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1.
Environ Monit Assess ; 193(3): 130, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33587190

RESUMO

Land use/cover change is the main driving force of urban expansion which influences human-environment interactions. Generally, the formation of urban heat islands (UHIs) can be referred to as a negative "by-product" of urbanization. In the context of rapid urbanization, the present paper aims to capture the landscape changes and three patterns of urban expansion (i.e., infill, extension, and leapfrog), and provide a better understanding of the formation of the surface urban heat island (SUHI) in Dongguan, China, during the past 20+ years. Urban land increased from 28.87 × 103 ha in 1994 to 78.89 × 103 ha in 2005 and 101.05 × 103 ha in 2015, with a compound annual urban growth rate of 9.57% (1994-2005) and 2.51% (2005-2015), respectively. Based on the mean land surface temperature difference (Δ mean LST) between urban land (UL) and green space (GS), the SUHI intensity (SUHII) increased from 1.46 °C in 1994 to 2.32 °C in 2005 and 3.83 °C in 2015 in Dongguan. Overall, the Δ mean LST of urban areas increased from 2.61 °C (1994-2005) to 4.78 °C (2005-2015). The Δ mean LST between the city center and its surrounding areas decreased from 1994 to 2015, and the Δ mean LST between the city center and the suburbs gradually increased, primarily in 2015. In particular, both dense urban and the infill pattern of urban expansion had high mean LSTs in Dongguan, thus having negative impacts on sustainable urban development. The limited green space and open land should be strictly controlled or prohibited for transformation in urban areas. Particularly in dense regions, green roofs, green areas, and urban renewal actions could be considered for mitigating the urban heat island effect.


Assuntos
Temperatura Alta , Reforma Urbana , China , Cidades , Monitoramento Ambiental , Humanos , Ilhas , Urbanização
2.
Artigo em Inglês | MEDLINE | ID: mdl-33504043

RESUMO

Urban resilience in the context of COVID-19 epidemic refers to the ability of an urban system to resist, absorb, adapt and recover from danger in time to hedge its impact when confronted with external shocks such as epidemic, which is also a capability that must be strengthened for urban development in the context of normal epidemic. Based on the multi-dimensional perspective, entropy method and exploratory spatial data analysis (ESDA) are used to analyze the spatiotemporal evolution characteristics of urban resilience of 281 cities of China from 2011 to 2018, and MGWR model is used to discuss the driving factors affecting the development of urban resilience. It is found that: (1) The urban resilience and sub-resilience show a continuous decline in time, with no obvious sign of convergence, while the spatial agglomeration effect shows an increasing trend year by year. (2) The spatial heterogeneity of urban resilience is significant, with obvious distribution characteristics of "high in east and low in west". Urban resilience in the east, the central and the west are quite different in terms of development structure and spatial correlation. The eastern region is dominated by the "three-core driving mode", and the urban resilience shows a significant positive spatial correlation; the central area is a "rectangular structure", which is also spatially positively correlated; The western region is a "pyramid structure" with significant negative spatial correlation. (3) The spatial heterogeneity of the driving factors is significant, and they have different impact scales on the urban resilience development. The market capacity is the largest impact intensity, while the infrastructure investment is the least impact intensity. On this basis, this paper explores the ways to improve urban resilience in China from different aspects, such as market, technology, finance and government.


Assuntos
Análise Espaço-Temporal , Reforma Urbana , China , Cidades , Humanos , Pandemias
3.
PLoS One ; 15(12): e0243344, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33332364

