Typical Medium-sized City Research Articles

Identifying the priority areas for ecological protection considering ecological connectivity and ecosystem integrity: A case study of Xianyang City, China

Identifying ecological protection priority areas (EPPAs) in municipal areas is essential for accurate ecological restoration and ensuring sustainable regional development. Xianyang represents a typical medium-sized city that is currently grappling with the dual challenges of ecological restoration and urban development. This study employed a multi-criteria method to evaluate ecological importance, considering both ecosystem services and ecological vulnerability. Based on this, ecological corridors and pinch points that enhance ecological connectivity were delineated using the circuit theory. Subsequently, the integrity of ecosystems is assessed from structural and functional perspectives to ensure their health and stability. With the support of Geographic Information System (GIS) technology, the three important areas for ecological protection were integrated to designate EPPAs. The results showed that: (1) the extremely important area spans 1956.44 km2, primarily made up of forests and grasslands. (2) There were found to be 19 ecological sources, 26 ecological corridors, and 23 ecological pinch points. (3) With excellent ecosystem integrity, the region was dominated by eco-lands, which accounted for 2692.71 km2. (4) In the end, this study identified 3328.83 km2 of EPPAs, 32.65 % of the study area. These are primarily located in the northern mountains and major watersheds. Human activities are found as the most important factor for the overall spatial variations in the area. A multi-level framework was developed to establish a continuous, comprehensive, and systematic method for identifying EPPAs, thereby enhancing ecological restoration, protection, and the sustainable use of regional ecosystems.

Impact on the German asymptomatic screening strategy based on actual user data from SARS-CoV-2 test centers

Since March 2021, Germany has been providing cost-free severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antigen tests, and many day-to-day activities following the lockdown have required negative test results. Yet it remains unclear how tests have been used and whether there are patterns connected to mitigation measures. We analyzed over 50,000 anonymized records from eight test centers in a typical medium-sized city, with one of them remaining open continuously from March until December 2021. The centers exhibit distinct patterns of visitor types, with the majority tested only once in the investigated period. Individuals who underwent repeated testing tended to favor the same location. A preference for spontaneous testing grew in proportion to the availability of spare tests. Visitors aged 18 to 30 years were distinctly overrepresented compared to the local demographic. A negative binominal model showed that implemented mitigation measures had an impact on the number of tests conducted. Cost-free testing in private facilities was implemented into the German complementary screening strategy, aiming to achieve weekly population-wide testing. This study demonstrates these facilities were rarely used for regular testing but rather for meeting requirements of certified tests. The results should aid authorities in making future decisions regarding infection control.

Personal air pollution exposure during morning commute car and active transport journeys

IntroductionCommuting by car in cities during rush hour can potentially result in the commuter being exposed to large concentrations of pollutants. We investigated the differences in pollutant concentrations by commute type in real world journeys in a typical medium-sized city in the UK. MethodsNO2, O3 and PM2.5 concentrations were monitored on weekday morning commutes into Leicester city centre on four routes. A driving commute was made on all four routes and were paired with measurements made via an active commute (either driving or cycling). The average commute exposure to pollutants was determined and the inhaled dosage was estimated. ResultsAverage in-car NO2 concentrations were 30.3 μg m−3and 24.9 μg m-3 higher than that measured in the cycling commutes, and 31.6 μg m−3 and 5.7 μg m−3 higher than average concentrations measured during walking commutes. In-car O3 concentrations were higher than concentrations measured during cycling (8.4 μg m−3, 35.6 μg m−3) and walking commutes (15.5 μg m−3and 33.1 μg m−3). Average in car PM2.5 were 1.8 μg m−3 and 4.3 μg m −3 lower than average concentrations measured during cycling and 1.9 μg m−3 and 1.5 μg m−3 lower than average concentrations measured whilst walking. We calculated higher cumulative doses of pollutants in the active commute compared to the driving commute. However, the health benefits of exercise, through improved physical and mental health as outlined in the literature are expected to outweigh any adverse impacts of the inhaled dosage of pollutants monitored. ConclusionsConcentrations of air pollutants in cars can be considerably higher than concentrations faced by active travellers. Commuters sitting in cars can both miss the benefits of physical activity and be exposed to higher levels of NO2 than in active transport, which is particularly important in countries like the UK with NOx exceedances.

