Is there a health penalty of China's rapid urbanization?

The Health Penalty of China's Rapid Urbanization

Rapid and unplanned urbanization of cities has been a cause of great concern world over. Increased urbanization has immensely altered the Land Use pattern of several Indian cities, thereby altering the physical properties of the land surface. The pronounced effect of urban heat island (UHI) apart from the acute stress on limited natural resources are consequences of this rapid urbanization. UHI effect manifests as unexpected rise in city temperatures when compared to their surrounding areas, thus making them unfriendly for habitation over time. The present work analyses the effect of UHI on Bhubaneswar, an Indian city undergoing rapid urbanization in recent times, utilizing land use and land cover (LULC) change data from Landsat over a 25 km radius about the city and MODIS land surface temperatures (LST) at 1 km2 spatial resolution for a period of 15 years (2000–2014). From the study, significant changes in LULC through over-exploitation of natural resources and the related spatio-temporal variations in LST has been identified as one major factor responsible for changes in the UHI effect over Bhubaneswar. Owing to rapid urbanization (83% increase in 15 years), the city has undergone major changes in LULC aggregating to a massive ~ 89% decrease in dense vegetation and ~ 83% decrease in crop fields over this time period. Analyses of the changes in the urban energy balance and resulting UHI effect across many such Indian cities undergoing rapid urban growth is quite essential for mitigating the negative impacts of urbanization for a long-term sustainability.

Africa continues to experience serious signs of multiple crises in the context of sustainability. These crises include vulnerability to climate change, rapid urbanization, food insecurity, and many others. One crisis, that defines Africa today, is the unprecedented rapid urbanization which continues to pose a big challenge to the diminishing available resources, environmental quality and human well-being. Cities in Africa continue to experience a fast horizontal growth of settlements due to influx of people from rural areas who often settle in the economically lowest segments in urban areas. This horizontal rapid growth has eaten up land set for agriculture around cities and promoted the rapid growth of informal settlements exacerbating the impacts of climate change leading to a negative impact on agricultural production. Policies linking rapid urbanization and climate change with agricultural productivity are need. This paper explores and documents the impact of rapid urbanization on climate change policies and subsequent impact on agriculture in Africa.

Africa continues to experience serious signs of multiple crises in the context of sustainability. These crises include vulnerability to climate change, rapid urbanization, food insecurity, and many others. One crisis, that defines Africa today, is the unprecedented rapid urbanization which continues to pose a big challenge to the diminishing available resources, environmental quality and human well-being. Cities in Africa continue to experience a fast horizontal growth of settlements due to influx of people from rural areas who often settle in the economically lowest segments in urban areas. This horizontal rapid growth has eaten up land set for agriculture around cities and promoted the rapid growth of informal settlements exacerbating the impacts of climate change leading to a negative impact on agricultural production. Policies linking rapid urbanization and climate change with agricultural productivity are need. This paper explores and documents the impact of rapid urbanization on climate change policies and subsequent impact on agriculture in Africa.

Urbanization, described as social development, benefits the human population if it is well planned. India contributes major distinctive facets of urbanization which is developing at remarkable rates. The regional distribution of population in India is irregular as only six large states are responsible for half of the urban populaces. India is also known for its different cultures, languages and food habits. Owing to the region-specific food habits, rice is cultivated widely and gives a better yield than the other grains. Pulses that are rich in protein are the next eminent source for people. One of the crucial underlying problems is people give more importance to the taste than nutritional value. As a consequence, immense counts of individuals who can manage to devour a healthy diet do not do so and instances of severe deficiency and malnutrition and certain other gut-associated diseases are seen. Colorectal cancer, which is the most prevailing cancer around the globe, is the major cause of cancer-associated mortality in developing countries. High-fat diet like animal fat that favors the growth of unwanted bacterial flora is the chief threat for colorectal cancer. It is well known that urbanization has fetched several modifications in the lifestyle and food habits which successively enhanced the threat of various diseases. Hence in this review, we focused mainly on the impact of rapid urbanization and other lifestyle and dietary habits on the development of colorectal cancer in India.

Urbanization is closely associated with land use land cover (LULC) changes that correspond to land surface temperature (LST) variation and urban heat island (UHI) intensity. Major districts of Bangladesh have a large population base and commonly lack the resources to manage fast urbanization effects, so any rise in urban temperature influences the population both directly and indirectly. However, little is known about the impact of rapid urbanization on UHI intensity variations during the winter dry period in the major districts of Bangladesh. To this end, we aim to quantify spatiotemporal associations of UHI intensity during the winter period between 2000 and 2019 using remote-sensing and geo-spatial tools. Landsat-8 and Landsat-5 imageries of these major districts during the dry winter period from 2000 to 2020 were used for this purpose, with overall precision varying from 81% to 93%. The results of LULC classification and LST estimation showed the existence of multiple UHIs in all major districts, which showed upward trends, except for the Rajshahi and Rangpur districts. A substantial increase in urban expansion was observed in Barisal > 32%, Mymensingh > 18%, Dhaka > 17%, Chattogram > 14%, and Rangpur > 13%, while a significant decrease in built-up areas was noticed in Sylhet < −1.45% and Rajshahi < −3.72%. We found that large districts have greater UHIs than small districts. High UHI intensities were observed in Mymensingh > 10 °C, Chattogram > 9 °C, and Barisal > 8 °C compared to other districts due to dense population and unplanned urbanization. We identified higher LST (hotspots) zones in all districts to be increased with the urban expansion and bare land. The suburbanized strategy should prioritize the restraint of the high intensity of UHIs. A heterogeneous increase in UHI intensity over all seven districts was found, which might have potential implications for regional climate change. Our study findings will enable policymakers to reduce UHI and the climate change effect in the concerned districts.

