Urban Population Density Research Articles

Urbanization and COVID‐19 incidence: A cross‐country investigation

AbstractThis paper investigates the determinants of the diffusion and intensity of the COVID‐19 at the country level, focusing on the role played by urban agglomeration, measured using three urban variables: percentage of the urban population, population density, and primacy. We estimate the influence of urban agglomeration on two outcome variables: cumulative number of cases and deaths per 100,000 inhabitants up to 31 December 2020, using both parametric and semiparametric models. We also explore possible spatial effects. The non‐linear effects of the urban variables on the intensity of the disease reveal non‐monotonous relationships, suggesting that it is the size of the urban system that is linked to a stronger incidence.

Geo-spatial Assessment of Flood Vulnerability Areas of the Gaza Strip Towards Preparedness and Humanitarian Response Planning

Nowadays, flood and drought will become more common as climate change causes. Due to climate change consequences, flood occurrence and its impact on Gaza people have been of great concern to the Palestinian water authority, as it has a negative influence on various humanitarian and social issues. The hazards and damages resulted by flooding cause loss of life, property, displacement of people and disruption of socioeconomic activities. This research focuses on assessing Gaza Strip vulnerability to flooding using analysis of GIS-based spatial information. Not only did it consider the physical-environmental flood vulnerability, it also investigated social flood vulnerability aspects e.g., population densities. Soil and slope were considered to have the highest weight in the vulnerability mapping, as they represent the main factors in urban hydro-ecosystem structure. The long term average rainfall, a climate function factor, has the lowest weight, because it could be considered as a threat factor in addition to a vulnerability factor. This research demonstrates that urban area and population density as strong factors influencing flood vulnerability for humanitarian and saving life purposes. The findings of Geospatial analysis were used to map vulnerable areas likely to be affected in the event of flood hazard and suggest future interventions and related adaptation strategies in Gaza areas for flood mitigation.

The Relationship between Urban Population Density Distribution and Land Use in Guangzhou, China: A Spatial Spillover Perspective.

Urban population density distribution contributes towards a deeper understanding of peoples’ activities patterns and urban vibrancy. The associations between the distribution of urban population density and land use are crucial to improve urban spatial structure. Despite numerous studies on population density distribution and land use, the significance of spatial dependence has attained less attention. Based on the Baidu heat map data and points of interests data in the main urban zone of Guangzhou, China, the current paper first investigated the spatial evolution and temporal distribution characteristics of urban population density and examined the spatial spillover influence of land use on it through spatial correlation analysis methods and the spatial Durbin model. The results show that the urban population density distribution is characterized by aggregation in general and varies on weekends and weekdays. The changes in population density within a day present a trend of “rapid growth-gentle decline-rapid growth-rapid decline”. Furthermore, the spatial spillover effects of land use exist and play the same important roles in population density distribution as the direct effects. Additionally, different types of land use show diverse direct effects and spatial spillover effects at various times. These findings suggest that balancing the population density distribution should consider the indirect effect from neighboring areas, which hopefully provide implications for urban planners and policy makers in utilizing the rational allocation of public resources and regarding optimization of urban spatial structure.

Relationship between urban heat island and population density of districts in Ho Chi Minh City derived from Sentinel - 3 SLSTR data

The urban heat island occurs due to the causes of the urbanization process, of which the main reason is an increase in population density leading to the changes in artificial objects on the ground surface. Recently, using the Split - Window algorithm for two thermal infrared spectral channels with wavelengths of 11 µm and 12 µm to calculate the daily surface temperature with two times of day and night serves to determine the change of land surface temperature. This method is intended to improve the reliability of the results and high technical efficiency. This study uses Sentinel - 3 SLSTR data to determine urban heat island in the districts of Ho Chi Minh City compared to areas bordering the city on May 15th 2020. In addition, population density is calculated according to the results of the census in 2020. The linear relationship between the urban heat island and population density was built with the coefficient of determination R2=0.64.

