scholarly journals Exploring the Joint Impacts of Natural and Built Environments on PM2.5 Concentrations and Their Spatial Heterogeneity in the Context of High-Density Chinese Cities

2021 ◽  
Vol 13 (21) ◽  
pp. 11775
Author(s):  
Shanyou Duan ◽  
Qian Liu ◽  
Dumei Jiang ◽  
Yulin Jiang ◽  
Yinzhi Lin ◽  
...  
Keyword(s):  
Land Use ◽  
Air Pollution ◽  
Spatial Heterogeneity ◽  
Urban Form ◽  
Central City ◽  
High Density ◽  
Air Pollutant ◽  
Least Square ◽  
Built Environments ◽  
Chinese Cities

Air pollution in China has attracted wide interest from the public and academic communities. PM2.5 is the primary air pollutant across China. PM2.5 mainly comes from human activities, and the natural environment and urban built environment affect its distribution and diffusion. In contrast to American and European cities, Chinese cities are much denser, and studies on the relationships between urban form and air quality in high-density Chinese cities are still limited. In this paper, we used the ordinary least square (OLS) and geographical weighted regression (GWR) models, selected an already high-density city, Shenzhen, as the study area, and explored the effects of the natural and built environments on air pollution. The results showed that temperature always had a positive influence on PM2.5 and wind speed had a varied impact on PM2.5 within the city. Based on the natural factors analysis, the paper found that an increase in the floor area ratio (FAR) and road density may have caused the increase in the PM2.5 concentration in the central city. In terms of land use mix, land use policies should be adopted separately in the central city and suburban areas. Finally, in terms of spatial heterogeneity, the GWR models achieved much better performances than the global multivariate regression models, with lower AICc and RMSE values and higher adjusted R2 values, ultimately explaining 60% of the variance across different city areas. The results indicated that policies and interventions should be more targeted to improve the air environment and reduce personal exposure according to the spatial geographical context.

The impact of urban form on disaster resiliency

2016 ◽  
Vol 7 (3) ◽  
pp. 259-275 ◽  
Author(s):  
Leila Irajifar ◽  
Neil Sipe ◽  
Tooran Alizadeh
Keyword(s):  
Land Use ◽  
Population Density ◽  
Urban Form ◽  
Disaster Recovery ◽  
Form Factors ◽  
High Density ◽  
Disaster Resilience ◽  
Content Type ◽  
Land Use Mix ◽  
The Impact

Purpose This paper examines the impact of urban form on disaster resiliency. The literature shows a complex relationship between urban form factors such as density and diversity and disaster recovery. The empirical analysis in this paper tests the impact of land use mix, population density, building type and diversity on the reconstruction progress in three, six and nine months after the 2010 flood in Brisbane and Ipswich as proxies of disaster resilience. Considerable debate exists on whether urban form factors are the causal incentive or are they mediating other non-urban form causal factors such as income level. In view of this, the effects of a series of established non-urban form factors such as income and tenure, already known as effective factors on disaster resilience, are controlled in the analysis. Design/methodology/approach The structure of this paper is based on a two-phase research approach. In the first phase, for identification of hypothetical relationships between urban form and disaster resiliency, information was gathered from different sources on the basis of theory and past research findings. Then in phase two, a database was developed to test these hypothetical relationships, employing statistical techniques (including multivariate regression and correlation analysis) in which disaster recovery was compared among 76 suburbs of Brisbane and Ipswich with differing levels of population density and land use mix. Findings The results indicate that population density is positively related to disaster resilience, even when controlling for contextual variables such as income level and home ownership. The association between population density and disaster reconstruction is non-linear. The progress of reconstruction to population density ratio increases from low, medium to high densities, while in very low and very high density areas the reconstruction progress does not show the same behavior, which suggests that medium-high density is the most resilient. Originality/value The originality of this paper is in extracting hypothetical relationships between urban form and resiliency and testing them with real world data. The results confirmed the contribution of density to recovery process in this case study. This illustrates the importance of attention to disaster resiliency measures from the early stages of design and planning in development of resilient urban communities.

scholarly journals Spatial Heterogeneity in the Determinants of Urban Form: An Analysis of Chinese Cities with a GWR Approach

2019 ◽  
Vol 11 (2) ◽  
pp. 479 ◽  
Author(s):  
Shijie Li ◽  
Chunshan Zhou ◽  
Shaojian Wang ◽  
Shuang Gao ◽  
Zhitao Liu
Keyword(s):  
Spatial Heterogeneity ◽  
Urban Form ◽  
Urban Expansion ◽  
Coastal Region ◽  
Policy Implications ◽  
Urban Systems ◽  
Theoretical Understanding ◽  
Chinese Cities ◽  
Shape Irregularity ◽  
Spatially Varying

