Representative Cities Research Articles

Impact of outdoor particulate matter 2.5 pollution on natural ventilation energy saving potential in office buildings in China

Natural ventilation improves building energy performance and indoor air quality, but its potential is hindered by outdoor pollution. This paper aims to evaluate the impact of outdoor Particulate Matter 2.5 (PM2.5) pollution on natural ventilation energy saving potential in office buildings in China. Firstly, a typical office building in five representative cities across all climatic regions was designed. Secondly, related weather data were obtained and preprocessed. Thirdly, a computer model was developed under the EnergyPlus environment with smart window ventilation control, space temperature reset using adaptive thermal comfort model, and a validated pollution transportation model that calculates the indoor PM2.5 concentration. The computer model was applied to three air-conditioning systems, i.e., constant air volume (CAV), variable air volume (VAV), and variable refrigerant flow (VRF) with three evaluation indices. The results show that the natural ventilation hours rate with/without considering the outdoor PM2.5 concentration level were 15%–55% and 28%–67%, respectively. Energy savings varied across regions, with mild regions having the highest potential and cold regions having the least. CAV demonstrates the highest energy savings, followed by VAV and VRF, except in Guangzhou where VAV performs the worst. This study contributes to understanding the impact of outdoor pollution on natural ventilation potential and provides practical insights for energy-saving strategies in office buildings. Its originality lies in the evaluation methodology, comprehensive approach, sophisticated computer model, comparative analysis of air-conditioning systems, and practical implications for energy-savings. The research outcomes can guide building facility engineers in implementing ventilation control strategies while maintaining indoor thermal comfort.

Massive Green Hydrogen Production Using Solar and Wind Energy: Comparison between Europe and the Middle East

This comparative study examines the potential for green hydrogen production in Europe and the Middle East, leveraging 3MWp solar and wind power plants. Experimental weather data from 2022 inform the selection of two representative cities, namely Krakow, Poland (Europe), and Diyala, Iraq (Middle East). These cities are chosen as industrial–residential zones, representing the respective regions’ characteristics. The research optimizes an alkaline water electrolyzer capacity in juxtaposition with the aforementioned power plants to maximize the green hydrogen output. Economic and environmental factors integral to green hydrogen production are assessed to identify the region offering the most advantageous conditions. The analysis reveals that the Middle East holds superior potential for green hydrogen production compared to Europe, attributed to a higher prevalence of solar and wind resources, coupled with reduced land and labor costs. Hydrogen production costs in Europe are found to range between USD 9.88 and USD 14.31 per kilogram, in contrast to the Middle East, where costs span from USD 6.54 to USD 12.66 per kilogram. Consequently, the Middle East emerges as a more feasible region for green hydrogen production, with the potential to curtail emissions, enhance air quality, and bolster energy security. The research findings highlight the advantages of the Middle East industrial–residential zone ‘Diyala’ and Europe industrial–residential zone ‘Krakow’ in terms of their potential for green hydrogen production.

Dioxin emissions from municipal solid waste incineration in the context of waste classification policy

Municipal solid waste incineration is gradually becoming the main method of waste disposal, but waste incineration produces many organic pollutants (e.g., dioxins). In order to better implement waste management, China identified 46 key cities to implement domestic waste classification first in 2017. This study predicts dioxin emissions in 2030 based on the background of waste classification policy, and analyzes the impact of waste classification on dioxin reduction. Firstly, k-means was used to classify the 46 cities of waste classification into four categories, and the representative cities in the four categories were selected to analyze the correlation between different influencing factors and municipal solid waste in each category through grey correlation analysis. And the municipal solid waste of each city in 2030 was predicted by bidirectional long and short term memory neural network. Finally, four scenarios are set up based on the background of waste classification policy to predict dioxin emissions in each city in 2030. It is found that at least 7.49%–13.07% dioxin emission reduction can be achieved by 2030 through waste classification. Waste classification has a positive impact on dioxin emission reduction.

