. The slope stabilities under the extreme conditions of a heavy storm and an earthquake are analyzed by performing simulations.展开更多
The Caofeidian Reclamation Project has been the biggest reclamation project in China so far, in which 310 km^2 sea areas were reclaimed along the coast of Hebei Province, and it also bring about many problems and defe...The Caofeidian Reclamation Project has been the biggest reclamation project in China so far, in which 310 km^2 sea areas were reclaimed along the coast of Hebei Province, and it also bring about many problems and defects for large reclaiming area. The study focuses on the influences of the engineering exerted on evolution of the Laolonggou Lagoon with the methods of topographical measurement and surface sediment analysis. The results demonstrate that the topographical changes in the Laolonggou Lagoon had been controlled obviously by the engineering at three stages. Besides, blocking and reopening of the shoal tidal channel also affected the geological environment of the lagoon area. In the aspect of topographical change, the Laolonggou Inlet first experienced deposition after the shoal tidal channel was blocked, followed by short-time eroding for quarrying and cofferdam construction in the east, then depositing slowly after the reclaiming activity ceased, and finally eroding after the shoal tidal channel was reopened. The project, particularly cofferdam construction led to the movement of the Laolonggou Inlet axis from west to east for 50 – 100 m. In the aspect of sediment variation, the reclamation project and hydrodynamic change resulted in the variation in compositions and distribution pattern. The western lagoon area has become land mainly constituted by silt, while the sediments in the eastern area have turned finer in size. After the shoal tidal channel was reopened, the current velocity in the Laolonggou Inlet has been enhanced, making the sediments at the bottom become coarser. The sediments around the Caofeidian foreland went through a process of changing in grain size from fine to coarse and back to fine again, and the sediments are mainly constituted by silt at present.展开更多
On the basis of previous researches on current eco-city indicator system in China, achievements of Caofeidian Eco-city and Sino-Singapore Tianjin Eco-city in the establishment of indicator system were compared, and th...On the basis of previous researches on current eco-city indicator system in China, achievements of Caofeidian Eco-city and Sino-Singapore Tianjin Eco-city in the establishment of indicator system were compared, and their differences in indicator construction framework, indicator component ratio and indicator valuation were summarized. It was found through studying the indicator systems that local indicators should stress characteristics of the city on the basis of national standards, and comply with urban construction conditions; and also that indicator system needed balance between macro and micro level, more reasonable value, and further improvement in the construction and management.展开更多
Objective The greatest advantage of the Caofeidian Harbor is its deep channel facing the Bohai Bay. The deep channel is a natural port hub for shipping of the Caofeidian Habor. The construction of the Caofeidian Harb...Objective The greatest advantage of the Caofeidian Harbor is its deep channel facing the Bohai Bay. The deep channel is a natural port hub for shipping of the Caofeidian Habor. The construction of the Caofeidian Harbor has impacted the hydrodynamic environment and the sediments movement, which has attracted much attention about the geomorphic evolution, slope stability and the evolution trend after submarine slope destruction. Insight from this study might be significant for the future development of the Caofeidian Habor, including planning, operation and maintenance.展开更多
The study area Caofeidian 18-1/2 structure is located in the Shadongnan structural belt at the southeast subduction end of the Shaleitian salient in the western Bohai Sea. The characteristics of reservoirs and fluid i...The study area Caofeidian 18-1/2 structure is located in the Shadongnan structural belt at the southeast subduction end of the Shaleitian salient in the western Bohai Sea. The characteristics of reservoirs and fluid inclusions from 13 core samples near the buried hills in the study area are studied,and regional geology and conditions for reservoir formation are analyzed to reveal the characteristics and the processes of reservoir formation. Phase I oil and gas inclusions are mainly developed,and the abundance of oil and gas inclusions in this period is high( GOI is about 15%). The homogenization temperature of the hydrocarbon-containing brine inclusions accompanying them is mainly 90-120 ℃ . The simulation results of burial history and thermal history show that the main charging period of oil and gas is the present Himalayan tectonic movement period since 8 Ma,and mainly through unconformities,faults,and drainage systems,they are migrated and accumulated into fault anticline traps of Dongying Formation mudstone( E_d).展开更多
