A study of impact of the reclamation and artificial island projects on tidal currents and sediment concentration in radial sand ridge field of the South Yellow Sea

The two-dimensional hydrodynamic model, MIKE21, is applied to simulate the tidal currents and sediment concentration in the radial sand ridges of the South Yellow Sea. Results are in accordance with in situ observations. Then the variations of tidal currents and suspended sediment concentration caused by reclamation and artificial islands projects are simulated. The results show that the impacts are limited around the project areas. After the projects, the fan-shaped, Jianggang centered tidal current pattern would be replaced by a pattern which is formed by two tidal paths. One locates at the Xiyang channel in north-south direction, and the other locates at the Huangshayang channel in east-west direction. The reclamation of Tiaozini separates the waters into south portion and north portion. The changes of sediment concentrations coincide with those of currents. Both the sediment concentrations and tidal currents increase at the northwest of Dongsha and the south of Gaoni, while both decrease at the north and south of Tiaozini, and the east and southwest of Dongsha.

Impact of the Sanya new airport artificial islands project on tidal dynamics of the Hongtang Bay

By establishing a 3-dimensional hydrodynamic model of the Hongtang Bay and the validation tests,tidal currents of the area before and after the construction of the Sanya new airport project,which include two artificial islands built respectively to accommodate the airport and its connected technology park,are simulated.The hydrodynamic impacts of the islands on the Hongtang Bay and surrounding waters were analyzed by comparing flow fields and velocities of tidal currents under the two conditions.

Spatio-temporal variation of subtidal macrobenthic fauna and the ecological assessment of Longkou Artificial Island construction in Bohai Sea, China

To evaluate the status and changes of macrobenthic communities related to the construction of the Longkou Artificial Island(LAI)in the Bohai Sea,China,four annual surveys were conducted from 2010 to 2013.Significant changes on environmental variations and macrobenthic communities were observed in 2013 after the LAI construction a couple of years later.The changing environment was primarily presented by lower values of pH,dissolved oxygen(DO),organic material(OM)percentage,and higher salinity,suspended particulate matter(SPM)concentration and oil concentration.The main dominant species shifted from Polychaeta taxa in 2010 to Mollusca taxa in 2013 due to the changes of environmental variables.An apparent miniaturization tendency in body size of macrobenthic species was presented from 2010 to 2013.The biodiversity indices increased yearly from 2010 to 2013.However,inter-site homogenization was observed in both the community structure and health status.Multivariate AZTI Marine Biotic Index(M-AMBI)analysis showed that the health status of stations changed depending on its original status and distance to the LAI.However,no significant differences were found in the spatial distribution of either environmental variables or abundance,biomass and biodiversity of macrobenthic communities.All the results will provide a basis for the long-term ecological assessment of reclamation.

Significance of Artificial Island in Overcoming the Scarcity of Land due to Global Warming and Sea-Level Rise

Abstract： This paper highlights the idea of constructing a building or group of buildings partially in the water. It attempts to describe the futuristic proposal of constructing on water due to scarcity of land and decreasing of lands due to global warming issues and the resulted sea level rise, also the consequences of making artificial （man-made） islands that are in direct connection to Bahrain Island. This report briefly examines the theoretical roots of the proposal including basic criteria and architectural aspects of structure within water body that could satisfy the human needs.

Effects of offshore artificial islands on beach stability of sandy shores:case study of Hongtang Bay,Hainan Province

Artificial island-type reclamation often exerts certain impacts on near-shore sandy shoreline resources and coastal ecological landscapes.The relationship between artificial islands and offshore beach evolution has attracted considerable attention in coastal protection and engineering construction.In this study,we consider Hongtang Bay in Hainan Province,China,as the research object.We adopted the Gao-Collins model to investigate the substrate transport trend in this sea area based on the analysis of the measured hydrologic and sediment data.The shore section from Nanshanjiao to Hongtangling(Taling),including the flat and straight shore sections,is dominated by the lateral transport trend of the vertical shore.The near-shore water has a strong lateral sediment transport capacity,while the outer deep-water area exhibits a sediment transport trend consistent with the tidal current movement.Using multi-year topographic data,the shoreline and seabed alterations in Hongtang Bay were analyzed,and the LITLINE beach evolution model was adopted to simulate the effects of three artificial island layouts with different island filling areas,offshore distances,and plan forms on the near-shore shoreline deformation.The results obtained indicate that the artificial island arrangement with a large offshore distance and a small area has relatively substantial advantages,such as minimizing the adverse effects of artificial island implementation on the near-shore beach.

