scholarly journals Asymmetrically Spatial Effects of Urban Scale and Agglomeration on Haze Pollution in China

2019 ◽  
Vol 16 (24) ◽  
pp. 4936 ◽  
Author(s):  
Qingyu Fan ◽  
Shan Yang ◽  
Shuaibin Liu
Keyword(s):  
Population Size ◽  
Urban Population ◽  
Rapid Expansion ◽  
Spatial Effects ◽  
Rapid Urbanization ◽  
Chinese Cities ◽  
Urban Economic ◽  
Haze Pollution ◽  
Economic Agglomeration ◽  
Urban Size

Rapid urbanization in China not only promotes the rapid expansion of urban population and economic agglomeration, but also causes the aggravation of haze pollution. In order to better clarify the asymmetric and nonlinear effects of urban scale and agglomeration on haze pollution, this paper quantitatively evaluates the spatial spillover effects of population size and economic agglomeration on haze pollution in 342 Chinese cities from 2001 to 2016 by using exploratory spatial data analysis (ESDA) and spatial econometric model. The results show the following: (1) During the research period, the distribution of urban scale, agglomeration, and haze pollution in China presented complex asymmetrical features, with the former two presenting a “core–periphery” distribution mode, while the latter having a tendency to spread around. In addition, under the influence of urban population size and economic agglomeration, haze pollution in Chinese cities presents significant spatial autocorrelation, with the agglomeration degrees showing a fluctuating upward trend during the study period. (2) Both urban scale and urban agglomeration have positive global spatiotemporal correlation with haze pollution. Local spatial correlation features are more obvious in China’s emerging urban agglomerations like Beijing–Tianjin–Hebei and Yangtze River Delta. (3) The spatial effects of haze pollution are better evaluated by spatial Durbin model (SDM) with spatial fixed effects, obtaining a coefficient of 0.416, indicating haze in neighboring cities affected each other and had significant spillover. By decomposing the effect of urban scale and agglomeration on haze as direct and indirect effects, the direct effect of urban population size and the indirect effect of urban economic agglomeration are found to be more prominent, reflecting that significant asymmetrical characteristics exist in the spatial effects of urban size and agglomeration on urban haze. (4) Among the control variables that affect China’s rapid urbanization, the level of urban economic development has a positive effect on haze pollution, while the high-level industrial structure and improved technical level can effectively reduce haze pollution. Continuous decline of haze concentration of Chinese cities in recent years has been indicating the spatial relationships between haze and urban size and agglomeration have a decoupling trend. The findings contribute to theory by emphasizing the spillover effect and spatial heterogeneities of geographical factors, and have implications for policy makers to deal with haze pollution reasonably and effectively.

Urbanization and Changes in Cropping Patterns at Kathmandu Valley

2007 ◽  
Vol 7 ◽  
pp. 113 ◽  
Author(s):  
Raj Man Shrestha
Keyword(s):  
Urban Areas ◽  
Cropping System ◽  
Considerable Change ◽  
Rapid Expansion ◽  
Leafy Vegetables ◽  
Kathmandu Valley ◽  
Rapid Urbanization ◽  
Average Growth ◽  
Cropping Patterns ◽  
Agriculture Land

The increase of population in Kathmandu valley is bringing a considerable change in cropping system. Rapid urbanization and introduction of new agriculture technology have encouraged the valley’s farmers to change their cropping patterns from traditional (low value crops) to new crops (high value crops). According to numerous studies made in Nepal, the change is seen considerably in winter crops than in summer crops and the land under cultivation of green leafy vegetables is increasing rapidly in the urban and semi-urban areas. An average growth of population at 3 % in the valley during the period 1951-2001 has resulted in the rapid expansion of area under urban coverage (24.6 % growth per year from 1984 - 2000) has made agriculture land of Katmandu valley to decline per year by 2.04 % (836.27 ha per year). If this trend of decline in agriculture land in Kathmandu valley continues in future too, it is expected that there will be no agriculture land left over by two and half decades in the valley. The planners should take note of this fact that if fertile land of Katmandu valley is to be preserved for agriculture necessary planning is urgently needed. <i>Nepal Journal of Science and Technology</i> Vol. 7, 2006

scholarly journals Does Economic Agglomeration Lead to Efficient Rural to Urban Land Conversion? An Examination of China’s Metropolitan Area Development Strategy

2021 ◽  
Vol 13 (4) ◽  
pp. 2002
Author(s):  
Ke Huang ◽  
Martin Dallimer ◽  
Lindsay C. Stringer ◽  
Anlu Zhang ◽  
Ting Zhang
Keyword(s):  
Development Strategy ◽  
Agricultural Land ◽  
Urban Land ◽  
Urban Land Use ◽  
Productive Efficiency ◽  
Land Conversion ◽  
Negative Consequences ◽  
Natural Habitats ◽  
Rapid Urbanization ◽  
Economic Agglomeration

