scholarly journals Delineating Functional Urban Areas Using a Multi-Step Analysis of Artificial Light-at-Night Data

2021 ◽  
Vol 13 (18) ◽  
pp. 3714
Author(s):  
Nataliya Rybnikova ◽  
Boris A. Portnov ◽  
Igal Charney ◽  
Sviatoslav Rybnikov
Keyword(s):  
Population Density ◽  
Urban Areas ◽  
Census Data ◽  
Low Frequency ◽  
Global Scale ◽  
Artificial Light ◽  
Light At Night ◽  
Commuting Flows ◽  
Novel Approach ◽  
City Population

A functional urban area (FUA) is a geographic entity that consists of a densely inhabited city and a less densely populated commuting zone, both highly integrated through labor markets. The delineation of FUAs is important for comparative urban studies and it is commonly performed using census data and data on commuting flows. However, at the national scale, censuses and commuting surveys are performed at low frequency, and, on the global scale, consistent and comparable data are difficult to obtain overall. In this paper, we suggest and test a novel approach based on artificial light at night (ALAN) satellite data to delineate FUAs. As ALAN is emitted by illumination of thoroughfare roads, frequented by commuters, and by buildings surrounding roads, ALAN data can be used, as we hypothesize, for the identification of FUAs. However, as individual FUAs differ by their ALAN emissions, different ALAN thresholds are needed to delineate different FUAs, even those in the same country. To determine such differential thresholds, we use a multi-step approach. First, we analyze the ALAN flux distribution and determine the most frequent ALAN value observed in each FUA. Next, we adjust this value for the FUA’s compactness, and run regressions, in which the estimated ALAN threshold is the dependent variable. In these models, we use several readily available, or easy-to-calculate, characteristics of FUA cores, such as latitude, proximity to the nearest major city, population density, and population density gradient, as predictors. At the next step, we use the estimated models to define optimal ALAN thresholds for individual FUAs, and then compare the boundaries of FUAs, estimated by modelling, with commuting-based delineations. To measure the degree of correspondence between the commuting-based and model-predicted FUAs’ boundaries, we use the Jaccard index, which compares the size of the intersection with the size of the union of each pair of delineations. We apply the proposed approach to two European countries—France and Spain—which host 82 and 72 FUAs, respectively. As our analysis shows, ALAN thresholds, estimated by modelling, fit FUAs’ commuting boundaries with an accuracy of up to 75–100%, being, on the average, higher for large and densely-populated FUAs, than for small, low-density ones. We validate the estimated models by applying them to another European country—Austria—which demonstrates the prediction accuracy of 47–57%, depending on the model type used.

scholarly journals Moving in the Dark—Evidence for an Influence of Artificial Light at Night on the Movement Behaviour of European Hedgehogs (Erinaceus europaeus)

Animals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1306
Author(s):  
Anne Berger ◽  
Briseida Lozano ◽  
Leon M. F. Barthel ◽  
Nadine Schubert
Keyword(s):  
Light Intensity ◽  
Urban Areas ◽  
Species Conservation ◽  
Urban Environments ◽  
Artificial Light ◽  
Movement Behaviour ◽  
Light At Night ◽  
Very High Frequency ◽  
Erinaceus Europaeus ◽  
The Mean

With urban areas growing worldwide comes an increase in artificial light at night (ALAN), causing a significant impact on wildlife behaviour and its ecological relationships. The effects of ALAN on nocturnal and protected European hedgehogs (Erinaceus europaeus) are unknown but their identification is important for sustainable species conservation and management. In a pilot study, we investigated the influence of ALAN on the natural movement behaviour of 22 hedgehogs (nine females, 13 males) in urban environments. Over the course of four years, we equipped hedgehogs at three different study locations in Berlin with biologgers to record their behaviour for several weeks. We used Global Positioning System (GPS) tags to monitor their spatial behaviour, very high-frequency (VHF) loggers to locate their nests during daytime, and accelerometers to distinguish between active and passive behaviours. We compared the mean light intensity of the locations recorded when the hedgehogs were active with the mean light intensity of simulated locations randomly distributed in the individual’s home range. We were able to show that the ALAN intensity of the hedgehogs’ habitations was significantly lower compared to the simulated values, regardless of the animal’s sex. This ALAN-related avoidance in the movement behaviour can be used for applied hedgehog conservation.

scholarly journals Diet Quality and Neighborhood Environment in the Atlantic Partnership for Tomorrow’s Health Project