Characteristics of VOCs and their Potentials for O3 and SOA Formation in a Medium-sized City in Eastern China

To understand the characteristics and environmental effects of volatile organic compounds (VOCs) in a typical medium-sized city in China, manual measurements including 56 species of the nonmethane hydrocarbons (NMHCs) were taken at three urban and suburban sites in Huai’an from April to September 2019, and automatic measurements including 106 species of VOCs were taken at the urban center in May and August 2019. Spatial and temporal characteristics of the VOC concentrations were analyzed. Positive matrix factorization (PMF) model was applied to apportion VOC sources. Ozone (O3) formation potentials (OFPs) and secondary organic aerosol (SOA) formation potentials (SOAFPs) were calculated. The results show that the mean VOC concentration was much lower in the urban center than in the suburbs. Generally, proportions of both alkenes and aromatic hydrocarbons were higher and proportion of alkanes was lower in Huai’an than that in big cities, indicating emissions from solvent usage and industrial process play a more important role in the medium-sized city. The results of source apportionment show that solvent usage and industrial process together contributed 53%, and vehicle emission contributed 27% to the ambient VOCs. The dependence of VOC concentrations on temperature indicates that a considerable part of VOCs may come from fugitive emissions. The two-peak pattern of diurnal variation suggests near-surface emissions contributed a lot to the VOCs. Aromatic hydrocarbons were identified as the key component to the formation of O3 and SOA. Furthermore, biogenic emission could contribute greatly (> 20%) to the ambient VOCs during daytime in summer, which may have significant effects on O3 formation. Aromatic hydrocarbons were identified as the key component to the formation of O3 and SOA, which should be given more attention in developing air pollution control strategies.

Source apportionment of VOCs in a typical medium-sized city in North China Plain and implications on control policy

Characteristics of atmospheric VOCs (volatile organic compounds) have been extensively studied in megacities in China, however, they are scarcely investigated in medium/small-sized cities in North China Plain (NCP). A comprehensive research on possible sources of VOCs was conducted in a medium-sized city of NCP, from May to September 2019. A total of 143 canister samples of 8 sites in Xuchang city were collected, and 57 VOC species were detected. The average VOC concentrations were 42.6 ± 31.6 μg/m3, with 53.7 ± 31.0 μg/m3 and 32.1 ± 27. 8 μg/m3, in the morning and afternoon, respectively. Alkenes and aromatics contributed 80% of the total ozone formation potential (OFP). Aromatics accounted for more than 95% of secondary organic aerosol potential (SOAP). VOCs were dominated by the local emission with significant transport from the southeast direction. PMF analysis extracted 6 sources, which were combustion (33.1%), LPG usage (19.3%), vehicular exhaust & fuel evaporation (15.8%), solvent usage (15.2%), industrial (9.11%) and biogenic (7.51%), respectively and they contributed 33.4%, 17.6%, 12.9%, 18.6%, 9.28% and 8.22% to the OFP, respectively. Combustion and LPG usage were the dominant VOC sources; and combustion, solvent usage and LPG usage were the main sources of OFP in Xuchang city, which were different to megacities in China with a high contribution from vehicular exhaust, solvent usage and industry, suggesting specific control strategies on VOCs need to be implemented in medium-sized city such as Xuchang city.

Data Collection and Application of COVID-19 in Medium-Sized Cities—Taking Macau as an Example

Convenient transportation and the large flow of residents in the city give rise to the wide spread of COVID-19. Data collection plays a crucial role in determining the effectiveness of the control of the pandemic. The pandemic is not only a serious problem in large cities, but also hitting medium-sized cities. Macau is a typical medium-sized city where the pandemic has been under effective control with comprehensive data collection. This thesis will conduct in-depth research on the collection and application of the statistics about COVID-19 in Macau. Macau collects data through the border, incorporating NAT (nucleic acid testing) data and health codes into daily-used mobile applications, which features a network with real-time updates and sharing. This thesis will connect to the construction of smart cities to provide ideas for handling large-scale public health issues in medium-sized cities.

