Volume articles

Variational assimilation technique, in conjunction with the ship reported data, is applied to a short term numerical prediction model in order to realize automatic short term SST forecast in the Bohai, the Yellow and the East China Seas. The prediction model, using the adjoint assimilation method, achieves a global optimization of the initial SST field. Corresponding to the four typical months (February, May, August and November) of four quarters respectively in 2002, we do forecast for a month continuously. The results indicate that the root mean square error between the hindcasts of 24 successive hours and the ship reported data is reduced to below 0.8 ℃. The mean absolute errors of SST are reduced markedly, compared with the values before assimilation. The forecast accuracy is improved with the adjoint assimilation method compared with the results from the objective analysis method.

The sea surface wind speed has a important impact on the navigation, ocean engineering and disaster prevision. In this paper, the observed wind data from Taiwan Island and South Korean was used to verify the validation of the T639 wind production during the typhoon “Fitow” and a cold air process. Results show that: (1) During the typhoon “Fitow”, there is a good consistency between the forecasting wind speed and the observed wind speed. (2) From the correlation coefficient, there is also a close relationship between the forecasting wind speed and the observed wind speed. About the Bias error, the forecasting value is slightly larger than the observed value. Comprehensive consideration of the root mean square error and mean absolute error, the precision of the T639 wind production is high. (3) During the typhoon “Fitow”, the T639 wind production can describe the characteristics of typhoon (including the typhoon eye and typhoon end mark) very well. The Waipu meteorology station, Dongjidao meteorology station and Lanyu meteorology station were effected by the typhoon noticeable but the Danshui meteorology station, Jinmen meteorology station and Lvdao meteorology station. The T639 wind production can also describe the cold air process very well.

The Ross Sea is located on the Pacific side of the Antarctica. Based on analysis of sedimentary, structural and temperature-pressure conditions,it is proved that Rose Sea has good conditions for the reservation and exploration prospects of gas hydrates. In this paper,the heat flow data are used to calculate the thickness of the gas hydrate stability zone. An integral method is conducted to estimate the amount of gas hydrate resources in this region. The results show that the amount of gas hydrate resources of Ross Sea region is 3.6×10 ¹¹ m ³, which means considerable economic value.

In this study, the U ^k ₃₇ indices for surface sediment samples derived from the South China Sea (SCS), Pacific Ocean, East China Sea (ECS) and Arctic Ocean are analysed, as well as the overlying averaged sea surface temperature (SST) at 0~30 m depth. The alkenone-derived U ^k ₃₇ index is justified as a useful palaeoenvironment proxy at extreme cold and warm end (-0.6 ℃~28 ℃) because the resulting U ^k ₃₇ indices show a significant correlated linear relationship with annual averaged SST. Simultaneously, U ^k ₃₇ indices have been correlated with averaged SST of four seasons in the SCS as well. However, the seasonal pattern of Coccolith ( E. huxleyi and G. oceanic), being source of alkenone, is showed prosperous in winter time. As a result, the sedimentary U ^k ₃₇ index may only reflect the winter SST of the overlying waters.

As Digital elevation model is an important geographic information, SAR(synthetic aperture radar) is one of the most effective means in digital elevation model extracting. Use Radarsat-2 fine Quad-polarization mode data (November 27, 2013)over Qushandao in Zhejiang province to figure out the polarization azimuth offset between two adjacent resolution cells, and then extract the gradient information and terrain elevation. Finally, test the accuracy of the digital elevation model by the measured data, whose average relative error turn out to be 20%,and the results showed that the main causes of errors is the change of the terrain basement caused by the sea clutter and the elevation deviation caused by the leaves and boughs of the vegetative cover.

In order to study the influence of the formation of biofilm on the corrosion of DH32 structural steel, the growth curve of a marine microorganism (Vibrio natriegens) was tested by UV-Vis spectra, the formation process of biofilm and the surface of the coupons were characterized by scanning electron microscope and atomic force microscope, respectively. The results show that the formation of biofilm closely associates with the growth of bacteria, the formation process of biofilm changes the chemical and physical state of the steel surface. Moreover, the formation of oxygen concentration cell and binding power of extracellular polymeric substances with metal ions greatly promotes the DH32 surface oxidation corrosion.

