Island Building Research Articles

Island Building Alters Waters Leagues Away and for Years After

Quantifying the impacts of dredging through satellite remote sensing could serve as a valuable resource in future geopolitical disputes over contested waters.

Experimental and Theoretical Study on the Heat Transfer Coefficients of Building External Surfaces in the Tropical Island Region

China is actively promoting ocean territory construction, and how to design low-energy buildings to fit the unique climate of tropical island regions has received much attention. The heat transfer coefficient of a building external surface plays a vital role in calculating air-conditioning load accurately. To obtain reasonable heat transfer coefficients in the tropical island region, this study introduced a naphthalene sublimation experiment to conduct full-scale measurements on convective heat transfer coefficients (CHTCs) in the tropical island region, and proposed a simplified calculation model of evaporative heat transfer coefficients (EHTCs). Results indicated that the function expression between CHTC and wind speed was CHTC = 5.56 + 4.48u (R2 = 0.94), and it was validated to be reliable. Furthermore, compared with CHTCs and radiation heat transfer coefficients (RHTCs), the EHTC had a wider changing range, owing to rainfall effects. Moreover, whether evaporation was considered or not, the difference of total heat transfer coefficients (THTCs) on building external surfaces was 5.2 W/(m2·K) for the whole year, so evaporation cannot be ignored directly. Additionally, THTCs with consideration of evaporation in winter and summer were 33.4 W/(m2·K) and 38.9 W/(m2·K) severally, which are much larger than the recommended values in the Chinese standard. This study would make up for the lack of surface heat transfer coefficients in energy conservation design of tropical island buildings.

Spatial and temporal changes in species composition of submersed aquatic vegetation reveal effects of river restoration

We examined temporal changes in spatial patterns of submersed aquatic vegetation (SAV) in response to the restoration of geomorphic habitat in Navigation Pool 8 of the Upper Mississippi River from 1998 to 2016. The frequency of occurrence and species composition of SAV at sampling sites were spatially interpolated for each year to create annual maps. Linear models were fitted to temporal changes in SAV within each map pixel. The frequency of occurrence of SAV (across all species) increased over time in much of the impounded region of the pool, including areas near restored islands. However, impounded areas maintained a relatively consistent species composition over time, with species known to be tolerant of higher flow velocities (>0.10 m/second) and wind fetch distances (>1,000 m) (e.g. Vallisneria americana) being most abundant. In contrast, areas protected by newly constructed islands transitioned from V. americana to species found in other protected backwater habitats and known to be intolerant of high flow velocities and wind fetch distances (e.g. Ceratophyllum demersum). The results suggest that previously reported improvements in water clarity may have improved growing conditions for all SAV species, especially in the lower impounded portion of the pool, while island restoration created more backwater‐like habitats and facilitated changes in species composition. Assessing changes in SAV occurrence alone offers only a partial view of local‐scale river restoration (e.g. island building), while analyses of species composition are likely to be more indicative of the types of changes (i.e. reduced flow velocity and wind fetch) associated with restoring geomorphic habitat.

Interpreting the law of the sea ‘regime of islands’: An opportunity for productive US leadership

This commentary describes an opportunity for clarification of the United Nations Convention on the Law of the Sea (UNCLOS) ‘regime of islands.’ It describes the growing need to authoritatively distinguish between islands, rocks, and artificial islands for the purpose of stabilizing claims to maritime territory. Sea level rise and island building activities in the South China Sea and elsewhere are increasing the pace at which new islands appear and existing islands disappear. This commentary proposes a two-part interpretation of UNCLOS, which (1) freezes the status of islands and rocks, and (2) asserts a practical distinction between ‘islands’ and ‘artificial islands.’ The United States is identified as a possible actor to forward this interpretation, and the benefits for that country and the international community as a whole are reviewed.