Evolution of Green Space under Rapid Urban Expansion in Southeast Asian Cities

Globally, rapid urban expansion has caused green spaces in urban areas to decline considerably. In this study, the rapid expansion of three Southeast Asia cities were considered, namely, Kuala Lumpur City, Malaysia; Jakarta, Indonesia; and Metro Manila, Philippines. This study evaluates the changes in spatial and temporal patterns of urban areas and green space structure in the three cities over the last two decades. Land use land cover (LULC) maps of the cities (1988/1989, 1999 and 2014) were developed based on 30-m resolution satellite images. The changes in the landscape and spatial structure were analysed using change detection, landscape metrics and statistical analysis. The percentage of green space in the three cities reduced in size from 45% to 20% with the rapid expansion of urban areas over the 25-year period. In Metro Manila and Jakarta, the proportion of green space converted to urban areas was higher in the initial 1989 to 1999 period than over the latter 1999 to 2014 period. Significant changes in green space structure were observed in Jakarta and Metro Manila. Green space gradually fragmented and became less connected and more unevenly distributed. These changes were not seen in Kuala Lumpur City. Overall, the impact of spatial structure of urban areas and population density on green space is higher in Jakarta and Metro Manila when this is compared to Kuala Lumpur. Thus, the results have the potential to clarify the relative contribution of green space structure especially for cities in Southeast Asia where only a few studies in urban areas have taken place.

Exploring the spectrum of urban area key figures using data from Finland and proposing guidelines for delineation of urban areas

Urban area definitions are commonly used worldwide to reflect countries’ urban population percentages. The measurements are based on local factors and differ widely across countries, making them non-comparable. This is well acknowledged among specialists; however, they are commonly used in everyday practice as universal measurements, and even compared with each other. The problem is that we do not know the degree of error in such comparisons. For this purpose, in the study presented here we analysed and categorised different European national urban area definitions, testing them in the case of Finland. Definitions from 27 European countries were divided into two main categories according to the end result areal unit of the definition and further into seven subcategories based on the criteria used. Thirteen different definitions in the case of Finland were tested using spatial analyses with GIS. The results indicate that urban population percentage varies widely according to different definitions, making their comparability infeasible. The difference is even greater in the case of urban area ratio and population densities of urban areas between the two main categories. The results prove that definitions based on LAU areas cannot illustrate urban areas and their densities coherently. In light of a literature review on certain relational urban area delineation methods and the case study, desirable characteristics for the delineation of urban areas were highlighted. Consequently, a constant, structured evaluation of urbanity measurements and their underlying logic is necessary to enable unambiguous discourse on urban area in urban sciences. The results could help in formulating the applicability of the concept of urban area in scientific and popular communication and media.

Assessment and mapping of demographic potential of urbanized territories of the Baikal-Mongol region

This article provides an assessment of the demographic potential of the Baikal-Mongolian region, which unites the adjacent territories of the two countries. The cores of the research site are the urbanized territories of Irkutsk, Ulan-Ude and Ulan-Bator, and communications are railways and highways connecting the main centres. The demographic potential is characterized by the level and possibilities for the development of demographic processes and population structures, and mainly numerous quantitative characteristics of the population of the territory are used. The authors limited themselves to using quantitative characteristics of the demographic potential according to statistical data for 2019–2020 within the territories of the municipal districts and urban districts of the Irkutsk region, the Republic of Buryatia and aimags of Mongolia. Data on density and proportion of urban population reflect the size of the main urban areas. Data on demographic processes reflect the characteristics of the natural and migration movement of the population. Demographic structures are represented by the age structure and the demographic load of the working-age population, which is minimal throughout Mongolia and in the suburbs of Russian regional centres. Generalizing characteristics of demographic potential calculated from the average sum of individual indicators.

