scholarly journals City-size bias in knowledge on the effects of urban nature on people and biodiversity

2020 ◽  
Vol 15 (12) ◽  
pp. 124035 ◽  
Author(s):  
Dave Kendal ◽  
Monika Egerer ◽  
Jason A Byrne ◽  
Penelope J Jones ◽  
Pauline Marsh ◽  
...  
Keyword(s):  
2020 ◽  
Vol 46 (3) ◽  
pp. 379-397
Author(s):  
Chunyang Wang

This paper measures the spatial evolution of urban agglomerations to understand be er the impact of high-speed rail (HSR) construction, based on panel data from fi ve major urban agglomerations in China for the period 2004–2015. It is found that there are signi ficant regional diff erences of HSR impacts. The construction of HSR has promoted population and economic diff usion in two advanced urban agglomerations, namely the Yang e River Delta and Pearl River Delta, while promoting population and economic concentration in two relatively less advanced urban agglomerations, e.g. the middle reaches of the Yang e River and Chengdu–Chongqing. In terms of city size, HSR promotes the economic proliferation of large cities and the economic concentration of small and medium-sized cities along its routes. HSR networking has provided a new impetus for restructuring urban spatial systems. Every region should optimize the industrial division with strategic functions of urban agglomeration according to local conditions and accelerate the construction of inter-city intra-regional transport network to maximize the eff ects of high-speed rail across a large regional territory.


Land ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 341
Author(s):  
Ralf-Uwe Syrbe ◽  
Ina Neumann ◽  
Karsten Grunewald ◽  
Patrycia Brzoska ◽  
Jiři Louda ◽  
...  

The quality of life in our cities critically depends on the intelligent planning and shaping of urban living space, in particular urban nature. By providing a wide range of ecosystem services (ES), urban nature essentially contributes to the well-being of city dwellers and plays a major role in avoiding common diseases through its positive impact on physical and mental health. Health is one of the most important factors underlying human welfare and is, thus, vital to sustainable development. The ES of urban green space provide other social-cultural functions alongside public health, for example by fostering environmental justice and citizenship participation. Thus, they should always be considered when searching for solutions to urban problems. The aim of this research was to determine the impact of green areas in three selected cities on the health and well-being of people by self-reporting of green areas’ visitors. To this end, we posed the research question: which types and characteristics of urban green space are most appreciated by city dwellers? Based on our findings, we have drawn up recommendations for practices to promote better living conditions. We have also pinpointed obstacles to and opportunities for leisure time activities as well as ways of supporting the public health of citizens.


2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Akram Hernández-Vasquéz ◽  
Carlos Rojas-Roque ◽  
Denise Marques Sales ◽  
Marilina Santero ◽  
Guido Bendezu-Quispe ◽  
...  

Abstract Background Peru is one of the countries with the lowest percentage of population with access to safe drinking water in the Latin American region. This study aimed to describe and estimate, according to city size, socioeconomic inequalities in access to safe drinking water in Peruvian households from 2008 to 2018. Methods Secondary analysis of cross-sectional data using data from the 2008–2018 ENAHO survey. Access to safe drinking water, determined based on the presence of chlorinated water supplied by the public network, as well as socioeconomic variables were analyzed. A trend analysis from 2008 to 2018, and comparisons between 2008 versus 2018 were performed to understand and describe changes in access to safe drinking water, according to city size. Concentration curves and Erreygers concentration index (ECI) were estimated to measure inequalities in access to safe drinking water. Results In 2008, 47% of Peruvian households had access to safe drinking water, increasing to 52% by 2018 (p for trend < 0.001). For small cities, access to safe drinking water did not show changes between 2018 and 2008 (difference in proportions − 0.2 percentage points, p = 0.741); however, there was an increase in access to safe drinking water in medium (difference in proportions 3.3 percentage points, p < 0.001) and large cities (difference in proportions 12.8 percentage points, p < 0.001). The poorest households showed a decreasing trend in access to safe drinking water, while the wealthiest households showed an increasing trend. In small cities, socioeconomic inequalities showed an increase between 2008 and 2018 (ECI 0.045 and 0.140, p < 0.001), while in larger cities, socioeconomic inequality reduced in the same period (ECI: 0.087 and 0.018, p = 0.036). Conclusions We report a widening gap in the access to safe drinking water between the wealthiest and the poorest households over the study period. Progress in access to safe drinking water has not been equally distributed throughout the Peruvian population. Promoting and supporting effective implementation of policies and strategies to safe drinking water, including equity-oriented infrastructure development and resource allocation for most vulnerable settings, including emerging small cities, is a priority.