It is of great significance to investigate the determinants of urban form for shaping sustainable urban form. Previous studies generally assumed the determinants of urban form did not vary across spatial units, without taking spatial heterogeneity into account. In order to advance the theoretical understanding of the determinants of urban form, this study attempted to examine the spatial heterogeneity in the determinants of urban form for 289 Chinese prefecture-level cities using a geographically weighted regression (GWR) method. The results revealed the spatially varying relationship between urban form and its underlying factors. Population growth was found to promote urban expansion in most Chinese cities, and decrease urban compactness in part of the Chinese cities. Cities with larger administrative areas were more likely to have dispersed urban form. Industrialization was demonstrated to have no impact on urban expansion in cities located in the eastern coastal region of China, which constitutes the country’s most developed regions. Local financial revenue was found to accelerate urban expansion and increase urban shape irregularity in many Chines cities. It was found that fixed investment exerted a bidirectional impact on urban expansion. In addition, urban road networks and public transit were also identified as the determinants of urban form for some cities, which supported the complex urban systems (CUS) theory. The policy implications emerging from this study lies in shaping sustainable urban form for China’s decision makers and urban planners.

INTEGRATION OF SUSTAINABILITY INDICATORS IN URBAN FORMATION: A GAP ANALYSIS

2021 ◽  
Vol 19 ◽  
Author(s):  
Ogungbenro Matthew Taiwo ◽  
Salfarina Samsudin ◽  
Dzurllkanian @ Zulkarnain Daud ◽  
Olukolajo Michael Ayodele
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Urban Form ◽  
Structural Equation ◽  
Gap Analysis ◽  
Social Sustainability ◽  
Partial Least Square ◽  
Least Square ◽  
Social Dimension ◽  
Specific Reference

Cities and urban centers are made for people and not vice versa. However, many policies on urban formation fail to take cognisance of human factors in their design and planning. Restructuring of cities to accommodate the economics and environmental demand of urbanisation alters the organic urban form. Modernists often concentrate on road construction, fresh air circulation, light, space, space for vehicles, etc., but ignore city architecture's social dimension. This study explores the psychological aspect of cities and housing due to the trends in the land-use change in sustainable city agenda with specific reference to Ibadan City. This work is an extract of research on the community perspective of land-use change on social sustainability. Data were collected through a structured questionnaire from 397 residents of the Central Local Government and analysed using Partial Least Square - Structural Equation Modelling (PLS-SEM) and Relative Importance Index (RII). The results show the urban form characterised by land-use change and its consequential effects on social sustainability. The alteration of the urban form through land-use changes by individual landowners' decisions impacts others' social sustainability. It was recommended that policymakers incorporate the sustainable social elements into the planning procedure.

Reducing cardiovascular health impacts from traffic-related noise and air pollution: intervention strategies

2013 ◽  
Vol 56 (02) ◽  
pp. 31-38 ◽  
Author(s):  
Jason H. Curran ◽  
Helen D. Ward ◽  
Mona Shum ◽  
Hugh W. Davies
Keyword(s):  
Land Use ◽  
Air Pollution ◽  
Land Use Planning ◽  
Cardiovascular Health ◽  
Road Traffic ◽  
Traffic Noise ◽  
Scientific Basis ◽  
Air Pollutant ◽  
Pollutant Emissions ◽  
Road Traffic Noise

Recent studies suggest that exposure to both traffic-related air pollution (TrAP) and to road traffic noise (RTN) are independent risk factors for cardiovascular disease (CVD). While the exact pathophysiologic mechanisms are not known, plausible biological models exist for both associations. This paper describes interventions and mitigating measures aimed at reducing both air and noise pollution emitted from traffic. Nine types of interventions are examined within the four strategic themes of (i) land-use planning and transportation management, (ii) reduction of vehicle emissions, (iii) modification of existing structures, and (iv) behavioral change. Not all interventions result in concomitant reductions of air and noise pollutant exposures. Most interventions that rely on a scientific basis to reduce CVD are directed at reducing TrAP. Interventions identified with the greatest potential benefits focus on the pollutant source, such as reductions in traffic volume and air pollutant emissions, and are more easily realized, and likely cheaper, if they are considered in the land-use planning stages with less reliance on behavioral changes.

