Coastal sea level variability in the Bohai Bay: influence of atmospheric forcing and prediction

The sea level variabilities, especially the atmosphere-driven sea level variabilities, which are diff erent in studies on diverse areas and timescales, need to be further documented in the Bohai Bay. Coastal sea level data and coincident meteorological data collected hourly at two observation stations (E1 and E2) in the Bohai Bay, which is a typical semi-enclosed coastal sea in China, are analyzed for the period from 19 August 2014 to 18 November 2014. The sub-sampled low-pass (<0.8 cpd) sea levels (SLSLs) at E1 and E2 are almost the same as each other, while the winds are not. On the whole, SLSLs at E1 and E2 are dominantly influenced by the across-shore wind;in detail, the dominant wind orientation at E1 is 65° measured clockwise from north, and SLSL at E2 is significantly influenced by the sub-sampled wind (SW) at 55°. Regression of SLSL onto the corresponding SW in dominant orientation and the atmospheric pressure is used to predict SLSL, which make the frequency of occurrences when the predicted total sea level is within 0.15 m from the observed values increase to 66.03% and 58.08% at E1 and E2 from original 36.71% and 34.80% without using it, respectively. The results indicate that for the prediction of the total sea level variability in the coastal shallow waters, the SLSL influenced by the atmospheric forcing, including local wind and atmospheric pressure, can be predicted using the multivariable linear regression model.

Impacts of Sea Level Rise on the Coastal Areas to the West of the Bohai Bay

Based on the assumption of global sea level rising between 30 and 100 cm in the future 100 years by IPCC (1990) in addition to the effect of local ground subsidence, the coastline will retrograde for 50-70 km whose altitudes will be 2.6-3 .3m above MSL of Huanghai Sea in the western coastal area of the Bohai bay in 2100. The transgrassive area is about 10,000-11 ,500 km. If the effect of set-up of storm surge is considered, the transgressive area will reach 16,000 km. Sea level rise which is a serious coastal disaster not only inundates a lot of coastal lowland, but also increases the frequency and intensity of storm tides, and results in the salinization of soils. In vies of this situation we recommend a trinity comprehensive measure of treatment, namely, "building seawall to prevent tides-diverting the Hunaghe River to settle its sediment loads -raising the constructional base".

Impact of tropical cyclone Matmo on mixed zone of the Yellow and Bohai Seas

The Bohai Sea is a low-lying semi-enclosed sea area that is linked to the Yellow Sea via the Bohai straits(mixed zone). Its of fshore seabed is shallow, which makes it vulnerable to serious marine meteorological disasters associated with the northward passage of Pacific tropical cyclones. Analyses on data of remote sensing and buoy of the mixed zone of the Yellow and Bohai seas indicate that all the wind speed, significant wave height, and salinity(SAL) increased, sea surface temperature decreased, and wind energy density changed considerably during the passage of tropical cyclone Matmo on July 25, 2014. It was found that the SAL inversion layer in the mixed zone of the Yellow and Bohai Seas was caused by the tropical cyclone. Furthermore, it was found that the tropical cyclone transported the northern Yellow Sea cold water mass(NYSCWM) into the mixed zone of the Yellow and Bohai Seas. The NYSCWM has direct influence on both the aquaculture and the ecological environment of the region. Therefore, further research is needed to establish the mechanism behind the formation of the SAL inversion layer in the mixed zone, and to determine the influence of tropical cyclones on the NYSCWM.

Diversity and distribution of bacterial community in the coastal sediments of Bohai Bay,China

In order to understand the diversity and distribution of the bacterial community in the coastal sediment of the Bohai Bay, China, high-throughput barcoded pyrosequencing of the 16S rRNA gene was used. Metagenomic DNA was extracted from the sediment samples, and was sequenced using a 454 GS FLX Titanium system. At 97% similarity, the sequences were assigned to 22 884 operational taxonomic units （OTUs） which belonged to 41 phyla, 84 classes, 268 genera and 789 species. At the different taxonomic levels, both the dominants and their distribution varied significantly among the six coastal sediments. Proteobacteria was the first dominant phylum across all the six coastal sediments, representing 57.52%, 60.66%, 45.10%, 60.92%, 56.63% and 56.59%, respectively. Bacteroidetes was the second dominant phylum at Stas S1, S2 and S4, while Chloroflexi was the second dominant phylum at Stas S3, S5 and S6. At class level, γ-Proteobacteria was the first dominant class at Stas S1,S2, S4 andS6, while δ-Proteobacteria became the first dominant class at Stas S3 and S5. In addition, a large proportion of unclassified representatives have distributed at the different taxonomic levels. Canonical correspondence analysis （CCA） results indicated that the sediment texture, water depth （D）, dissolved oxygen （DO）, total nitrogen （TN） and nine EPA priority control polycyclic aromatic hydrocarbons （PAHs） including naphthalene, acenaphthylene, acenaphthene, fluorine, phenanthrene, fluoranthene, pyrene, benzo[a]anthracene and indeno[1,2,3-cd]pyrene were the important factors in regulating the bacterial community composition. Those results are very important to further understand the roles of bacterial community in the coastal biogeochemical cycles.