Coral Reef Island Initiation and Development Under Higher Than Present Sea Levels

AbstractCoral reef islands are considered to be among the most vulnerable environments to future sea level rise. However, emerging data suggest that different island types, in contrasting locations, have formed under different conditions in relation to past sea level. Uniform assumptions about reef island futures under sea level rise may thus be inappropriate. Using chronostratigraphic analysis from atoll rim islands (sand‐ and gravel‐based) in the southern Maldives, we show that while island building initiated at different times around the atoll (~2,800 and ~4,200 calibrated years before present at windward and leeward rim sites, respectively), higher than present sea levels and associated high‐energy wave events were actually critical to island initiation. Findings thus suggest that projected sea level rise and increases in the magnitude of distal high‐energy wave events could reactivate this process regime, which, if there is an appropriate sediment supply, may facilitate further vertical reef island building.

Morphodynamic simulation of sediment deposition patterns on a recently stripped bedrock anastomosed channel

Abstract. Some mixed bedrock-alluvial dryland rivers are known to undergo cycles of alluvial building during low flow periods, punctuated by stripping events during rare high magnitude flows. We focus on the Olifants River, Kruger National Park, South Africa, and present 2-D morphodynamic simulations of hydraulics and sediment deposition patterns over an exposed bedrock anastomosed pavement. We examine the assumptions underlying a previous conceptual model, namely that sedimentation occurs preferentially on bedrock highs. Our modelling results and local field observations in fact show that sediment thicknesses are greater over bedrock lows, suggesting these are the key loci for deposition, barform initiation and island building. During peak flows, velocities in the topographic lows tend to be lower than in intermediate topographic areas. It is likely that intermediate topographic areas supply sediment to the topographic lows at this flow stage, which is then deposited in the lows on the falling limb of the hydrograph as velocities reduce. Subsequent vegetation establishment on deposits in the topographic lows is likely to play a key role in additional sedimentation and vegetation succession, both through increasing the cohesive strength of alluvial units and by capturing new sediments and propagules.

The Interpretation and Inheritance of Green Local Building Material System in Modern Architecture - Case Study of Century Fishing Village Eelgrass Cottage Resort in Dayu Island, Shidao Bay, Jiaodong Peninsula

Dayu island sea cottage is the most typical carrier of the fish culture in the coastal area of Jiaodong. In recent years, economic development, changes in fishermen's living habits led to a the dismantling of a large number of traditional sea cottages and gradual disappearing of unique Dayu island building materials system comprising of eelgrass roof, local granite stone wall and soil kang chimney. In order to protect the local cultural characteristics so they can be passed down, the paper sorted out the original traditional eelgrass cottage building material system. The project of Century Fishing Village Eelgrass Cottage Resort represents experimentation and innovation on the original material system, forming a novel construction material system. Such a system not only satisfies the requirement of new buildings on thermal insulation, energy and space conservation, but also enhances safety and resistance to wind, erosion. The wide adoption of the new material system in new buildings enhances the technique of integrating traditional construction materials and modern architecture in both form and function, making it an ideal design strategy.

Experimental and Numerical Studies on Sloshing Dynamics of PCS Water Tank of Nuclear Island Building

Water tank is one important component of passive containment cooling system (PCS) of nuclear island building. The sloshing frequency of water is much less than structure frequency and large-amplitude sloshing occurs easily when subjected to seismic loadings. Therefore, the sloshing dynamics and fluid-structure interaction (FSI) effect of water tank should be considered when the dynamic response of nuclear island building is analyzed. A 1/16 scaled model was designed and the shaking table test was done, in which the hydrodynamic pressure time histories and attenuation data of wave height were recorded. Then the sloshing frequencies and 1st sloshing damping ratio were recognized. Moreover, modal analysis and time history analysis of numerical model were done by ADINA software. By comparing the sloshing frequencies and hydrodynamic pressures, it is proved that the test method is reasonable and the formulation of potential-based fluid elements (PBFE) can be used to simulate FSI effect of nuclear island building.

