Wards Of Tokyo Research Articles

Block-level Trip Generation/Attraction and Travel Characteristics Using GPS Data and Building Usage Composition in Tokyo Wards

Block-level Trip Generation/Attraction and Travel Characteristics Using GPS Data and Building Usage Composition in Tokyo Wards

Tokyo’s urban tree challenge: Decline in tree canopy cover in Tokyo from 2013 to 2022

The important contributions of urban trees and green spaces to climate moderation, disaster mitigation, and public health have been widely recognized. Tree canopy cover is one of the simplest proxies for assessing the extent of urban forests and their associated benefits. Many cities are targeting increases in the extent of their urban canopies as a means of mitigating the impact of urbanization and climate change. This is the first study to examine the spatiotemporal changes in tree canopy cover over 9 years from 2013 to 2022 in the 23 wards of Tokyo, Japan. It aims to clarify the main spatiotemporal characteristics of urban tree cover. We extracted tree canopy cover from satellite imagery using object-based image analysis incorporating land-use data. Topography, historical green spaces, and social geography have variously influenced the distribution of tree cover among Tokyo’s 23 wards. Tree canopy cover declined by 1.9% from 9.2% in 2013 to 7.3% in 2022. Tree cover loss amounted to 38.0% on public land and 57.0% on private land. The highest percentage of tree cover loss occurred in residential areas: single-family houses (39.8%), followed by roads (14.7%), educational and cultural facilities (10.8%), and parks (10.4%). The main factors responsible for tree cover loss are private housing developments, urban redevelopments, and the removal of trees in parks, along streets, and in educational and cultural facilities. Tokyo is currently facing significant challenges related to tree cover loss and it is crucial to integrate urban forestry into the urban planning framework.

Relationship between working hours and sleep quality with consideration to effect modification by work style: a community-based cross-sectional study.

Although longer working hours are associated with lower sleep quality, it is still necessary to work a certain number of hours to make a living. In this study, we investigated the relationship between working hours and sleep quality in a community setting. We then explored how to manage work style while maintaining the sleep quality of workers without markedly reducing working hours. 4388 day-time workers in various occupations living in Ota ward in Tokyo were included in the analysis. The relationship between working hours and sleep quality measured by the Athens Insomnia Scale was examined by ANOVA and linear regression models. Effect modification by work style (work end time, shift in working start and end time, current work from home status, change in work place) on the relationship between working hours and sleep quality was investigated by multivariate linear regression models. Longer working hours were significantly associated with lower sleep quality. The magnitude of the relationship between long working hours and low sleep quality was significantly larger when work end time was later (p for trend of interaction < 0.01) and when working start and end time were shifted later (vs no change, p for interaction = 0.03). The relationship was marginally greater when the proportion of work from home was increased (vs no change, p for interaction = 0.07). A relationship between longer working hours and lower sleep quality was observed among workers. Leaving work earlier or optimizing the work environment at home may diminish the adverse effect of long working hours on sleep quality.

Application and Issues of Minimum Lot Size Regulation by Zoning Area in the Wards of Tokyo

Application and Issues of Minimum Lot Size Regulation by Zoning Area in the Wards of Tokyo

Classification of Facility Composition and Human Flow Pattern in Commercial Districts and Their Stay and Travel Characteristics in Tokyo Wards

Classification of Facility Composition and Human Flow Pattern in Commercial Districts and Their Stay and Travel Characteristics in Tokyo Wards

Change of Walking Tendency of Workers and Visitors in Large-Scale Urban Development Agglomeration Areas in Tokyo Wards

Change of Walking Tendency of Workers and Visitors in Large-Scale Urban Development Agglomeration Areas in Tokyo Wards

Study on Microclimate and Thermal Comfort in Small Urban Green Spaces in Tokyo, Japan—A Case Study of Chuo Ward

Small urban green spaces are abundant in densely populated urban areas, but little is known about their impact on the urban heat island effect and thermal comfort. Therefore, this study selected as research sites four small urban green spaces in a typical high-density built-up area, Chuo Ward in Tokyo, Japan. The ENVI-met software 5.1.1 simulation method was used to analyze these sites’ microclimate and thermal comfort conditions. The following are the results: (1) Small urban green spaces significantly reduce urban air temperatures, particularly during hot weather, with temperature reductions ranging from 2.40 °C to 2.67 °C, consistently lower than the highest temperatures in Tokyo’s Chuo Ward, mainly between 1:00 and 2:00 p.m. (2) Thermal comfort analysis indicates that small urban green spaces can significantly improve urban thermal comfort during the day, particularly around noon, by reducing one or two thermal comfort levels compared to typical urban street blocks. However, these differences gradually diminish throughout the evening and night, and thermal comfort inside and outside green spaces becomes more uniform. (3) Green space size is not the only factor influencing thermal comfort; the layout of plants within the green space and the layout of the surrounding buildings also have an impact. Despite their small size, even small green spaces can significantly enhance comfort. This study highlights the need to promote urban sustainability through the extensive integration of small green spaces in dense urban environments. Small green spaces can serve as a high-frequency, low-cost solution for environmental sustainability by addressing the increasingly severe urban heat island effect as well as environmental challenges that in the urbanization process.