Sources and trends of oxidized and reduced nitrogen wet deposition in a typical medium-sized city of eastern China during 2010–2016

Fluxes and composition dynamics of atmospheric nitrogen deposition play key roles in better balancing economic development and ecological environment. However, there are some knowledge gaps and difficulties in urban ecosystems, especially for small and medium-sized cities. In this study, both flux and composition (ratio of NH4+-N to NO3−-N, RN) of wet-deposited dissolved inorganic nitrogen (DIN, sum of NO3−-N and NH4+-N) were estimated and sources were identified at a long-term urban observation station in Tongling, a typical medium-sized city in eastern China during 2010–2016, respectively. Results showed that wet-deposited DIN fluxes were 33.20 and 28.15 kgN ha−1 yr−1 in Tongling city during 2010–2011 and 2015–2016, respectively. Compared to these two periods, both DIN and NO3−-N fluxes decreased by 15.2% and 31.8% for a series of NOx abatement measures applied effectively, respectively. At the same time, the NH4+-N flux remained stable and ranged from 19.53 to 20.62 kgN ha−1 yr−1, and the RN increased from 1.7 to 2.2. Seasonally, winds from the southwest and west-southwest with higher frequencies and speeds in spring and summer brought more NH4+-N and DIN wet deposition from an ammonia plant, which could threaten the safety of regional hydrosphere ecosystems. On the whole, the wet-deposited NH4+-N was threatening regional ecosystems of both the hydrosphere and forest. The wet-deposited DIN including NH4+-N in Tongling city stemmed mainly from a combined source of coal combustion and dust from Cu extraction and smelting, ammonia production, and roads. Therefore, production lines should be updated for Cu extraction and smelting industries, thermal power generations and the ammonia plant, old vehicles should be eliminated, and the use of new energy vehicles should be promoted for regional sustainable development and human health in the medium-sized city.

City Profile: Datong, China

Small- and medium-sized cities have not received enough scholarly attention in China. In fact, these cities have a larger share of urban population than large-sized cities. Therefore, the paper focuses on one such typical medium-sized city in North China named Datong; a resource-reliant city with a long history but undergoing a difficult phase of transformation. Its industrial structure is upgrading from unitary resource-dependence to balanced development, but it is also accompanied by recessive unemployment and a depressed consumption pattern of its residents. Datong’s urban planning generally reflects the ideas of its leaders and often demonstrates high efficiency and execution. However, abrupt change in the leadership has brought new challenges such as constant adjustment and restructuring along with huge investment and financial risks to cities. This model also fully illustrates the self-repairing and error-correcting ability, which is guiding Datong towards sustainable development.

Fraction distribution of arsenic in different-sized atmospheric particulate matters.

The sequential extraction method was used to determine the fraction of arsenic (As) in different-sized particulate matters (PMs) (i.e., PM2.5, PM10, and total suspended particles (TSP)). Samples were collected from Baoding, a typical medium-sized city with the serious haze pollution in China. The bioavailabilities of As in the samples were estimated based on the fraction results. A large percentage of fine particles were detected in TSP, with the average PM2.5/PM10 and PM10/TSP ratios all above 0.69. The total concentrations of As in PM2.5, PM10, and TSP samples were in the range of 4.5-296.4, 14.1-708.0, and 32.8-798.0ngm-3, respectively. The mass percentages of As in PM2.5, PM2.5-10, and PM10-100 were calculated; the results indicated that As tended to concentrate in fine particles. PM-bound As mainly presented in the nonspecifically sorbed fraction (F1) during all of the sampling periods. The percentages of F1-As and bioavailability of As were higher in PM2.5, followed by PM10 and TSP. By contrast, the residual fraction (F5-As) contents declined in the order of TSP > PM10 > PM2.5. Significant differences in the speciation and bioavailability of As in different-sized PMs were found, and the influence of particle size on the speciation and bioavailability of As in PMs was verified. Fine particles adsorbed more Aswith higher bioavailability, and potentially led to more serious adverse effects on human health than the larger ones.