Ambient Air Quality and General Health Outcomes in Nigde (Turkey) between 2011 and 2017

Background:We aimed to provide information for health practitioners and other related people about the association between ambient air quality and adverse health outcomes in the general population of Nigde, a central Turkish city, within the context of current health data epidemiological evidence.Methods:The present study highlights the connection between health problems and time series of particulate matter (PM10) and sulphur dioxide (SO2) in Nigde, Turkey between 2011 and 2017. Significant morbidity is linked to ambient air pollution, resulting in a significant economic cost to society.Results:We found that the required funds to treat cancers and chronic obstructive pulmonary disease triggered by ambient air pollution in Nigde, exceed 9 million US dollars per year, even when only the city center is taken into account.Conclusion:As Turkish cities grow and urban population density increases, air pollution issues need to be given priority in order to protect the health of the public and support sustainable development for future generations. It is recommended that particulate matter concentration in this urban center should be significantly reduced to minimize health problems.

Spatiotemporal Characteristics of the Surface Urban Heat Island and Its Driving Factors Based on Local Climate Zones and Population in Beijing, China

The increasing degree of urbanization has continuously aggravated the surface urban heat island (sUHI) effect in China. To investigate the correlation between spatiotemporal changes of sUHI and urbanization in Beijing, land surface temperature in summer from 2000 to 2017 and the distribution of local climate zones (LCZs) in 2003, 2005, 2010, and 2017 was retrieved using remote sensing data and used to analyze the sUHI area and intensity change. The statistical method GeoDetector was utilized to investigate the explanatory ability of LCZs and population as the driving factors. The year of 2006 was identified as the main turning year for sUHI evolution. The variation the sUHI from 2000 showed first an increasing trend, and then a decreasing one. The sUHI pattern changed before and after 2009. Before 2009, the sUHI mainly increased in the suburbs, and then, the enhancement area moved to the central area. The sUHI intensity change under different LCZ conversion conditions showed that the LCZ conversion influences the sUHI intensity significantly. Based on population distribution data, we found that the relationship between population density and sUHI gets weaker with increasing population density. The result of GeoDetector indicated that the LCZ is the main factor influencing the sUHI, but population density is an important auxiliary factor. This research reveals the sUHI variation pattern in Beijing from 2000 and could help city managers plan thermally comfortable urban environments with a better understanding of the effect of urban spatial form and population density on sUHIs.

Change in Urban Land Use Efficiency in China: Does the High-Speed Rail Make a Difference?

High-speed rail (HSR) increases the non-local connections in cities and plays an essential role in urban land use efficiency. This paper uses a multi-period difference-in-difference model and a threshold model based on sample data that cover 284 Chinese cities from 2003–2018 to investigate the impact of HSR on urban land use efficiency. The results show that there is a 0.021 increase in urban land use efficiency after opening the HSR. The number of HSR stations and routes can increase the urban land use efficiency by 0.004 and 0.013, respectively. Compared with the cities in the East, the midwestern ones are more vulnerable to the impact of HSR. In particular, the positive impact of the number of HSR stations on the urban land use efficiency in cities with an urban population density exceeding 795 person/km2 is two times larger than cities with an urban population density of less than 795 person/km2. In addition, the impact of the number of HSR routes on urban land use efficiency in cities with an urban population density of less than 1003 person/km2 is five times larger than that of cities with an urban population density exceeding 1003 person/km2.

The Effects and Counter-Effects of Unemployment and Stringency Responses to COVID-19: An International Analysis Using Simultaneous Equations Models

ABSTRACT By applying the data from 59 countries to simultaneous equations models with 3SLS and GMM estimations, we analyse the effects and counter-effects of stringency of movement restrictions on unemployment rate and COVID-19 infection cases. On the one hand, our results show that the unemployment rate rises when the governments impose more stringent movement restrictions. On the other hand, a higher unemployment rate leads the government to lower stringency of movement restrictions. Our findings provide evidence on the tradeoff between unemployment rates and infection cases under the government’s virus containment intervention policies. This allows the policymakers to find a balance between public health emergencies and the economy. We also find that the stringency is affected positively by infection cases, negatively by the number of hospital beds per capita and healthcare spending per capita; the number of infection cases is affected positively by urban population density and negatively by an individualism index; and the unemployment rate is affected negatively by GDP.