Association between seasonal influenza vaccination and antimicrobial use in Japan from the 2015-16 to 2020-21 seasons: from the VENUS study.

Seasonal influenza vaccination might be considered an antimicrobial resistance (AMR) countermeasure because it can reduce unnecessary antimicrobial use for acute respiratory infection by mitigating the burden of such diseases. To examine the association between seasonal influenza vaccination and antimicrobial use (AMU) in Japan at the community level and to examine the impact of influenza vaccination on the frequency of unnecessary antimicrobial prescription for upper respiratory infection. For patients who visited any healthcare facility in one of the 23 wards of Tokyo, Japan, due to upper respiratory infection and who were aged 65 years or older, we extracted data from the Vaccine Effectiveness, Networking, and Universal Safety (VENUS) study database, which includes all claims data and vaccination records from the 2015-16 to 2020-21 seasons. We used the average treatment effect (ATE) with 1:1 propensity score matching to examine the association of vaccination status with frequency of antibiotic prescription, frequency of healthcare facility consultation, risk of admission and risk of death in the follow-up period of the same season (from 1 January to 31 March). In total, 244 642 people were enrolled. Matched data included 101 734 people in each of the unvaccinated and vaccinated groups. The ATE of vaccination was -0.004 (95% CI -0.006 to -0.002) for the frequency of antibiotic prescription, -0.005 (-0.007 to -0.004) for the frequency of healthcare facility consultation, -0.001 (-0.002 to -0.001) for the risk of admission and 0.00 (0.00 to 0.00) for the risk of death. Our results suggest that seasonal influenza vaccination is associated with lower frequencies of unnecessary antibiotic prescription and of healthcare facility consultation.

Decarbonisation technologies can halve the nonlinear increase in electricity demand in densely populated areas due to climate change

This study projects past and future net electricity consumption (EC) in the Tokyo metropolitan area under various global warming scenarios (ranging from -1.0 °C to +3.0 °C in 0.5 °C increments) using fine-scale temperature sensitivity data (on the order of a few kilometers). The results reveal that EC for space-cooling escalates nonlinearly from present to future climates due to climate change. Conversely, EC for space-heating diminishes. As a result, the net EC grows nonlinearly. The change in EC is minor in regions with lower population densities, such as the northern Kanto region. However, in areas with high population densities, such as the Tokyo 23 wards of central Tokyo, EC surges with warming. Within these wards, EC varies based on building use, with business and commercial districts being particularly sensitive to global warming. Meanwhile, residential areas display fewer changes in EC. Implementing measures in business and commercial districts, which are more vulnerable to global warming, could be instrumental in decarbonisation and urban heat island mitigation. Our projections also indicate that the adoption of increased building insulation, enhanced air conditioning efficiency, and reductions in internal heat gains could halve the anticipated increase in EC.

Spatial variation of PM2.5 component concentrations in 23 Tokyo wards

Spatial variation of PM2.5 component concentrations in 23 Tokyo wards

A field experiment on discrimination against foreigners in the rental housing market in Japan examining the 23 wards of Tokyo

Discrimination against foreigners in rental housing markets has been recognized mainly in the U.S. and European countries. In Japan, the difficulties experienced by foreigners who move into rental housing have been reported only by media or government questionnaire surveys, and there is little quantitative evidence. We conduct a correspondence study to observe discrimination against foreigners in rental housing markets in Tokyo's 23 wards during December 2019 and February 2020. Our results show that those who use a Chinese or Korean name decrease their probability of receiving affirmative responses to rental applications by approximately 13% compared with those who use Japanese names. Additionally, we find that the COVID-19 crisis increased the discriminatory behavior of rental housing owners and realtors.

CONCERNS OF PROSPECTIVE HOMEBUYERS IN TOKYO

The purpose of this study is to clarify the concerns for the living environment among residents and people who are considering to purchase the new housings. The paper discussed the nature and exclusivity of people’s unique behavior in relation to the living environment of Tokyo, based on the following three points of analysis; 1) Concern for the living environment in Tokyo wards area, 2) Geographical characters of the concerns, 3) Background of the formation of concerns and discussions.

