scholarly journals Towards a Comprehensive Measure of the Ambient Population: Building Estimates Using Geographically Weighted Regression

2021 ◽  
Author(s):  
Annabel Whipp ◽  
Nick Malleson ◽  
Jonathan Ward ◽  
Alison Heppenstall
Keyword(s):  
Urban Areas ◽  
Small Area ◽  
Human Mobility ◽  
Statistical Modelling ◽  
City Centre ◽  
Night Time ◽  
Significant Relationships ◽  
The City ◽  
Ambient Population ◽  
Inform Decision Making

Estimates of the resident population fail to account for human mobility, which significantly impacts the numbers of people in urban areas. Employing the ambient population provides a more nuanced approach to small-area population estimation. This paper utilises statistical modelling and novel data to estimate the size of the ambient population in an urban area. Models of the daytime and night-time ambient populations are produced for the city of Leeds, West Yorkshire, UK. Interestingly, the presence of cash machines and hospitality venues were found to be statistically significant and were identified as the most important predictors of the ambient population. In contrast to the literature, the number of retail hubs, transport hubs, and the density of mobile phone cell towers were not found to have statistically significant relationships with footfall camera counts. Footfall camera data and the results of the predictive model were validated through comparison with manually collected pedestrian counts. The results of this validation process demonstrated that at five out of the six locations in Leeds city centre, the model produced expected estimates of the size of the ambient population. The results suggest that the approach of this study can be used as a tool to inform decision-making within local government and studies in which small area estimates of ambient populations are required.

scholarly journals Understanding Spatial Variability of NO2 in Urban Areas Using Spatial Modelling and Data Fusion Approaches

Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 179
Author(s):  
Said Munir ◽  
Martin Mayfield ◽  
Daniel Coca
Keyword(s):  
Data Fusion ◽  
Spatial Variability ◽  
Urban Areas ◽  
Road Traffic ◽  
Dispersion Model ◽  
Low Cost ◽  
Spatial Modelling ◽  
City Centre ◽  
Small Scale ◽  
The City

Small-scale spatial variability in NO2 concentrations is analysed with the help of pollution maps. Maps of NO2 estimated by the Airviro dispersion model and land use regression (LUR) model are fused with measured NO2 concentrations from low-cost sensors (LCS), reference sensors and diffusion tubes. In this study, geostatistical universal kriging was employed for fusing (integrating) model estimations with measured NO2 concentrations. The results showed that the data fusion approach was capable of estimating realistic NO2 concentration maps that inherited spatial patterns of the pollutant from the model estimations and adjusted the modelled values using the measured concentrations. Maps produced by the fusion of NO2-LCS with NO2-LUR produced better results, with r-value 0.96 and RMSE 9.09. Data fusion adds value to both measured and estimated concentrations: the measured data are improved by predicting spatiotemporal gaps, whereas the modelled data are improved by constraining them with observed data. Hotspots of NO2 were shown in the city centre, eastern parts of the city towards the motorway (M1) and on some major roads. Air quality standards were exceeded at several locations in Sheffield, where annual mean NO2 levels were higher than 40 µg/m3. Road traffic was considered to be the dominant emission source of NO2 in Sheffield.

scholarly journals Green Spaces in Residential Areas of Dar es Salaam City: Types, Coverage and Uses

2021 ◽  
Vol 14 (3) ◽  
pp. 121
Author(s):  
Nicholaus Mwageni ◽  
Robert Kiunsi
Keyword(s):  
Urban Areas ◽  
Green Space ◽  
Dar Es Salaam ◽  
Economic Benefits ◽  
Natural Vegetation ◽  
Green Spaces ◽  
City Centre ◽  
Building Density ◽  
Dar Es Salaam City ◽  
The City

Green spaces in urban areas including in Dar es Salaam City provide multiple ecological, social and economic benefits. Despite their benefits they are inadequately documented in terms types, coverage and uses. This paper attempts to provide information on types, coverage and uses of green space in Dar es Salaam City. A number of methods including literature review, interpretation of remotely sensed image, interviews, focus group discussions and questionnaires were used to document city greenery. The research findings show that residential greenery is made up of greenery found within and external to plots. The dominant green spaces external to residential plots were natural and semi natural vegetation while within plots were woody plants, plots farms vegetable and ornamental gardens. Distribution of greenery varied among the wards due to differences in building density and distance from the city centre. Natural and semi natural vegetation increased with decrease of building density and increase of distance from the city centre, while the number of plots with trees for shade increased with increase of building density. Only Kawe ward that had greenery above Tanzania space planning standards, the other three wards which are informal settlements had green space deficit. Three quarters of the households use green spaces for shade provision and cooling, two thirds as a source of food products and a quarter for recreation and aesthetic purposes. The study reveals that Dar es Salaam City residents invest predominantly on shade trees in their residential plots compared to other green space types.