Nutrients ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 3217
Author(s):  
Kaitlyn Gilham ◽  
Qianqian Gu ◽  
Trevor J. B. Dummer ◽  
John J. Spinelli ◽  
Rachel A. Murphy
Keyword(s):  
Population Density ◽  
Diet Quality ◽  
Rural Areas ◽  
Urban Areas ◽  
Census Data ◽  
Social Deprivation ◽  
Neighborhood Environment ◽  
Neighbourhood Environment ◽  
Deprived Neighbourhoods ◽  
Intermediate Density

An understanding of relationships between different constructs of the neighbourhood environment and diet quality is needed to inform public health interventions. This study investigated associations between material deprivation, social deprivation and population density with diet quality in a cohort of 19,973 Canadian adults aged 35 to 69 years within the Atlantic PATH cohort study. Diet quality, a metric of how well diet conforms to recommendations was determined from a 24-item food frequency questionnaire. Neighbourhood environment data were derived from dissemination area level Census data. Two deprivation indices were evaluated: material and social deprivation, which reflect access to goods and amenities and social relationships. Multi-level models were used to estimate relationships (mean differences and 95% CI) between neighbourhood environment and diet quality, adjusting for covariates. Mean diet quality was lower in the most socially deprived neighbourhoods compared to the least socially deprived: −0.56, 95% CI (−0.88, −0.25). Relationships between diet quality and population density differed between urban and rural areas (p-interaction < 0.0001). In rural areas, diet quality was higher in intermediate-density neighbourhoods: 0.54, 95% CI (0.05, 1.03). In urban areas, diet quality was lower in intermediate-density and the most-dense neighbourhoods: −0.84, 95% CI (−1.28, −0.40) and −0.72, 95% CI (−1.20, −0.25). Our findings suggest socially deprived and high-density neighbourhoods are associated with lower diet quality and possible urban-rural differences in neighbourhood environment-diet quality relationships. Additional studies are needed to determine the temporal nature of relationships and whether differences in diet quality are meaningful.

scholarly journals Model simulations of cooking organic aerosol (COA) over the UK using estimates of emissions based on measurements at two sites in London

2016 ◽  
Vol 16 (21) ◽  
pp. 13773-13789 ◽  
Author(s):  
Riinu Ots ◽  
Massimo Vieno ◽  
James D. Allan ◽  
Stefan Reis ◽  
Eiko Nemitz ◽  
...  
Keyword(s):  
Population Density ◽  
Atmospheric Chemistry ◽  
Rural Areas ◽  
Urban Areas ◽  
Census Data ◽  
Organic Aerosol ◽  
Balance Model ◽  
Rural Site ◽  
Annual Average ◽  
The Uk

Abstract. Cooking organic aerosol (COA) is currently not included in European emission inventories. However, recent positive matrix factorization (PMF) analyses of aerosol mass spectrometer (AMS) measurements have suggested important contributions of COA in several European cities. In this study, emissions of COA were estimated for the UK, based on hourly AMS measurements of COA made at two sites in London (a kerbside site in central London and an urban background site in a residential area close to central London) for the full calendar year of 2012 during the Clean Air for London (ClearfLo) campaign. Iteration of COA emissions estimates and subsequent evaluation and sensitivity experiments were conducted with the EMEP4UK atmospheric chemistry transport modelling system with a horizontal resolution of 5 km  ×  5 km. The spatial distribution of these emissions was based on workday population density derived from the 2011 census data. The estimated UK annual COA emission was 7.4 Gg per year, which is an almost 10 % addition to the officially reported UK national total anthropogenic emissions of PM2.5 (82 Gg in 2012), corresponding to 320 mg person−1 day−1 on average. Weekday and weekend diurnal variation in COA emissions were also based on the AMS measurements. Modelled concentrations of COA were then independently evaluated against AMS-derived COA measurements from another city and time period (Manchester, January–February 2007), as well as with COA estimated by a chemical mass balance model of measurements for a 2-week period at the Harwell rural site (∼ 80 km west of central London). The modelled annual average contribution of COA to ambient particulate matter (PM) in central London was between 1 and 2 µg m−3 (∼ 20 % of total measured OA1) and between 0.5 and 0.7 µg m−3 in other major cities in England (Manchester, Birmingham, Leeds). It was also shown that cities smaller than London can have a central hotspot of population density of smaller area than the computational grid cell, in which case higher localized COA concentrations than modelled here may be expected. Modelled COA concentrations dropped rapidly outside of major urban areas (annual average of 0.12 µg m−3 for the Harwell location), indicating that although COA can be a notable component in urban air, it does not have a significant effect on PM concentrations on rural areas. The possibility that the AMS-PMF apportionment measurements overestimate COA concentrations by up to a factor of 2 is discussed. Since COA is a primary emission, any downward adjustments in COA emissions would lead to a proportional linear downward scaling in the absolute magnitudes of COA concentrations simulated in the model.

scholarly journals Artificial light at night alters life history in a nocturnal orb-web spider