RESUMO

Urban, peri-urban forests and other natural areas provide a wide range of material and non-material benefits to people known as ecosystem services. Access to these areas has been linked to benefits for physical and mental health of local populations. In the spring of 2020, the COVID-19 global pandemic forced many governments to impose a set of restrictions including the closure of businesses, cancelation of public events and schooling, social distancing, limitations on the size of social gatherings, and travel restrictions. During this period of restrictions, we conducted a study assessing the importance of urban and peri-urban forests and other natural areas to people living in and around the city of Burlington, Vermont, USA. We evaluated the self-reported use and changes in personal importance related to these natural areas before and during the period of restrictions. We received over 400 responses to our field survey. The results show that 69.0% of the respondents had increased or greatly increased their visitation rate to our natural areas and urban forests, and 80.6% of respondents considered that the importance of these areas, and access to them, either increased or greatly increased. Moreover 25.8% of the sample had either never, or very rarely accessed their local natural areas before the pandemic, but 69.2% of the first time or infrequent visitors reported that having access to these areas during COVID-19 as 'very important'. People reported that these areas were important for a wide range of activities from exercise to birding, but also reported values related to reducing stress in a time of global chaos. Our results indicate the increasing demand and value of such areas in times of crisis such as COVID-19. Experts in zoonotic disease predict the potential for more frequent pandemic events, thus predicating the importance for continued funding for, maintenance of, and improved access to, natural areas to our largely urban civilization.


Assuntos
Conservação dos Recursos Naturais , Florestas , Pandemias , Reforma Urbana , Humanos , Vermont
4.
PLoS One ; 15(12): e0244084, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33347454

RESUMO

Regional differences in socioeconomic factors are important for assessing the regional development of an area. While much research has focused on the overall patterns of regional differences within independent cities and areas, the hierarchical spatiotemporal structures of megacity regions have seldom been discussed. To fill this gap, this paper investigates the multilevel regional differences within megacity regions. Employing GDP, population and total retail sales as socioeconomic indicators, the spatiotemporal patterns of socioeconomic trends are identified. A hierarchical clustering approach that utilizes socioeconomic similarities is proposed for the identification of the spatiotemporal patterns of individual cities. At the megacity regional level, gravity centers and pathways are constructed to evaluate spatial imbalances and temporal change intensities. Taking the Guangdong-Hong Kong-Macao Greater Bay Area (GBA) as its study area, this research produces results that show diverse spatiotemporal patterns among the individual cities, revealing high/low starting point and high/low growth rate modes in terms of city interactions. From the perspective of the entire GBA, the spatial imbalance of GDP is the highest of the factors, followed by the spatial imbalance of the total retail sales of the region and, finally, by that of its population. Total retail sales exhibit the highest level of temporal change intensity, followed by GDP and population. In terms of the contribution of the various cities to the overall regional changes, Guangzhou, Shenzhen and Hong Kong dominate the spatiotemporal changes in the gravity centers, while Foshan and Dongguan show significant potential to contribute to these socioeconomic patterns. These results provide effective guidance for the sustainable development of megacity regions.


Assuntos
Conservação dos Recursos Naturais , Reforma Urbana , Cidades , Hong Kong , Macau , Fatores Socioeconômicos
5.
PLoS One ; 15(12): e0243949, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33362258

RESUMO

Small-scale urban agriculture is associated with positive health and environmental outcomes. Previous studies examined factors that drive people to grow foods in urban areas mainly drawing on qualitative data. This research investigates quantitatively what determines consumer preferences for growing foods in community gardens, informing efforts to upscale urban agriculture. We conducted choice experiments in North America and performed latent class analysis of contextual and intrapsychic factors affecting consumers' preferences for growing foods in cities. Results show that providing tools and guidance are the most important contextual factors affecting community garden participation. The preferences of proponents of growing foods are explained by their high subjective knowledge about growing foods and reasons tied to the benefits of participating in community gardening. Opponents of growing foods at community gardens are characterized by low knowledge. The findings can be used to design policies that promote sustainable food systems in urban areas.


Assuntos
Agricultura , Abastecimento de Alimentos , Alimentos , Reforma Urbana/normas , Cidades , Participação da Comunidade , Jardinagem , Jardins , Humanos , América do Norte/epidemiologia
6.
PLoS One ; 15(10): e0224959, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33031384

RESUMO

Heat poses an urgent threat to public health in cities, as the urban heat island (UHI) effect can amplify exposures, contributing to high heat-related mortality and morbidity. Urban trees have the potential to mitigate heat by providing substantial cooling, as well as co-benefits such as reductions in energy consumption. The City of Boston has attempted to expand its urban canopy, yet maintenance costs and high tree mortality have hindered successful canopy expansion. Here, we present an interactive web application called Right Place, Right Tree-Boston that aims to support informed decision-making for planting new trees. To highlight priority regions for canopy expansion, we developed a Boston-specific Heat Vulnerability Index (HVI) and present this alongside maps of summer daytime land surface temperatures. We also provide information about tree pests and diseases, suitability of species for various conditions, land ownership, maintenance tips, and alternatives to tree planting. This web application is designed to support decision-making at multiple spatial scales, to assist city officials as well as residents who are interested in expanding or maintaining Boston's urban forest.