基金The project is financially supported by the National key Basic Research and Development Program(973 Program,No.2003CB415206)the National Natural Science Foundation of China (Grant No.50379027)
文摘Based on the characteristics of waves, tidal currents, sediment and seabed evolution in the Caofeidian sea area in the Bohai Bay, a 2D sediment mathematical model of waves and tidal currents is employed to study the development schemes of the harbor. Verification of spring and neap tidal currents and sediment in the winter and summer of 2006 shows that the calculated values of tidal stages as well as flow velocities, flow directions and sediment concentration of 15 synchronous vertical lines are in good agreement with the measured data. Also, deposition and erosion of the sea area in front of Caofeidian ore terminal induced by suspended load under tidal currents and waves are verified; it shows that the calculated values of depth of deposition and erosion as well as their distribution are close to the measured data. Furthermore, effects of reclamation scheme of island in front of the land behind Caofeidian harbor on the hydrodynamic environment are studied, including changes of flow velocities in the deep channels at the south side of Caofeidian foreland and Laolonggou and in various harbor basins, as well as changes of deposition and erosion of seabed induced by the project.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.51061130546 and 51379127)the Key Projects in the National Science&Technology Pillar Program(Grant No.2012BAC07B02)
文摘In order to study the mechanism of flow-sediment movement, it is essential to obtain measured data of water hydrodynamic and sediment concentration process with high spatial and temporal resolution in the bottom boundary layer （BBL）. Field observations were carried out in the northwest Caofeidian sea area in the Bohai Bay. Near 2 m isobath （under the lowest tidal level）, a tripod system was installed with AWAC （Acoustic Wave And Current）, ADCP （Acoustic Doppler Current Profilers）, OBS-3A （Optical Backscatter Point Sensor）, ADV （Acoustic Doppler Velocimeters）, etc. The accurate measurement of the bottom boundary layer during a single tidal period was carried out, together with a long-term sediment concentration measurement under different hydrological conditions. All the measured data were used to analyze the characteristics of wave-current-sediment movement and the BBL. Analysis was performed on flow structure, shear stress, roughness, eddy viscosity and other parameters of the BBL. Two major findings were made. Firstly, from the measured data, the three-layer distribution model of the velocity profiles and eddy viscosities in the wave-current BBL are proposed in the observed sea area; secondly, the sediment movement is related closely to wind-waves in the muddy coast area where sediment is clayey silt： 1） The observed suspended sediment concentration under light wind conditions is very low, with the peak value generally smaller than 0.1 kg/m^3 and the average value being 0.03 kg/m^3; 2） The sediment concentration increases continuously under the gales over 6-7 in Beaufort scale, under a sustained wind action. The measured peak sediment concentration at 0.4 m above the seabed is 0.15-0.32 kg/m^3, and the average sediment concentration during wind-wave action is 0.08-0.18 kg/m^3, which is about 3-6 times the value under light wind conditions. The critical wave height signaling remarkable changes of sediment concentration is 0.5 m. The results show that the suspended load sediment concentration is mainly influenced by wave-induced sediment suspension.
基金funded by China National Project (DD20191003, DD20160147, DD20189503)National Natural Science Foundation of China (41506119, 41276060).
文摘In this paper, by studying bathymetric survey and shallow seismic detection data over multiple periods of history, the authors outline the geomorphic features of the Caofeidian Channel. The results of our studies indicate that the channel at the front end is dominated by erosion. The maximum water depth reaches 42.2 m, which sets the highest record for the water depth in Bohai Bay;the authors preliminarily conclude that the formation of the early channel occurred because the subsidence rate of the deep structure is slightly smaller than the deposition rate of the upper strata, and the Caofeidian Channel has existed for a long time, over 20 ka. The trending of the channel experienced a transition from the NS to the NE and then NW direction;the authors conclude that endogenic and exogenic processes, such as geological structures, the evolution of the ancient Luanhe River Delta, marine hydrodynamics, and human activity, jointly control the development and evolution of the geographic system in the Caofeidian sea area. The slope stabilities under the extreme conditions of a heavy storm and an earthquake are analyzed by performing simulations.