Multiscale mapping of local climate zones in Tokyo using airborne LiDAR data, GIS vectors, and Sentinel-2 imagery

ABSTRACT Multisource remote sensing and geographic information system (GIS) data have contributed powerfully to the large-scale automated mapping of local climate zones (LCZs). However, the accessibility of high-resolution height data, the applicability of standard thresholds to local contexts, and the dependence of mapping scales have limited LCZ classification studies. In this study, we combined airborne LiDAR data, Sentinel-2 imagery, and GIS vector (buildings and roads) data to develop a multiscale automated LCZ classification scheme in the 23 special wards of Tokyo. Based on the optimized thresholds of seven LCZ properties, GIS-based LCZ mapping was implemented using fuzzy logic classifiers at the block scale and at different grid-cell scales (100 m–1000 m). In addition to assessing accuracy using reference samples, multidate thermal infrared data (Landsat-8 and ASTER data) were used to understand the LCZ-LST (land surface temperature) relationship at multiple scales. The results showed that the overall accuracies of LCZs could be significantly increased by threshold optimization at all scales. Significant differences in LCZs and LSTs among different mapping units were observed. The highest overall accuracy was greater than 80% at the 100-m grid-cell scale. As the size of grid cells increased, the overall accuracy of LCZ classification decreased. For each LCZ, the mean daytime/nighttime LST exhibited more variation by date than by scale. This study provides a promising picture of GIS-based LCZ mapping and LCZ-LST relationships at multiple scales.

A Study on the actual condition of Civic Green Spaces in five wards of Tokyo and its continuity focusing on the sense of ownership

A Study on the actual condition of Civic Green Spaces in five wards of Tokyo and its continuity focusing on the sense of ownership

東京都特別区における鮮魚の品質分布と小売店の販売戦略

東京都特別区においてランダム抽出した鮮魚販売店で丸のマアジとマイワシをサンプリングし，Fish AnalyzerTM Proを用いて品質を調査した。得られたデータを主成分分析とクラスター分析にかけることで，小売店の販売戦略の類型化を試みた。品質調査から，サンプリングされた魚の大半は生食には適さない鮮度であることや，脂肪度の範囲がマイワシで特に大きいことが分かった。統計解析からは鮮魚販売店の戦略が大きく4つに分類できることが示され，品質を含むデータセットを用いた販売戦略類型化の有用性が示唆された。

Association between periodontal pocket depth determined during dental check-ups and new onset of diabetes in community residents: the LIFE study

Objectives Recent studies have shown a bidirectional association between diabetes and periodontal disease. However, the longitudinal association between periodontal pocket depth and new onset of diabetes remains controversial. Therefore, this study aimed to examine the association between periodontal pocket depth and new onset of diabetes using dental check-up data in a community-based population.Methods The study comprised 5,163 participants aged≥20 years (mean age±standard deviation, 57.4±13.9 years; women, 66.3%) who underwent dental check-ups between April 2016 and March 2019 in a Tokyo ward. We classified the participants into three groups using community periodontal index codes from dental check-ups: healthy periodontal pocket group, periodontal pocket 4-5 mm group, and periodontal pocket ≥6 mm group. The participants were followed until the end of March 2020. Additionally, data on individuals who developed diabetes in the same ward were acquired from the National Health Insurance and Latter-Stage Older Persons Health Care System using ICD-10 codes. As the study outcome, we identified individuals who developed diabetes after the dental check-up date. Diabetes incidence rates were compared using the log-rank test and Cox regression analysis. Additionally, we performed a sensitivity analysis using a similar framework.Results The log-rank test showed that the cumulative incidence of diabetes between the three groups was significantly different (P<0.01). A Cox regression analysis model adjusted for sex, age, smoking habits, number of teeth present, and oral hygiene status showed that the diabetes development hazard ratio (HR) for the periodontal pocket ≥6 mm group was 1.44 (95% confidence interval [CI]; 1.04-2.00) when compared with that of the healthy periodontal pocket group. In the sensitivity analysis of individuals aged ≥40 years, the HR for the periodontal pocket ≥6 mm group was 1.55 (95% CI; 1.11-2.16) when compared with that of the healthy periodontal pocket group. Similarly, among men aged ≥40 years, the HR for the periodontal pocket ≥6 mm group was 1.72 (95% CI; 1.04-2.85) when compared with that of the healthy periodontal pocket group. However, no significant association between new onset of diabetes and periodontal pocket depth was found for women aged ≥40 years (HR=1.39, 95% CI; 0.89-2.18).Conclusion This The study suggests a longitudinal association between periodontal pocket depth and new onset of diabetes. The association was particularly pronounced in men aged ≥40 years. Therefore, men aged <40 years should maintain good oral health through appropriate dental health guidance to prevent the future development of diabetes.