In this study, a data sample has been established including 13 sorts of water quality index and 400 stations of hypothesis sampling according to the <National Water Quality Standard (NWQS)> for the evaluation model of coastal water quality. By calculating the KMO, sphericity test as well as the correlation matrix of all indices, we found that there was a good correlation among indexes, which indicated that the principal component analysis (PCA) could be applied to extract information. For 13 indexes of water quality, only the first two principal components with eigenvalues ??greater than 1 are effective, which could represent 81.25% information of the samples, as a result, a quality automatic classification layout (evaluation model) which could accurately classify four kinds of waters has been set up. A thematic map of water quality classification in the coastal waters of Leizhou Peninsula in 2010 was drawn according to the water quality automatic evaluation method. In this map, case IV waters were in the Zhanjiang harbor, Jianjiang Estuary and Tieshan harbor sea area, and case III waters were mainly in the southwest of Donghai Island, offshore area of Jianjiang estuary, northeast of Xuwen, Liusha Bay and Jianghong harbor sea areas, and on the other sea area of Leizhou Peninsula, they were case I and II waters in 2010. This study provides a better distribution in water quality environment of the coastal waters of Leizhou Peninsula, which offers some references for the comprehensive treatment and utilization in this area.

The national nature reserve of Shuangtai River Estuary is located in the lower reaches of Liaohe River Estuary, there are many wetlands in the region, the land use/cover types of which are various. The author analysed the land use and land cover (LUCC) and their driving forces in the national nature reserve of Shuangtai River Estuary from 1984 to 2013 by utilizing the Landsat TM, ETM, OLI-TIRS remote-sensing images of 5 different periods in the past 30 years. The method which combines GIS spatial analysis with mathematical statistics was adopted. The results show that the marsh reeds area and aquaculture area increased widely, the natural water area and beachland area diminished widely, the single land use dynamics of aquaculture area was the largest during 1984 to 1992. The farmland area and beachland area increased fast, the natural water area and marsh reeds diminished fast, the comprehensive land use dynamics was the largest during 1992 to 2000. The aquaculture area increased widely during 2000 to 2007. The construction land increased widely during 2007 to 2013. The LUCC of the national nature reserve of Shuangtai River Estuary was influenced by many factors and population, economy, policy were the mainly social economic factors.The performance of each factors were different during different periods.

Coastal landscape is the foundation of sustainable social and economic development in coastal areas .It is significant to make a analysis change of landscape ecological risk on coastal zone to optimize the evolution of the coastal landscape planning and rational development of landscape resources. The study, based on the Landsat TM/ETM+ remote sensing data of 1990-2010 and field survey ,analyzes the temporal-spatial change of landscape ecological risk on coastal zone of Xiangshangang bay. The results show that: (1) Over 20 years, Great changes of landscape patterns have taken place in Xiangshangang bay . The area of arable, sea, woodland decreased. While the area of construction land, unused land and farming land increased. (2) Since 1990, Xiangshangang coastal landscape ecological risk grade has constantly increasing trend. Some low, low grade of ecological risk area evolved in high grade and extremely high grade.(3) Judging from different levels of ecological risk from space area distribution ,It embodies in the space that the extremely low and low grade ecological risk areas shrink to upstream during 1990~2010, and the area show a downward trend. The medium, high and extremely high grade ecological risk areas expand to the coastal areas. In terms of the evolutionary rate, nearly 10 years of high and extremely high ecological risk area has significantly accelerated the rate of increase over the previous 10 years.

We propose a new method for tidal energy utilization using water-hammer in pipeline. The hydro-ram can convert potential energy of low water head to higher head by pumping sea water to high reservoir,which avoid the energy conversion from tidal power to pumped storage. Model pump test was carried out to simulate the 1~3 m working condition of pumping sea water to 5~20 m high reservoir. We got the efficiency and output power of several supply head in the test. The experiment shows that the efficiency can be higher than 60% in the working condition and remain stable when water level changes.

Based on the survey in Sanmen Bay in May 2013, a preliminary research on the net-phytoplankton community characteristics was carried out. The results show that a total of 9 phyla' 253 species are found in the survey area, and the community is mainly composed of Bacillariophyta (71.5%), followed by Dinophyta (16.6%), and other phyla occupies low ratio. The average value of cell abundance is (2 227±3 883)×10 ³个/m ³, and the highest value appeares in the northeastern area near the mouth of the bay (EMB). The dominant species are Eucampia zodiacus, Biddulphia sinensis, Chaetoceros castracanei, Coscinodiscus concinnus, Skeletonema costatum, Coscinodiscus jonesianus and Nitzschia sigma. Because the effect of water temperature, salinity or other environmental factors, the dominants distribution demonstrates spatial difference among the mouth, the middle and the top of the bay. Besides, comparing with the historical data, it is found that the phytoplankton cell abundance increases and the diatom species declines in percentage of the total species.