An improved evaluation method for public service efficiency from the perspective of residents′ perception

Research on Public Service Efficiency (PSE) can provide effective clues for city governors to plan the public service provision well. Whilst extant studies have extensively explored PSE performance, they are hardly oriented to resident perception. In light of this gap, this study presents a PSE evaluation framework by considering the resident perception. The study aims to uncover the PSE performance and to examine the temporal evolution and spatial disparities in a sample of 35 representative Chinese cities. To this end, Data Envelopment Analysis (DEA) and the Malmquist index are applied, and the data adopted covers the period from 2012 to 2020. The demonstration findings are as follows. (1) The majority of cities in the sample were found to have efficient public services, with the Central region performing better than the Eastern and Western regions in terms of PSE. (2) The Malmquist index shows an overall decline in PSE over the surveyed period except for Chongqing and Shenzhen. (3) The Malmquist index reveals that the Eastern region exhibited the highest degree of volatility, with the Western and Central regions following closely behind. Theoretically, this study provides an effective framework for investigating PSE by taking resident perception into account. The methodology adopted in this study exemplifies how to examine PSE in considering resident perception in a broad context internationally. Practically, the evaluation results can provide valuable references for local managers to customize measures to elevate PSE performance.

Understanding the Spatial Distribution and Behavior of Elderly Residents in Age-Friendly Communities: An Analysis of Outdoor Space Features in Hangzhou, China

In the context of an aging population and the rise of age-friendly communities, the creation of outdoor spaces that cater to the daily needs of elderly residents, promote their physical and mental well-being, and strengthen their sense of community is a pressing matter requiring immediate attention and solutions. This study focuses on boosting the outdoor space of communities that are age-friendly. The research sample consists of four age-friendly communities in the representative city of Hangzhou. Aerial and ground surveys were carried out to examine the spatial distribution and behavioral tendencies of elderly citizens in outdoor community gathering locations. A GoPro MAX panoramic camera and a weather meter were utilized to evaluate the outside space’s landscape components, spatial attributes, and microclimate. Using Pearson correlation and multiple linear regression analyses, we discovered the key parameters impacting the spatial gathering and behaviors of elderly residents in age-friendly communities’ outdoor spaces. When constructing outdoor gathering spaces for the elderly, our findings indicate that weatherproof amenities, a greater variety of pavers, and greenery should be prioritized. Community fitness facilities should be considered throughout the development and refurbishment phases for activity areas. Consideration should also be given to the construction of weatherproof facilities with less walls and increased hard surface areas for chess spaces.

A Cross-Sectional Survey on Prevalence and Behaviour of Smokeless Tobacco Use Among Tobacco Users in China

Summary Increasing tobacco control and public health awareness have increased smokers’ attempts to quit smoking. However, some smokers also seek alternative products claimed to pose less risks. The use of smokeless tobacco (ST) products may thus increase in some countries which are not traditionally ST markets. To provide a cross-sectional picture on ST usage in China, a survey was conducted from December 2019 to March 2020 in representative metropolitan cities (divided into three tiers by their populations and gross domestic product (GDP) sizes), from which 3,000 tobacco users and 801 ST users were randomly recruited to provide a snapshot of ST usage behaviour and other pertinent factors for Chinese tobacco users. The study included questionnaires designed to probe potential reasons behind ST use, usage habits, and nicotine dependence attributes. These questions were devised to cover the type of tobacco products used, users’ age, gender, city of residence, residence time, household monthly income, etc., and was supported by some verification questions. Mann-Whitney-analysis was used for significance analysis between different groups. The results showed that ST prevalence for Chinese tobacco users was around 2.1%. The proportion of exclusively ST use was about 8.99%, and the mean conversion time to habitual ST use was about three months. Demographic information such as the city tiers where ST users lived, their age, gender, educational and income levels appeared to correlate with ST use habits although more studies are needed to verify the observations. The fact that a small but measurable population of Chinese ST users exists has important implications for tobacco control. This study provides the first large-scale, single-time-point survey on Chinese ST user profiles, which may help the future research on tobacco control policy regarding ST products in China.

