Urban Sci., Volume 6, Issue 2 (June 2022) – 16 articles

Over the past few decades, development in China (including Shenzhen) has been led by the State, meaning that the government has been responsible for major decisions in urban construction and management. However, the current enormous contradiction between people’s demand for livability and Shenzhen’s unequal and inadequate urban development means that leaving all the administrative work to the government alone has become unsustainable. Since 2020, Shenzhen has introduced a new urban management approach called “We Garden”, in which the government supports public participation aimed to transform idle public lands into green spaces in the form of community gardens. Because this ongoing but novel community garden experiment is a recent development in China, literature investigating the phenomenon context, especially the associated motivations and governance structure, remains scarce. This paper aims to clarify the governance structure and operation mechanism of the Shenzhen community garden program through all stages: from planning and design through construction or implementation to management. Fieldwork with active participation, direct observation, and semi-structured, qualitative interviews as participant in a nonprofit organization revealed that the Shenzhen experiment was driven by urban environmental public governance rather than individual needs. The community garden development approach is a new top-down governance structure that expands on existing governance types in the literature, while emphasizing the key role that nonprofit organizations play in the process. Therefore, this new governance approach expands beyond the environmental improvement of urban communities, serving as a new mechanism for sustainable public participation in urban environmental protection. Full article

Lagos, Nigeria, is considered a rapidly growing urban hub. This study focuses on an urban development characterization with remote sensing-based variables for Lagos as well as understanding spatio-temporal precipitation responses to the changing intensity of urban development. Initially, a harmonic analysis showed an increase in yearly precipitation of about 3 mm from 1992 to 2018 for the lower bound of the fitted curve and about 2 mm for the upper bound. The yearly total precipitation revealed no significant trend based on the Mann–Kendall trend test. Subsequent analyses first involved characterizing urbanization based on nighttime light and population density data and then combined them together for the final analysis. Each time, the study area was subdivided into four zones: Zone 0, Zone 1, Zone 2, and Zone 3, which refer to non-urbanized, low-urbanized, mid-urbanized, and highly urbanized regions, respectively. The results from the Google Earth Engine-based analysis uncovered that only Zone 1 has a statistical monotonic increasing precipitation trend (Tau 0.29) with a 0.03 significance level when the combined criteria were applied. There is about a 200 mm precipitation increase in Zone 1. Insignificant patterns for the other three zones (Zone 2, Zone 3, and Zone 4) indicate that these trends are not consistent, they might change over time, and fluctuate heavily. Full article

Some housing researchers have criticized the United States housing subsidy scheme referred to as the Low-Income Housing Tax Credit (LIHTC) program for failing to promote better opportunities for low-income persons. In this study, therefore, we examine the socio-economic and built-environment characteristics of LIHTC developments at the neighborhood level. Specifically, we aim to investigate the characteristics associated with LIHTC developments compared to neighborhoods without this kind of development. We focus on California statewide initially and then narrow our focus to examine LIHTC developments in Los Angeles County (LAC). We then compare the results from the two levels of government. We compiled data from several sources including the U.S. Census Bureau, the State of California, the Southern California Association of Governments, and other secondary sources; used Geographic Information Systems (GIS) to aid in creating several location-based indicators; and employed logistic regression for analyses. Our results show that LIHTC developments at the statewide and county levels tend to be in racially/ethnically diverse neighborhoods with higher levels of economic hardship, lower rents, a higher percentage of renters, and spatial clustering of LIHTC developments. With LAC removed from the state-level analysis, economic hardship is not more likely to occur in LIHTC neighborhoods. This finding suggests, except for in LAC, state policies may be having some level of success in locating LIHTC housing outside of hardship areas. Finally, in examining additional built-environment variables in LAC, we find LIHTC developments were more likely to be in a neighborhood with a park than other neighborhoods in the county. We discuss these results further and conclude with a brief recap of results, policy recommendations, and suggestions for future research. Full article

The sheer size, growth, and complexity of cities worldwide are creating an ever-increasing burden of negative externalities on society and the environment. This systematic review aims to illuminate the broad range of negative urban development externalities and to analyze them in way that sharpens our ability to perceive, anticipate, and manage them. After finding that negative urban development externalities are more complex and diverse than has been previously articulated in the literature, the paper categorizes a representative sample by type (social, environmental, and economic) and identifies three modes of impact (visibility, emergence, and distribution) that make them extremely challenging to anticipate and mitigate. The most problematic negative externalities are social or environmental, with low visibility, cumulative patterns of emergence, and effects that extend beyond regulating jurisdictions. The analysis then draws on welfare economics to strengthen the case for the proactive management of these negative externalities and analyzes the competencies and capacities of local governments to strategically intervene in order to more effectively achieve sustainable development. Full article