Calculation of aircraft impact load on the NPP nuclear island buildings

The IAEA safety requirements require that the design of nuclear power plants (NPPs) considers both the potential technological disaster and acts of nature. One of the applicable mandatory IAEA SRS 87 requirements is assessing the risk of heavy commercial aircraft crashing into or attacking nuclear power plant reinforced concrete structures. The standards determine the distribution of loads on the building structures as a result of the impact of such aircrafts as the Boeing 720 and the Boeing 707-320. In the simplest case, when an aircraft strikes a plane low-deformable target normally, the structural load can be considered directly as a distributed force mapped on the target face. However, when an aircraft strikes at a tangent to the surface of the structure or when the load is imposed on the surface of complex-geometry structures or the possibility of successive target penetration needs to be considered, this loading method is useless. This paper suggests a universal methodology for modeling the loads imposed on building structures as a result of an aircraft impact. Aircraft modeling is based on the Eulerian formulation of the finite element method (FEM). The obtained relations can be used to identify the geometry, structural and mass parameters of the finite element aircraft model for a given load and determined impact imprint. The comparison of specified pressure loads and impact loads on the reinforced concrete structure shows a close match of the results. The obtained mathematical model of a heavy commercial aircraft can be used for numerical simulation of an aircraft crash into NPP buildings and structures in accordance with the new IAEA requirements.

O mundo das miudezas

O projeto de lei complementar do Plano de Preservação do Conjunto Urbanístico de Brasília encontra-se em tramitação no âmbito do Poder Legislativo, do Distrito Federal, Brasil. Infelizmente, o projeto não considera históricos problemas da cidade: rupturas do tecido urbano; vazios sem justificativa funcional, bioclimática ou expressiva; questões de acessibilidade universal; má definição de espaços para a vida pública; uma das mais perversas estratificações socioespaciais do mundo. Décadas de crítica a configurações modernas, que não consideram o espaço ‘entre edifícios’ como alvo da atenção projetual, são ignoradas. Mais que em projetos do período clássico do urbanismo moderno (anos 1960), projetos recentes fazem proliferar espaços definidos por paredes cegas, ou edifícios-ilhas em esquemas introvertidos: atividades abrem para o interior dos prédios e esvaziam o âmbito público de transições entre fechado e aberto. As iniciativas do ‘homem comum’ de Certeau, sempre a reinventar a cidade mediante fascinantes ‘fissuras urbanas’ na ordem hegemônica, são ignoradas. Em vez de atacar problemas estruturais da cidade, o Plano perde-se em pormenorizar atributos das parcelas urbanas, no furor legislativo de quase duzentos artigos e uma miríade de anexos. O mundo das miudezas.

Research on FSI effect and simplified method of PCS water tank of nuclear island building under earthquake

Water tank is one of the most important components of passive containment cooling system (PCS) in advanced nuclear power plant. Moreover, the dynamic characteristics of shield building and auxiliary building might be changed because of fluid-structure interaction (FSI) of the PCS. Therefore, FSI between cooling water and the shield building should be considered in the dynamic analysis of the nuclear island building. To study the FSI effect and propose an effective and simplified method, three numerical models were established and analyzed under three-dimensional seismic loadings. Acceleration time histories of reference points in the shield building and auxiliary building were got and floor response spectra were calculated. The results show that FSI effect could not be regarded to decrease the seismic response simply but it should be considered in structure design and analysis. A simplified model is proposed in this study and proved to have a good agreement with the FSI model in the curves of floor response spectra. The conclusions could provide reference for further study in the field of nuclear island building.

Reef Island Evolution and Dynamics: Insights from the Indian and Pacific Oceans and Perspectives for the Spermonde Archipelago

Along southwestern Sulawesi, Indonesia, the Spermonde Archipelago comprises some 120 islands of variable size and degree of anthropogenic modification. Comparable to adjacent areas in Southeast Asia, the Spermonde Archipelago is characterized by the congregation of a naturally high marine biodiversity and, at the same time, a high population density influencing the surrounding environmental conditions. As a consequence, during the last decades, research projects that have been carried out in the Spermonde mainly focused on social, ecological, political and economic interactions. However, geological and geomorphological aspects of the coral reef islands are less well understood and there have been few studies undertaken since the pioneering work of Umbgrove, Kuenen and Verstappen in the Indonesian archipelago in the early to mid-20th century. Here we review the existing studies, with a focus on the Spermonde Archipelago, and reconcile them with more recent works on reef island evolution and dynamics from the Indian and Pacific Oceans. This synthesis shows that reef islands in the Spermonde Archipelago are well suited for geomorphological investigations, and provides perspectives for future reef island research in that area that will have global interest. We identify four research priorities: 1) To identify the timing and chronology of island formation; 2) Improved understanding of carbonate budgets and sediment generation that contribute to island building; 3) Document morphological changes in reef islands at seasonal to decadal timescales, and; 4) Quantify the process regime that drives sediment transport and island change with particular focus on the role of different monsoon seasons.