The role of urbanisation in the spread of Aedes mosquitoes and the diseases they transmit-A systematic review.

BackgroundThis systematic review aims to assess how different urbanisation patterns related to rapid urban growth, unplanned expansion, and human population density affect the establishment and distribution of Aedes aegypti and Aedes albopictus and create favourable conditions for the spread of dengue, chikungunya, and Zika viruses.Methods and findingsFollowing the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a systematic review was conducted using the PubMed, Virtual Health Library, Cochrane, WHO Library Database (WHOLIS), Google Scholar, and and the Institutional Repository for Information Sharing (IRIS) databases. From a total of 523 identified studies, 86 were selected for further analysis, and 29 were finally analysed after applying all inclusion and exclusion criteria. The main explanatory variables used to associate urbanisation with epidemiological/entomological outcomes were the following: human population density, urban growth, artificial geographical space, urban construction, and urban density. Associated with the lack of a global definition of urbanisation, several studies provided their own definitions, which represents one of the study’s limitations. Results were based on 8 ecological studies/models, 8 entomological surveillance studies, 7 epidemiological surveillance studies, and 6 studies consisting of spatial and predictive models. According to their focus, studies were categorised into 2 main subgroups, namely “Aedes ecology” and “transmission dynamics.” There was a consistent association between urbanisation and the distribution and density of Aedes mosquitoes in 14 of the studies and a strong relationship between vector abundance and disease transmission in 18 studies. Human population density of more than 1,000 inhabitants per square kilometer was associated with increased levels of arboviral diseases in 15 of the studies.ConclusionsThe use of different methods in the included studies highlights the interplay of multiple factors linking urbanisation with ecological, entomological, and epidemiological parameters and the need to consider a variety of these factors for designing effective public health approaches.

Characterizing and classifying urban watersheds with compositional and structural attributes

AbstractCurrent land‐use classifications used to assess urbanization effects on stream water quality date back to the 1980s when limited information was available to characterize watershed attributes that mediate non‐point source pollution. With high resolution remote sensing and widely used GIS tools, there has been a vast increase in the availability and precision of geospatial data of built environments. In this study, we leverage geospatial data to expand the characterization of developed landscapes and create a typology that allows us to better understand the impact of complex developed landscapes across the rural to urban gradient. We assess the ability of the developed landscape typology to reveal patterns in stream water chemistry previously undetected by traditional land‐cover based classification. We examine the distribution of land‐cover, infrastructure, topography and geology across 3876 National Hydrography Dataset Plus catchments in the Piedmont region of North Carolina, USA. From this dataset, we generate metrics to evaluate the abundance, density and position of landscape features relative to streams, catchment outlets and topographic wetness metrics. While impervious surfaces are a key distinguishing feature of the urban landscape, sanitary infrastructure, population density and geology are better predictors of baseflow stream water chemistry. Unsupervised clustering was used to generate a distinct developed landscape typology based on the expanded, high‐resolution landscape feature information. Using stream chemistry data from 37 developed headwater catchments, we compared the baseflow water chemistry grouped by traditional land‐cover based classes of urbanization (rural, low, medium and high density) to our composition and structure‐based classification (a nine‐class typology). The typology based on 22 metrics of developed landscape composition and structure explained over 50% of the variation in NO3−‐N, TDN, DOC, Cl−, and Br− concentration, while the ISC‐based classification only significantly explained 23% of the variation in TDN. These results demonstrate the importance of infrastructure, population and geology in defining developed landscapes and improving discrete classes for water management.