The Impact of Managing Diversity on Building the Smart City A Comparison of Smart City Strategies: Cases From Europe, America, and Asia

The use of ICT to optimize urban processes, activities, efficiency and effectiveness of services turns cities into smart. Smart cities make it necessary to plan, monitor and analyze the city, except for the routine functions of the city. The study examined what smart city research projects are in five representative smart cities (London, New York, Singapore, Barcelona, and Istanbul) and whether there are similarities or differences in background assumptions. The literature used has a global reach; cities around the world have been chosen for comparison. By evaluating the existing literature, it has been evaluated that smart cities are the most successful and the weakest issues. Despite the centrality of New York and London’s smart city policies; they are fairly superior in economic competition. Public participation in smart city projects is already weak in Singapore and Istanbul. Barcelona has a more participatory policy than other cities, but it needs to develop a smart governance perspective. The study concludes with how the smart city ideology achieves its goals. The study adds value to smart city research by a critical look at the subject. Combining the results of practical smart city initiatives, it concludes the practicality and usefulness of smart city development.

Prevalence, risk factors, impact and management of pneumonia among preschool children in Chinese seven cities: a cross-sectional study with interrupted time series analysis

BackgroundPneumonia is a common disease worldwide in preschool children. Despite its large population size, China has had no comprehensive study of the national prevalence, risk factors, and management of pneumonia among preschool children. We therefore investigated the prevalence of pneumonia among preschool children in Chinese seven representative cities, and explore the possible risk factors of pneumonia on children, with a view to calling the world's attention to childhood pneumonia to reduce the prevalence of childhood pneumonia.MethodsTwo group samples of 63,663 and 52,812 preschool children were recruited from 2011 and 2019 surveys, respectively. Which were derived from the cross-sectional China, Children, Homes, Health (CCHH) study using a multi-stage stratified sampling method. This survey was conducted in kindergartens in seven representative cities. Exclusion criteria were younger than 2 years old or older than 8 years old, non-permanent population, basic information such as gender, date of birth and breast feeding is incomplete. Pneumonia was determined on the basis of parents reported history of clearly diagnosed by the physician. All participants were assessed with a standard questionnaire. Risk factors for pneumonia, and association between pneumonia and other respiratory diseases were examined by multivariable-adjusted analyses done in all participants for whom data on the variables of interest were available. Disease management was evaluated by the parents’ reported history of physician diagnosis, longitudinal comparison of risk factors in 2011 and 2019.ResultsIn 2011 and 2019, 31,277 (16,152 boys and 15,125 girls) and 32,016 (16,621 boys and 15,395 girls) preschool children aged at 2–8 of permanent population completed the questionnaire, respectively, and were thus included in the final analysis. The findings showed that the age-adjusted prevalence of pneumonia in children was 32.7% in 2011 and 26.4% in 2019. In 2011, girls (odds ratio [OR] 0.91, 95%CI [confidence interval]0.87–0.96; p = 0.0002), rural (0.85, 0.73–0.99; p = 0.0387), duration of breastfeeding ≥ 6 months(0.83, 0.79–0.88; p < 0.0001), birth weight (g) ≥ 4000 (0.88, 0.80–0.97; p = 0.0125), frequency of putting bedding to sunshine (Often) (0.82, 0.71–0.94; p = 0.0049), cooking fuel type (electricity) (0.87, 0.80–0.94; p = 0.0005), indoor use air-conditioning (0.85, 0.80–0.90; p < 0.0001) were associated with a reduced risk of childhood pneumonia. Age (4–6) (1.11, 1.03–1.20; p = 0.0052), parental smoking (one) (1.12, 1.07–1.18; p < 0.0001), used antibiotics (2.71, 2.52–2.90; p < 0.0001), history of parental allergy (one and two) (1.21, 1.12–1.32; p < 0.0001 and 1.33, 1.04–1.69; p = 0.0203), indoor dampness (1.24, 1.15–1.33; p < 0.0001), home interior decoration (1.11, 1.04–1.19; p = 0.0013), Wall painting materials (Paint) (1.16, 1.04–1.29; p = 0.0084), flooring materials (Laminate / Composite wood) (1.08, 1.02–1.16; p = 0.0126), indoor heating mode(Central heating)(1.18, 1.07–1.30, p = 0.0090), asthma (2.38, 2.17–2.61; p < 0.0001), allergic rhinitis (1.36, 1.25–1.47; p < 0.0001), wheezing (1.64, 1.55–1.74; p < 0.0001) were associated with an elevated risk of childhood pneumonia; pneumonia was associated with an elevated risk of childhood asthma (2.53, 2.31–2.78; p < 0.0001), allergic rhinitis (1.41, 1.29–1.53; p < 0.0001) and wheezing (1.64, 1.55–1.74; p < 0.0001). In 2019, girls (0.92, 0.87–0.97; p = 0.0019), duration of breastfeeding ≥ 6 months (0.92, 0.87–0.97; p = 0.0031), used antibiotics (0.22, 0.21–0.24; p < 0.0001), cooking fuel type (Other) (0.40, 0.23–0.63; p = 0.0003), indoor use air-conditioning (0.89, 0.83–0.95; p = 0.0009) were associated with a reduced risk of childhood pneumonia. Urbanisation (Suburb) (1.10, 1.02–1.18; p = 0.0093), premature birth (1.29, 1.08–1.55; p = 0.0051), birth weight (g) < 2500 (1.17, 1.02–1.35; p = 0.0284), parental smoking (1.30, 1.23–1.38; p < 0.0001), history of parental asthma (One) (1.23, 1.03–1.46; p = 0.0202), history of parental allergy (one and two) (1.20, 1.13–1.27; p < 0.0001 and 1.22, 1.08–1.37; p = 0.0014), cooking fuel type (Coal) (1.58, 1.02–2.52; p = 0.0356), indoor dampness (1.16, 1.08–1.24; p < 0.0001), asthma (1.88, 1.64–2.15; p < 0.0001), allergic rhinitis (1.57, 1.45–1.69; p < 0.0001), wheezing (2.43, 2.20–2.68; p < 0.0001) were associated with an elevated risk of childhood pneumonia; pneumonia was associated with an elevated risk of childhood asthma (1.96, 1.72–2.25; p < 0.0001), allergic rhinitis (1.60, 1.48–1.73; p < 0.0001) and wheezing (2.49, 2.25–2.75; p < 0.0001).ConclusionsPneumonia is prevalent among preschool children in China, and it affects other childhood respiratory diseases. Although the prevalence of pneumonia in Chinese children shows a decreasing trend in 2019 compared to 2011, a well-established management system is still needed to further reduce the prevalence of pneumonia and reduce the burden of disease in children.