Seismic Response Analysis of Nuclear Island Buildings on Non-rock Foundation

A key technical problem of seismic response analysis of nuclear island buildings under the condition of non-rock foundation is the effective simulation of soil-structural interaction (SSI) and the nonlinear characteristics of soil. A seismic response analysis calculation model of nuclear island buildings on non-rock foundation is established on the basis of software platform of SuperFLUSH, which adopts equivalent linear method to describe the nonlinear dynamic characteristics of the near field ground, by setting viscous artificial boundary in the limited area of foundation to simulate the impact of radiation damping, and takes advantage of one-dimensional finite element method to make a response analysis of free field for the ground motion input. At last, by taking calculation model of CPR1000 nuclear reactor on the non-rock foundation as the object of study, the numerical examples verify the reliability and engineering application of the established model. Furthermore, the results of study can provide reference for seismic analysis of adaptability of inland nuclear power plant foundation and optimization design of foundation treatment scheme under the condition of non-rock foundation.

Dynamic Behavior of AP1000 Nuclear Island Building in Japanese Kobe 1995 Earthquake

Dynamic Behavior of AP1000 Nuclear Island Building in Japanese Kobe 1995 Earthquake

Effect of highly reflective roofing sheet on building thermal loads for a school in Osaka

Currently, urban heat island (UHI) phenomenon and building energy consumptions are becoming serious. Strategies to mitigate UHI and reduce building energy consumptions are implemented worldwide. In Japan, as an effective means of mitigating UHI and saving energy of buildings, highly reflective (HR) and green roofs are increasingly used. In order to evaluate the effect of roofs with high reflection and thermal insulation on the energy conservation of buildings, we investigated the roof solar reflectivity of the subject school in Osaka, in which the HR roofing sheet was installed on the roof from 2010. Thermal loads, including cooling and heating loads of the top floor of school, were calculated using the thermal load calculation software, New HASP/ACLD-β. Comparing the thermal loads after HR roofing sheet installation to previous, the annual thermal load decreased about 25 MJ/m 2 -year and the cooling load decreased about 112 MJ/m 2 -year. However, the heating load increased about 87 MJ/m 2 -year in winter. To minimize the annual thermal load, thermal insulation of the roof was also considered be used together with HR roofing sheet in this study. The results showed that the combination of HR roofing sheet and high thermal insulation is more effective to reduce the annual thermal load.

The South China Sea Award, Artificial Islands and Territory

Although artificial island building is a centuries-old practice, international law has remained relatively silent on the status of artificial islands. While much remains unsettled, two things are c...

Dynamic Response of AP1000 Nuclear Island Due to Safe Shutdown Earthquake Loading

AP1000 is a standard nuclear power plant developed by Westinghouse and its partners by using an advanced passive safety feature. Among the five principle building structures, namely the nuclear island, turbine building, annex building, diesel generator building and radwaste building, the safety of the nuclear island building is the most concerned. This paper investigates the dynamic response of the nuclear island building of the AP1000 plant subjected to safe shutdown earthquake loadings. A finite element model for the building, which is assumed to be built in a hard-rock base, is developed and its dynamic response is computed with the aid of the commercial finite element package ANSYS. The dynamic characteristics, including the natural frequencies, the vibration modes, and the time histories for displacements, velocities, and accelerations of the building are obtained for two typical safe shutdown earthquakes, El Centro and Kobe earthquakes. The dynamic behavior of the building due to the earthquakes and its safety is examined and highlighted.