<p>Typhoon and windstorm induced extreme winds (e.g., daily maximum wind speed, DMWS) cause enormous economic losses and deaths in China every year, and rapid urbanization increased surface roughness might play a key role in extreme wind speed variability. Here, observed near-surface (at 10 m height) DMWS from 115 meteorological stations and combined DMSP/OLS (Defense Meteorological Satellite Program/Operational Linescan System) and NPP/VIIRS (Suomi National Polar-orbiting Partnership/Visible Infrared Imaging Radiometer Suite) nighttime light data from 1992-2016 in Yangtze River Delta, a rapidly urbanized area of China, were used to analyze the impact of urbanization on DMWS variability. Raw wind speed observations were subject to a robust quality control and homogenization protocol using the Climatol package. The stations were firstly classified into six urbanized groups by the difference of nighttime light indices of each station between 1992 and 2016. The results show that DMWS in Yangtze River Delta has significantly (p < 0.05) declined by -0.209m s<sup>-1 </sup>decade<sup>-1</sup> annually, with negative trends in most seasons, particularly in winter (-0.470 m s<sup>-1 </sup>decade<sup>-1</sup>, p < 0.05) and autumn (-0.300 m s<sup>-1 </sup>decade<sup>-1</sup>, p < 0.05), followed by spring (-0.178 m s<sup>-1 </sup>decade<sup>-1</sup>, p > 0.10), while a weak increase in summer DMWS was found (+0.002 m s<sup>-1 </sup>decade<sup>-1</sup>, p > 0.10). The stations in the highly urbanized group show a higher magnitude in the decline of annual DMWS, indicating the key role of urbanization in weakening DMWS. Further, this is confirmed by the regional climate model (RegCM4) sensitive experiments conducted with different land use and cover data, that is, DMWS in 1992 was higher in the experiment using the real land use and cover data than in the experiment using the land use and cover data in 2016.</p>

Through the study of the daily heavy rainfall observation records of 659 meteorological stations in China from 1951 to 2010, we find that rapid urbanization may trigger the significant increase of large-scale heavy rainfall in China. The main conclusions are as follows: Decadal heavy rainfall amounts (HRA), heavy rainfall days (HRD) and heavy rainfall intensity (HRI) in China have increased significantly, with an increase of 68.71%, 60.15% and 11.52% respectively, and the increase of station number is 84.22%, 84.22% and 54.48% respectively, showing a time change process of “rapid slow re rapid increase” and a spatial change from Southeast Coast to Central, Southwest, North and Northeast China. The rapid urbanization factors, including the output value of the second industry (GDP2), the proportion of urban population (UP) and the annual average haze days (HD), are likely to be the main reasons for the increase of heavy rainfall in China. Their variance explanations for the HRA, HRD and HRI in China are 61.54%, 58.48% and 65.54% respectively, of which the variance explanations for the heavy rainfall rainfall, rainy day and rain intensity are respectively high only by haze 25.93%, 22.98% and 26.64% respectively, while the variance interpretation of climate factors, including WPSH, ENSO, AMO and AAO, is only 24.30%, 26.23% and 21.92% respectively. Compared with the forcing factors of rapid urbanization, the impact of these climate factors is only 1/3 of the former. The panel data of the annual mean of the total population and visibility days at the county level in China are significantly related to the HRA, HRD and HRI in China. The spatial correlation coefficient gradually increased from 1950s to 2000s, that is, the total population at the county level increased from 0.35, 0.36 and 0.40 to 0.54, 0.55 and 0.58 respectively, and the annual mean of visibility days increased from 0.36, 0.38 and 0.48 to 0.55, 0.57 and 0.58. It is further indicated that the rapid urbanization triggered the significant increase of heavy rainfall in China.