基金supported by the National Natural Science Foundation of China (No. 40876033)the China Geological Survey Project (No. DD20160144)。
文摘The Caofeidian Reclamation Project has been the biggest reclamation project in China so far, in which 310 km^2 sea areas were reclaimed along the coast of Hebei Province, and it also bring about many problems and defects for large reclaiming area. The study focuses on the influences of the engineering exerted on evolution of the Laolonggou Lagoon with the methods of topographical measurement and surface sediment analysis. The results demonstrate that the topographical changes in the Laolonggou Lagoon had been controlled obviously by the engineering at three stages. Besides, blocking and reopening of the shoal tidal channel also affected the geological environment of the lagoon area. In the aspect of topographical change, the Laolonggou Inlet first experienced deposition after the shoal tidal channel was blocked, followed by short-time eroding for quarrying and cofferdam construction in the east, then depositing slowly after the reclaiming activity ceased, and finally eroding after the shoal tidal channel was reopened. The project, particularly cofferdam construction led to the movement of the Laolonggou Inlet axis from west to east for 50 – 100 m. In the aspect of sediment variation, the reclamation project and hydrodynamic change resulted in the variation in compositions and distribution pattern. The western lagoon area has become land mainly constituted by silt, while the sediments in the eastern area have turned finer in size. After the shoal tidal channel was reopened, the current velocity in the Laolonggou Inlet has been enhanced, making the sediments at the bottom become coarser. The sediments around the Caofeidian foreland went through a process of changing in grain size from fine to coarse and back to fine again, and the sediments are mainly constituted by silt at present.
文摘On the basis of previous researches on current eco-city indicator system in China, achievements of Caofeidian Eco-city and Sino-Singapore Tianjin Eco-city in the establishment of indicator system were compared, and their differences in indicator construction framework, indicator component ratio and indicator valuation were summarized. It was found through studying the indicator systems that local indicators should stress characteristics of the city on the basis of national standards, and comply with urban construction conditions; and also that indicator system needed balance between macro and micro level, more reasonable value, and further improvement in the construction and management.
基金supported by the National Natural Science Foundation of China(Grant No.41276060)
文摘Objective The greatest advantage of the Caofeidian Harbor is its deep channel facing the Bohai Bay. The deep channel is a natural port hub for shipping of the Caofeidian Habor. The construction of the Caofeidian Harbor has impacted the hydrodynamic environment and the sediments movement, which has attracted much attention about the geomorphic evolution, slope stability and the evolution trend after submarine slope destruction. Insight from this study might be significant for the future development of the Caofeidian Habor, including planning, operation and maintenance.
基金Supported by Tianjin Branch of CNOOC(China)Co.,Ltd.(CCL2014TJX ZSS0870)。
文摘The study area Caofeidian 18-1/2 structure is located in the Shadongnan structural belt at the southeast subduction end of the Shaleitian salient in the western Bohai Sea. The characteristics of reservoirs and fluid inclusions from 13 core samples near the buried hills in the study area are studied,and regional geology and conditions for reservoir formation are analyzed to reveal the characteristics and the processes of reservoir formation. Phase I oil and gas inclusions are mainly developed,and the abundance of oil and gas inclusions in this period is high( GOI is about 15%). The homogenization temperature of the hydrocarbon-containing brine inclusions accompanying them is mainly 90-120 ℃ . The simulation results of burial history and thermal history show that the main charging period of oil and gas is the present Himalayan tectonic movement period since 8 Ma,and mainly through unconformities,faults,and drainage systems,they are migrated and accumulated into fault anticline traps of Dongying Formation mudstone( E_d).