Deciphering the Shift in America's South China Sea Policy

The tensions resulting from the territorial and maritime jurisdictional disputes between China and five Southeast Asian countries--Brunei, Indonesia, (1) Malaysia, the Philippines, and Vietnam--have for years dominated the headlines on the South China Sea and defined the lens through which the issue is seen. While the United States has at times expressed its concerns over incidents in which destabilizing actions occurred, these developments had minimal impact on the US grand strategy of preventing the rise of a potential hegemon in the Western Pacific. Prior to China's push to enlarge the features it occupies in the Spratly Islands, US officials largely viewed the sovereignty dispute as a matter to be resolved between China and the Association of Southeast Asian Nations (ASEAN), and were careful in framing the issue as a diplomatic rather than a military challenge. While Washington had always emphasized its commitment to, and the need for all sides to respect, freedom of navigation and overflight and the unimpeded flow of global commerce, it has never enunciated in unequivocal terms what the United States would do to uphold these principles. This position would change as a result of US assessments of the implications of China's artificial island building beginning in late 2013. The United States is not a party to the South China Sea dispute. Yet it is a party to a disagreement and contest with a rising China on the meaning of freedom of the seas--a principle that is central to US core interests--and what the regional security landscape of the Asia-Pacific ought to look like in future years. Understanding the crux of this contest is important for grasping the role that the South China Sea plays in US grand strategy, and factors that can lead to substantive changes in US policy on the issue, or lack thereof. This article begins by deciphering what the United States views as its core interests in the South China Sea that have the potential to either support or upend US grand strategy. It posits that the United States has two fundamental and enduring core interests in the South China Sea: defending its view on freedom of the seas, and maintaining the naval and air superiority of the United States in the Western Pacific. The article moves on to offer an overview of America's South China Sea policy in the context of the US rebalance to the Asia-Pacific region, and is based on the premise that US officials began to devote significantly more attention and resources to the issue as a result of greater US focus on regional issues, especially with regard to Southeast Asia. This section also sheds light on the evolving nature of the disagreement between Beijing and Washington in light of the US rebalance. It presents a context for understanding how China's artificial island building, if strategically deployed, can be a nexus between these two sets of disputes, with the of causing the fundamental disagreement between the United States and China to spill over into the South China Sea. The following section elaborates official US views on China's reclamation activities and its implications for US core interests and grand strategy in the Asia Pacific. It seeks to capture the shift in US strategy on the South China Sea. This article concludes that the United States has responded with a new, active strategy that aims to: first, deter China from taking further actions at its reclaimed features that would alter the existing military balance of power in the region; and second, make it pay a net effect for its behaviour--should it continue to pursue an aggressive course of action--by engaging more forcibly with Southeast Asian partners. The final section outlines how the new shift in US policy has manifested itself to date, and analyzes the extent of its effectiveness as of this writing towards China's actions and for US core interests. This article seeks to capture a US-centric view of the evolving nature of the South China Sea dispute in relation to its grand strategy. …

Island building in the South China Sea: detection of turbidity plumes and artificial islands using Landsat and MODIS data.

The South China Sea is currently in a state of intense geopolitical conflict, with six countries claiming sovereignty over some or all of the area. Recently, several countries have carried out island building projects in the Spratly Islands, converting portions of coral reefs into artificial islands. Aerial photography and high resolution satellites can capture snapshots of this construction, but such data are lacking in temporal resolution and spatial scope. In contrast, lower resolution satellite sensors with regular repeat sampling allow for more rigorous assessment and monitoring of changes to the reefs and surrounding areas. Using Landsat-8 data at ≥15-m resolution, we estimated that over 15 km2 of submerged coral reef area was converted to artificial islands between June 2013 and December 2015, mostly by China. MODIS data at ≥250-m resolution were used to locate previously underreported island building activities, as well as to assess resulting in-water turbidity plumes. The combined spatial extent of observed turbidity plumes for island building activities at Mischief, Subi, and Fiery Cross Reefs was over 4,300 km2, although nearly 40% of this area was only affected once. Together, these activities represent widespread damage to coral ecosystems through physical burial as well as indirect turbidity effects.

Assessing China’s South China Sea Policy, 2009-2015

This paper identifies three phases of China’s South China Sea policy since 2009: reactive assertiveness from 2009 to 2011, forceful response from 2012 to 2013, and proactive adjustment from 2014 to the present. These three distinct phases suggest that China does not have a grand strategy for the South China Sea. The paper also assesses the consequences of China’s island building in the South China Sea and the costs of its deliberate ambiguity on the international legal front.