Natural and human-induced effects on grain size of surface sediments along the Lianyungang muddy coast,China

To examine spatial variations of grain-size characteristics caused by both natural and human-induced processes along the Lianyungang muddy coast,China,129 samples were collected and measured using standard sieving and sedimentation techniques.Results show that sediment diameter tends to increase with increasing water depth from nearshore to offshore.Size-frequency distributions indicate a gradual mixing process of coarse and fine diameter material.Grain size trend analysis indicates that a man-made structure,the West Breakwater,along with Liandao Island itself,has resulted in severe siltation in Haizhou Bay and the Lianyungang port area,where sediment quality is also poor.Results demonstrate that grain size can be used as a natural tracer to infer how sediments respond to the effects caused by both natural and human-induced processes.

A new method for the estimation of oceanic mixed-layer depth using shipboard X-band radar images

Shipboard X-band radar images acquired on 24 June 2009 are used to study nonlinear internal wave characteristics in the northeastern South China Sea.The studied images show three nonlinear internal waves in a packet.A method based on the Radon Transform technique is introduced to calculate internal wave parameters such as the direction of propagation and internal wave velocity from backscatter images.Assuming that the ocean is a two-layer finite depth system,we can derive the mixed-layer depth by applying the internal wave velocity to the mixed-layer depth formula.Results show reasonably good agreement with in-situ thermistor chain and conductivity-temperature-depth data sets.

Effect of background parabolic current on characteristics and energetics of internal solitary waves by numerical simulation

Based on modifications of the observed background parabolic current in upper layer of the northeastern South China Sea （SCS）, the effects of eight kinds of background currents on the characteristics and energy conversion of internal solitary waves （ISWs） are investigated by an Internal Gravity Wave （IGW） model. It is found that, although the background current has little effect on the number of the generated ISWs, it reduces the resulted phase speed of ISW. When the background parabolic current appears with its lower boundary near or above the main thermocline, the ISW amplitude and the depth of the isopycnal undergoing maximum displacement increase; when the background parabolic current curvature is reduced, the ISW amplitude and the ratio of baroclinic to barotropic energy reduce, whilst the phase speed of ISW, the baroclinic energy, and the ratio of baroclinic kinetic energy （KE） to available potential energy （APE） increase; when the lower boundary of background parabolic current extends down to the seabed and the background current curvature is reduced, the ISW amplitude and phase speed decrease, whilst the barotropic kinetic energy, the baroclinic energy and the ratio of KE to APE increase. At a whole depth, when the lower background current curvature is reduced and the upper current curvature is increased, the ISW amplitude, and phase speed, the ratio of baroclinic to barotropic energy, the baroclinic energy, and the ratio of KE to APE all increase.

Analysis of Urban Greening of Tai'an City in China Based on Remote Sensing Image with High Resolution

By taking urban greening of Tai'an City of Shandong Province for example,selecting remote sensing image Quickbird with high resolution,and combining visual interpretation with automatic classification of the computer,based on urban green space systematic planning map,green space information of the built-up area has been selected for the research centering on green lands in urban parks,productive green lands,green lands attached to residential areas and units,green lands attached to the road,other green lands,water surfaces and so on.Through the statistics and analysis,the distribution condition of each type of urban green land has been obtained,and some suggestions have been proposed in view of existing problems of urban greening.It should enhance the construction of green lands in urban parks,residential areas and units,improve road greening level,implement vertical greening,increase the area of productive green lands and fully make use of idle lands.