Hindered visibility improvement despite marked reduction in anthropogenic emissions in a megacity of southwestern China: An interplay between enhanced secondary inorganics formation and hygroscopic growth at prevailing high RH conditions

The PM2.5-bound visibility improvement remains challenging in China despite vigorous control on anthropogenic emissions in recent years. One critical issue could exist in the distinct physicochemical properties especially of secondary aerosol components. Taken the COVID-19 lockdown as an extreme case, we focus on the relationship between visibility, emission cuts, and secondary formation of inorganics with changing optical and hygroscopic behaviors in Chongqing, a representative city characterized with humid weather and poor diffusion conditions in Sichuan Basin, southwest of China.It is found that the increased secondary aerosol abundance (e.g., PM2.5/CO and PM2.5/PM10 as a proxy) with enhanced atmospheric oxidative capacity (e.g., O3/Ox, Ox = O3 + NO2), combined with insignificant meteorological dilution effect, might partly offset the benefit on the improved visibility from substantial reduction in anthropogenic emissions during the COVID-19 lockdown. This is in line with the efficient oxidation rates of sulfur and nitrogen (i.e., SOR, NOR), increasing more significantly with PM2.5 and relative humidity (RH) in comparison to O3/Ox. The resulted larger fraction of nitrate and sulfate (i.e., fSNA) would promote the optical enhancement (i.e., f(RH)) and mass extinction efficiency (MEE) of PM2.5, especially under highly humid conditions (e.g., RH > 80 %, with approximately half of the occurrence frequency). This could further facilitate secondary aerosol formation via aqueous-phase reaction and heterogeneous oxidation, likely due to enhanced water uptake and enlarged size/surface area upon hydration. In combination of gradually increased atmospheric oxidative capacity, this positive feedback would in turn inhibit the visibility improvement particularly at high RH environment.Considering the current air pollution complex status over China, further work on the formation mechanisms of major secondary species (e.g., sulfate, nitrate, and secondary organics), size-resolved chemical and hygroscopic properties, together with their interactions are highly recommended. Our results are hoping to assist in the atmospheric pollution complex mitigation and prevention in China.