According to the investigation results of Dongshan Bay and its adjacent sea area in May and August 2011, DIN、DSi、SRP、TN、TP、COD、DOC、TOC、Chl- a and total abundance of phytoplankton associated with eutrophication were analyzed with principal component analysis(PCA).Three principal components (PCs) were extracted with principal component analysis: phytoplankton、TP and COD for PC1, N nutrients and silicon nutrients for PC2 and P nutrients for PC3. Distribution of PC1、PC2、PC3 and CPC in spring and summer show the high eutrophication risk regions, where were Zhangjiang Estuary and Bachimen adjacent areas. The correlation analysis with salinity showed that eutrophication pressure was mainly from Zhangjiang in Dongshan Bay, and enhanced in summer. COD and phytoplankton are dominating factors in assessing the variation of eutrophication in Dongshan Bay and its adjacent area.

CEOF and wavelet methods were employed to discuss the relationship between the main modes of upper circulation anomalistic field in the North Pacific during winter and the PDO, NPGO modes. The results show that the first and second CEOF modes of the upper circulation anomalies are the reflection of the PDO and NPGO modes on the circulation field. Firstly, the real time coefficients of the first two modes have obvious decadal periods of about 20 and 13 years, respectively, which are the same as the periods of PDO and NPGO modes. Secondly, the regression fields of the first two time coefficients with the SSTA in the North Pacific are quite similar to the spatial feature of PDO and NPGO modes. The distributions of dynamic anomalies of near-surface temperature obtained by the vertical movement of the first two modes of the upper circulation anomalies are similar to those of PDO and NPGO modes. This means that the vertical movement of oceanic flow is the important reason of formation of PDO and NPGO modes.

High wind speed data were obtained by using the angular momentum model and their precision was verified by the weather station recorded data. A wind speed inversion algorithm for altimeter was developed by using these wind speeds. The results show that this new algorithm can inverse the sea surface wind speed more accurately when typhoon passes through, which realizes the high wind speed (10~40 m/s) inversion for altimeter. This, therefore, can be taken as the supplement of altimeter wind inversion algorithm for Jason-1 at the high wind speed, and improve the precision of altimeter wind inversion algorithm.

The processing and prediction of tidal current signal are significant and valuable in various aspects. This study introduced a signal sparse representation theory, constructed a sparse AR model in order to find out the connection among the tidal currents, and to carry out the forecast analysis. Firstly, we established the conventional AR model by measuring current signal, so we could get a set of complete sparse matrix. Secondly, we randomly extracted parts of this to create underdetermined system of equations. We acquired the sparse AR coefficients by using sparse optimization algorithm. After repeating above steps for many times, the stability increased and reached to average sparse AR coefficients. Finally, the last step was to reconstruct or predict the tidal current signal by using the last sparse AR coefficients. By using the measured observations of tidal current, especially the observations with many peaks or rotary current phenomenon. Many experiments had been done to establish the sparse AR model and prediction. Comparing this AR model with flow harmonic method, the sparse AR model is much better than the traditional tidal harmonic method especially in analysing the region with changeable tidal current. Moreover, the variance of the sparse AR model is less than that of the traditional tidal harmonic analysis.

There are three main manganese oxides in polymetallic nodules. They are vernadite、todorokite and birnessite. Different manganese oxides have their specific origins and growth environments. It is found that there is a special opal-layer which is full of todorokite veinlets in the polymetallic nodules from the Eastern Pacific Ocean. Microscope、EPMA (Electron Probe MicroAnalysis) and ICP-OES (Inductively Coupled Plasma Optical Emission Spectrometer) methods were used to find out the micro-structure and geochemical features of the opal-layer and its surrounding minerals, in order to investigate the origin of the opal-layer. It shows that: (1) The special opal-layer and its surrounding area are mainly composed of todorokite,vernadite and opal. (2) Todorokite has high reflectivity and Mn/Fe ratio. It is mainly composed of MnO and of diagenetic origin. (3) Vernadite has moderate reflectivity and low Mn/Fe ratio. It is mainly composed of MnO and FeO, it is of hydrogenic origin. (4) Opal has low reflectivity. It is mainly composed of SiO ₂ and of biogenic origin. A model was set up for the formation of the opal-layer and the todorokite veinlets inside. It could be divided into 5 stages as follows:(1)In the oxidizing environment, vernadite was formed on the surface of the half-buried nodule.(2) The dissolving of biogenic opaline silica leaded to a vast amount of colloidal silica in the upper water of the seafloor. The colloidal silica deposited on the surface of the half-buried nodule, forming the opal-layer.(3) In the oxidizing environment, vernadite was formed on the surface of the half-buried nodule. At the same time, the diagenesis of the nodule and dehydration of opal led to the formation of cracks in the opal-layer.(4) The nodule was buried by the silica-rich sediments. In the reducing environment, the todorokite veinlets formed in the previous cracks by the invasion of interstitial water from the surrounding sediments.(5) The nodule re-exposured in the water, forming vernadite on its surface in the oxidizing environment.

