Impact Analysis of Bridging on Remote Island Population

We analyzed the determinants of building bridges after comparing bridge islands and non-bridge islands.In addition,we examined the population change before and after the bridge building and the factors influencing the change.As a result,a remote island with high cost-effectiveness was selected and bridged.The early bridge was built in remote islands with fragile social infrastructure,and the outflow of population was suppressed owing to the improvement in standard of living by securing the medical care and education available in the bridge destination.However,around the year 2000,there are few remote islands where the changes in populations are influenced after a bridge was built.

A quantitative approach to monitoring new sand cay migration in Nansha Islands

Sand cay is a special kind of islet formed by coral detritus and bioclast, which is common in Nansha Islands of China. Some sand cays play an important role in ocean strategy and economy, but surprisingly we know little about them, especially those recently formed sand cays. In this research, we monitor migration of a new sand cay in Nanxun Jiao（Gaven Reef） using a series of Quick Bird and World View-2 satellite images between June 2006 and August 2013. We conduct a regression between migration distance and wind observational data to examine the migration patterns of the new sand cay. The migration distance is calculated based on the sand cay locations extracted based on Normalized Difference Water Index（NDWI）. The wind observational data downloaded from NOAA are reformed into four wind direction vectors. Based on the results of regression, we concluded that the migration of the new sand cay on Nanxun Jiao was significantly associated with the east, west and north wind.East wind was the main influence factor of the migration; its impact strength was almost twice as the west and north wind. The south wind has little effect on the migration of the sand cay, which is partly blocked by the artificial structure in the south.

Shengshan——A Remote and Quiet Island

An Island Further East than'Dongji Island'Located at the northeastern part of the Zhoushan Islands and the eastern part of the Shengsi Islands,Shengshan Island is China’s farthest island in the east.It deserves the name of'Farthest island to the east'as it was described in the Chinese film'Continent.'Also known as'Jinshan'。

Control method for the stable operation of distributed inverters following the introduction of large-scale renewable energy to a remote island grid

The introduction of large-scale renewable energy requires a control system that can operate multiple distributed inverters in a stable way.This study proposes an inverter control method that uses information corresponding to the inertia of the synchronous generator to coordinate the operation of battery energy storage systems.Simulation results for a system with multiple inverters applying the control method are presented.Various faults such as line-to-line short circuits and three-phase line-to-ground faults were simulated.Two fault points with different characteristics were compared.The voltage,frequency and active power quickly returned to their steady-state values after the fault was eliminated.From the obtained simulation results,it was verified that our control method can be operated stably against various faults.

Identifying fish assemblages in tropical lagoon ecosystem:First record from Luang Island,South-west Maluku Indonesia

The aim of this study was to record demersal species from lagoon in Luang Island,a small and remote island in Maluku,Indonesia.Quantitative and qualitative methods were employed with the assistance of the local fishers using 4 different methods of fishing:gillnets,spear guns,traps,and handlines.Fisher knowledge informed fish abundance and frequency of occurrence.A total of 348 individual fish distributed across 53 species were recorded from the catch of 4 gear types.Bray-Curtis similarity scores of fish assemblages at different habitats was ranged from 7.19%to 10.35%.The nMDS bi-plot visualized a distinct dimension with which to allocate 3 habitats separately from the sand-seagrass habitat.Significant similarity of species at 4 different habitats(ANOSIM R^(2)=0.124,P=0.002)suggested that the habitat parameter was not able to predict different communities of fish.This paper is the first contribution on the composition of lagoon ichthyofaunal in Southwest Maluku Regency.Wise attitude towards marine resource exploitation such as traditional conservation,less fishing pressure and marine culture will maintain the healthy ichthyofaunal assemblages in a tropical lagoon ecosystem.

Use of hydrogen storage in an off-grid system for implementing a renewable-energy system

This paper presents the purpose,advantages,system constitution,operation method and estimation results of using hydrogen storage in a small-scale electric power(off-grid)system when renewable energy sources are introduced.It is assumed that all electricity is supplied from renewable energy sources without using a diesel generator that requires fossil fuels.In other words,for a small-scale electric power system on a remote island,a power-supply system comprising a photovoltaic power-generation system,storage battery,hydrogen-production system,storage tank and a fuel cell is considered.The condition under which the total construction cost is minimized by considering the equipment capacity,operation method of the battery and fuel cell as parameters is investigated.The results demonstrate that the construction cost can be reduced by applying the method of surplus magnification and hydrogen storage.The initial cost is~70%when hydrogen storage is added as compared with the case in which a storage battery alone is used.Such a cost-effective system can contribute to Japan’s self-reliance with regard to the energy sector in the future.