A Preliminary Study on Geological and Seismogenic Structures in the Region of 1969 M 7.4 Bohai Sea Earthquake

A more detailed and deep-going analysis of tectonic conditions for the 1989 Bohai Sea M 7.4 earthquake area has been made based on the data of oil geological exploration and results of seismological researches. The obtained result fills the gap in seismotectonic research of Large Bohai Sea earthquake area of North China. The earthquake area is located in the eastern part of Cenozoic rifted basin of the Bohai Gulf, along the intersection zone between the NNE-trending Yingkou-Weifang fault zone and the NW-trending Beijing-Penglai fault zone. In the early-Tertiary fault-depression stage, three sets of faults, the NNE-, NW-, and W-E-trending faults, were developed in the upper crust in the area. They are listric and planar in the form, of normal fault character and mostly the major faults in faulted depressions. In the fault-depression stage since late Tertiary, the preexisting faults have undergone movement to different extent. Meanwhile, a new NE-trending Huanghekou (Yellow River Mouth)-Miaoxibei fault zone was developed. The focal faulting of the M 7.4 earthquake, striking to N45°E and dipping to SE, is nearly vertical, with dextral strike-slip nature, and buried down to depth of 15～34 km. The seismogenic fault for the large earthquake is not the Yingwei fault, but the newly generated Huanghekou-Miaoxibei fault.

Possible effect of climate changes on the coastal zone of the Yangtze River Delta

A coastal historical evolution of the Yangtze River Delta was discussed in this paper on the basis of the historical data of the coastal zone and an estimation was made for the future change of the coast The emphasis was put on the future climate change that will have influence on the sea wall, coastal navigation and freshwater resources in the Delta It was also pointed out that the global warming and precipitation increase in the Yangtze River Valley may exert more impact on the zone In addition, some measures describing how to adapt to the climate change and reduce its impact were put forward

Distribution and phenogenetic diversity of Synechococcus in the Bohai Sea, China

Synechococcus is one of the most abundant picocyanobacteria in marine ecosystem,and the absence of Prochlorococcus would make it indispensable as a primary producer in the Bohai Sea,North China.However,the abundance distribution and genetic diversity of Synechococcus in this region have rarely been reported.In this study,the distribution pattern of Synechococcus abundance was investigated during four cruises in April,June,August,and November from 2018 to 2019,moreover,its phenogenetic diversity was studied based on high-throughput sequencing of the cpe BA operon.The results demonstrate that phycoerythrin-containing Synechococcus was most abundant in August when temperature was high and oxygen saturation was low.During this period,Synechococcus pigment type(PT)2 was abundant in the Bohai Bay and Laizhou Bay under conditions of high nutrient concentration,temperature,and turbidity.In comparison,PT3,especially those clusters characterized with high or variable ratio of phycourobilin and phycoerythrobilin,was predominant in the Bohai Strait and Liaodong Bay under conditions of high salinity,pH,and oxygen saturation.Furthermore,co-occurrence correlations using network analysis revealed that Synechococcus PTs were related to 15.37%-43.48%of the prokaryotic genera.Synechococcus PT3c/PT3d and PT2 were the most important PTs in the network.The hierarchical clustering revealed that taxa co-occurred with Synechococcus PTs diff ered among samples.It could be attributed to the substance exchange and the environmental impact,which calls for more studies in the future.

The research of sea-land breeze (SLB) on the west coast of Bohai Bay based on field observation

Four automatic meteorological stations were set up in a line from beach to inland perpendicular to the west coast of Bohai Bay. Wind direction and velocity at altitudes of 2 m, 4 m and 12 m were surveyed with 10 minute intervals. On ＂Sea-Land Breeze＂ （SLB） days, the transition from sea breeze to land breeze was very evident in the study area. Direction of sea breeze was basically perpendicular to the coast and mainly from the ENE and E. Duration of sea breeze varied by the stations＇ distance to the coastline, and the near-coast wind velocity was larger than that of the inland and decreases as it reaches inland. There was increased development of SLB on sunny days than on overcast days. The term ＂Climatic Coastal Zone＂ can be defined for the area influenced by SLB, which reaches more than 74 km inland on a typical SLB day but less than 10 km on a non-typical SLB day.

