Investigation and Analysis of Urban Spatial Structure around the Train Stations in Kitakyushu by Using Space Syntax and GIS

Although many methods of spatial analysis have been developed for a better understanding and modelling of urban space analysis, there is still a need for exploration of new analytical techniques for modelling urban spaces. Space Syntax models the spatial configurations of urban spaces by using a connectivity graph representation. Such a configuration of space identifies patterns that can be used to study urban structures and human behaviors. This paper tries to present a new methodology to investigate the urban spatial structure by using Space Syntax with the GIS information including land use, buildings’ characteristics and practical evaluations of the potential of the Space Syntax approach with GIS and multivariate analysis technique. Finally we try to offer some recommendations that attempt to improve the identified problems faced in Kitakyushu, Japan.

Unexpected/contrary behavior of aerosol mass concentration in response to the individual components'concentration reduction in Kitakyushu,Japan

In the suburbs of Kitakyushu,Japan,the inorganic aerosol mass concentration(IAM)was about 32.7μg/m^(3),with the aerosol pH of 3.3.To study the thermodynamics of aerosol when its individual components'concentration is reduced,sensitive tests were performed using the ISORROPIAⅡmodel,in which the seven control species—TNaCl,TNH_(4)^(+),TSO_(4)^(2-),TNO_(3)^(-),TMg^(2+),TK^(+),and TCa^(2+)—were taken into account.IAM and inorganic aerosol pH after reducing TNaCl,TNO_(3)^(-),TMg^(2+),TK^(+),and TCa^(2+)responded linearly(0%≤concentration reduction ratio(CRR)≤100%,with the exception of 100%in TNaCl);the nonlinear variations of these two parameters could be observed by controlling TNH_(4)^(+)and TSO_(4)^(2-).Unexpected aerosol behavior occurred at 100%reduction of TNaCl,which was caused by the sudden increase of NO_(3)^(-),NH_(4)^(+),and aerosol liquid water content(ALWC);the increase of IAM was also observed after controlling TSO_(4)^(2-)(60%≤CRR≤100%)and TCa^(2+)(0%≤CRR≤100%),which was mainly related to the variation of ALWC driven by the response of CaSO_(4).Multiple regression analysis showed that ALWC was statistically and strongly related to the variations of NO_(3)^(-),Cl-,SO_(4)^(2-),HSO_(4)^(-),HNO_(3),and NH_(3)(P<0.05),with regression coefficients of 1.68,5.23,1.83,2.81,0.34,and 0.57,respectively.The highest coefficient(5.23)was found for Cl^(-),revealing that sea salts significantly influenced particle responses.Overall,this study comprehensively investigated aerosol characteristics and inner responses for the reduction of components,which is of great significance for a better understanding of atmospheric chemistry in Kitakyushu,Japan.

Land use change of Kitakyushu based on landscape ecology and Markov model

Based on four phases of TM images acquired in 1990, 1995, 2000 and 2005, this paper took Kitakyushu in Japan as a case study to analyze spatial change of land use landscape and corresponding effects on environmental issues guided by landscape ecology theory in virtue of combining technology of Remote Sensing with GIS. Firstly, land use types were divided into 6 classes （farmland, mountain, forestland, water body, urban land and unused land） according to national classification standard of land use, comprehensible ability of TM image and purpose of this study. Secondly, following the theory of landscape ecology analysis, 11 typical landscape indices were abstracted to evaluate the environmental effects and spatial feature changes of land use. Research results indicated that land use has grown more and more diversified and unbalanced, human activities have disturbed the landscape more seriously. Finally, transfer matrix of Markov was applied to forecast change process of land use in the future different periods, and then potential land use changes were also simulated from 2010 to 2050. Results showed that conversion tendency for all types of land use in Kitakyushu into urban construction land were enhanced. The study was anticipated to help local authorities better understand and address a complex land use system, and develop improved land use management strategies that could better balance urban expansion and ecological conservation.