Improving land-cover-based expert matrices to quantify the dynamics of ecosystem service supply, demand, and budget: Optimization of weight distribution

Although the land-cover-based expert matrices have been widely used for ecosystem service assessment, criticisms about the accuracy and reliability of this method have never ceased. In this study, we introduced a weight distribution approach called Full Permutation Polygon Synthetic Indicator (FPPSI) into the land-cover-based expert matrices, trying to reduce the systemic flaws caused by the default weight assignment and accumulative calculation form of general matrices method. Taking Hangzhou, a representative city in the rapid urbanization process of China as an example, we used the weight optimization expert matrices to quantify the dynamics of ecosystem service supply, demand, and budget during the period of dramatic land cover change from 1990 to 2020. An indicator named supply–demand balanced index (SDBI) was formulated to describe the supply–demand situation among ecosystem services. The results indicated that with the continuous encroachment of the artificial surface on suburban cultivated land, the supply and demand of the 12 selected ecosystem services had experienced a decreasing trend in varying degrees. The evaluation results derived from the general method indicated that the ecosystem service budget of the study area had dropped by an average of 11.1% in the past 30 years, while the percentage was only 5.7% through the weight optimization method. Through literature review and discussion, we note that ecosystem services assessment is a process fraught with uncertainty. The weight optimization method has the advantage of being convenient, intuitive, and adjustable. It can also export more conservative evaluation results compared with the general method, which can better reflect the dynamic and non-linear process between land use types and ecosystem services to a certain extent. The above findings provide new insights for reducing uncertainty in land-cover-based expert matrices assessments, which can be applied to the practical assessment of ecosystem supply and demand with dramatic land use/land cover changes.

How can mega-events contribute to urban tourism in developing countries? A case study of the 2016 G20 Summit in Hangzhou, China

ABSTRACT Hangzhou is a representative tourism city of natural culture, which has been widely accepted by both domestic and foreign tourists. The success of the 2016 G20 Summit has injected new spirit and connotations into the city’s image. The main purpose of the paper is to investigate how the summit affects Hangzhou’s tourism image and from what aspect it has improved the urban competitiveness of Hangzhou. The statistical data based on questionnaires shows that the G20 Summit does have a great impact on Hangzhou’s tourism development. Furthermore, multivariate factor analysis for the collected data reveals that the summit has the greatest impact on tourism resources and public transport in Hangzhou, which shows that the G20 has a long-term and sustainable impact on the city.

Research on Passive Design Strategies for Low-Carbon Substations in Different Climate Zones

In the energy-saving design of substations, the building envelope thermal parameters, window-to-wall ratio, and shape factor are three crucial influencing factors. They not only affect the building’s appearance but also have an important impact on the total building energy consumption. In this paper, we applied the energy consumption simulation software DeST-c to study the influence of the above three elements on the total energy consumption of the building in a representative city with different thermal zones. The optimal envelope thermal parameters, optimal window-to-wall ratio, and optimal shape factor were derived through combination with economic analysis. Finally, the sensitivity analysis of different elements was carried out to determine the suitable passive design solutions for substations in different climate zones. It was found that the thickness of roof insulation has the greatest influence on the energy consumption of substation buildings among all envelopes. The optimal window-to-wall ratios were 0.4, 0.4~0.5, 0.3, 0.3~0.4, and 0.5 for severe cold, cold, hot summer and cold winter, hot summer and warm winter, and mild regions, respectively; and the optimal shape factors were 0.29, 0.30, 0.23, 0.31, and 0.33, respectively. The conclusions of this study can provide architects with energy-saving design strategies and suggestions for substations in different climate zones, and provide references for building energy-saving designs and air conditioning and heating equipment selection.