China's transportation sector carbon dioxide emissions efficiency and its influencing factors based on the EBM DEA model with undesirable outputs and spatial Durbin model

The threat of global climate change has caused the international community to pay close attention to atmospheric levels of greenhouse gases such as carbon dioxide. Transportation sector carbon dioxide emissions efficiency (TSCDEE) is a key indicator used to prioritize sustainable development in the transportation sector. In this paper, the epsilon-based measure data envelopment analysis model with undesirable outputs is applied to estimate TSCDEE for 30 provinces in China from 2010 to 2016. We also analyze influencing factors using the spatial Durbin model. Research shows that the overall TSCDEE of the Chinese provinces studied was 0.618, indicating that most regions are still in need of improvements. The provinces with the highest TSCDEE are located in developed coastal regions of China. This study shows that factors such as transportation structure, traffic infrastructure level, and technological progress have prominent positive effects on TSCDEE, while both urbanization level and urban population density exert significantly negative effects on TSCDEE. The findings should have a far-reaching impact on the sustainable development of global transportation.

Spatial Analysis of Intra-Urban Land Use Dynamics in Sub-Saharan Africa: The Case of Addis Ababa (Ethiopia)

Currently, circa 30% of the population in sub-Saharan Africa resides in cities, and this figure is expected to double in 2040. The recent literature describes the urban expansion processes of African cities in much detail. However, the urbanization wave in Africa also leads to important intra-urban land use dynamics, which have important consequences on the quality of life within existing cities, which has received less attention. This study aims to contribute to these information gaps by (1) analyzing the extent of the urban land use conversion in contrasting urban locations using satellite images for physical criteria-based classifications and (2) assessing the potential consequences of these intra-urban conversions on the quality of life. Intra-urban land use changes were documented based on satellite imagery for the period 2002–2020. Based on some representative attributes, Addis Ababa city was selected for the case study. Urban land use dynamics and population density changes were examined based on the selected case study neighborhoods and randomly identified land parcels in the city, respectively. Urban development strategies and programs that emerged over recent decades had caused intra-urban land use dynamics, which brought significant population density changes. Moreover, these changes have caused an unbalanced distribution of socio-economic amenities across the city.

کاربرد مدلهای شبکه عصبی مصنوعی، نسبت فراوانی و تابع شواهد قطعی در تهیه نقشه حساسیت به وقوع سیل در حوزه آبخیز هراز: الگویی برای مطالعات مخاطرات سیلاب شهری

کاربرد مدلهای شبکه عصبی مصنوعی، نسبت فراوانی و تابع شواهد قطعی در تهیه نقشه حساسیت به وقوع سیل در حوزه آبخیز هراز: الگویی برای مطالعات مخاطرات سیلاب شهری

Urban effects on saprophagous macroarthropods are mainly driven by climate: A global meta-analysis

Macrodecomposers provide important ecosystem services even in human dominated habitats including urban ecosystems, but the effect of urban land conversion on their species diversity and abundance has not been explored at global scale. Here, we present the first meta-analysis to quantify the general response of two major arthropod taxa, terrestrial isopods and millipedes to urbanization and to reveal the underlying mechanisms. Climatic (temperature, precipitation, growing season length), edaphic (pH, organic carbon, CaCO3 and clay content of surface soils), urban (population density, city age, vegetation cover and mean actual evapotranspiration) parameters and methods of study (duration, sampling technique, replications) were used as moderators. We used a hierarchical meta-analytic approach to consider the dependence of multiple effect sizes obtained from one study. Altogether 156 paired observations were extracted from 59 urban studies conducted between 1980 and 2020. Urbanization had a negative effect on species diversity (species richness and Shannon index) of both macroarthropod taxa. However, both the direction and strength of their abundance response varied to a greater extent, resulting in a neutral effect of urban disturbance on them. The key drivers influencing the urban effects on macroarthropods were mean annual temperature and precipitation, absolute minimum temperature and length of growing season. The study also highlighted the importance of sampling methods: direct sampling (hand collecting) resulted in stronger urban effects presumably due to several sources of sampling bias. Our global synthesis highlighted that urbanization is a threat to soil arthropods, particularly to litter-dwelling detritivores, which potentially alters plant residue processing and ultimately soil biogeochemical cycles.