Urban DAS recording of a vibroseismic campaign with a 21km-long dark fibre in Potsdam, Germany

2021 ◽  
Author(s):  
CharLotte Krawczyk ◽  
Christopher Wollin ◽  
Stefan Lüth ◽  
Martin Lipus ◽  
Christian Cunow ◽  
...  
Keyword(s):  
Urban Areas ◽  
District Heating ◽  
Telecommunication Networks ◽  
Seismic Exploration ◽  
City Centre ◽  
Data Set ◽  
Geothermal Potential ◽  
First Results ◽  
Local Geology ◽  
The City

<p>The de-carbonization strategy of the city of Potsdam, Germany, incorporates the utilization of its geothermal potential.  As a first step of developing a deep geothermal project for district heating, an urban seismic exploration campaign of the Stadtwerke Potsdam took place in December 2020 in the city centre of Potsdam.  Since urban measurements are often difficult to setup and a low-footprint alternative is sought for, we supplemented the contractor-performed Vibroseis survey along three profiles by distributed acoustic sensing (DAS).  In close cooperation with the municipal utilities, we interrogated a 21 km-long dark telecommunication fibre whose trajectory followed the seismic lines as close as possible.  This was accompanied by a network of 15 three-component geophones for further control and research.</p><p>In this contribution we present the data set, the approach for geo-referencing the fibre, and first results regarding DAS recording capabilities of vibroseismic signals in an urban environment.  Following the paradigm that the high density of telecommunication networks in urban areas may facilitate the exploration of the often insufficiently known local geology, we strive to further shed light on the possibilities of their employment for urban exploration.  In this respect we aim at tackling the question of the accuracy of fibre localization, recording sensitivity and range of active stimulation.</p>

scholarly journals Mapping Urban Areas Using a Combination of Remote Sensing and Geolocation Data

2019 ◽  
Vol 11 (12) ◽  
pp. 1470 ◽  
Author(s):  
Nan Xia ◽  
Liang Cheng ◽  
ManChun Li
Keyword(s):  
Remote Sensing ◽  
Land Surface ◽  
Urban Areas ◽  
Large Scale ◽  
High Spatial Resolution ◽  
Human Life ◽  
Human Movement ◽  
Night Time ◽  
Urban Mapping ◽  
The City

Urban areas are essential to daily human life; however, the urbanization process also brings about problems, especially in China. Urban mapping at large scales relies heavily on remote sensing (RS) data, which cannot capture socioeconomic features well. Geolocation datasets contain patterns of human movement, which are closely related to the extent of urbanization. However, the integration of RS and geolocation data for urban mapping is performed mostly at the city level or finer scales due to the limitations of geolocation datasets. Tencent provides a large-scale location request density (LRD) dataset with a finer temporal resolution, and makes large-scale urban mapping possible. The objective of this study is to combine multi-source features from RS and geolocation datasets to extract information on urban areas at large scales, including night-time lights, vegetation cover, land surface temperature, population density, LRD, accessibility, and road networks. The random forest (RF) classifier is introduced to deal with these high-dimension features on a 0.01 degree grid. High spatial resolution land cover (LC) products and the normalized difference built-up index from Landsat are used to label all of the samples. The RF prediction results are evaluated using validation samples and compared with LC products for four typical cities. The results show that night-time lights and LRD features contributed the most to the urban prediction results. A total of 176,266 km2 of urban areas in China were extracted using the RF classifier, with an overall accuracy of 90.79% and a kappa coefficient of 0.790. Compared with existing LC products, our results are more consistent with the manually interpreted urban boundaries in the four selected cities. Our results reveal the potential of Tencent LRD data for the extraction of large-scale urban areas, and the reliability of the RF classifier based on a combination of RS and geolocation data.

Analysis of temperature trends and urban heat island in Madrid

2020 ◽  
Author(s):  
Gregorio Maqueda ◽  
Carlos Yagüe ◽  
Carlos Román-Cascón ◽  
Encarna Serrano ◽  
Jon Ander Arrillaga
Keyword(s):  
Urban Heat Island ◽  
Urban Areas ◽  
Surface Energy Budget ◽  
City Centre ◽  
Synoptic Situation ◽  
Heat Island ◽  
Temperature Trends ◽  
Measuring Period ◽  
Urban Heat ◽  
The City

