Impacts of the Qingcaosha Reservoir on saltwater intrusion in the Changjiang Estuary

The massive Qingcaosha Reservoir (QCSR) is located in the Changjiang Estuary along the northwest coast of Changxing Island. The reservoir significantly narrowed the upper reaches of the North Channel and deepened the channel near the reservoir. These topographical changes inevitably influenced hydrodynamic processes and saltwater intrusion in the estuary. A well-validated model was employed to investigate the influence of the QCSR on saltwater intrusion in the Changjiang Estuary. The model results showed that the narrowed upper reaches of the North Channel decreased the water diversion ratio and thus increased salinity in the North Channel. During the moderate tide after neap tide, the salinity decreased at the water intake of the QCSR because saltwater intrusion was obstructed at flood slack at the surface, while the salinity increase during the moderate tide after spring tide was mainly due to the intensified saltwater intrusion during spring tide. The deepening of the channel near the QCSR resulted in an increased water diversion ratio, and the salinity in the Eastern Chongming Shoal decreased by more than 0.5 psu during spring tide; however, the saltwater intrusion was enhanced due to the strengthened baroclinic force, which is proportional to the water depth. During neap tide, the salinity in the entire North Channel decreased because of a 1.4% increase in the water diversion ratio of the North Channel and the relatively weak tide.

The Interannual Evolution of PAHs in Columnar Sediments in Offshore Area of Changxing Island Industrial Zone, China

Changxing Island, located in the northwest of Dalian City in Liaoning, China, is a beautiful island on the West side of the Liaodong Peninsula. Since 1980, along with the development of the economic benefits and the environmental evolution of the Changxing Island marine belt, its ecological environment has changed to a certain extent. In this paper, the interannual evolution and organic pollution of polycyclic aromatic hydrocarbons (PAHs) in borehole core samples were studied, based on the survey data of coastal substrates and sedimentation chemistry of two columnar stations (C4 and C6) in Changxing Island, China, in 2017. It was found that the distribution of PAHs in the region was controlled by sedimentary types and hydrodynamic factors. The PAH content in the vertical direction of the borehole part was at the level of the environmental background value before 1980. However, from 1981 to the present, the overall increasing trend of PAHs content was evident, and there were obvious fluctuations with the changes of the surrounding environment. In the C4 column, the total concentration of 16 PAHs was 32.8–349.0 ng/g (dry weight), and it was 22.2–81.3 ng/g (dry weight) in the C6 column. Among them, the concentration range of PAHs species composition was from high to low, followed by tricyclic, quadricyclic, bicyclic, pentacyclic, hexacyclic, and the monomer with the highest content in the sea area was tricyclic phenanthrene. The supports were thereby provided for environmental pollution research, comprehensive evaluation, environmental carrying capacity forecasting, and early warning in this region, and it was served as the basis for development and antipollution feasibility demonstration.

Design and Implementation of a Remote Calibration Monitoring System for TT&C Ships

In order to improve the orbit determination precision of TT&C equipments, relevant parameters have to be calibrated accurately by using the calibration tower during the dock calibration. Based on analysis of the control objects in remote control mode, this paper builds the wireless communication system, through selecting wireless bridge to develop the network control module and relevant software. It realizes the remote monitoring for the calibration equipment, facilities and instruments. Results of the test show that the system is reasonable, convenient, reliability and extensibility, which is quietly completely suitable to control the remote equipment of Changxing island calibration tower for TT&C ship.