Urbanization involves expansion of the amount of land covered by urban uses. Rural to urban land conversion (RULC) can satisfy demand for the additional space that growing cities require. However, there can be negative consequences, such as the loss of productive agricultural land and/or the destruction of natural habitats. Considerable interest therefore exists among policy makers and researchers regarding how the efficiency of RULC can be maximized. We used the Gini index and a data envelopment analysis to quantify the relationship between RULC and economic development for 17 metropolitan areas in China. We did this from two perspectives: (i) coordination; and (ii) efficiency. We found that economic agglomeration fosters the coordination of the amount of rural land that is allocated to be converted to urban uses. Similarly, economic agglomeration increases the efficiency of RULC in terms of the processes of socio-economic production. Through production technology innovation and readjustment in the scale of input factors, the productive efficiency of RULC can be promoted. Our findings suggest a need to strictly limit the amount of RULC, design differential land management policies according to location and development level, and adjust RULC allocation between different cities. Further, in harnessing the potential of intensive urban land use and restructuring, production factors, including land, can be enhanced through technological innovation. Research presented in this paper provides insights for areas of the world which are yet to undergo the rapid urbanization that China has experienced, but where it is projected to occur over the coming decades.

scholarly journals Incidence and Risk Factors of Hyperuricemia among 2.5 Million Chinese Adults during the Years 2017–2018

2021 ◽  
Vol 18 (5) ◽  
pp. 2360
Author(s):  
Ruiqi Shan ◽  
Yi Ning ◽  
Yuan Ma ◽  
Xiang Gao ◽  
Zechen Zhou ◽  
...  
Keyword(s):  
Risk Factors ◽  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Population Size ◽  
Incidence Rate ◽  
Urban Population ◽  
Filtration Rate ◽  
Chinese Adults ◽  
Estimate Glomerular Filtration Rate ◽  
Fat Liver

Objective: To assess the incidence and risk factors of hyperuricemia among Chinese adults in 2017–2018. Methods: A total of 2,015,847 adults (mean age 41.2 ± 12.7, 53.1% men) with serum uric acid concentrations assayed on at least two separate days in routine health examinations during 2017–2018 were analyzed. Hyperuricemia was defined as fasting serum urate concentration >420 μmol/L in men and >360 μmol/L in women. The overall and sex-specific incidence rate were stratified according to age, urban population size, geographical region, annual average temperature and certain diseases. Logistic regression analyses were performed to explore risk factors associated with hyperuricemia. Results: 225,240 adults were newly diagnosed with hyperuricemia. The age- and sex-standardized incidence rate per 100 person-years was 11.1 (95%CI: 11.0–11.1) (15.2 for men and 6.80 for women). The risk of hyperuricemia was positively associated with younger age, being male, larger urban population size, higher annual temperature, higher body mass index, lower estimate glomerular filtration rate, hypertension, dyslipidemia and fat liver. Conclusions: The incidence of hyperuricemia was substantial and exhibited a rising trend among younger adults, especially among men. Socioeconomic and geographic variation in incidence were observed. The risk of hyperuricemia was associated with estimate glomerular filtration rate, fat liver and metabolic factors.

Capital Production and Social Equity: Finding Balance in Chinese Cities

2014 ◽  
pp. 28-35
Author(s):  
Andrew Liang
Keyword(s):  
Economic Reform ◽  
Capital Accumulation ◽  
Global Economy ◽  
Social Equity ◽  
Modern Society ◽  
Global Market ◽  
Wealth Creation ◽  
Rapid Urbanization ◽  
Chinese Cities ◽  
The One

China’s massive capital accumulation, economic ascent and wealth production has largely been the result of their rapid urbanization effort. While it is indisputable that the country has largely succeeded in its economic reform efforts given its status as the world’s second largest economy and in that process lifted hundreds of millions of its population out of poverty, it has also, in that process, created severe social inequality and friction. This essay largely argues that Chinese cities are purpose-built financial instruments for capital accumulation, a result of the forces of globalization which could only have happened in sync with the time and space of a global economy. Though highly successful, so far the process has marginalized the objective of social integration into its performative matrix indexing. In this regard China has pursued an exploitive model of market driven urbanization and the resultant morphological and spatial attributes of the Chinese cities, while having achieved spectacular results on many levels, are nevertheless disjunctive. They are commodities of generic sameness that are mass-produced and exhibit the same anesthetizing effects of the spectacle that are ever prevalent in today’s global market production process, product and place. Recognizing that globalization and capitalism are here to stay in the immediate future, it begs the question if China, while having already undertaken extreme economic reform experimentations allowing it to now bask in its temporal success, will be able to leverage its acquired market knowledge and wealth creation to prospectively overcome the incredibly complex challenge of creating equitable cities in the future — ones that balance the demands of capital production on the one hand and social equity on the other — or rather will it sink deeper into the “neoliberal modern society” that it has already become.

scholarly journals Multiperiod Hierarchical Location Problem of Transit Hub in Urban Agglomeration Area