Use and Acceptance of Smart Elderly Care Apps Among Chinese Medical Staff and Older Individuals: Web-Based Hybrid Survey Study.

With the advent of China's aging population and the popularization of smartphones, there is a huge demand for smart elderly care apps. Along with older adults and their dependents, medical staff also need to use a health management platform to manage the health of patients. However, the development of health apps and the large and growing app market pose a problem of declining quality; in fact, important differences can be observed between apps, and patients currently do not have adequate information and formal evidence to discriminate among them. The aim of this study was to investigate the cognition and usage status of smart elderly care apps among older individuals and medical staff in China. From March 1, 2022, to March 30, 2022, we used the web survey tool Sojump to conduct snowball sampling through WeChat. The survey links were initially sent to communities in 23 representative major cities in China. We asked the medical staff of community clinics to post the survey link on their WeChat Moments. From April 1 to May 10, 2022, we contacted those who selected "Have used a smart elderly care app" in the questionnaire through WeChat for a request to participate in semistructured interviews. Participants provided informed consent in advance and interviews were scheduled. After the interviews, the audio recordings were transcribed into text and the emerging themes were analyzed and summarized. A total of 810 individuals participated in this study, 54.8% (n=444) of whom were medical staff, 33.1% (n=268) were older people, and the remaining participants were certified nursing assistants (CNAs) and community workers. Overall, 60.5% (490/810) of the participants had used a smart elderly care app on their smartphone. Among the 444 medical staff who participated in the study, the vast majority (n=313, 70.5%) had never used a smart elderly care app, although 34.7% of them recommended elderly care-related apps to patients. Among the 542 medical staff, CNAs, and community workers that completed the questionnaire, only 68 (12.6%) had used a smart elderly care app. We further interviewed 23 people about their feelings and opinions about smart elderly care apps. Three themes emerged with eight subthemes, including functional design, operation interface, and data security. In this survey, there was a huge difference in the usage rate and demand for smart elderly care apps by the participants. Respondents are mainly concerned with app function settings, interface simplicity, and data security.

Does Entrepreneurship Policy Encourage College Graduates’ Entrepreneurship Behavior: The Intermediary Role Based on Entrepreneurship Willingness

With the development of the country’s social and economic transformation, the topic of innovation and entrepreneurship has received widespread attention from society. However, from the current situation, due to the high uncertainty and challenges of entrepreneurship, China’s college graduates’ willingness to start their own business is generally low, and entrepreneurship policy, as a pioneering factor, has an important influence on college graduates’ willingness to start their own business. This study investigates college graduates in more than 20 representative cities, such as Shenyang, Xi’an, and Hangzhou, and examines the influence path and mechanism of entrepreneurship policy on entrepreneurship behavior based on MOA (Model of Attraction) model. This study used SPSS and AMOS to empirically analyze 288 valid questionnaires, verifying that there is a significant positive relationship between entrepreneurship policy, entrepreneurship willingness, and entrepreneurship behavior of college graduates. Entrepreneurship willingness plays a part in mediating the effect between entrepreneurship policy and entrepreneurship behavior, and the willingness to use entrepreneurship policy moderates the path of influence of entrepreneurship policy on entrepreneurship willingness. At the same time, it provides a reference for the promulgation of government entrepreneurship policies and the optimization of the implementation effect of entrepreneurship policy, provides suggestions for universities to improve entrepreneurship education, and has guiding significance for stimulating the entrepreneurship behavior of college graduates.