Phosphorus Release from Sediments in a Riparian <i>Phragmites australis</i>Community at the Estuary of the Chikugogawa River, Western Japan

In order to determine the contribution of aquatic macrophyte communities on nutrition to sustain the high primary productivity of an estuary aquatic community, we analyzed the process of phosphorus release from sediments in aquatic macrophyte community in the estuary of the Chikugogawa River, South-Western Japan. Vertical profile of PD3-4 concentration and redox potential (Eh) of pore water in sediments were investigated within and outside the Phragmites australis community. Sediment horizon lower than 23 cm layer from the surface showed anaerobic (Eh australis community, whereas sediment was constantly oxic (Eh > 0 mV) up to 50 cm depth outside the P. australis community without organic matter accumulation. Non-vegetated sediment with organic matter accumulation showed anoxic profile as vegetated site. PD3-4 concentration in anaerobic parts of sediment showed higher than oxic parts, and higher PD3-4 concentration in sediment pore water corresponded to sulfur deposition in sediment. Sulfate ion supplied from the sea water is reduced under the anoxic condition and S2- reacts with water-insoluble phosphorus salts e.g. Fe3(PO4)2 or AlPO4 and Fe2S3 or Al2S3 precipitates. Thus PD3-4 was mobilized and released under anoxic sediments. P. australis supply organic litter to sediment and the sediment within the P. australis community showed anoxic after aerobic decomposition of organic substances in sediment. Incubation of sediments under N2 atmosphere accumulated PD3-4 in the medium corresponding to low Eh (3-4 was released under anaerobic condition. Estuary P. australis community has function for supplying PD3-4 to river water.

Effects of Salinity on Germination, Seedling Growth and Ecological Properties of <i>Phragmites australis</i>Communities in the Estuary of the Chikugogawa River, Southwestern Japan

Salt tolerance of Phragmites australis populations was investigated in natural reed habitats in the estuary of the Chikugogawa River, southwestern Japan. P. australis populations were selected along the salinity gradient in the estuary, including limnetic (salinity 0.05%), oligohaline (0.4%) and polyhaline sections (2.5%). The ratio of Total-P/Total-N of river water showed high values in the oligohaline section and the above ground biomass, population height and culm diameter of P. australis showed maximum values in this section. Sufficient phosphorus supply could sustain the high productivity of the community in the oligohaline section, irrespective of the salinity of inundated water. The seed production of P. australis was lowest in the polyhaline section. Thus, the ecological performance of P. australis was highest in the oligohaline section and the performance declined with the increasing salinity of the habitat. The effects of salinity on germination and seedling growth were evaluated by means of cultivation in 0.0% -5.0% (NaCl w/w%) salinity medium. Seeds of P. australis collected from every natural population in the estuary failed to germinate at salinity levels above 2.3%. Growth of shoot length and above-ground biomass of seedlings germinated in the fresh water medium were measured for 21 days’ exposure to constant salinity solutions ranging from 0.0% -5.0%. Although mortality was high at salinity levels 3.5% and 5.0%, elongation of shoots of some plants was evident at a salinity level of 5.0%. Seeds from the population in the limnetic section never germinated at a salinity of 3.5%, whereas seedlings obtained from the seeds of the same population germinated in freshwater conditions grew under a salinity of 3.5%. Thus, P. australis seedlings have higher salt tolerance compared to that during the germination stage of the seeds. In this study, it is clarified that P. australis has low salt tolerance during the germination stage and then it acquires salt tolerance during the stage of seedling growth.

The Evaluation Method of Gully Village’s Ecological Sustainable Development in the Gully Regions of Loess Plateau

The gully region of Loess Plateau is one of the earliest human settlement areas and the most ecologically sensitive areas in China. It has been facing challenges for future development. Gully village is the smallest social units on Loess Plateau that owns large amount of agricultural population. However, due to inappropriate development planning and lack of developing directions, they are gradually disappearing. Based on the practical investigations of the Gully Regions of Loess Plateau, this paper aims to explore a new way for the future development of gully villages. Firstly, it classifies the gully villages by the distribution of location. Secondly, selecting ecological construction evaluation factors of gully village and completing the quantitative evaluation are applied on the suitability and sensitivity of ecological sustainable development classification. Thirdly, according to the comprehensive evaluation, the developing condition of each gully village is divided into “Good”, “General” and “Poor”. Finally, this paper figures out the future developing direction for gully villages in different developing conditions.