As one of the major generated place of the Antarctic Bottom Water (AABW), the Weddell Sea is a very important margin sea in Antarctic, its hydrodynamic environmental change and its response has important significance to the global change. Over the past century, the global change characterized by global warming had affected Antarctic and the Southern Ocean. In order to understand the hydrodynamic environmental changes in this region, ²¹⁰Pb dating, grain size parameter and ice-rafted detritus content were analyzed and discussed for a short sediment core of ANT28-D5-6 which was taken in the north of Weddell Sea, south to the South Orkney Islands and east to the Antarctic Peninsula. The results show that the hydrodynamic force of Northern Weddell Sea had significant change in nearly hundred years from 1922 to 2011. During 1922-1972, the Northern Weddell Sea was in a high-energy, high-speed and turbulent hydrodynamic environment, and a large amount of ice raft debris was carried and deposited, which was corresponded well to the relatively low temperature stage of the earth. In the course of them, there were twice hydrodynamic environment weakened events happened during 1930-1936 and 1946-1952. The twice increased events of ice-rafted detritus content in 1939 and 1950 might be related to the longitudinal enhancement of Weddell Gyre, which was caused by 17 ^th and 18 ^th Solar Maximum Year. During 1972-2011, the Northern Weddell Sea remained relatively calm and low energy hydrodynamic condition, which was corresponded well to the continual warming up stage of the world. During 1955-1972, it was a rapid transition from the high-energy and turbulent state to the low-energy water dynamic of the Northern Weddell Sea.

Sediment survey was carried out in the tidal sand ridges and troughs west of Taiyangsha Ridge in the southern Yellow Sea. Samples were taken with vibrating piston sampler in dense stations. Based on results of grain size analyses, the space distribution characteristics of the surface and shallow sediments with thickness some 2~3 m were elaborately studied. The results show that fine sands of the surface sediments mainly distribute on the tidal sand ridges and coast beach, while other finer sediment types mainly distribute in tidal troughs, appearing a basic feature of sediment-morphology pattern of “ridge-sand and trough-soil”. Meanwhile, the distribution scope of the surface fine sands on the tidal sand ridges is clearly related to the distance between the ridges and the coast. Apart from the influence of tidal currents, this is mainly due to the wave energy consumption by the outer ridges. Based on the above characteristics of sediment-morphology pattern, evolution of sedimentary environment was also discussed.

The analysis on the coastal landscape pattern evolution has great significance to understand the relationship between human activities and landscape pattern evolution, and to promote the sustainable development of coastal area. Based on the Landsat TM images of 1990, 2000 and 2010, landscape pattern evolution of coastal zone around the Xiangshangang Bay was analyzed by using “3S” techniques. The results showed as follows: (1) The areas of the woodland, the sea and the farmland decreased, while the construction land, water area, aquaculture land and unused land increased, and the area of beach increased at first and then decreased. (2) The patch number (NP), the patch density (PD) increased, the mean patch area (MPS) decreased, the perimeter density (ED) and the shape index (LSI) increased, Shannon's diversity index (SHDI) and Shannon's evenness index (SHEI) increased, and the landscape heterogeneity increased. (3) The whole dynamic degree showed a rising trend, and the landscape of coastal zone around the Xiangshangang Bay changed more frequently because of human activities intensity about development and utilization. (4) Human activities and natural factors led to the landscape pattern evolution of coastal zone around the Xiangshangang Bay.

Using interferometric principle, GeoSwath Interferometric sonar can get bathymetry data and side scan sonar image. There are some differences between the interferometric systems and traditional side-scan sonar. The GeoSwath Plus System 125 kHz was compared with Klein System 3000 in their theory, technical specification, software and test data. The results show that these two systems are different in types of the acquisition data, which leads to the difference in their purpose. The GeoSwath Plus System is more complex, but its applicable depth is shallower. The kinds of acquisition software which can be used in GeoSwath Plus are less, and its post-processing softwares are required more powerful. But there are more choices for Klein System 3000 in its acquisition and post-processing software. It is found by compared the measured data that the position of GeoSwath Plus image is more accuracy, but the quality and resolution of its sonar image are worse than those from Klein System 3000 because of bigger beam horizontal angle and hanging installation.

Nano-SnO ₂ photocatalyst was obtained by the chemical precipitation method with SnCl ₄·5H ₂O as the raw material. The particle size of powders, object and morphology have been characterized using the X-ray diffraction and electron microscope. The photocatalytic degradation of ammonia nitrogen in aquaculture wastewater was investigated by using our home-made nano-SnO ₂. The effects of different degradation variables on the degradation efficiency were investigated, and the results show that nano-SnO ₂ catalyst dosage, the initial mass concentration of ammonia-N in wastewater, pH value, the mass concentration of H ₂O ₂ are the main effect factors. The optimum reaction conditions are as follows: nano-SnO ₂ catalyst dosage is 1.2 g/L, the initial concentration of ammonia-N is 20 mg/L, pH value is 8.0, reaction time is 2 hours and H ₂O ₂ concentration is 1.0 g/L. Under such condition, the removal rate of ammonia-N can nearly reach 72%.