DEVELOPING BOHAI SEA ZONE AND TIANJIN INTO A METROPOLITAN AREA IN THE EAST ASIAN & ASIA-PACIFIC ECONOMIC BELT

Compared with the stagnanteconomy of the rest world,Asian-Pa-cific economy has been experiencingthe hightest growth since the 1980s.Now,most researchers and officials,and even entrepreneurs believe

A Lagrangian mean theory on coastal sea circulation with inter-tidal transports Ⅱ. Numerical Experiments

The results of the new concept of coastal sea circulation are demonstrated by numerical simulations for the first time.The numerical experiments in three types of rectangular model seas illustrate the dependence of circulation on tidal phases due to the convectively nonlinear effect which is estimated by a newly defined drift dispersion index.Then,the present theory is applied in the Bohai Sea of China.At the Bohai Straits and the Huanghe River mouth area the circulation direction even reverses owing to different initial tidal phases which shows that the theory copes with nonlinearity well.The calculated M2 tide-induced residual circulation shows that a clockwise gyre exists in the center of an anticlockwise gyre in the central Bohai Sea due to the topographic features.In the Bohai Gulf the tide induced circulation shows a 3D structure with outflow at the surface and the inflow at the bottom which can partly explains the spread of the Huanghe River fresh water out of the Bohai Gulf and the inflow of the sediment from the Huanghe River.

Protist Interactions and Seasonal Dynamics in the Coast of Yantai, Northern Yellow Sea of China as Revealed by Metabarcoding

Facilitated by the high-throughput sequencing(HTS)technique,the importance of protists to aquatic systems has been widely acknowledged in the last decade.However,information of protistan biotic interactions and seasonal dynamics is much less known in the coast ecosystem with intensive anthropic disturbance.In this study,year-round changes of protist community composition and diversity in the coastal water of Yantai,a city along the northern Yellow Sea in China,were investigated using HTS for the V4 region of 18S rDNA.The interactions among protist groups were also analyzed using the co-occurrence network.Data analyses showed that Alveolata,Chlorophyta,and Stramenopiles are the most dominant phytoplanktonic protists in the investigated coastal area.The community composition displayed strong seasonal variation.The abundant families Dino-Group-I-Clade-1 and Ulotrichales_X had higher proportions in spring and summer,while Bathycoccaceae exhibited higher ratios in autumn and winter.Alpha diversities(Shannon and Simpson)were the highest in autumn and the lowest in spring(ANOVA test,P<0.05).Nutrients(SiO42−,PO43−),total organic carbon(TOC),and pH seemed to drive the variation of alpha diversity,while temperature,PO43−and TON were the most significant factors influencing the whole protist community.Co-variance network analyses reveal frequent co-occurrence events among ciliates,chlorophytes and dinoflagellate,suggesting biotic interactions have been induced by predation,parasitism and mixotrophy.

The ecological cost of land reclamation and its enlightenment to coast sustainable development in the northwestern Bohai Bay,China

Land has been widely reclaimed in large area in coastal zones all over the world to relieve the pressure of land shortage,promoting social development and economic growth.Asia has become a focus of land reclamation with the rapid industrialization and urbanization.From the Binhai New Area of Tianjin to the Caofeidian New Area of Tangshan,the undergoing project of land reclamation on the northwest coast of Bohai Bay,China,is the largest in the world.To clarify the environmental issues and benefit sustainable development of the coastal zone,we conducted both retrospective and predictive assessments of the ecological cost caused by land reclamation on the northwest coast of Bohai Bay,China.We calculated the ecological costs of ten aspects of the four ecosystem services,i.e.,supply,regulation,support and culture,with the monetary estimate approach.The results indicate that the ecological cost of the new land reclamation is US$971.9 million from 2000 to 2010 and that the cost will be US$702.1 million from 2010 to 2020.The costs of gas regulation and marine food supply account for the greatest parts of the total value.Suggestions for land reclamation oriented to sustainable development in the study area are put forward,including a rational planning based on the comprehensive evaluation,reducing the amount of land reclamation area,optimizing the structure of the reclaimed land,reclaiming land with the concept of ＂low impact development＂ and implementing ecological compensation mechanisms,etc.