Assuntos
Conservação de Recursos Energéticos/métodos , Árvores/crescimento & desenvolvimento , Agricultura , Boston , Tomada de Decisões , Temperatura Alta , Reforma Urbana
7.
Artigo em Inglês | MEDLINE | ID: mdl-32899909

RESUMO

In the past decade, Chinese urban areas have seen rapid development, and rural areas are becoming the next construction hotspot. The development of rural buildings in China has lagged behind urban development, and there is a lack of energy-efficient rural buildings. Rural houses in severe cold regions have the characteristics of large energy exchange, a long heating cycle, and low construction costs. Energy consumption is a crucial issue for rural houses in severe cold regions. How to balance the energy efficiency and building cost become a crucial problem. To solve this problem, we investigate the energy consumption of rural housing in cold regions, using Longquan Village in Heilongjiang Province, northeast China, as a case study. A low-energy design framework is established that considers the spatial layout, building type, enclosure system, and heating system. With the support of project funds, a demonstration house is constructed, and the energy savings performance of the building is investigated during the heating period. The results indicate that the energy savings rate of the demonstration house is 66%. The demonstration building enables local residents to learn construction methods for low-energy houses and promotes energy efficiency.


Assuntos
Conservação dos Recursos Naturais , Indústria da Construção , Calefação , Habitação , China , Humanos , População Rural , Reforma Urbana
8.
Sci Total Environ ; 744: 140996, 2020 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-32947762

RESUMO

Rapid urban expansion often leads to substantial encroachment on ecological lands and destruction of natural environments. We developed a new cellular automata model (named CACEO) that uses cross-entropy optimization (CEO) to reproduce and project urban expansion into coastal areas and to assess urban encroachment on ecological lands. The CEO algorithm automatically searches for the near-optimal CA parameters and is capable of objectively parameterizing CA models to predict multi-objective scenarios. We calibrated CACEO by simulating urban expansion at Wenzhou from 1995 to 2005, validated the model from 2005 to 2015 using real data, and then predicted urban expansion for 2025 and 2035. End-state overall accuracies were 93.8% for 2005 and 94.4% for 2015, while figure-of-merit metrics were 27.9% for 2005 and 19.1% for 2015. We predicted four different scenarios to year 2025 and 2035: (1) a business-as-usual (BAU)-scenario using benchmark settings; (2) a District-scenario based on a district-oriented urban development strategy; (3) a Road-scenario based on a road network-oriented urban development strategy; and (4) a Coast-scenario based on a coast-oriented urban development strategy. Each scenario predicts a substantially different pattern of urban encroachment on ecological land and significant loss of farmland, forest, wetland and grassland. These scenarios should be useful in adjusting urban development strategies at Wenzhou and elsewhere.


Assuntos
Conservação dos Recursos Naturais , Reforma Urbana , Algoritmos , China , Entropia , Florestas
9.
Environ Sci Pollut Res Int ; 27(32): 39865-39878, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32748362