2018 ◽  
Author(s):  
Nikolas J Willmott ◽  
Jessica Henneken ◽  
Caitlin J Selleck ◽  
Therésa M Jones
Keyword(s):  
Life History ◽  
Urban Areas ◽  
Future Research ◽  
Artificial Light ◽  
Light At Night ◽  
Night Time ◽  
Juvenile Mortality ◽  
Web Spider ◽  
Orb Web ◽  
Juvenile Development

The prevalence of artificial light at night (ALAN) is increasing rapidly around the world. The potential physiological costs of this night lighting are often evident in life history shifts. We investigated the effects of chronic night-time exposure to ecologically relevant levels of LED lighting on the life history traits of the nocturnal Australian garden orb-web spider (Eriophora biapicata). We reared spiders under a 12-hour day and either a 12-hour natural darkness (~0 lux) or a 12-hour dim light (~20 lux) night and assessed juvenile development, growth and mortality, and adult reproductive success and survival. We found that exposure to ALAN accelerated juvenile development, resulting in spiders progressing through fewer moults, and maturing earlier and at a smaller size. There was a significant increase in daily juvenile mortality for spiders reared under 20 lux, but the earlier maturation resulted in a comparable number of 0 lux and 20 lux spiders reaching maturity. Exposure to ALAN also considerably reduced the number of eggs produced by females, largely associated with ALAN-induced reductions in body size. Despite previous observations of increased fitness for some orb-weavers in urban areas and near night lighting, it appears that exposure to artificial night lighting may lead to considerable developmental costs. Future research will need to consider the detrimental effects of ALAN combined with foraging benefits when studying nocturnal insectivores that forage around artificial lights.

scholarly journals Artificial light at night alters life history in a nocturnal orb-web spider

2018 ◽  
Author(s):  
Nikolas J Willmott ◽  
Jessica Henneken ◽  
Caitlin J Selleck ◽  
Therésa M Jones
Keyword(s):  
Life History ◽  
Urban Areas ◽  
Future Research ◽  
Artificial Light ◽  
Light At Night ◽  
Night Time ◽  
Juvenile Mortality ◽  
Web Spider ◽  
Orb Web ◽  
Juvenile Development

The prevalence of artificial light at night (ALAN) is increasing rapidly around the world. The potential physiological costs of this night lighting are often evident in life history shifts. We investigated the effects of chronic night-time exposure to ecologically relevant levels of LED lighting on the life history traits of the nocturnal Australian garden orb-web spider (Eriophora biapicata). We reared spiders under a 12-hour day and either a 12-hour natural darkness (~0 lux) or a 12-hour dim light (~20 lux) night and assessed juvenile development, growth and mortality, and adult reproductive success and survival. We found that exposure to ALAN accelerated juvenile development, resulting in spiders progressing through fewer moults, and maturing earlier and at a smaller size. There was a significant increase in daily juvenile mortality for spiders reared under 20 lux, but the earlier maturation resulted in a comparable number of 0 lux and 20 lux spiders reaching maturity. Exposure to ALAN also considerably reduced the number of eggs produced by females, largely associated with ALAN-induced reductions in body size. Despite previous observations of increased fitness for some orb-weavers in urban areas and near night lighting, it appears that exposure to artificial night lighting may lead to considerable developmental costs. Future research will need to consider the detrimental effects of ALAN combined with foraging benefits when studying nocturnal insectivores that forage around artificial lights.

scholarly journals Artificial Light at Night (ALAN) Is the Main Driver of Nocturnal Feral Pigeon (Columba livia f. domestica) Foraging in Urban Areas

Animals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 554
Author(s):  
Lucas M. Leveau
Keyword(s):  
Urban Areas ◽  
Columba Livia ◽  
Common Species ◽  
Artificial Light ◽  
Feral Pigeon ◽  
Nocturnal Activity ◽  
Light At Night ◽  
Urban Centers ◽  
Main Driver ◽  
Nocturnal Foraging

Artificial light at night (ALAN) is one of the most extreme environmental alterations in urban areas, which drives nocturnal activity in diurnal species. Feral Pigeon (Columba livia f. domestica), a common species in urban centers worldwide, has been observed foraging at night in urban areas. However, the role of ALAN in the nocturnal activity of this species is unknown. Moreover, studies addressing the relationship between ALAN and nocturnal activity of diurnal birds are scarce in the Southern Hemisphere. The objective of this study is to assess the environmental factors associated with nocturnal activity of the Feral Pigeon in Argentinian cities. Environmental conditions were compared between sites where pigeons were seen foraging and randomly selected sites where pigeons were not recorded foraging. Nocturnal foraging by the Feral Pigeon was recorded in three of four surveyed cities. ALAN was positively related to nocturnal foraging activity in Salta and Buenos Aires. The results obtained suggest that urbanization would promote nocturnal activity in Feral Pigeons. Moreover, nocturnal activity was mainly driven by ALAN, which probably alters the circadian rhythm of pigeons.