<p>The temperature in the cities is affected by both global climate change and local changes due to human activities and the different land use compared to rural surroundings. These local changes, which modify the surface energy budget in urban areas, include the replacement of the natural surfaces by buildings and pavements and the heat of anthropogenic origin (heating, air conditioning, traffic). Madrid city (Spain) has a current population of near 3.3 million people and a larger metropolitan area reaching around 6.5 million people. Hence, it is affected by the phenomenon called urban heat island (UHI), which indicates that a higher temperature is found in the city compared with the surrounding rural areas. UHI is defined as the temperature difference between the urban observatory and the rural one and especially affects the minimum temperatures since urban areas cool down to a lesser extent than the neighbouring rural sites. Moreover, the intensity of the UHI is modulated by the meteorological conditions (wind, cloudiness, surface pressure, precipitation), highly associated with different synoptic situations. In this work, we use the Madrid-Retiro meteorological station as the urban one, which has regular and homogeneous data from the beginning of XX century; and the station at Barajas airport (12 km from the city centre) as well as other stations out of Madrid city (but within a range of 20 km from the city centre) as the rural stations. They all have a common measuring period from 1961 until present. The main objectives of the work are: 1) to identify temperature trends in the meteorological stations (both urban and rural); 2) to evaluate the intensity of the UHI for the different rural stations; 3) to apply a systematic and objective algorithm to classify each day in different categories (related to synoptic situation) that produce a different degree of UHI intensity; and, 4) to evaluate possible trends in the UHI intensity.</p>

scholarly journals In the shadow of the urban regeneration megaproject: Urban transitions in downtown Łódź, Poland

2018 ◽  
Vol 56 (4) ◽  
pp. 41-52
Author(s):  
Jarosław Kazimierczak ◽  
Piotr Kosmowski
Keyword(s):  
Public Space ◽  
Urban Areas ◽  
Large Scale ◽  
Urban Regeneration ◽  
Point Of View ◽  
Business Community ◽  
City Centre ◽  
Functional Changes ◽  
Post Industrial ◽  
The City

Abstract The Nowe Centrum Łodzi project that was completed in 2007 in Łódź, Poland is one of the biggest contemporary large-scale urban (re)development projects in Europe and the largest project of this type in Central Europe. The principal goals of the mega-project in question include the regeneration of degraded post-industrial and post-railway land in the city centre of Łódź and the enhancement of competitiveness and the metropolitan position of the city. The authors seek to identify spatial and functional changes at a mezo-scale, i.e. in the so-called immediate neighbourhood of the urban regeneration megaproject (URMP), which have accompanied the implementation of the Nowe Centrum Łodzi project over the years 2013–2016. The other aim was to classify urban areas neighbouring the URMP based on features of spatial and functional transformation identified in these areas. The studies allowed the researchers to identify three categories of urban area in the immediate neighbourhood of the URMP which revealed differences in spatial and functional transformations. We indicated that the transformation of the immediate neighbourhood of the URMP involved not only the local authorities responsible for the overall improvement of the quality of public space but also other users, inter alia, residents, local urban activists, the business community, public institutions, and NGOs, that in most cases complemented efforts initiated by the Municipality. From the methodological point of view the authors use a case study including desk research, an urban planning inventory, and direct observation.

scholarly journals Housing Demand in Urban Areas and Sanitary Requirements of Dwellings in Italy

2020 ◽  
Vol 2020 ◽  
pp. 1-6 ◽  
Author(s):  
Marco Dettori ◽  
Lucia Altea ◽  
Donatella Fracasso ◽  
Federica Trogu ◽  
Antonio Azara ◽  
...  
Keyword(s):  
Public Health ◽  
Social Relations ◽  
Urban Areas ◽  
Housing Demand ◽  
City Centre ◽  
Italian Population ◽  
Housing Conditions ◽  
Foreign Born ◽  
Urban Context ◽  
The City

The phenomenon of urbanisation is becoming increasingly prevalent on a global level, and the health issues regarding the urban environment are of primary importance in public health. Accordingly, the present manuscript describes an analysis of the housing conditions of Italian urban areas, referring to the city of Sassari (Sardinia), Italy, focused on the dwelling structural and sanitary conditions issued by the Italian regulations. Data relating to the housing conditions of the population were acquired by the Local Hygiene and Public Health Service (SISP), in a period between 2012 and 2016. Qualitative variables were summarised with absolute and relative (percentages) frequencies, whereas quantitative variables with means and standard deviations depending on their parametric distribution. Statistical comparisons for qualitative and quantitative variables were performed with the χ2 test or Student’s t-test, respectively. A p value less than 0.05 was considered statistically significant. Finally, the dwellings and the collected variables were georeferenced on a city map. During the 2012–2016 observation period, 363 certification requests were received from 193 (53.2%) foreign-born citizens and 170 (46.8%) Italians at the SISP offices. The main reasons relate to the request for a residency permit (46.6%) and to obtain a subsidy from the local government (32.8%). Overall, 15.4% of dwellings were found to be improper, while 35.3% and 22.0% were found to be unhygienic and uninhabitable, respectively. The foreigners’ homes were found to be suitable in 82.7% of cases; the housing of Italian citizens, on the contrary, was found to be suitable in 28% of the observations. The present study offers a cross section of the housing conditions of Italian urban areas, referring to the city of Sassari. To the authors’ best knowledge, this observation is the first one carried out in Sardinia and one of the first observations in Italy. It has emerged that “hygienically unsuitable” homes are those that, in most cases, are located in the city centre. Moreover, the Italian population is hit by a significant housing problem, due to overcrowding, uninhabitability, and unhygienic conditions. Overall, our findings suggest that it is necessary to develop a multidisciplinary approach to guarantee public health, with safe dwellings homes and the surrounding urban context alongside the development of social relations. Nevertheless, there is still little evidence available today on the population housing conditions, especially regarding the private indoor environment, and further research is needed to bridge this knowledge gap.