Phasolosma esculenta is a peculiar edible marine economic species in China. In this study, the antimicrobial effect and physical and chemical characteristics of coelomic fluid extracted from Phasolosma esculenta was examined with agar diffusion and plate counting method. The result shows that this fluid is found to have an antibacterial activity against three G ⁺ bacteria ( Staphylococcus aureus, etc), but has no obvious antibacterial activity against three G ^- bacteria ( Escherichia coli, etc) and the yeast Candida lusitaniae. Results also show that: (1) Different extraction procedure shows different antibacterial activity. Three extraction procedures are compared: (a) the coelomic fluid without any treatment; (b) with ultra sonication and (c) mixed with 2% acetic acid. Pretreated with an ultra-sonication step, the extract has the best antibacterial effect. (2) The antibacterial activity of this component is effective up to 90 minutes and freezing-resistant. With its optimal temperature of 25 ℃, it shows an antibacterial effect within temperature ranging from 5 to 30 ℃. The fluid is inactivated with water bath treatment at 60 ℃ for 10 minutes. In addition, the antibacterial activity is independent from the metal ions. (3) Moreover, by separating fluid components based on molecular weights, it shows that the effective component is larger than 100 kDa.

In order to provide the theory basis for the scientific control of dissolved oxygen in the process of transportation and culture for juvenile fish, the oxygen consumption rate and the suffocation point of the juveniles for five species of mariculture fish ( Plectropomus leopardus、 Cromileptes altivelis、 Epinephelus fuscoguttatus、 Epinephelus akaara and the hybrid of Epinephelus Lanceolatus ♂ ×Epinephelus fuscoguttatus♀) of which weight ranged from 53.6 g to 84.5 g under the condition of different temperature(20 ℃, 25 ℃and 30 ℃) were investigated using closed breathing experimental method. The results show that both the oxygen consumption rate and the suffocation point of the juveniles for five species of mariculture fish increase with increasing water temperature under the salinity condition of 30 degree. The oxygen consumption rates of Plectropomus leopardus are the highest, which are 0.15 mg/(g·h), 0.21 mg/(g·h) and 0.31 mg/(g·h) at the water temperature 20 ℃, 25 ℃ and 30 ℃ respectively, while the oxygen consumption rates of the hybrid of Epinephelus Lanceolatus ♂ ×Epinephelus fuscoguttatus♀ are the lowest, which are 0.08 mg/(g·h), 0.15 mg/(g·h) and 0.16 mg/(g·h) at the same water temperature . The suffocation points of Cromileptes altivelis are the highest, they are 1.00 mg/L, 1.12 mg/L and 1.21 mg/L at the water temperature 20 ℃, 25 ℃ and 30 ℃ respectively, while the suffocation points of the hybrid of Epinephelus Lanceolatus ♂ ×Epinephelus fuscoguttatus♀ are the lowest, they are 0.19 mg/L, 0.24 mg/L and 0.25 mg/L at the water temperature 20 ℃, 25 ℃ and 30 ℃ respectively.

Primary productivities and features of the phytoplankton composition in the nearshore waters of Tianjin from 2012 to 2013 were studied. In spring, the primary productivities were 2.20 to 23.18 mgC/(m ²·d), and the average value was 9.54 mgC/(m ²·d), while in summer, the primary productivities were 6.37 to 138.37 mgC/(m ²·d), and the average value was 44.13 mgC/(m ²·d), which were lower than those from 1982 to 1983 and from 1992 to 1993. The horizontal distribution of primary productivities in Tanggu was higher in spring, while those in Beitang and Hangu were higher in summer. Total 2 phyla including 59 species of phytoplankton were commonly found in the survey area, in which 83.1% were diatoms and 16.9% were dinoflagellates. The dominant species were Rhizosolenia delicatula, Ditylum brightwellii, Bidduiphia sinensis, Skeletonema costatum, Chaetoceros curvisetus, Nitzschia pungens, Leptocylindrus danicus and Eucampia zoodiacus. Phytoplankton cell abundance from 2012 to 2013 was from 3.32×10 ³ to 3.85×10 ⁷ cell/m ³ in spring and 2.48×10 ⁶ to 4.65×10 ⁹ cell/m ³ in summer, which was higher than that in spring clearly. The horizontal distribution of phytoplankton cell abundance in north and south of Tianjin nearshore waters was higher than that in the middle, which was due to the river distribution. Shannon-Wiener index of phytoplankton community average value was 1.865 in spring and 1.560 in summer. Features of the phytoplankton community form 2012 to 2013 were mainly influenced by depth, COD, pH, DO and phosphorus.