Resilience of healthy cities in the post-pandemic era: Findings based on internet of things data and artificial intelligence algorithms

This study aims to improve urban resilience in the face of public health emergencies. Therefore, based on the urban resilience development theory, a resilience evaluation index system for healthy cities is constructed. In addition, the Back Propagation Neural Network (BPNN) algorithm and entropy method are combined to empirically evaluate 7 representative cities in the Yangtze River Delta urban agglomeration. Linear regression analysis is carried out on the index weight of the evaluation system, relative proximity degree, and score of urban resilience. The results reveal that social environment and infrastructure are two important factors in the resilience evaluation of healthy cities. Nanjing and Shanghai have relatively good resilience, while Ma'anshan has the worst resilience. It is also found that economic status is the most critical factor affecting urban resilience. Thus, this study enriches the theories related to urban resilience, expands the evaluation system of urban resilience, and opens up a new approach to the quantitative evaluation of urban resilience.

Spatial Pattern and Mechanism of the Life Service Industry in Polycentric Cities: Experience from Wuhan, China

The life service industry is the basic industry to increase employment and to meet people’s needs. Therefore, it is important to reveal its spatial pattern and mechanism. In this paper, we apply the methodologies of kernel density analysis, entropy index, and standard deviational ellipse (SDE) to the point of interest data to explore the spatial distribution of the life service industry in Wuhan, a representative polycentric city in China. We focus on the following seven types of the life service industry: catering, scenic leisure, shopping, scientific-educational, transportation, sports, and healthcare. Our results show that (1) all seven types of the life service industry display a distribution of coexistence of single and multiple centers. (2) The spatial distribution of the seven types of the life service industry in Wuhan shows a pattern of a high degree of mixed use in the central urban area but a low degree in the peripheral urban area. (3) The centers of the SDE are close to one another and are distributed in Wuchang and Jianghan. (4) Except for transportation, the other six types of the life service industry show a trend of development toward the southeast. Our study provides key information for the spatial planning of the life service industry in polycentric cities.

Land Subsidence Monitoring and Building Risk Assessment Using InSAR and Machine Learning in a Loess Plateau City—A Case Study of Lanzhou, China

As a representative city located in the Loess Plateau region of China, Lanzhou is affected by various environmental and engineering factors, such as precipitation, earthquake subsidence, and building construction, which all lead to frequent geological disasters. Obtaining information on land subsidence over a long time series helps us grasp the patterns of change in various types of ground hazard. In this paper, we present the results of using Interferometric Synthetic Aperture Radar (InSAR) to monitor land subsidence in the main urban area of Lanzhou from 26 October 2014 to 12 December 2021. The main influential factors leading to subsidence were analyzed and combined via machine learning simulation to assess the land subsidence risk grade distribution of a building unit. The results show that the annual average deformation rate in Lanzhou ranged from −18.74 to 12.78 mm/yr. Linear subsidence dominated most subsidence areas in Lanzhou during the monitoring period. The subsidence areas were mainly distributed along the Yellow River, the railway, and villages and towns on the edges of urban areas. The main areas where subsidence occurred were the eastern part of Chengguan District, the railway line in Anning District, and the southern parts of Xigu District and Qilihe urban area, accounting for 38.8, 43.5, 32.5, and 51.8% of the area of their respective administrative districts, respectively. The random forest model analysis results show that the factors influencing surface subsidence in Lanzhou were, in order of importance, precipitation, the distribution of faults, the lithology of strata, high-rise buildings, and the distance to the river and railway. Lanzhou experienced excessive groundwater drainage in some areas from 2015 to 2017, with a 1 m drop in groundwater and 14.61 mm surface subsidence in the most critical areas. At the same time, extensive subsidence occurred in areas with highly compressible loess ground and most railway sections, reaching a maximum of −11.68 mm/yr. More than half of the super-tall building areas also showed settlement funnels. The area at a very high risk of future subsidence in Lanzhou covers 22.02 km2, while the high-subsidence-risk area covers 54.47 km2. The areas at greatest risk of future subsidence are Chengguan District and Qilihe District. The city contains a total of 51,163 buildings in the very high-risk area, including about 44.57% of brick-and-timber houses, 51.36% of old housing, and 52.78% of super-tall buildings, which are at especially high risk of subsidence, threatening the lives and properties of the population. The deformation results reveal poor building safety in Lanzhou, providing an essential basis for future urban development and construction.