scholarly journals Urbanization drives the evolution of parallel clines in plant populations

2016 ◽  
Vol 283 (1845) ◽  
pp. 20162180 ◽  
Author(s):  
Ken A. Thompson ◽  
Marie Renaudin ◽  
Marc T. J. Johnson
Keyword(s):  
Snow Cover ◽  
Urban Areas ◽  
Urban Ecosystems ◽  
Urban Environments ◽  
City Centre ◽  
Freezing Damage ◽  
Urban Centre ◽  
Dominant Feature ◽  
Urbanization Gradients ◽  
The City

Urban ecosystems are an increasingly dominant feature of terrestrial landscapes. While evidence that species can adapt to urban environments is accumulating, the mechanisms through which urbanization imposes natural selection on populations are poorly understood. The identification of adaptive phenotypic changes (i.e. clines) along urbanization gradients would facilitate our understanding of the selective factors driving adaptation in cities. Here, we test for phenotypic clines in urban ecosystems by sampling the frequency of a Mendelian-inherited trait—cyanogenesis—in white clover ( Trifolium repens L.) populations along urbanization gradients in four cities. Cyanogenesis protects plants from herbivores, but reduces tolerance to freezing temperatures. We found that the frequency of cyanogenic plants within populations decreased towards the urban centre in three of four cities. A field experiment indicated that spatial variation in herbivory is unlikely to explain these clines. Rather, colder minimum winter ground temperatures in urban areas compared with non-urban areas, caused by reduced snow cover in cities, may select against cyanogenesis. In the city with no cline, high snow cover might protect plants from freezing damage in the city centre. Our study suggests that populations are adapting to urbanization gradients, but regional climatic patterns may ultimately determine whether adaptation occurs.

Psychiatric Hospital Admissions in Bristol. I. Geographical and Ethnic Factors

1984 ◽  
Vol 145 (6) ◽  
pp. 600-604 ◽  
Author(s):  
B. Ineichen ◽  
G. Harrison ◽  
H. G. Morgan
Keyword(s):  
Psychiatric Hospital ◽  
Urban Areas ◽  
Hospital Admissions ◽  
City Centre ◽  
High Concentration ◽  
Psychiatric Admissions ◽  
Indian Origin ◽  
Ethnic Factors ◽  
The City ◽  
Do So

SummaryThe distribution of in-patient psychiatric admissions throughout the city of Bristol during the period 1978–1981 is described. High rates were found from the central urban areas of low social class and with a high concentration of immigrants. The findings suggest that immigrant groups (mainly of West Indian origin) are no more likely than others living in the city centre to become psychiatric hospital in-patients, but when they do so, they are more likely to require compulsory admission.

scholarly journals Big data insight on global mobility during the Covid-19 pandemic lockdown

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Adam Sadowski ◽  
Zbigniew Galar ◽  
Robert Walasek ◽  
Grzegorz Zimon ◽  
Per Engelseth
Keyword(s):  
Human Mobility ◽  
Weighted Average ◽  
Global Perspective ◽  
Huge Number ◽  
Significant Relationships ◽  
Global Mobility ◽  
Recreation Areas ◽  
The Difference ◽  
Time Offset ◽  
The City

AbstractThe Covid-19 pandemic that began in the city of Wuhan in China has caused a huge number of deaths worldwide. Countries have introduced spatial restrictions on movement and social distancing in response to the rapid rate of SARS-Cov-2 transmission among its populations. Research originality lies in the taken global perspective revealing indication of significant relationships between changes in mobility and the number of Covid-19 cases. The study uncovers a time offset between the two applied databases, Google Mobility and John Hopkins University, influencing correlations between mobility and pandemic development. Analyses reveals a link between the introduction of lockdown and the number of new Covid-19 cases. Types of mobility with the most significant impact on the development of the pandemic are “retail and recreation areas", "transit stations", "workplaces" "groceries and pharmacies”. The difference in the correlation between the lockdown introduced and the number of SARS-COV-2 cases is 81%, when using a 14-day weighted average compared to the 7-day average. Moreover, the study reveals a strong geographical diversity in human mobility and its impact on the number of new Covid-19 cases.

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