Based on sea surface salinity (SSS) observations from Argo profiling floats during 1996—2012, SSS response to typhoons was analyzed by a synthetic analytical method. The results show that there exists an apparent asymmetry in the SSS response to typhoons: the SSS on the right side of the track increases markedly, however on the left side,it increases within radius of 50 knots wind speed ( R₅₀) while decreases outside the R₅₀. Further analyses indicate that intensity, translation speed of typhoon and ocean mixed layer depth all have significant impacts on the SSS response. Strong or slow moving typhoons can produce SSS rises in a large area, whereas SSS increases (decreases) on the right (left) side of the track during the period of weak or fast moving typhoons. In summer (Jun.-Sep.), SSS generally rises more in magnitude and area after the passage of typhoon in regions of shallow mixed layer than in deep one,where SSS rises slightly within radius of 2 R₅₀ and decreases on the left side far away from typhoon track.

Twenty historical typhoons which had a great impact on the Zhoushan sea area, were selected to perform analyses and inductions of the measured tidal level data at Dinghai station. It was found that in these twenty typhoons, the maximum storm surge was 207.1 cm under the Typhoon 5612, and the maximum storm high tidal level was 283.7 cm under the Typhoon 9711. Further, a 3D baroclinic hydrodynamics model, SELFE, was used to establish an unstructured triangular grid astronomical tide-storm surge coupled model, through adding the typhoon pressure field and wind field modules. The numerical results show that the baroclinic effect is more obvious while the nonlinear coupling is relatively weaker. But the two-tides-coupled storm surge data are still better than the single-factor data and closer to the measured data. On this basis, in the north and south of the original path of the Typhoon 5612, two parallel paths at certain intervals were designed respectively. The corresponding results show that the supposed typhoon which adopts the parameters of the Typhoon 5612 and moves along the S1 parallel path in the south of the original typhoon path at a distance interval of a maximum wind radius, can induce the probable maximum storm surge of approximately 243.9 cm. Finally, supposing that the probable maximum storm surge separately encounters the astronomical high, middle or low tidal level, it is found that there appears a probable maximum storm high tidal level of about 400 cm when encountering the astronomical high tide.

By using RS and GIS technology, four satellites remote sensing images of 1970, 1992, 2003 and 2014 were used to create the maps of land use status in Xiushan Island. Intensity analytical method was applied to quantify the annual intensity of the changes at three levels: time interval, category, and transition. The results show that forest and grass land, cropland, construction land and tideland are the main types in Xiushan Island. Overall, the transforming rate of land use type increases initially and then decreases afterwards. The main directions of land use type transfer were the conversions from cropland to construction land. Analyses of the results reveal that the land use change is associated with the land policy, economic growth and employment structure.

Aiming to the demand of sea area dynamic changes monitoring, two periods of remote sensing dynamic monitoring from September, 2012 to October, 2013 were carried in Tangshan. The results show that the sea area changes in Tangshan have the characteristics of great quantity, large area and high frequency. The main reasons for the sea area change are human developmental activities such as land reclamation, infrastructure construction and reclamation aquaculture. According to the demand of remote sensing monitoring, the monitoring model, the monitoring frequency, the monitoring time and the business system of the dynamic monitoring of sea area were researched. The model of remote sensing information of sea area dynamic changes was constructed. Finally, the design scheme of the business monitoring system of sea area using dynamic changes with remote sensing was presented.

As a major project lying in the Changjiang Estuary, Qingcaosha reservoir leads to change of river regime in the North Channel markedly. The change of river regime could induce change of current field and sediment concentration, and then influence bed erosion and deposition. The three-dimensional hydrodynamic and sediment model were used to calculate and analyze the impacts of the project on current filed, sediment concentration, erosion and deposition in area around the reservoir. After the project, width of upper reaches of the North Channel was narrowed, which results in increase of both current speed and sediment concentration in the major channel on the north of Qingcaosha reservoir. On the contrary, the current speed and sediment concentration decrease in areas on east of the reservoir, lower reaches of the North Channel and sand bar due to the decrease of river discharge and tidal prism flowing into the North Channel. Using the formula of bed erosion and deposition based on experience and theory, and the modeled current, sediment concentration and water level, the erosion and deposition caused by reservoir project was calculated. Strong erosion occurs in the North Channel on north of reservoir, with maximum of 3 m, which matches well both in shapes and values with the observed depth change before and after the project. The numerical model simulated the distributions and magnitude of bed erosion and deposition fairly well caused by Qingcaosha reservoir project.