Study and Proposal to Build the Maintenance Systematization for Preservation of Buildings Aiming at Long-Lived Buildings

Systematization for the maintenance of buildings enables their supporting system to be more practical than before. This study aims to make the maintenance and the long-term repairs for the buildings to be easier. In Japan, 30-40-year-old buildings seem to have been planned and built with little thought about their future maintenances, which have made them very difficult to be repaired on a large scale. This is why effective management systems about dealing with the data should be strongly suggested. Since the Building Standard Law was amended on April 1, 2008, in Japan, the regular investigation and report for particular buildings are legally obligated every three years, thus a variety of useful data can be obtained through Kitakyushu City cases as well as former data personally obtained. With those data used usefully, systematization for the maintenance of the buildings will produce satisfactory results by building up a connection between those data and the long-term repair planning.

Present Assessment of Public Traffic System Based on GIS in Kitakyushu

With increasing of serious environment problems and the coming of the aging society, new traffic systems should be urgently rebuilt. It is necessary to evaluate the traffic service level by utilizing new technique and tool. This paper takes Kitakyushu city as case study to carry out an evaluation of urban traffic system. The concept of accessibility and mobility is used to evaluate the present condition of existing public traffic system based on GIS technology, and then establishment of new route is discussed according to the evaluation results. Additionally, this paper established GIS database and illustrated the relationship between the public traffic and population density. The regions without enough existing traffic were identified. Moreover, the essential terms and considerations were put forward to simulate a new route of public traffic line.

Influence of the PCM Layer Location on the Multilayer Wall Thermal Performance

PCMs (Phase Change Materials) can be integrated into building envelopes to decrease the building energy consumption, refine the indoor thermal comfort, shift and reduce the peak electricity load due to its relatively large latent heat. In this study, influence of the PCM layer location on the multilayer wall thermal performance is numerically researched in four walls under the climate conditions of Chengdu, China. The results only shows when the phase change of PCM occurs;its latent thermal storage performance can be played and have the significant influence on wall thermal performance. Due to phase change of PCM occurs, the fluctuation amplitudes of inner surface temperature and heat flow are reduced obviously;the temperature peak value is delayed in the phase-change occurred periods. In addition, the PCM layer can reduce inner surface heat flow, especially in summer and transition season, which is in the phase-change occurred periods. The average annual heat flow can be reduced by 8.5% - 11.8%. And when the PCM layer is closer to the wall internal side, the influence of the PCM layer location on the multilayer wall thermal performance is more significantly.

Study of Rectangular Underexpanded Microjets

The underexpanded microjet emerging from a rectangular convergent nozzle with a high aspect ratio at the nozzle exit is investigated numerically using the Reynolds-averaged Navier-Stokes (RANS) simulation with the Menter’s shear stress transport (SST) k-ω turbulence model. The simulation is performed at the nozzle pressure ratio of 5.0 to produce a strong shock and it is validated by a comparison with a rainbow schlieren picture of the microjet. The three-dimensional structure of the shock-containing rectangular microjet is demonstrated using the isopycnic surface and bright-field schlieren representations.

Variation characteristics of acid rain in Zhuzhou,Central China over the period 2011-2020