2017 ◽  
Vol 2017 ◽  
pp. 1-15
Author(s):  
Ting-ting Li ◽  
Rui Song ◽  
Shi-wei He ◽  
Ming-kai Bi ◽  
Wei-chuan Yin ◽  
...  
Keyword(s):  
Travel Time ◽  
Urban Population ◽  
Location Problem ◽  
Clonal Selection ◽  
Urban Agglomeration ◽  
Population Migration ◽  
Clonal Selection Algorithm ◽  
Rapid Urbanization ◽  
Transportation Demand ◽  
Hierarchical Location

With the rapid urbanization in developing countries, urban agglomeration area (UAA) forms. Also, transportation demand in UAA grows rapidly and presents hierarchical feature. Therefore, it is imperative to develop models for transit hubs to guide the development of UAA and better meet the time-varying and hierarchical transportation demand. In this paper, the multiperiod hierarchical location problem of transit hub in urban agglomeration area (THUAA) is studied. A hierarchical service network of THUAA with a multiflow, nested, and noncoherent structure is described. Then a multiperiod hierarchical mathematical programming model is proposed, aiming at minimizing the total demand weighted travel time. Moreover, an improved adaptive clonal selection algorithm is presented to solve the model. Both the model and algorithm are verified by the application to a real-life problem of Beijing-Tianjin-Hebei Region in China. The results of different scenarios in the case show that urban population migration has a great impact on the THUAA location scheme. Sustained and appropriate urban population migration helps to reduce travel time for urban residents.

scholarly journals Per capita incidence of sexually transmitted infections increases systematically with urban population size: a cross-sectional study

2015 ◽  
Vol 91 (8) ◽  
pp. 610-614 ◽  
Author(s):  
Oscar Patterson-Lomba ◽  
Edward Goldstein ◽  
Andrés Gómez-Liévano ◽  
Carlos Castillo-Chavez ◽  
Sherry Towers
Keyword(s):  
Sexually Transmitted Infections ◽  
Population Size ◽  
Urban Population ◽  
Cross Sectional Study ◽  
Sectional Study ◽  
Cross Sectional ◽  
Sexually Transmitted ◽  
Per Capita

scholarly journals Scenario of hill cuttings in and around the Chittagong City of Bangladesh

2011 ◽  
Vol 42 ◽  
pp. 183-188
Author(s):  
Asib Ahmed
Keyword(s):  
South Asian ◽  
Urban Growth ◽  
Urban Population ◽  
Industrial Growth ◽  
Rapid Urbanization ◽  
Asian Region ◽  
Green Vegetation ◽  
Land Surfaces ◽  
The City ◽  
South Asian Region

This paper reveals that the Chittagong City is dotted with numerous hills and hillocks, and has gained a peculiar and typical landscape because of these hills. Moreover, it has given the city some environmental advantages with its green vegetation clad slopes and fertile valleys. It also reveals that the city is growing very rapidly and the urban population also increasing alarmingly in the recent years. The rapid urbanization and industrial growth have turned the Chittagong to a most densely city in the South Asian region. In order to facilitate this urban growth tremendous pressure has been exerted on the limited land surfaces in and around the city. These have led into an increasing spree of excavations and cuttings of hillocks and hills in Chittagong City areas. In the present paper, the ca uses, nature and effects of these unwise human interferences in nature have been examined and analyzed.

Do double-edged swords cut both ways? Housing inequality and haze pollution in Chinese cities

2020 ◽  
Vol 719 ◽  
pp. 137404 ◽  
Author(s):  
Qian Zhou ◽  
Xiaoling Zhang ◽  
Jie Chen ◽  
Yanyan Zhang
Keyword(s):  
Chinese Cities ◽  
Haze Pollution ◽  
Housing Inequality

scholarly journals Spatial Effects of Urban Agglomeration on Energy Efficiency: Evidence from China

2020 ◽  
Vol 12 (8) ◽  
pp. 3338 ◽  
Author(s):  
Jiang Du ◽  
Mengqin Zhao ◽  
Ming Zeng ◽  
Kezhen Han ◽  
Huaping Sun
Keyword(s):  
Energy Efficiency ◽  
Spatial Structure ◽  
Spatial Location ◽  
Rapid Expansion ◽  
Spatial Effects ◽  
Positive Role ◽  
Large Cities ◽  
Central Regions ◽  
Spatial Location Information ◽  
Concentration Degree

The rapid expansion of large cities in China has substantially increased energy consumption. With ever stringent environmental policy in force, energy efficiency becomes an important issue. As the emergence of these urban agglomerations (UAs) is usually due to externality effects of spatially concentrated factors, this paper investigates how these factors can affect energy efficiency. Based on mono index, which is used to describe the spatial location information, we have constructed the spatial-structure index of UAs. Using panel data on ten major UAs in China from 2008 to 2017, we find that, in the whole sample, there is an inverse relationship between the spatial structure of UAs and energy efficiency: The higher the concentration degree of factors of UAs, the lower the energy efficiency. Across different regions, however, the relationship between spatial structure and energy efficiency is heterogeneous. The concentration degree of factors in the eastern and central regions of China is relatively high, and the spatial structure there does lead to a decrease in energy efficiency. By contrast, UAs in China’s western region are in a period of factor concentration, with spatial structure playing, in that region, a positive role in improving energy efficiency.

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