Research on tidal flat evolution at strong-tide bay is important for marine exploitation, environmental protection and disaster prevention. By using remote sensing and GIS technology, tide flat evolution in a strong tide bay-Wendu Bay in north Fujian Province was studied. The conclusions are showed as follows: Since 1991, tidal flat at the bayhead of Wendu Bay is in a silting state, and the deposition rate is increasing especially after 2005. The main reason of tidal flat siltation may be the bay mouth narrowing by bay reclamation, which results in flow velocity increasing and seabed scouring, so the scouring sediment at bay mouth can be transported to the bayhead and finally accumulates on the tidal flat at bayhead.

The growing inhibitory properties on Isochrysis galbana, Platymonas subcordiformis and Navicula of thirteen 2-(N-arylaminomethyl)-3-oxo-benzo[d]isothiazoles were investigated, and the effects on biological activity of barnacle nauplii were also studied. The results indicate that the tested compounds have favourable growing inhibitory activities to the marine algas, and the better inhibitory activities are on Isochrysis galbana and Platymonas subcordiformis. The results also indicate when the lowest concentration is 2.0 mg/L, the tested compounds show a favourable growing inhibitory activity on barnacle larvae except the compound g and l. The relationship between compounds' structure and plankton growth inhibitory activity reveals that meta-substituent is better than para-substituent.

Our knowledge on diazotrophs is limited in the Indian Ocean, which is considered an important source of biological N ₂ fixation of the global ocean. Phylogenetic diversity of nifH genes in the southwest Indian Ocean was studied through cloning and sequencing methods. After sequences were checked, two nifH gene libraries were established. Overall, 76 nifH gene sequences are recovered from Station CTD13, including 46 nifH gene sequences of 10 OTUs from libraries CTD13-30 m, and 30 nifH gene sequences of 8 OTUs from libraries CTD13-125 m, respectively. Results of phylogenetic analysis show that most nifH gene sequences fall into Cluster I and III, only 3 recovered nifH gene sequences are grouped with Cluster II. In Cluster I, most of nifH gene sequences cluster with unicellular cyanobacteria Group B, while in Cluster III, most nifH gene sequences are closely related with uncultured clone from active sludge. No nifH gene sequences clustered with Trichodesmium are recovered, which may be attributed to low water temperature. In general, diazotroph community in the southwest Indian Ocean is different from those in tropical and subtropical oligotrophic ocean.

The rapid development of cage culture has brought high pressure to the marine ecological environment in recent years. Although the environmental quality of cage culture area has been analysed and evaluated at different aspects by scholars, there is lack of universally accepted evaluation criterias and methods, and integrated assessment in these researches. In this study, by using analytic hierarchy process(AHP), a comprehensive indicator system for environmental quality evaluation of cage culture area was constructed from two aspects: the environmental suitability, the quality and safety of aquatic products. Based on the historical and current monitoring data of cage culture area in the Xihu Bay, Ningbo City, along with related literatures, the evaluating indicators were selected, and the evaluation criterias were determined. Combined with the index evaluation, these indicators were applied to evaluate the environmental quality of cage culture area in the Xihu Bay. The evaluation results show that the comprehensive quality of the cage culture area in the Xihu Bay in 2011 was rated as ‘comparatively good’, and the main risks identified were eutrophication and the heavy metal pollution in aquatic products.

Dynamic shear modulus in marine clay containing sand was tested using RCA resonant column test system produced by GDS Company of UK. At the same time, comparing to the dynamic shear modulus in pure sand sample, the various factors such as the consolidation pressure, initial compactness, clay content, etc. influencing the maximum dynamic shear modulus of soil were studied systematically.The results show that the maximum dynamic shear modulus increases along with the effective consolidation pressure increasing and the initial density increasing, while it decreases along with the clay content increasing.

In order to find out the eco-environmental characteristics and variation trends around the Chengdao Oilfield sea areas in the Yellow River Estuary, using the methods of single factor index and comprehensive index, the monitoring data of the seawater and sedimentary quality over years were evaluated, and the changes of marine biology around the Chengdao Oilfield sea areas were also analyzed. The results showed that except for inorganic nitrogen in 2009, 2010, 2011, and phosphate in 2011, the water quality of the investigated areas reached the second-class water quality according as The Chinese National Standard of Seawater Quality. The sedimentary quality of the investigated areas reached the first-class sedimental quality according as The Chinese National Standard of Sediment Quality. The oil contents of sea water and sediment in 2006-2011 had a good corresponding relation with the annual oil production of Chengdao Oilfield. Offshore oil development caused a reduction in the total number of phytoplankton and benthic species, and the total density, biomass and community diversity index of benthos also declined. The offshore oil development caused some negative impacts on the environment around Chengdao Oilfield sea areas.