Optimal Management Strategy for the Deviation of Urban Metro Public Space Development Tendency—Case Study Guangzhou City, China

Based on the existing literature and field observation, the research takes Guangzhou as representative city and its deviation in the development of urban metro public space represented as the research object. It is believed that the deviation is mainly manifested in six dimensions: variables of social demography, details of taking metro, daily stress perception of passengers, perception on humanized design level of metro, perception on integration and intelligent level of metro space, perception on characteristic design and humanistic design level of metro space, and their correlation will be verified through data collection and analysis. The results found that: 1) Stress perception of passengers will lead to a negative predictive effect on passengers’ perception on metro public space development trend. 2) Passengers’ perception on humanized design level of metro will have positive and active effect on their perception on metro public space development trend. 3) Characteristic design and humanistic design level of metro space will lead to a positive predictive effect on passengers’ perception on metro public space development trend. 4) In the process that humanized design level of metro affects passengers’ perception on metro public space development trend, characteristic design and humanistic design level of metro space play a mediating role. 5) Passengers’ stress perception have moderating effect in the process that humanized design level of metro indirectly affects the passengers’ perception on metro public space development trend.

Popular cuisines at tourist tables: Moroccan bissara and its rising path between heritage and commodification

In the current context of debate about food heritage and its implications for territories and communities, this text seeks to trace the history and path of a Moroccan food preparation - the bissara (a fava bean soup) - enlightening the narrative reconfigurations to which this dish has been subjected over time, focusing on its resignification and valorization in the framework of a new global heritage order. Starting from an analysis of historical sources and cookbooks focused on the Moroccan territory, this text also builds on ethnographic fieldwork carried out in Chefchaouen (Morocco) in which participant observation was carried out in markets and restaurants, as well as interviews were conducted with tourists and local inhabitants. The text will discuss how, in a territory marked by the heritage reasoning triggered by the classification of the “Mediterranean Diet” in 2010 by UNESCO - of which Chefchaouen is the representative city of Morocco - the way bissara was re-signified and valued, in its conversion from humble dish to a strong identity dish, is part of a recurrent and contemporary process of obliteration of the past for the creation of commodities with heritage value.

Transient supply-demand matching and numerical parametric study of solar absorption thermal battery for space cooling

Efficient use of renewable energy, e.g., solar energy, is an important pathway towards net-zero energy buildings and carbon neutrality. However, renewable energy is difficult to be fully utilized due to its instability and intermittency. Thermal energy storage technologies applied in buildings can bridge the gap between renewable energy sources and heating/cooling demands. This study employs a solar absorption thermal battery (SATB) in a building for space cooling. The annual dynamic performance of the SATB is investigated and compared in four representative cities by simulation using an experimentally validated model, considering transient supply–demand matching. Besides, parametric studies are conducted for the SATB designed with different solar collector sizes and solution charges. Results indicate that the SATB achieves satisfactory cooling met ratios (MRs) in different climates when 0.49 m2 solar collector is equipped for each square meter of the serviced room. The highest cooling MR of 0.95 is obtained in Singapore, with an energy storage efficiency (ESE) of 0.66 for the ATB unit, a system ESE (solar-to-cooling) of 0.24, and an energy storage density (ESD) of 125.8 kWh/m3. The maximum ESEs of the ATB unit and the SATB system are 0.71 and 0.30, respectively. The highest ESD of 157.1 kWh/m3 is achieved by the SATB system, which is much higher than the sensible and latent thermal batteries for space cooling. This paper demonstrates a transient supply–demand matching operation scheme of the SATB system in different climates with excellent annual performance, which can facilitate the promotion and development of ATB technology.