Increased urbanization means human beings become the dominant species and reduction in canopy cover. Globally, urban trees grow under challenging and complex circumstances with urbanization trends of increasing anthropogenic carbon dioxide (CO₂) emissions, high temperature and drought stress. This study aims to provide a better understanding of urban trees’ morpho-physio-biochemical attributes that can support sustainable urban greening programs and urban climate change mitigation policies. Globally, urban dwellers’ population is on the rise and spreading to suburban areas over time with an increase in domestic CO₂ emissions. Uncertainty and less information on urban tree diversification and resistance to abiotic stress may create deterioration of ecosystem resilience over time. This review uses general parameters for urban tree physiology studies and employs three approaches for evaluating ecosystem resilience based on urban stress resistance in relation to trees’ morphological, physiological and biochemical attributes. Due to the lack of a research model of ecosystem resilience and urban stress resistance of trees, this review demonstrates that the model concept supports future urban tree physiology research needs. In particular, it is necessary to develop integral methodologies and an urban tree research concept to assess how main and combined effects of drought and/or climate changes affect indigenous and exotic trees that are commonly grown in cities. Full article

Urban informal settlements or slums are among the most vulnerable places to climate-change-related health risks. Yet, little data exist documenting environmental and human health vulnerabilities in slums or how to move research to action. Citizen science, where residents co-define research objectives with professionals, collect and analyze data, and help translate findings into ameliorative actions, can help fill data gaps and contribute to more locally relevant climate justice interventions. This paper highlights a citizen-science, climate justice planning process in the Mukuru informal settlement of Nairobi, Kenya. We describe how residents, non-governmental organizations and academics partnered to co-create data-gathering processes and generated evidence to inform an integrated, climate justice strategy called the Mukuru Special Planning Area, Integrated Development Plan. The citizen science processes revealed that <1% of residents had access to a private in-home toilet, and 37% lacked regular access to safe and affordable drinking water. We found that 42% of households were subject to regular flooding, 39% reported fair or poor health, and 40% reported a child in the household was stunted. These and other data were used in a community planning process where thousands of residents co-designed improvement and climate change adaptation strategies, such as flood mitigation, formalizing roads and pathways with drainage, and a water and sanitation infrastructure plan for all. We describe the participatory processes used by citizen scientists to generate data and move evidence into immediate actions to protect human health and a draft a long-range, climate justice strategy. The processes used to create the Mukuru Special Planning Area redevelopment plan suggest that participatory, citizen-led urban science can inform local efforts for health equity and global goals of climate justice. Full article

Built environment design is implicated in virtually all socio-ecological sustainability problems. Nonetheless, paradoxically, construction will be essential to creating sustainability by increasing social and natural life-support systems. Given the rates of land, resource, water, and biodiversity depletion, urban development must do more than restore nature. It must increase nature and environmental justice in real, not relative, terms. The necessary technologies and design concepts for nature-positive development already exist. However, most sustainable building regulations, design criteria, and performance standards only aim to regenerate landscapes and integrate more nature into cities. This cannot sustain nature or society. This paper canvasses contemporary sustainable design and development thinking and finds that a progression toward ‘nature positive’ is occurring. However, so-called ‘sustainable buildings’ still do not compensate for past inequities or nature degradation, let alone the material flows, pollution, or biodiversity losses they themselves cause. This is partly because current standards and measurements are based on existing conditions, not sustainability standards, and do not distinguish net-positive from regenerative outcomes. Positive Development (PD) theory provides a comprehensive alternative to conventional sustainability frameworks, planning analyses, decision-making structures, design paradigms, and assessment tools. This paper provides criteria for evaluating the potential of conventional and alternative methods for achieving nature-positive outcomes. Full article

Development of urban housing requires participation of various stakeholders, from the state, private sector, and community to the civil society organizations. Cognizant of that fact, this research sought to establish the measurement model for stakeholders’ participation in an urban housing development from the neo-liberal perspective. The study employed a quantitative approach, in which a structured questionnaire containing 25 indicator variables identified from literature was administered to a total of 214 respondents drawn from key institutions involved in housing development and planning in Lusaka, Zambia. Data collected were analyzed through exploratory factor analysis (EFA) as well as confirmatory factor analysis (CFA), with goodness-of-fit based on a two-index strategy used in determining model acceptability. Results revealed that stakeholders’ participation is defined by seven variables, namely: private sector participation in the provision of affordable housing finance; private sector participation through construction of rent-to-buy housing; private sector participation through partnering in the provision of basic services; community participation in the develop of housing programs; the state facilitating access to affordable housing finance; the state stimulating private sector involvement in affordable housing provision; non-governmental organizations participation by coordinating the communities. The study outlines roles of various actors in housing development from a developing country’s perspective. Full article