An Integrated Coastal Zone Management （ICZM） Project： CoastLearn in Black Sea （CLBS）

The importance attached to the need for sustainable development in the coastal areas is increasing. A management plan is required to minimize the environmental destruction resulting from the complexity of the property in coastal areas, of human activities and of natural systems and to utilize the coastal resources effectively. The utilization of coasts, besides becoming very important particularly in views of tourism, has faced pressures caused by huge. These areas are mostly self-contradictory demands for the environmental protection. The project is an EU Life Long Learning Programme Project and the project duration is 24 months. The aim of the CoastLearn in Black Sea （CLBS） is to mobilize the human resources in the tourism and coastal management sector in Black Sea in general and notably Sinop, Varna and Constanta by raising awareness among the local decision making mechanisms of the integrated coastal zone management in order to encourage people to utilize the coastal resources in a coherent and balanced way.

Dynamic of ENSO towards upwelling and thermal front zone in the east coast of Peninsular Malaysia

The El Ni?o Southern Oscillation(ENSO) is a natural phenomenon that relates to the fluctuation of temperatures over the Pacific Ocean. The ENSO significantly affects the ocean dynamics including upwelling event and coastal front. A recent study discovered the seasonal upwelling in the east coast of Peninsular Malaysia(ECPM), which is significant to the fishery industry in this region. Thus, it is vital to have a better understanding of the influence of ENSO towards the coastal upwelling and thermal front in the ECPM. The sea surface temperature(SST) data achieved from moderate resolution imaging spectroradiometer(MODIS) aboard Aqua satellite are used in this study to observe the SST changes from 2005 to 2015. However, due to cloud cover issue, a reconstruction of data set is applied to MODIS data using the data interpolating empirical orthogonal function(DINEOF) to fill in the missing gap in the dataset based on spatial and temporal available data. Besides, a wavelet transformation analysis is done to determine the temperature fluctuation throughout the time series. The DINEOF results show the coastal upwelling in the ECPM develops in July and reaches its peak in August with a clear cold water patch off the coast. There is also a significant change of SST distribution during the El Ni?o years which weaken the coastal upwelling event along the ECPM. The wavelet transformation analysis shows the highest temperature fluctuation is in 2009–2010 which indicates the strongest El Ni?o throughout the time period. It is suggested that the El Ni?o is favourable for the stratification in water column thus it is weakening the upwelling and thermal frontal zone formation in ECPM waters.

Observed characteristics of the North Yellow Sea water masses in summer

In this paper, we characterize the North Yellow Sea （NYS） water masses in summer by analyzing temperature and salinity data surveyed in 2006. The Liaonan Coastal Water is characterized by low salinity westward and southward flow paths. The westward path flows parallel to land, turns to the south, then to the southeast adjacent to the mouth of the Lushun River, where it mixes with other coastal water directly to the southwest. It becomes the main source of low salinity water in the deep water area west of 123°E. The high-salinity Lubei Coastal Water is the remnant of the winter Lubei Coastal Water, which is located mostly in a small area between Yantai and Weihai, and does not originate in the Bohai Sea Coastal Water. The two NYS zones demarcated at 123°E have distinctly different temperature and salinity characteristics. There are two high-salinity centers east of 123°E, whereas there is low-salinity water to the west whose temperature and salinity structures are complex, composed of the coastal water south of Chengshantou, the Liaonan Coastal Water and the Bohai Sea Water.

Analysis of the Mamaia Bay shoreline Retreat with Hard and Soft Protection Works

Integrated Coastal Zone Management is a complex concept that involves various economic, social and environmental factors. There are often conflicting approaches to these factors. Furthermore, when it is decided to implement structural works in the coastal area, it must be taken into account the particularity of the area, the way in which it is developed and the type of work to be done. The Gulf of Mamaia in the Romanian Black Sea coast is the target of structural changes through the implementation of an extensive coastal rehabilitation program. The works made are of “hard” type and aim to change the shore line configuration. From this perspective, the target of the present paper is to make an analysis between the type of work that is being carried out and another kind of "soft" work aiming especially to favor the ecological reconstruction of the area and the approach of an environmentally friendly concept. Thus, we propose to analyze the two types of works with a view to apply the Bruun rule in order to mitigate the effect of the increase of the sea level and to prevent the shoreline retreat.