RESUMO

Urban Heat Island (UHI) is related to the theory of higher atmosphere and surface temperature taking place in the city area as compared to the nearby rural areas. The study results explain the advantages of green spaces in urban areas. Landsat TM/OLI concept of 1998 and 2017 years was attained from USGS for this work. To find out the land-use and land cover pattern supervised classification, the maximum prospect process is adopted. A total of four classes were mapped for the study area which includes built-up, barren land, vegetation, and water bodies. Effective sensor brightness temperature has been acquired from spectral radiance by using Plank's reverse function. On the basis of surface emissivity, Normalize Difference Vegetation Index (NDVI) classes are used to find out the ultimate temperature of the land surface (LST). The maximum temperature was recorded in the built-up area and barren land of the city and minimum temperatures were noted in areas with a greater cover of vegetation. The presence of UHI temperature is obvious from the land surface temperature views. An increase of 2 °C in surface temperature is recorded in district Lahore during the last two decades. Rise of 2.2 °C and 2.4 °C surface temperature has taken place in Faisalabad and Multan Districts in the last 19 years, respectively. In the establishment of a correlation among the LST, built-up, and vegetation, there is a positive sign present in their relation. With the increase in the built-up area, LST does increase as well. Moreover, with the reduction in vegetation cover, the LST is also raised. The study has revealed that there is a need for proper planning for the durable management of urbanization.


Assuntos
Tecnologia de Sensoriamento Remoto , Reforma Urbana , Cidades , Monitoramento Ambiental , Temperatura Alta , Ilhas , Temperatura , Urbanização
10.
J Environ Manage ; 274: 111166, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32835871

RESUMO

Reliance on new and alternative water supply sources is a desirable option for upgrading existing and ageing urban water system infrastructure that is no longer able to cater for steadily increasing water demand. This transformation will increasingly involve the use of decentralised, more complex and energy intensive urban water systems. Modelling capability that takes a holistic systems approach to optimize the dynamic interactions between water and energy is needed to evaluate the performance of fit-for-purpose water supply systems for the urban sector. This paper presents a simulation-optimisation model to concurrently simulate and optimize an urban water supply system based on minimum energy use when water of alternative quality is supplied to different users on a 'fit-for-purpose' basis. The model uses a System Dynamics approach to simulate the energy use of different water supply systems in the form of stocks and flows combined with a Genetic Algorithm (GA) technique to optimize energy use while satisfying all the water demands. The comprehensive model framework is built on a Matlab/Simulink® platform. Life Cycle Energy Assessment (LCEA) is used to generate the embodied energy use variables which are input to the simulation-optimisation model. The model is sufficiently flexible to accommodate water supply systems of variable spatial scales and analyse water and energy use at variable time scales. The application of the modelling framework on the Aurora urban development estate, Australia, shows that the model produces essential information about the water supply and energy use intensity according to specified criteria.


Assuntos
Modelos Teóricos , Água , Austrália , Cidades , Reforma Urbana , Abastecimento de Água
11.
J Environ Manage ; 275: 111177, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32829263

RESUMO

Rapid urbanization exacerbates urban metabolic activities associated with irreversible environmental degradation. Evaluating urban metabolic performance is an effective method to meet targets for sustainable development in contemporary urban areas. Neighborhoods, which are regarded as the basic parts of cities, can detail the metabolic structure and interactions from a bottom-up perspective. In consequence, this study proposed an eco-efficiency model which combined emergy synthesis and slack-based measure data envelopment analysis. A case study with questionnaire and statistical data for eight communities in Chongqing, China was used to shed a light on the properties of emergy metabolic flows and eco-efficiency. The results showed that the study communities heavily depended on external resources. Intense communal activities within relatively small geographic areas caused immediate surroundings to suffer from enhanced environmental pressures. Eco-efficiency performances were mostly invalid, and a significant heterogeneity existed among communities. Enhancing the performance of renewable and non-renewable resources whilst also reducing the production of wastes was essential to improve the overall eco-efficiency of local communities. To assist with this, a neighbor-level sustainable renewal framework was proposed which took account of metabolic flows and communal renewal operations. The findings of this study can provide a paradigmatic example for urban renewal projects elsewhere that embed metabolic performance in neighborhood redevelopment.