A total of 3 phyla 60 genera and 114 taxa(not including undefined species) were identified by the Utermöhl method in the survey area. The major groups were diatom and dinoflagellate. The ecotypes of most phytoplankton were temperate and coastal species. The dominant species were Dictyocha fibula, Gymnodinium sp., Gyrodinium spirale, Diploneis bombus and Paralia sulcata. The cell abundance of phytoplankton ranged from 0.037 0× 10 ³ to 32.3 × 10 ³ cells·L ^-1, with an average of 2.04 × 10 ³ cells·L ^-1. The cell abundance of phytoplankton decreased offshore. Cell abundance was highest in west region of the northern Yellow Sea, about 32.3×10 ³cells·L ^-1, and was also relatively high in southeast region in the survey area. The vertical distribution of phytoplankton was generally decreased with the increasing of water depth, and gradually decreased from coast to offshore. The Shannon-Wiener diversity was high in the southwest survey area, and the Pielou's evenness index was high in the eastern survey area. According to canonical correspondence analysis (CCA), the main factors that influence the abundance distribution of dominant species are nutrients, and the correlation with salinity and temperature is not obvious.

Using the production of two coupled model from CCCma, and based on the information theory,the predictability of the Madden-Julian Oscillation including the actual forecast skill and potential predictability and the most predictable compnents of ISV were evaluated.The influence of different average time scale was also discussed. It is found that MJO has skillful forecast up to the lead time around ten days in these two coupled models, similar to the current forecast models.MJO can be forecasted potentially at more than one month of lead time. The actual forecast skill and potential predictability of MJO can be further developed as the averaging time scale increased from daily to ten days, especially the potential predictability increased more significantly. Further analysis found that the MJO signal strength of initial condition is the main factor to influence the forecast skill, if the MJO signal is strong, it has the best skill, vice versa. At last,the most predictable distributions of ISV were analyzed and the methods using such distributions to improve the actual forecast skill of ISV were discussed.

The skills of seasonal forecast of East-Asian precipitation, especially for summer seasons were studied. In the perfect model scenario, the potential predictability of East-Asian precipitation in seasonal time scale using signal-to-noise ratio and information-based indices were commented. The most predictable components and corresponding spatial patterns were also derived by PrCA analysis. The results show that the relationship of forecasts and observations displayed by correlation coefficient is characteristic of higher level in ocean region at low latitudes than in land region at high latitudes. While root mean square error skill shows that forecast diverging degree from observations in ocean region is much more than that in land region. Both agree with the current level for forecast. By estimating potential predictability, it shows that the potential predictability exists a spatial variation and it decays from low to high latitude and from ocean to land region. Further analysis of signal and noise components reveals the important role of marine forcing. The skill of seasonal rainfall is quite limited for lacking of apparent marine forcing in the mainland. By projecting the time series of the leading two modes onto the SSTA field, it shows that the forcing of ocean is the main source of potential predictability of East-Asian precipitation prediction in seasonal time scale. Despite the complexity of ENSO, it is clear that it has great influence on East-Asian monsoon, and the teleconnection between East-Asian precipitation prediction and ENSO may reveal the internal relations of them.

A detailed spatial structure of the tidal residual currents (TRCs) in the coastal area off Zhejiang and Fujian Provinces in the East China Sea was simulated by an unstructured grid-volume, three-dimensional, primitive equations ocean model (FVCOM). The simulated TRCs have apparent horizontal 2-D characters. The TRCs were further divided into three regions from north to south according to their velocity and direction, i.e., Region I, Region II and Region III. The TRCs in Region I and Region III are stronger but in opposite direction, flowing along isobaths in the southwestward with a velocity of 0.6~2.5 cm/s and northeastward directions with a velocity of 0.5~1.5 cm/s, respectively. The TRCs in Region II are weaker (less than 0.6 cm/s), and their directions are unticlockwise with the distance away from the coast. The analysis shows that the TRCs are directly proportional to the topographic beta factor dd x1H, this is consistent with the previous studies, and indicates the rectification of tidal currents when they flow over the steep bottom topography.

Using 15 year's TRMM-measured precipitation data, the diurnal variations of non-typhoon and typhoon precipitation in Northwest Pacific were studied. The diurnal signal of non-typhoon precipitation reaches its maximum at 06∶00, with a smaller maximum occurring around 15∶00. The typhoon precipitation within 500 km radius from the typhoon center shows a clear diurnal signal, and reaches its maximum around 03∶00~09∶00, and both of its mean and diurnal variation are larger than those of non-typhoon precipitation. Meanwhile, both the numbers of typhoon intensification and rapid intensification during 03∶00~08∶00 are bigger than other periods. From the satellite images of typhoon ‘HaiShen’, the area of extreme convection cloud is much larger in 06∶00 than in 18∶00, which is consistent with the diurnal variation pattern of precipitation.