The impact of rapid urbanization in cities on their microclimate is at present a great cause of global concern. One of the major consequences is the unexpected rise in temperatures in the cities compared to their surrounding areas, termed as the Urban Heat Island (UHI) effect. Over the past many years, several Indian cities are under severe stress owing to such extreme anomalous changes in their micro-meteorological conditions making them unfriendly for habitation. Presented here is a case study on Bhubaneswar - one such city on the east coast of India undergoing rapid urbanization in recent times. In this study, Land Surface Temperatures (LST) from MODIS Terra and Aqua instruments at 1 km2 spatial resolution along with the Land Use and Land Cover (LULC) change data from Landsat was used over a 25 km radius about the city for a 15 years' period from 2000 to 2014. Preliminary analyses indicate spatio-temporal changes in LULC to be one of the primary and significant factors responsible for changes in the UHI effect over the city. Investigations on the spatio-temporal variations in LST across the city and its relationship with vegetation cover indicate that overexploitation of various resources demanded by a fast growing population has led to significant changes in LULC patterns in the last few years. Analysis of the changes in the urban energy balance and resulting UHI effect across the city under various urban growth scenarios and different proportions of green urban area are in progress.

Written specifically as a teaching text and authored by a team of leading academics in the field, this is the first book to bring together the key issues of rapid urbanisation with approaches to planning and housing. Outlining and explaining core concepts from ‘informal settlements’ to ‘sustainability’, it focuses on the rapid urbanization of developing countries with case studies from Latin America, Asia and Sub-Saharan Africa. The impact of rapid urbanization and associated globalization on land-use and housing is described and analyzed with reference to the particular issues of poverty, health and the environment of these areas. Providing an accessible introduction to the key issues as well as enhancing current theoretical debates and exploring practical applications, this book is an essential resource for students and researchers in this area.

Rapid urbanization comes after push and pull factors of urbanization. These factors are considered as employment, greater opportunities and better facilities. It consequently brings high demand on built facilities which consequently bring several problems comprising reduction of forest and agricultural lands, lack of transportation and infrastructure, and mental health issues. In addition rapid urbanization has often led to unplanned urbanization and unconscious decisions of urban planners. These kinds of development is facing with dramatic changes on urban morphology. This study through typomorphological analysis tries to find out the outcomes of rapid urbanization in coastal city of Alanya. Also the study tries to provide an opportunity for its planned transformation for the future development.

Global warming and rapid urbanization have great impacts on local temperature and urban heat island (UHI) effects. However, most of the previous research paid very little attention to the impact of natural terrain on UHI effects. This work reported the effects of complex terrain on UHI characteristics. As the second largest city in Northwest China, Lanzhou was selected as the research region since it is a typical valley city with rapid urbanization processes. We analyzed the variation characteristics of UHI effects at annual, seasonal and daily scales, in order to explore the differences and similarities of UHI effects between plain cities, coastal cities and valley cities. Then we evaluated the contribution of urbanization effect to urban surface temperature change. Finally, we examined the link between urbanization and UHI effects. The results of this study will be useful to urban planners and environmentalists in ecological environment construction, urban architectural design and urban planning.

An econometric analysis of three health economic issues in China

River networks are the typical hydrological characteristic of the Yangtze delta plain. They have important ecological service functions and a unique landscape, which has been significantly degraded during the past 50 years. Qingpu District in Shanghai has been used as study area to develop an integrated method for riverscape assessment in floodplain areas with a dense river network. This integrated method bridges geomorgraphy, landscape, and regional planning. Indicators of sinuosity, connectivity, and circuitry have been integrated into a three-level framework, including river, intersection, and river network level. Furthermore, this method was integrated by the geographic information system method and stepwise regression to identify the riverscape response to the changes in the use of the land. The spatial and temporal changes of the riverscape and land use were calculated for each grid (3000 m×3000 m) from 1965 to 2006. The results indicated that the riverscape had been significantly degraded during the study period in terms of sinuosity, connectivity, and circuitry reducing. The land use changed significantly with more building areas and less water regions and agricultural land. Additionally, the regression results indicated that several specific land use conversion types had had strong effects on the change in the riverscape structure. Finally, according to the assessing method, we have proposed specific planning and management recommendations based on the pressure-state-response model to protect the riverscape from the impact of rapid urbanization.

Rapid urbanization is responsible for the increased vulnerability of land systems and the loss of many crucial ecosystem services. Land systems are typical complex systems comprised of different land use types which interact with each other and respond to external environment processes (such as urbanization), resulting in dynamics in land systems. This work develops a methodology approach by integrating complex networks and disruptive scenarios and applies it to a case study area (Wuhan City in China) to explore the effects of urbanization on land system structural vulnerability. The land system network topologies of Wuhan City during five time periods from 1990 to 2015 are extracted. Our results reveal that (1) the urban land expands at a higher speed than the urban population in Wuhan City; (2) the period of 2005–2010 has witnessed more land area conversions from ecological lands to urban land than other periods; (3) the land system is more vulnerable to intentional attacks on nodes with higher integrated node centrality and larger land area, such as paddy, dryland, and lake; and (4) the network efficiency of the land system would decline sharply if the area shrinkage of paddy, dryland, and lake is larger than 30%, 50%, and 20%, respectively. The results provide some insights into building a resilient urban land system, such as increasing the efficiency of existing urban land and controlling the shrinkage rate of important land use types. This study contributes to existing literature on complex networks by expanding its application in land systems, which highlight the potential of complex networks to capture the complexity, dynamics, heterogeneity, and emergent phenomena in land systems.