Assuntos
Reforma Urbana , Urbanização , China , Cidades , Conservação dos Recursos Naturais
12.
PLoS One ; 15(7): e0235250, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32730256

RESUMO

OBJECTIVES: To elicit citizen preferences for national budget resource allocation in Uganda, examine respondents' preferences for health vis-à-vis other sectors, and compare these preferences with actual government budget allocations. METHODS: We surveyed 432 households in urban and rural areas of Mukono district in central Uganda.We elicited citizens' preferences for resource allocation across all sectors using a best-worst scaling (BWS) survey. The BWS survey consisted of 16 sectors corresponding to the Uganda national budget line items. Respondents chose, from a subset of four sectors across 16 choice tasks, which sectors they thought were most and least important to allocate resources to. We utilized the relative best-minus-worst score method and a conditional logistic regression to obtain ranked preferences for resource allocation across sectors. We then compared the respondents' preferences with actual government budget allocations. RESULTS: The health sector was the top ranked sector where 82% of respondents selected health as the most important sector for the government to fund, but it was ranked sixth in national budget allocation, encompassing 6.4% of the total budget. Beyond health, water and environment, agriculture, and social development sectors were largely underfunded compared to respondents' preferences. Works and transport, education, security, and justice, law and order received a larger share of the national budget compared to respondents' preferences. CONCLUSIONS: Among respondents from Mukono district in Uganda, we found that citizens' preferences for resource allocation across sectors, including for the health sector, were fundamentally misaligned with current government budget allocations. Evidence of respondents' strong preferences for allocating resources to the health sector could help stakeholders make the case for increased health sector allocations. Greater investment in health is not only essential to satisfy citizens' needs and preferences, but also to meet the government's health goals to improve health, strengthen health systems, and achieve universal health coverage.


Assuntos
Orçamentos/estatística & dados numéricos , Comportamento do Consumidor/estatística & dados numéricos , Alocação de Recursos para a Atenção à Saúde/estatística & dados numéricos , Governo Local , Alocação de Recursos/estatística & dados numéricos , Adulto , Orçamentos/organização & administração , Estudos Transversais , Feminino , Alocação de Recursos para a Atenção à Saúde/organização & administração , Habitação/economia , Habitação/organização & administração , Humanos , Masculino , Pessoa de Meia-Idade , Setor Público/economia , Setor Público/organização & administração , Alocação de Recursos/organização & administração , Participação dos Interessados , Transportes/economia , Uganda , Assistência de Saúde Universal , Reforma Urbana/economia , Reforma Urbana/organização & administração , Adulto Jovem
13.
Artigo em Alemão | MEDLINE | ID: mdl-32632724

RESUMO

Cities can be described by different factors. From a health perspective, density is a factor of great importance. Cities are seen as dynamic places with interaction between built and social environments as well as design by societal stakeholders. This is illustrated through the example of noise and greenspaces as determinants of health and the provision of health services. Different city types and guiding principles of spatial and urban development are explained through the health lens. The potential to influence health determinants through local interventions is illustrated by planning instruments of urban development and environmental protection. Participation of the public and other stakeholders plays a crucial role in local settings. This paper shows the great potential of healthy urban development, which is not utilized in many cases.


Assuntos
Política de Saúde , Reforma Urbana , Cidades , Alemanha , Ruído
14.
PLoS One ; 15(7): e0235858, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32645068

RESUMO

The characteristics of urban spatial structure and the objective evaluation of the development level of urban economy have always been the concern of urban researchers, However, the spatial relationship between urban spatial structure and urban economic development level is often deliberately ignored. Through the point of interest (POI), the identification framework is constructed, the spatial structure of the city is identified and evaluated, and the Geographically Weighted Regression analysis is carried out with the distribution of unit GDP (Gross Domestic Product) in this study. The research shows that Kunming and Guiyang are polycentric spatial structures and Kunming's structure is more significant. Kunming's economic level is generally higher than Guiyang, but the unit area cannot be compared. The city center will promote the development of the central area in this city, and the more urban centers are distributed within the geographical and spatial range, the greater contribution would have to economic development. In addition, the results of this study will have a positive impact on urban planning and construction, and will also provide a new perspective for the study of cities and related disciplines.