Zhuzhou was one of the most polluted cities in China with the serious acid rain.Due to the implementation of air pollution control measures from 2016 to 2018,the acid rain pollution in this city has reduced.In order to understand the recent situation,a comprehensive study on the acid rain was carried out from January 2011 to December 2020.The pH values during the study period varied from 3.3 to 7.5,with a volume-weighted mean value of 4.7.The predominant acidic components of the precipitation were SO_(4)^(2-)and NO_(3)^(-),accounting for 89.3% of the total anions.The ratio of non-sea-salt SO_(4)^(2-)to NO_(3)^(-)showed a decreasing trend,revealing that the pollution type of acid rain changed from sulfuric acid type to sulfuric acid and nitric acid compound type.The correlation analysis(p<0.05)showed that SO_(4)^(2-)was positively correlated with NH_(4)^(+),Ca^(2+),and Mg^(2+);hence,it predominated in precipitation as(NH_(4))_(2)SO_(4),NH_(4)HSO_(4),CaSO_(4),and MgSO_(4).Significant positive correlation of Ca^(2+)with Mg^(2+)shows that they may originated mainly from crust.Significant positive correlation between SO_(4)^(2-)and F^(-)and Cl^(-)indicate that their source may be related to the non-ferrous metal smelting industry in Zhuzhou.Further correlation analysis shows that emissions from the non-ferrous metal smelting industry in the area have a large significant on SO_(4)^(2-)and F^(-)in precipitation,while Cl^(-)may still be emitted from other anthropogenic sources.

A Model for Regional Energy Utilization by Offline Heat Transport System and Distributed Energy Systems—Case Study in a Smart Community, Japan

Under the Kyoto Protocol,Japanwas supposed to reduce six percent of the green house gas (GHG) emission in 2012. However, until the year 2010, the statistics suggested that the GHG emission increased 4.2%. What is more challenge is, afterFukushimacrisis, without the nuclear energy,Japanmay produce about 15 percent more GHG emissions than1990 inthis fiscal year. It still has to struggle to meet the target set by Kyoto Protocol. The demonstration area of “smart community” suggests Japanese exploration for new low carbon strategies. The study proposed a demand side response energy system, a dynamic tree-like hierarchical model for smart community. The model not only conveyed the concept of smart grid, but also built up a smart heat energy supply chain by offline heat transport system. Further, this model promoted a collaborative energy utilization mode between the industrial sector and the civil sector. In addition, the research chose the smart community inKitakyushuas case study and executed the model. The simulation and the analysis of the model not only evaluate the environmental effect of different technologies but also suggest that the smart community inJapanhas the potential but not easy to achieve the target, cut down 50% of the CO2 emission.

Review on People’s Lifestyle and Energy Consumption of Asian Communities: Case Study of Indonesia, Thailand, and China

This paper focuses on the residential housing performance and people’s lifestyle in terms of energy use. The research has to be continuously study in order to change the Asian people’s lifestyle moving toward the low energy consumption. The research began with collecting data by questionnaires which already distributed to some cities of some countries in Asia. In this paper, we conducted review of energy behavior in housing of three different countries, Indonesia, China, and Thailand. Through questionnaire surveys distributed to more than 600 households, we revealed the housing unit characteristics, household characteristics, ownership of domestic electrical appliances, use of indoor thermal equipment, and monthly energy use. Based on questionnaire results from all households in the seven districts, we conducted statistical analyses to find the major factors influencing the energy use in households. Finally, the research results will be used to indicate the energy use and develop an idea for energy conservation in Asian countries. For further studies, the researchers also try to discover the new way of changing the people’s lifestyle in terms of energy consumption.

Multi-Schlieren CT Measurements of Supersonic Microjets from Circular and Square Micro Nozzles

Instantaneous three-dimensional (3D) density distributions of a shock-cell structure of perfectly and imperfectly expanded supersonic microjets escaping into an ambient space are measured. For the 3D observation of supersonic microjets, non-scanning 3D computerized tomography (CT) technique using a 20-directional quantitative schlieren optical system with flashlight source is employed for simultaneous schlieren photography. The 3D density distributions data of the microjets are obtained by 3D-CT reconstruction of the projection’s images using maximum likelihood-expectation maximization. Axisymmetric convergent-divergent (Laval) circular and square micro nozzles with operating nozzle pressure ratio 5.0, 4.5, 4.0, 3.67, and 3.5 have been studied. This study examines perfectly expanded, overexpanded, and underexpanded supersonic microjets issued from micro nozzles with fully expanded jet Mach numbers Mj ranging from 1.47 - 1.71, where the design Mach number is Md = 1.5. A complex phenomenon for free square microjets called axis switching is clearly observed with two types “upright” and “diagonal” of “cross-shaped”. The initial axis-switching is 45° within the first shock-cell range. In addition, from the symmetry and diagonal views of square microjets for the first shock-cells, two different patterns of shock waves are viewed. The shock-cell spacing and supersonic core length for all nozzle pressure ratios are investigated and reported.