The impacts of ICT-based mobility services vary in different cities, depending on socioeconomic, urban form, and cultural parameters. The impacts of car-sharing and ridesourcing on public transport have not been investigated appropriately in post-Soviet Union cities. This study presents exploratory evidence on how ridesourcing and car-sharing affect public transport usage in Moscow. Additionally, it studies how demographics, spatial parameters, attitudes, and travel preferences influence the frequency of use of ridesourcing and car-sharing in Moscow. An online mobility survey was conducted at the beginning of 2020 among respondents (sample size is 777) in the Moscow agglomeration. Overall, 66% of ridesourcing users shifted from public transport to these mobility services, which shows the substitutional impact of ridesourcing on public transport. Additionally, the logit model indicates that the regular use of ridesourcing negatively correlates with the regular use of buses/trams/trolleybuses in Moscow. The impact of car-sharing on public transport seems less substitutional and more complementary than the impact of ridesourcing. Overall, 40% of car-sharing users would replace their last car-sharing trip with public transport if car-sharing was unavailable. Moreover, the logit model indicates a positive association between the regular use of car-sharing and the use of buses/trams/trolleybuses. Moreover, the modal split analysis shows a bigger share of public transport use and walking than car use among citizens’ urban journeys in Moscow. Full article

With the rapid urbanization occurring across African cities, the emergence of a middle class is exerting its influence on the urban form and structure. Matching their social status and drawing on global influences, the housing characteristics of this class are distinctive in spatial organization, material choice, and location, among others. Understanding these emerging typologies is critical for urban housing policy to be responsive to the needs and preferences of this class. The present paper aims first to develop a new approach for defining the middle class in the African context and second, to analyze its housing typology through a multidimensional analysis based on housing attributes and socio-economic characteristics in Casablanca City. A data-driven approach based on principal component analysis (PCA) has been used to define multidimensionally the middle class and its housing typology. Through the construction of a multidimensional composite index to measure middle class, the study highlighted that middle-class housing is characterized by an adequate condition, a suitable size (two to three rooms), and affordability between 8000 and 11,000 Moroccan dirhams (MAD) per square meter. In addition, although the Moroccan modern houses (two-floor single-family housing) and apartments (four floors or greater) are the most occupied by the middle class, the study showed that as income and social mobility increase, the apartment building and the villa are increasingly preferred to the Moroccan modern house. Full article

Today’s cities are increasing their space zones while becoming more vulnerable to natural disasters and man-made threats. The initial evaluation of the resilience of city systems is of great importance and helps develop policies and measures that would improve resilience. This paper, using a descriptive–analytic method, defines the characteristics of a resilient city, and natural disasters are addressed. At the same time, the process of reaching a resilient city is investigated. Then, the indicators of resilience have been defined in pillars of ecologic, physiological, social, economic, and managerial–institutional dimensions for the evaluation of a resilient city in Iran. As the sample of the study, the indicators of the study were evaluated in the city of Sanandaj and prioritized in the network analysis process (ANP). The results of this analysis showed that zones one and two, respectively, were the weakest parts regarding urban resilience. In order to move toward a resilient city, future investments should go beyond financial investment and technical solutions and consider human and community development, as well as institutional capacity and inter-organizational cooperation. Full article

The COVID-19 pandemic is a severe ongoing health crisisworldwide. Studying the socio-economic impacts of COVID-19 can help policymakers develop successful pandemic management plans. This paper focuses on the spatial epidemiology of COVID-19 among different social classes in the Kermanshah metropolis, Iran. This cross-sectional study uses the data of people infected with COVID-19 in the Kermanshah metropolis in 2020, acquired from the official COVID-19 Registry of Kermanshah. The results show that 2013 people were infected with COVID-19 (male = 1164 and female = 849). The mean age of the patients was 45 ± 18.69. The Moran’s I show that COVID-19 in different social classes was clustered across the neighbourhoods in the Kermanshah metropolis. The mean ages of men and women were 44.51 ± 18.62 and 45.69 ± 18.76, respectively. Importantly, COVID-19 was highly prevalent in the middle-class groups. Age group comparisons indicate that older people were the most infected in poorer neighbourhoods. In the middle-classtheage group of 0–14 years and in the rich neighbourhoods the age group of 15–64 years were the most exposed to the disease. The findings of this study suggest that older people and lower socioeconomic classes should be prioritised while developing and implementing preventative programs for COVID-19 and similar pandemics. Full article