Assuntos
Planejamento de Cidades , Desenvolvimento Econômico , Reforma Urbana , China , Cidades , Planejamento de Cidades/economia , Planejamento de Cidades/métodos , Humanos , Regressão Espacial , Reforma Urbana/economia , Reforma Urbana/métodos , Urbanização
15.
Water Sci Technol ; 81(9): 1927-1940, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32666946

RESUMO

New industrial and urban developments in water-scarce regions are often inhibited by their high demand for water from natural resources. In addition, there often is a lack of water for purposes that contribute to an improved quality of life, such as urban green spaces. Therefore, the integrated industrial-urban water-reuse concept presents a strategy by linking and reusing treated industrial and municipal wastewater flows to increase urban water-reuse potentials. The concept of combining different reuse water flows, from wastewater treatment plants from industrial parks, aims at significantly increasing the water-saving potentials compared to a separate consideration of the industrial wastewater flows.


Assuntos
Águas Residuárias , Purificação da Água , Conservação dos Recursos Naturais , Qualidade de Vida , Reforma Urbana , Eliminação de Resíduos Líquidos , Água , Abastecimento de Água
16.
PLoS One ; 15(6): e0233888, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32603333

RESUMO

Urban development relies on many factors to remain viable, including infrastructure, services, and government provisions and subsidies. However, in situations involving federal or state level policy, development responds not just to one regulatory signal, but also to multiple signals from overlapping and competing jurisdictions. The 1982 U.S. Coastal Barrier Resources Act (CoBRA) offers an opportunity to study when and how development restrictions and economic disincentives protect natural resources by stopping or slowing urban development in management regimes with distributed authority and responsibility. CoBRA prohibits federal financial assistance for infrastructure, post-storm disaster relief, and flood insurance in designated sections (CoBRA units) of coastal barriers. How has CoBRA's removal of these subsidies affected rates and types of urban development? Using building footprint and real estate data (n = 1,385,552 parcels), we compare density of built structures, land use types, residential house size, and land values within and outside of CoBRA units in eight Southeast and Gulf Coast states. We show that CoBRA is associated with reduced development rates in designated coastal barriers. We also demonstrate how local responses may counteract withdrawal of federal subsidies. As attention increases towards improving urban resilience in high hazard areas, this work contributes to understanding how limitations on infrastructure and insurance subsidies can affect outcomes where overlapping jurisdictions have competing goals.


Assuntos
Conservação dos Recursos Naturais/métodos , Política Ambiental , Financiamento Governamental , Reforma Urbana/economia , Desastres , Inundações , Humanos , Seguro , Sudeste dos Estados Unidos
17.
PLoS One ; 15(7): e0235227, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32645013

RESUMO

The growth of administrative data made available publicly, often in near-real time, offers new opportunities for monitoring conditions that impact community health. Urban blight-manifestations of adverse social processes in the urban environment, including physical disorder, decay, and loss of anchor institutions-comprises many conditions considered to negatively affect the health of communities. However, measurement strategies for urban blight have been complicated by lack of uniform data, often requiring expensive street audits or the use of proxy measures that cannot represent the multifaceted nature of blight. This paper evaluates how publicly available data from New York City's 311-call system can be used in a natural language processing approach to represent urban blight across the city with greater geographic and temporal precision. We found that our urban blight algorithm, which includes counts of keywords ('tokens'), resulted in sensitivity ~90% and specificity between 55% and 76%, depending on other covariates in the model. The percent of 311 calls that were 'blight related' at the census tract level were correlated with the most common proxy measure for blight: short, medium, and long-term vacancy rates for commercial and residential buildings. We found the strongest association with long-term (>1 year) commercial vacancies (Pearson's correlation coefficient = 0.16, p < 0.001). Our findings indicate the need of further validation, as well as testing algorithms that disambiguate the different facets of urban blight. These facets include physical disorder (e.g., litter, overgrown lawns, or graffiti) and decay (e.g., vacant or abandoned lots or sidewalks in disrepair) that are manifestations of social processes such as (loss of) neighborhood cohesion, social control, collective efficacy, and anchor institutions. More refined measures of urban blight would allow for better targeted remediation efforts and improved community health.