Potential morphological responses of an artificial beach to a flood in extreme events: field observation and numerical modelling

Conch Island is a typical artificial island at the Tanghe Estuary in Bohai Sea,China.To improve natural environment and boost local tourism,beach nourishment will be applied to its north-western shore.The projected beach is landward and opposite to the Jinmeng Bay Beach.Nowadays,with climate changes,frequent heavy rainfalls in Hebei Province rise flood hazards at the Tanghe Estuary.Under this circumstance,potential influences on the projected beach of a flood are investigated for sustainable managements.A multi-coupled model is established and based on the data from field observations,where wave model,flow model and multifraction sediment transport model are included.In addition,the impacts on the projected beach of different components in extreme events are discussed,including the spring tides,storm winds,storm waves,and sediment inputs.The numerical results indicate the following result.(1)Artificial islands protect the coasts from erosion by obstructing landward waves,but rise the deposition risks along the target shore.(2)Flood brings massive sediment inputs and leads to scours at the estuary,but the currents with high sediment concentration contribute to the accretions along the target shore.(3)The projected beach mitigates flood actions and reduces the maximum mean sediment concentration along the target shore by 20%.(4)The storm winds restrict the flood and decrease the maximum mean sediment concentration by 21%.With the combined actions of storm winds and waves,the maximum value further declines by 38%.(5)A quadratic polynomial relationship between the deposition depths and the maximum sediment inputs with flood is established for estimations on the potential morphological changes after the flood process in extreme events.For the uncertainty of estuarine floods,continuous monitoring on local hydrodynamic variations and sediment characteristics at Tanghe Estuary is necessary.

Drivability of Large Diameter Steel Cylinders During Hammer-Group Vibratory Installation for the Hong Kong–Zhuhai–Macao Bridge

The Hong Kong–Zhuhai–Macao Bridge(HZMB)involved the installation of 120 mega-cylinders with a diameter of 22 m,weights up to 513 t,and penetration depths up to 33 m using an eight-vibratory hammer group.Due to the lack of engineering experience on the drivability of large-diameter cylinders under multiple vibratory hammers,predicting the penetration rate and time of steel cylinders is an open challenge that has a considerable impact on the construction control of the HZMB.In this study,the vibratory penetration of large-diameter steel cylinders in the HZMB is investigated based on geological surveys,field monitoring,and drivability analysis.The vibratory penetration rate,installation accuracy,and dynamic responses of the steel cylinders at both the eastern and western artificial islands are analyzed.The dynamic soil resistance has a great influence on the cylinder drivability.However,the current design methods for estimating the vibratory driving soil resistance are proven inaccurate without considering the scale effects.Therefore,a modified method with a normalized effective area ratio A_(r,eff)is proposed in this study to calculate the vibratory soil resistance for open-ended thin-wall cylinders under unplugged conditions.Considering the scale effects on the vibratory driving soil resistance,the proposed method leads to closer results to the measured data,providing a reference for future engineering practice.

NUMERICAL SIMULATION AND EXPERIMENTAL STUDY OF THE FLOW FIELD AROUND A CIRCULAR CYLINDRICAL ARTIFICIAL ISLAND UNDER THE ACTION OF WAVES AND VISCOUS CURRENT

Experimental study and theoretical research were described in the paper on the characteristics of the flow field around a vertical circular cylindrical artificial island under the . action of waves and viscous current. Flow field and hydrodynamic coefficientS of an artificial island under the action of waves and viscous current were computed and compared with those for the cases of pure viscous current and pure incident waves and those of measured resultS with good agreement.

Climate Refugee and Disappearing States： In Need for a New Legal Regime？

Climate change brings unprecedented challenges to both the international community as well as international law. For example, extreme weather conditions might cause States to disappear and force its populations to migrate. These phenomenon creates new challenges for current international law. First, under current legal frameworks, there is no provision regarding the disappearance of a State due to climate change. Second, for people who are forced to migrate due to climate change whether caused internally or internationally, current legal framework is also unclear to whether they could be classified as refugees and to what extent should they be protected. Despite these uncertainties, people of these endangered States cannot be left to fend themselves simply because there is a legal vacuum. This paper proposes a way forward for to meet this challenge and urge the international community to use this opportunity to refine the currently existing legal regime in order to solve the various challenges posed by climate change.