Application of the comprehensive design system in reference to each ward’s social conditions and housing policies

This study aims to provide an overview of how comprehensive design system has been used in three wards in central Tokyo. In the first half of the paper, we describe the evolution of the Tokyo Metropolitan Government’s rules on permission in reference to the comprehensive design system and each ward’s housing policies. In the second half, to analyze the impact of each policy described in the first half, we describe changes in the use, the number of households, and relaxed rules in each period of the comprehensive design system. The analysis reveals the particular trend and challenges in each area.

Double suicide in Japan in the post-war reconstruction period, with reference to contemporary Japan.

After Japan's post-war reconstruction, in the early 1950s, cases of double suicide, in which two people (particularly young lovers) leave a suicide note and die together, were a relatively frequent occurrence. During the three-year period between 1954 and 1956, 5466 suicides were recorded in the special wards of Tokyo, including 79 cases of double suicides, accounting for 158 deaths. In these double suicide cases (2.89% of all deaths by suicide), the evidence revealed that 65.8% involved lovers and 29.1% involved married couples. By contrast, contemporary data indicate a large drop in suicide pacts between lovers to 15.9% and an increase between spouses to 48.8%. Conceivably, the relatively high double-suicide rate after post-war reconstruction reflected difficulties for the younger generation in reconciling 'marriage based primarily on love' and the traditional family system, specifically marriage problems and stress caused by rapidly changing post-war values. One notable difference between victims of double suicide in 1954-1956 and the contemporary period is the younger average age of the former. Another important shift was found in the most common causes of death among victims of double suicide: in 1954-1956 these were poisoning by cyanide or hypnotic drugs, compared to carbon monoxide poisoning and hanging in modern times. We discuss similarities and differences concerning double suicides in relation to social and economic conditions in Japan in the 1950s and today.

Relative Preference for Living in a Safer Place from Natural Disasters: A Case Study at Tokyo, Japan

While it would be desirable to encourage people to live in places that are safer from natural disasters to minimize casualties and property damage, few studies have focused on people’s relative preference for living in such places. The present study has sought to clarify the extent to which Tokyo residents consider safety from natural disaster to be more important than other factors relevant to the choice of residential location, as well as what personal attributes may be correlated with this perception. An online survey was conducted to collect 1554 valid responses from residents in the 23 city wards of Tokyo, Japan, and statistical analysis (a chi-square test and multivariable logistic regression analysis) was then applied to the collected responses. The results demonstrated that, on average, 45.1% of the respondents considered that “safety from natural disasters” was relatively important among twelve such factors related to the selection of a suitable residential location. It was also found that showing a hazard map to Tokyo residents or educating them to take more interest in their health and the surrounding natural environment could be effective to increase the number of people preferring to live in safer places.

Association between maternal PM₂.₅ exposure and gestational diabetes mellitus in Tokyo, Japan

Introduction Recent epidemiological findings suggested that PM₂.₅ exposure is a risk factor for diabetes, and the association between PM₂.₅ and glycaemia and insulin resistance provided the biological mechanistic support. Based on these, a hypothesis has been proposed that maternal exposure to PM₂.₅ contributes to the development of gestational diabetes mellitus (GDM). However, the association between PM₂.₅ and GDM was controversial, and there was limited evidence regarding exposure to specific components of PM₂.₅. In this study, we examined the association between the PM₂.₅-GDM association in the Asian population. Methods From 2013 to 2015, we had permission to the Japan Society of Obstetrics and Gynaecology, and obtained the data on all mothers who delivered births after 22 gestational weeks at 39 cooperating hospitals in 23 Tokyo wards from the Japan Perinatal Registry Network database. We collected fine particle on a filter each day at one fixed monitoring site, and analysed carbon and ion components of PM₂.₅. The average concentrations of PM₂.₅ and its components over the 3-month before pregnancy, the first trimester (0-13 gestational weeks) and the second trimester (14-27 weeks) were calculated, and assigned to each mother. We applied a multi-level logistic regression analysis. Results Of the 83,319 mothers (mean age at delivery = 33.7 years), the proportion of GDM was 4.8%. The median concentration of total PM₂.₅ over the first trimester was 16.1 (interquartile range (IQR) = 3.6) &amp;#x3bc;g/m³. When we simultaneously included three exposure windows of total PM₂.₅, only exposure over the first trimester was associated with GDM (odds ratio per IQR = 1.09, 95%CI = 1.02-1.16). For specific components, we observed the association between exposure to carbon constituents over the first trimester and GDM. Conclusion Our findings provided the additional evidence for the association between maternal exposure to PM₂.₅ and GDM. Key words fine particle, chemical element, GDM,