Spatial distribution of SO2 concentration and population exposure in the tropical city of Villahermosa, Mexico

A hybrid system to compute a fine-resolution spatial distribution of population exposure to SO2 concentration due to mobile and area sources in the tropical city of Villahermosa is described, which consists of an air dispersion model, GIS analysis techniques, and a static exposure model. A methodology to spatially allocate SO2 emissions has been applied, which is adapted to the characteristics of a typical medium-sized city in a developing country. It was estimated that 363.2 tons of SO2 was emitted in the Villahermosa Metropolitan Zone, 21.3 % of which was produced by area sources and 78.7 % by mobile sources. The highest spatially allocated emissions were located in main road intersections, where they reached a maximum value of 39,804 μg s−1, and, in a lesser measure, in the most populated areas of Villahermosa. Performance of the ISCST3 model to simulate hourly SO2 concentrations was similar to that of other studies. The highest SO2 concentrations were located at intersections of main roads in the south-central and southwestern Villahermosa. On the other hand, the lowest SO2 concentrations were found in its north-central district. The highest population exposure to SO2 concentrations was located in areas with high population density like southwestern, south-central, and northeastern Villahermosa. On the other hand, its north-central zone had the lowest exposure due to a low SO2 concentration and low population density.

Establishment and evaluation of a model of a community health service in an underdeveloped area of China

To develop and evaluate an applicable model for a community health service (CHS) in an underdeveloped area of China that ensures efficient, convenient and affordable primary healthcare access for all residents. The current study was carried out in Puyang, a typical medium-sized city in central-eastern China. Based on the healthcare requirements of the residents in Puyang, a CHS network was set up and its operation was evaluated from 1999 to 2006. The system is characterized by its focus on community health education (CHE). Firstly, 8231 residents, selected at random, were surveyed to investigate the healthcare requirements of the local residents. Meanwhile, the operation of the pre-existing healthcare resources was investigated in Puyang. Based on the information gained, a network-based CHS system was proposed and established, with CHE as the major focus. This study compared CHS operation prior to and after establishment of the network. Finally, an analytic hierarchy process based evaluation model was applied to evaluate the operation of the CHS network. There was a high prevalence (86.98 per thousand) of chronic diseases among the residents who participated in this investigation. The majority (84.39%) of the residents who had healthcare requirements resorted to professional health care; the other residents did not have access to health services. Among those residents who sought professional treatment, 71.3% visited primary healthcare institutions. This information reflects the enormous requirement for a CHS in primary health care but the lack of accessibility among the residents; this motivated the authors to establish a system to solve the problem. The improvement in CHS operation after the network was established suggests the importance of a network for optimizing the primary healthcare system. The improvement was indicated by better understanding of the residents regarding the CHS, and enhanced capability of self-monitoring for chronic diseases such as hypertension after the network was established. Moreover, the residents' knowledge of health care was significantly increased and, accordingly, the incidence of health risk behaviour was reduced after the network was established. Furthermore, the CHE index between 1999 and 2006 showed good correlation (r=0.988, p<0.005) with the CHS index, suggesting the important role of CHE in CHS development. A network-characterized CHS system was established in Puyang, and improved the primary healthcare situation. This study provides a feasible model for the development of a CHS in medium and small cities in underdeveloped parts of China.

Police and the Policed: A Comparison of Value Orientations and Ideological Perspectives

The local foundations of law enforcement, public schools, and numerous types of special purpose governments are intended to ensure a close relationship between prevailing community values and policy preferences. Community policing is one of such attempts to promote police and resident partnership in reducing local social disorder and crimes. This article makes use of Rokeach's theory of human values and his survey instrument and analytical methodology to assess the degree to which the values and ideological perspectives of police officers differ from those of the citizens they serve in a typical medium-sized city (about 170 000 population) in the Western region of the United States. The results reported here indicate that there is a substantial difference in value orientations and in ideological perspectives between police officers and citizens in this city. The implications of these findings are discussed with respect to the successful implementation of community policing.

Projects: The PUMP Algebra Project Plays in Peoria

The Peoria Urban Mathematics Plan (PUMP) Algebra Project is a systemic effort to increase the number of students, particularly minorities, in the algebra track of schools in a typical medium-sized city. Funded by the National Science Foundation, this three-and-a-half-year project is based in Peoria, Illinois, a district with a 50 percent African American enrollment among its 17 000 students.