Assuntos
Participação da Comunidade , Sistemas de Dados , Monitoramento Ambiental/métodos , Saúde da População Urbana , Reforma Urbana/organização & administração , Algoritmos , Humanos , Governo Local , Cidade de Nova Iorque
18.
Artigo em Inglês | MEDLINE | ID: mdl-32570739

RESUMO

Urban clusters are important carriers for cities to participate in international competition and cooperation, and a booster for urban sustainable development. This study measured the degree of urban clusters by utilizing the panel data of 278 cities in China during 2004-2016. Then, an extended meta-frontier data envelopment analysis (EM-DEA) model was applied to estimate the total-factor ecological performance (UTEP) and decompose it into two sub-index from the perspective of "resource conservation" and "environmental friendliness". On these bases, we employed a dynamic panel data approach to examine and demonstrate the relationship between urban cluster and UTEP in two dimensions, and further explored transmission channels of urban clusters on UTEP by adding the mediating effect. The results show that resource conservation increases first and then decreases with the increasing of urban clustering level, while environmental friendliness showed the opposite trend, making the latter become the main way for urban clusters to improve the UTEP. Industrial structure supererogation and rationalization are transmission channels for environmental friendliness rather than resource conservation in the way of improvement of UTEP. Technology innovation, as well as technology diffusion, also improves UTEP to some extent. In addition, urban clusters in eastern and central China have the greatest improvement in UTEP, while such effects are not the case in western China. Urban clusters in the second half sample period are more conducive to the improvement of the UTEP, with these potentially being the gains from the improvement of the level and quality of urban clusters.


Assuntos
Conservação dos Recursos Naturais , Indústrias , Reforma Urbana , China , Cidades , Desenvolvimento Sustentável
19.
Artigo em Inglês | MEDLINE | ID: mdl-32545840

RESUMO

In the context of "space of flow", urban interaction has become the key force impacting urban landscape evolution and urban sustainable development. Current research on urban interaction analysis is mainly conducted based on the interaction of geographical elements, the virtual flow of information in cyberspace has not been given sufficient attention, particularly the information flows with explicit geographical meaning. Considering the dramatic population migration and the explosive growth of cyberspace in China's main urban agglomerations, we constructed the information flow of migrant attention (IFMA) index to quantify the urban information interaction derived from public migrant concern in cyberspace. Under the framework coupling spatial pattern analysis and spatial network analysis, exploration spatial data analysis (ESDA) and complex network analysis (CNA) were adopted to identify the urban interaction features depicted by IFMA index in the three main urban agglomerations in China. The results demonstrated that, in the study area: (1) The IFMA index presented a reasonable performance in depicting geographical features of cities; (2) the inconformity between urban role in the network and development positioning confirmed by national planning existed; (3) in the context of New-type urbanization of China, urban interaction feature can be a beneficial reference for urban spatial reconstruction and urban life improvement. Using the cyber information flow with geographical meaning to analyze the urban interaction characteristics can extend the research angle of urban relationship exploration, and provide some suggestion for the adjustment of urban landscape planning.


Assuntos
Planejamento de Cidades , Emigrantes e Imigrantes , Urbanização , China , Cidades , Humanos , Internet , População Urbana , Reforma Urbana
20.
PLoS One ; 15(6): e0234522, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32579615

RESUMO

A deep understanding of urban functions is the basis for the optimization of urban spatial structure and for the sustainable development of urban space. Previous research mainly focused on the identification and classification of urban functions using a variety of data and methods; however, little attention has been paid to the quantitative measurement of changes in urban functions, and to their temporal and spatial evolution. With the help of urban land use maps, we used the overlay analysis and the transition matrix to quantitatively measure the enhancement and weakening of urban functions and their spatial differences, by analyzing the relationship between urban land development and redevelopment. Accordingly, the change state of urban function enhancement and weakening could be divided into six categories. Moreover, the results of research on residential, commercial, public service, and industrial functions show that changes in different urban functions have different temporal and spatial characteristics. Our findings on the enhancement and weakening of urban functions in the central city of Changchun provide theoretical support for the sustainable development of urban space in the future.


Assuntos
Conservação dos Recursos Naturais , Indústrias/tendências , Reforma Urbana , Urbanização/tendências , Humanos
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