scholarly journals National Scale Spatial Variation in Artificial Light at Night

2020 ◽  
Vol 12 (10) ◽  
pp. 1591 ◽  
Author(s):  
Daniel T.C. Cox ◽  
Alejandro Sánchez de Miguel ◽  
Simon A. Dzurjak ◽  
Jonathan Bennie ◽  
Kevin J. Gaston
Keyword(s):  
Human Health ◽  
National Parks ◽  
Urban Areas ◽  
Infrared Imaging ◽  
Natural World ◽  
Light Pollution ◽  
Artificial Light ◽  
Light At Night ◽  
Challenges And Opportunities ◽  
Per Capita

The disruption to natural light regimes caused by outdoor artificial nighttime lighting has significant impacts on human health and the natural world. Artificial light at night takes two forms, light emissions and skyglow (caused by the scattering of light by water, dust and gas molecules in the atmosphere). Key to determining where the biological impacts from each form are likely to be experienced is understanding their spatial occurrence, and how this varies with other landscape factors. To examine this, we used data from the Visible Infrared Imaging Radiometer Suite (VIIRS) day/night band and the World Atlas of Artificial Night Sky Brightness, to determine covariation in (a) light emissions, and (b) skyglow, with human population density, landcover, protected areas and roads in Britain. We demonstrate that, although artificial light at night increases with human density, the amount of light per person decreases with increasing urbanization (with per capita median direct emissions three times greater in rural than urban populations, and per capita median skyglow eleven times greater). There was significant variation in artificial light at night within different landcover types, emphasizing that light pollution is not a solely urban issue. Further, half of English National Parks have higher levels of skyglow than light emissions, indicating their failure to buffer biodiversity from pressures that artificial lighting poses. The higher per capita emissions in rural than urban areas provide different challenges and opportunities for mitigating the negative human health and environmental impacts of light pollution.

scholarly journals Artificial light at night alters life history in a nocturnal orb-web spider

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5599 ◽  
Author(s):  
Nikolas J. Willmott ◽  
Jessica Henneken ◽  
Caitlin J. Selleck ◽  
Therésa M. Jones
Keyword(s):  
Life History ◽  
Urban Areas ◽  
Future Research ◽  
Artificial Light ◽  
Light At Night ◽  
Night Time ◽  
Juvenile Mortality ◽  
Web Spider ◽  
Orb Web ◽  
Juvenile Development

The prevalence of artificial light at night (ALAN) is increasing rapidly around the world. The potential physiological costs of this night lighting are often evident in life history shifts. We investigated the effects of chronic night-time exposure to ecologically relevant levels of LED lighting on the life history traits of the nocturnal Australian garden orb-web spider (Eriophora biapicata). We reared spiders under a 12-h day and either a 12-h natural darkness (∼0 lux) or a 12-h dim light (∼20 lux) night and assessed juvenile development, growth and mortality, and adult reproductive success and survival. We found that exposure to ALAN accelerated juvenile development, resulting in spiders progressing through fewer moults, and maturing earlier and at a smaller size. There was a significant increase in daily juvenile mortality for spiders reared under 20 lux, but the earlier maturation resulted in a comparable number of 0 lux and 20 lux spiders reaching maturity. Exposure to ALAN also considerably reduced the number of eggs produced by females, and this was largely associated with ALAN-induced reductions in body size. Despite previous observations of increased fitness for some orb-web spiders in urban areas and near night lighting, it appears that exposure to artificial night lighting may lead to considerable developmental costs. Future research will need to consider the detrimental effects of ALAN combined with foraging benefits when studying nocturnal insectivores that forage around artificial lights.

Development of a Pedestrian Walkability Database of Northern Kentucky Using Geographic Information Systems (GIS)

2009 ◽  
Vol 6 (3) ◽  
pp. 374-385 ◽  
Author(s):  
William Hansen ◽  
Ned Kalapasev ◽  
Amy Gillespie ◽  
Mary Singler ◽  
Marsha Ball
Keyword(s):  
Population Density ◽  
Urban Areas ◽  
Census Data ◽  
The United States ◽  
Geographic Information ◽  
Ohio River ◽  
Suitability Assessment ◽  
Ranking Criteria ◽  
Census 2000 ◽  
Over Time

Background:Rising obesity rates in the United States has spurred efforts by health advocates to encourage more active lifestyles including walking. Ensuring the availability, quality, and safety of pedestrian walkways has become an important issue for government at all levels.Methods:