scholarly journals A COMPARATIVE ANALYSIS OF TRANSIT ORIENTED DEVELOPMENT GUIDELINES BETWEEN MALAYSIA AND OTHER COUNTRIES

2021 ◽  
Vol 19 (15) ◽  
Author(s):  
Nurul Ardila Azmi ◽  
Mariana Mohamed Osman ◽  
Noor Suzilawati Rabe ◽  
Nuranisa Huda Ramlan ◽  
Ainina Azizan ◽  
...  
Keyword(s):  
Land Use ◽  
Comparative Analysis ◽  
Public Transportation ◽  
Urban Form ◽  
Document Analysis ◽  
High Density ◽  
Current Policy ◽  
Transit Oriented Development ◽  
Mixed Use ◽  
Land Use Development

Transit Oriented Development (TOD) is an emerging concept to optimise the land use development surrounding a transit station and to create a reliable relationship between a densely compact urban form and high public transportation ridership. In Malaysia, the concept of TOD was initiated in the first National Physical Plan in 2005 and mentioned again in National Physical Plan 2 in 2010. This paper identifies the principle of TOD applied in Malaysia and other countries, and discusses the differences and similarities of the TOD practices using comparative analysis and document analysis methods. Findings of this study indicate that mixed-use development, high density, intensity and connectivity are the main TOD principles adopted in Malaysia and other countries around the globe. The current policy and practises of these countries tend to focus more on the better management and increase ridership of these transit rail stations, including ways to encourage users to shift from private vehicles to public transportation. The findings of this study would contribute towards policy decisions and practices of TOD in Malaysia.

scholarly journals Development and intercity transferability of land-use regression models for predicting ambient PM<sub>10</sub>, PM<sub>2.5</sub>, NO<sub>2</sub> and O<sub>3</sub> concentrations in northern Taiwan

2021 ◽  
Vol 21 (6) ◽  
pp. 5063-5078
Author(s):  
Zhiyuan Li ◽  
Kin-Fai Ho ◽  
Hsiao-Chi Chuang ◽  
Steve Hung Lam Yim
Keyword(s):  
Land Use ◽  
Air Pollution ◽  
Air Pollutants ◽  
Measurement Data ◽  
Air Pollutant ◽  
Population Exposure ◽  
Land Use Regression ◽  
Suspended Particulates ◽  
Model Based ◽  
Northern Taiwan

Abstract. To provide long-term air pollutant exposure estimates for epidemiological studies, it is essential to test the feasibility of developing land-use regression (LUR) models using only routine air quality measurement data and to evaluate the transferability of LUR models between nearby cities. In this study, we developed and evaluated the intercity transferability of annual-average LUR models for ambient respirable suspended particulates (PM10), fine suspended particulates (PM2.5), nitrogen dioxide (NO2) and ozone (O3) in the Taipei–Keelung metropolitan area of northern Taiwan in 2019. Ambient PM10, PM2.5, NO2 and O3 measurements at 30 fixed-site stations were used as the dependent variables, and a total of 156 potential predictor variables in six categories (i.e., population density, road network, land-use type, normalized difference vegetation index, meteorology and elevation) were extracted using buffer spatial analysis. The LUR models were developed using the supervised forward linear regression approach. The LUR models for ambient PM10, PM2.5, NO2 and O3 achieved relatively high prediction performance, with R2 values of > 0.72 and leave-one-out cross-validation (LOOCV) R2 values of > 0.53. The intercity transferability of LUR models varied among the air pollutants, with transfer-predictive R2 values of > 0.62 for NO2 and < 0.56 for the other three pollutants. The LUR-model-based 500 m × 500 m spatial-distribution maps of these air pollutants illustrated pollution hot spots and the heterogeneity of population exposure, which provide valuable information for policymakers in designing effective air pollution control strategies. The LUR-model-based air pollution exposure estimates captured the spatial variability in exposure for participants in a cohort study. This study highlights that LUR models can be reasonably established upon a routine monitoring network, but there exist uncertainties when transferring LUR models between nearby cities. To the best of our knowledge, this study is the first to evaluate the intercity transferability of LUR models in Asia.

Air pollution dispersal in high density urban areas: Research on the triadic relation of wind, air pollution, and urban form

2020 ◽  
Vol 54 ◽  
pp. 101941 ◽  
Author(s):  
Junyan Yang ◽  
Beixiang Shi ◽  
Yi Shi ◽  
Simon Marvin ◽  
Yi Zheng ◽  
...  
Keyword(s):  
Air Pollution ◽  
Urban Form ◽  
Urban Areas ◽  
High Density ◽  
Triadic Relation
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