破解海岸带环境司法困境:基于陆海统筹原则

我国海岸带环境案件存在管辖权冲突、法律适用有争议、原告资格不明确、诉讼性质认定有争鸣、诉讼程序衔接未确定、司法执行机制不完善等环环相扣的问题,造成海岸带环境司法困境。究其根源,主要在于陆海“二分法”的分类思维影响较大,其与陆海统筹合为表里的内涵尚未得到全面、深入的理解。为破解海岸带环境司法困境,既要重视海岸带环境案件的特殊性,将其确立为类型化案件并由海事法院专门管辖,又要贯彻陆海统筹原则,实现司法规则内在融贯、法治环节协调一致。

海-陆交互作用与海岸带碳中和农业驱动

海岸带既是生态脆弱区也是低碳农业发展“前哨”。推动和发展碳中和农业符合时代所需,也符合绿色、可持续发展理念。基于此,本文阐述了在海岸带区域发展碳中和农业的相关问题和重要性。首先,本文阐释了海陆交互作用以及海岸带碳中和农业发展理念;然后,分析了海岸带碳中和农业驱动中的碳中和农业生物、人工光合作用与农业驱动以及该理念的工程化应用问题;最后,深入剖析了如何识别海岸带农业核心碳汇,包括原位监测、同位素标记与统计学分析方法,并在此基础上提出了农业碳汇增强技术,为后续海岸带碳中和农业的构建、发展和实践提供参考,同时对促进脆弱的海岸带生态系统的保护和绿色低碳农业的发展具有重要意义。

渤海和黄海北部工程设计冰厚变化趋势分析

针对渤海和黄海北部沿岸风电、光伏和核电等新兴能源中的工程海冰设计问题,本文研究了重现期冰厚及其在大气候背景下的变化趋势。本文分析72 a冰级时间序列表明渤海和黄海北部总体冰情等级呈明显下降趋势;在此影响下,基于20 a渤海和黄海北部海冰多源观测数据和精细化海冰数值预报资料,研究发现不同重现期冰厚较之前海冰区划值存在不同程度的降低。此外,不同场址设计冰厚受当地海洋环境条件影响较大,单一参考海冰区划值可能存在较大误差。研究表明:针对特定作业地点的工程设计冰厚,需要有针对性地开展精细化评估并考虑大气候背景变化的影响,才能为相关工程海冰参数设计提供更加可靠的依据。

Structural deformation and fault activity of the Tan-Lu Fault zone in the Bohai Sea since the late Pleistocene

The Tan-Lu Fault zone (TLFZ) is a significant fractural zone in eastern China and also a seismicity belt in North China. Based on total 4000-km-long shallow penetrated single seismic data with high-resolution, structural deformation and fault activity of the TLFZ in the Bohai Sea since the late Pleistocene are discussed in detail. The results show that the TLFZ with a discontinuous distribution and a general NNE-trending consists of 14 active subfaults with an NNE or NE strike in the Bohai Sea. Seismic data reveal that deformation zones along the subfaults in the central Bohai Sea and the Laizhou Bay are wider and more complex than those in the Liaodong Gulf. Related folds and lots of secondary normal faults which are characterized by nearly vertical fault planes and a same or reverse dip construct the fractural zone in the Laizhou Bay and the central Bohai Sea. Usually, micro sym-metrical grabens develop on the top of anticlines. In the Liaodong Gulf, subfault fractural zones usually consist of secondary normal faults with the same inclination or opposite inclination. Ages of seismic sequences and cutting relation between subfaults and seismic sequences suggest that the latest faulting age of the TLFZ is the end of the late Pleistocene in the Liaodong Gulf and the early Holocene in the Laizhou Bay and the central Bohai Sea. There is a good match between distribution of earthquakes and that of the subfaults in the Laizhou Bay and the central Bohai. Statistical result shows that total vertical offset of the TLFZ since the late Pleistocene ranges from 6 to 11 m. On the basis of offsets of the subfaults, the vertical slip rate is calculated and results show that average vertical slip rates in the central Bohai Sea are larger than those in the Liaodong Gulf and the Laizhou Bay. Slip rates more than 0.06 mm/a during 23-10 ka B.P. and 85-65 ka B.P. are larger than those in other stages. The TLFZ was mainly dominated by tensional normal component since the late Pleistocene. Synthesizing shallow deformation, activity and distribution of earthquakes, the TLFZ in the Bohai Sea can be divided into three segments: the Laizhou-Bay segment, the Bozhong segment, and the Liaodong-Gulf segment.