2021 ◽  
pp. 127100
Author(s):  
Hongxiao Liu ◽  
Ren Hai ◽  
Roy P. Remme ◽  
Huifu Nong ◽  
Chunhua Sui
Keyword(s):  

1995 ◽  
Vol 24 (4) ◽  
pp. 794-795
Author(s):  
R.V. Pouyat
Keyword(s):  

Author(s):  
Min Shang ◽  
Ji Luo

The expansion of Xi’an City has caused the consumption of energy and land resources, leading to serious environmental pollution problems. For this purpose, this study was carried out to measure the carbon carrying capacity, net carbon footprint and net carbon footprint pressure index of Xi’an City, and to characterize the carbon sequestration capacity of Xi’an ecosystem, thereby laying a foundation for developing comprehensive and reasonable low-carbon development measures. This study expects to provide a reference for China to develop a low-carbon economy through Tapio decoupling principle. The decoupling relationship between CO2 and driving factors was explored through Tapio decoupling model. The time-series data was used to calculate the carbon footprint. The auto-encoder in deep learning technology was combined with the parallel algorithm in cloud computing. A general multilayer perceptron neural network realized by a parallel BP learning algorithm was proposed based on Map-Reduce on a cloud computing cluster. A partial least squares (PLS) regression model was constructed to analyze driving factors. The results show that in terms of city size, the variable importance in projection (VIP) output of the urbanization rate has a strong inhibitory effect on carbon footprint growth, and the VIP value of permanent population ranks the last; in terms of economic development, the impact of fixed asset investment and added value of the secondary industry on carbon footprint ranks third and fourth. As a result, the marginal effect of carbon footprint is greater than that of economic growth after economic growth reaches a certain stage, revealing that the driving forces and mechanisms can promote the growth of urban space.


2021 ◽  
Vol 13 (5) ◽  
pp. 2930
Author(s):  
Pengfei Ban ◽  
Wei Zhan ◽  
Qifeng Yuan ◽  
Xiaojian Li

Cities defined mainly from the administrative aspect can create impact and problems especially in the case of China. However, only a few researchers from China have attempted to identify urban areas from the morphology dimension. In addition, previous studies have been mostly based on the national and regional scales or a single prefecture city and have completely ignored cross-boundary cities. Defining urban areas on the basis of a single data type also has limitations. To address these problems, this study integrates point of interest and nighttime light data, applies the breaking point analysis method to determine the physical geographic scope of the Guangzhou–Foshan cross-border city, and then compares this city with Beijing and Shanghai. Results show that Guangzhou–Foshan comprises one core urban area and six suburban counties, among which the core urban area extends across the administrative boundaries of Guangzhou and Foshan. The urban area and average urban radius of Guangzhou–Foshan are larger than those of Beijing and Shanghai, and this finding contradicts the city size measurements based on the administrative division system of China and those published on traditional official statistical yearbooks. In terms of urban density value, Shanghai has the steepest profile followed by Guangzhou–Foshan and Beijing, and the profile line of Guangzhou–Foshan has a bimodal shape.


Author(s):  
Paul de Boissieu ◽  
Serge Guerin ◽  
Véronique Suissa ◽  
Fiona Ecarnot ◽  
Aude Letty ◽  
...  