Urban sprawl in developing countries changes urban land use structure and function, and threatens the sustainable development of regional ecology and security patterns of city landscapes. A new way to control urban sprawl is to develop a comprehensive landscape security plan, analyze factors influencing urban growth, optimize land use and demarcate a growth boundary. Here, we use Xi’an, China, as a case study to analyze scenarios of landscape security pattern and urban spatial control to explore urban spatial zoning. We construct a theoretical framework of a landscape security pattern to manage urban spatial expansion from the perspective of landscape security and urban smart growth. As a first step, the integrated landscape security pattern is constructed based on four factors: hydrology, geological disasters, cultural heritage, and recreation. Second, the urban spatial expansion model is simulated based on a cellular automata model. Finally, nine land-use patterns are developed by overlaying integrated landscape security patterns and urban spatial expansion. Thus, urban space is divided into three types of zoning scenarios: suitable construction, restricted construction, and prohibited construction. The calculations indicate that the zoning area of the three types accounted for 10.4%, 14.7%, and 74.9%, respectively, of the total area in Xi’an. It is of great significance to determine the spatial contradiction between development and protection in the process of urban expansion and to establish a schema of suitable urban land use. We discuss the rapid urbanization process in developing countries at the macro scale, and formulate a land use plan that balances development and protection. Full article

The pandemic’s lockdown has made physical inactivity unavoidable, forcing many people to work from home and increasing the sedentary nature of their lifestyle. The link between spatial and socio-environmental dynamics and people’s levels of physical activity is critical for promoting healthy lifestyles and improving population health. Most studies on physical activity or sedentary behaviors have focused on the built environment, with less attention to social and natural environments. We illustrate the spatial distribution of physical inactivity using the space scan statistic to supplement choropleth maps of physical inactivity prevalence in Chicago, IL, USA. In addition, we employ geographically weighted regression (GWR) to address spatial non-stationarity of physical inactivity prevalence in Chicago per census tract. Lastly, we compare GWR to the traditional ordinary least squares (OLS) model to assess the effect of spatial dependency in the data. The findings indicate that, while access to green space, bike lanes, and living in a diverse environment, as well as poverty, unsafety, and disability, are associated with a lack of interest in physical activities, limited language proficiency is not a predictor of an inactive lifestyle. Our findings suggest that physical activity is related to socioeconomic and environmental factors, which may help guide future physical activity behavior research and intervention decisions, particularly in identifying vulnerable areas and people. Full article

Sporadic efforts have been introduced to control emissions in Delhi, but the air quality has declined further due to the rapid development of different sectors. In this study, the impact of various mitigation scenarios on air quality for PM₁₀, ozone, and its precursors are studied using a chemical transport model, namely WRF-Chem. The Emission Database for Global Atmospheric Research emission inventory was modified and introduced into the WRF-Chem model to assess the impact of selected emission control scenarios on different sectors. The simulations were conducted with reduced emissions for these sectors over the study domain: (a) implementation of Bharat Stage—VI norms in the transport sector, (b) conversion of fuel from coal to natural gas in the energy sector, and (c) fuel shift to LPG in the residential sector. The transport sector noted a decrease of 4.9% in PM₁₀, 44.1% in ozone, and 18.9% in NOx concentrations with emission reduction measures. In the energy sector, a marginal reduction of 3.9% in NOx concentrations was noted, and no change was observed in PM₁₀ and ozone concentrations. In the residential sector, a decrease of 8% in PM-10, 47.7% in ozone, and 49.8% in NOx concentrations were noted. The VOC-to-NOx ratios were also studied, revealing the ozone production over the study domain was mostly VOC-limited. As the inclusion of control measures resulted in varying levels of reduction in pollutant concentrations, it was also studied in the context of improving the air quality index. The WRF-Chem model can be successfully implemented to study the effectiveness of any regulated control measures. Full article

In Ethiopia, the flourishing of industrial parks in the suburbs of major urban centers is a recent phenomenon. The outbreak of COVID-19 has had an adverse impact on the emerging industrial parks and prospects of cluster cities. The aim of this article is to explore the different urban planning measures employed during the pandemic and to propose sound planning methods for the development of sustainable industrial-oriented urban centers. In Ethiopia, industrial-oriented urbanization started in the 1920s with the advent of the railway line. Currently, more than 25 industrial park-based cluster cities have flourished adjacent to cities. A number of initiatives have been undertaken by major stakeholders in these cluster cities to combat COVID-19. Their efforts, however, were made difficult because urban planners were not proactive and did not have foresight in the selection of sites that can mitigate the impact of COVID-19 or other similar pandemics. The researchers believe the problem could have been addressed if the planners used a science-based, human-focused, computer-aided decision-making approach, i.e., space syntax. Therefore, this article recommends that planners become proactive and work in collaboration with different stakeholders for the creation of resilient and livable industrial parks-oriented urban centers. Full article