Mapping local climate zones and their associated heat risk issues in Beijing: Based on open data

The “Urban Heat Island” (UHI) effects in cities pose great threats to heat health risks for urban dwellers, but they present great differences inside cities. Local climate zones (LCZs), with distinct surface morphologies and physical structures, can be used to better explore differences of UHI effects inside cities and can also solve their different heat risks there. However, there still existed some gaps to map LCZs and their associated heat risks in cities, due to lack of detailed urban building data. Thus, we focused on mapping LCZs and their associated heat risks in Beijing, based on open data of four urban morphology parameters, including sky view factors, permeable surface fraction, building surface fraction and building height. Seven types of land cover LCZs and eight types of artificial built LCZs were divided. In spite of only 11% of total area, artificial built types of LCZ played vital roles in local economic development. Different types of LCZ were highly related with their urban functions, and most of artificial built LCZs were located in the Capital Functional Core Area and the Urban Functional Development Area. Open low-rise and open midrise were two important artificial built types of LCZ in Beijing, due to their high value of traditional and cultural buildings. Beijing faced serious heat risks in summer, especially for artificial built type LCZs. About 6% of total area and 58% of all residents suffered heat risks in Beijing, and most of them were located in artificial built type of LCZs. Lightweight low-rise suffered the most serious heat risks, and more than 90% of its area and residents were under heat risks. Considering climate change, about 4.0~7.4 million more people would suffer heat risks in future, and the LCZ of compact high-rise was highly sensitive to future climate change in Beijing. Urban morphology, economic function, population density and heat risks existed great differences among various LCZs in Beijing, and thus different strategies should be applied to mitigate heat risks in different LCZs for future city planning.

Assessment of sanitation service gap in urban slums for tackling COVID-19

Coronavirus disease 2019 (COVID-19), caused by Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), has been declared as a global pandemic by the World Health Organization (WHO). As the disease is highly infectious, the Global South countries are in a vulnerable situation with high urban population density and lack of Water, Sanitation, and Hygiene (WASH) services. The situation for the urban slum dwellers and low-income group clusters are becoming worse. Lack of health and sanitation service availability has already been an issue for them before the beginning of the pandemic. So, it is predictable that adopting this massive global pandemic is a critical challenge for them. This paper assesses the sanitation service gap in urban slums, which has become a severe challenge to tackle due to COVID-19. The study areas of this research are the Ranarmath slum and the Khema slum of Khulna city, Bangladesh. The SERVQUAL model has been used to identify the quality of sanitation service available in these informal residential settlements. The interpretation of questionnaire survey data from the two slums reveals that one slum lacks Assurance and Empathy, where the other slum lacks Tangibility and Responsiveness. However, the Tangibility, Reliability, and Responsiveness condition of both slums are flawed with the lack of latrine functionalities and services from concerned authorities. The incompatibility of the condition has been identified by evaluating the WHO's different sanitation management policy for COVID-19. The research concludes that sanitation services like handwashing facilities and water supply availability in the latrine directly related to COVID-19 prevention are indigent for these slums.

Empirical Analysis on Influencing Factors of Traffic Casualties in China

In order to further explore the complex correlation between the influencing factors of road traffic accidents in China, this paper takes the road traffic safety-related data of 31 provinces from 2004 to 2018 as the sample data, selects five index data that may affect the occurrence of traffic accidents in various regions of the country, i.e. resident population, urban population, population density, GDP and number of car drivers, and uses Eviews software for stepwise regression analysis to establish a fixed effect model of the influencing factors of traffic accidents and analyze the macro and micro factors that affect the death toll of traffic accidents in China. The model shows that each index has a significant impact on the number of road traffic casualties. Urban population, population density and number of car drivers are positively correlated with the number of road traffic casualties. The resident population and GDP are negatively correlated with the number of road traffic casualties. According to the research conclusions, this paper puts forward some suggestions, such as optimizing the management technology of road traffic construction, strengthening the education system of traffic safety awareness of residents in the new urbanization, increasing the investment in traffic construction, and establishing an institution for differentiated training and management of drivers based on driving experience.