Application of Rainbow Schlieren Deflectometry for Jets from Round Laval Nozzles Followed by Cylindrical Ducts

The jet from a round Laval nozzle followed by a cylindrical duct with an inner diameter of 10 mm and a length of 50 mm is investigated experimentally. The Laval nozzle has a design Mach number of 1.5. Quantitative flow visualization of the jet issued from the duct exit is performed over a range of nozzle pressure ratios from 2.0 to 4.5 using the rainbow schlieren deflectometry combined with the computed tomography to investigate the jet three-dimensional structure. The flow features of the near-field shock systems in the jets are displayed with the density contour plot at the cross-section including the jet centerline. Effects of the nozzle pressure ratio on the density profile along the jet centerline are clarified quantitatively. In addition, a comparison between the present experiment and the previous one with a conventional Laval nozzle for jet centerline density profiles is carried out to examine the effect of the cylindrical duct. Furthermore, the three-dimensional structures of overexpanded and underexpanded jets are demonstrated with the isopycnic surfaces to visualize the internal flow features.

Maintenance of an abrupt boundary between needle-leaved and broad-leaved forests in a wetland near coast

There is an abrupt boundary between two well-developed wetland forests, a stand consisting of a broad-leaved, nitrogen-fixer Alnus japonica and a stand of the needle-leaved Picea glehnii Masters, in eastern Hokkaido, Japan.To clarify maintenance mechanisms, we studied the forest profile, water level, groundwater and precipitation chemistry, seedling establishment patterns in relation to microhabitats, and seed migration.The profile of groundwater level insufficiently explained the abrupt boundary formation, while the groundwater che-mistry differed significantly between the two forests;i.e., EC, Na+, K+, Mg2+, Ca2+ and Cl-were higher in P.glehnii forest and pH was lower.Precipitation in P.glehnii forest contained richer Na+, Ca2+ and Cl-, indicating that the differences in surface-water chemistry were mostly derived from precipitation.Solar radiation was less than 2.2 MJ·m-2·d-1 on P.glehnii forest in late June, while that was patchily distributed in A.japonica forest with a range from 1.0 to 3.7 MJ·m-2·d-1.Moss cover on the soil surface, most of which were made of Sphagnum spp., was 60% in P.glehnii forest, but was 10% in A.japonica forest.Surface water chemistry represented by pH was considered to determine the development of Sphagnum moss.About 70% of P.glehnii seedlings < 1.3 m in height established on moss cover.Seed-sowing experiments suggested that seed germination and seedling survival for both species were significantly higher in P.glehnii forest.Therefore, the regeneration of P.glehnii in A.japonica forest was negligible, owing to the paucity of favorable microhabitats and low seedling establishment.A.japonica regenerated only by resprouting, and the seedlings were few in both forests.In addition, A.japonica seed migration into the P.glehnii forests was greatly restricted, and low solar radiation in the P.glehnii forest contributed to low seedling survival.Based on those results, we concluded that Picea glehnii and Alnus japonica could develop distinct and selfish environments being unsuitable for the other species and inhibit natural afforestation of another species each other by excluding invasion.

Optical Measurements of Shock Waves in Critical Nozzles at Low Reynolds Numbers

Two-dimensional critical nozzle flows at low Reynolds numbers are visualized by the rainbow schlieren deflectometry. Experiments have been performed in a region of overexpanded nozzle flow. The variation of the shock structure against the back pressure ratio can be clearly visible with color gradation. Static pressure rises due to the shock-induced flow separation are compared with the previous theories. The unsteady characteristics of overexpanded critical nozzle flows at low Reynolds numbers are quantitatively and qualitatively visualized using laser schlieren and Mach-Zehnder interferometer systems combined with a high-speed digital camera. It was found that an oscillating normal shock wave appears inside the nozzle, and that the shock wave has a specified dominant frequency. Also the time-history of the oscillating shock wave is obtained from both the systems and compared with each other.