Abstract Background There is a compelling need to prepare our societies and healthcare systems to deal with the oncoming wave of population ageing. The majority of older persons maintain a desire to be valued and useful members of society and of their social networks. Aims We sought to investigate the perception of usefulness among persons aged 65 years and over in four European countries. Methods We performed a cross-sectional survey with a representative sample of individuals aged 65 years or older from the population of retired persons (including recently retired persons and oldest-old individuals) from 4 European countries selected using quota sampling. In February 2016, an internet questionnaire was sent to all selected individuals. The characteristics used for the quota sampling method were sex, age, socio-professional category, region, city size, number of persons in household, autonomy, marital status, place of residence, income and educational status. The questionnaire contained 57 questions. Sociodemographic characteristics were recorded. Responses were analysed with principal components analysis (PCA). Results A total of 4025 persons participated; 51% were males, and 70% were aged 65–75 years. PCA identified six classes of individuals, of which two classes (Classes 2 and 3) were characterized by more socially isolated individuals with little or no sense of usefulness, low self-esteem and a poor sense of well-being. These two classes accounted for almost 20% of the population. Younger and more autonomous classes reported a more salient sense of usefulness. Conclusions The loss of the sense of usefulness is associated with dissatisfaction with life and a loss of pleasure, and persons with profiles corresponding to Classes 2 and 3 should, therefore, be targeted for interventions aimed at restoring social links.


2019 ◽  
Vol 43 (6) ◽  
pp. 632-654
Author(s):  
Daidai Shen ◽  
Jean-Claude Thill ◽  
Jiuwen Sun

In this article, the socioeconomic determinants on urban population in China are empirically investigated with a theoretical equilibrium model for city size. While much of the research on urban size focuses on the impact of agglomeration economies based on “optimal city size” theory, this model is eschewed in our research due to its theoretical paradox in the real world, and we turn instead toward an intermediate solution proposed by Camagni, Capello, and Caragliu. This equilibrium model is estimated on a sample of 111 prefectural cities in China with multiple regression and artificial neural networks. Empirical results have shown that the model explains the variance in the data very well, and all the determinants have significant impacts on Chinese city sizes. Although sample cities have reached their equilibrium sizes as a whole, there is substantially unbalanced distribution of population within the urban system, with a strong contingent of cities that are either squarely too large or too small.


2020 ◽  
Vol 12 (15) ◽  
pp. 5954
Author(s):  
Juste Raimbault ◽  
Eric Denis ◽  
Denise Pumain

Cities are facing many sustainability issues in the context of the current global interdependency characterized by an economic uncertainty coupled to climate changes, which challenge their local policies aiming to better conciliate reasonable growth with livable urban environment. The urban dynamic models developed by the so-called “urban science” can provide a useful foundation for more sustainable urban policies. It implies that their proposals have been validated by correct observations of the diversity of situations in the world. However, international comparisons of the evolution of cities often produce unclear results because national territorial frameworks are not always in strict correspondence with the dynamics of urban systems. We propose to provide various compositions of systems of cities in order to better take into account the dynamic networking of cities that go beyond regional and national territorial boundaries. Different models conceived for explaining city size and urban growth distributions enable the establishing of a correspondence between urban trajectories when observed at the level of cities and systems of cities. We test the validity and representativeness of several dynamic models of complex urban systems and their variations across regions of the world, at the macroscopic scale of systems of cities. The originality of the approach resides in the way it considers spatial interaction and evolutionary path dependence as major features in the general behavior of urban entities. The models studied include diverse and complementary processes, such as economic exchanges, diffusion of innovations, and physical network flows. Complex systems dynamics is in principle unpredictable, but contextualizing it regarding demographic, income, and resource components may help in minimizing the forecasting errors. We use, among others, a new unique source correlating population and built-up footprint at world scale: the Global Human Settlement built-up areas (GHS-BU). Following the methodology and results already obtained in the European GeoDiverCity project, including USA, Europe, and BRICS countries, we complete them with this new dataset at world scale and different models. This research helps in further empirical testing of the hypotheses of the evolutionary theory of urban systems and partially revising them. We also suggest research directions towards the coupling of these models into a multi-scale model of urban growth.


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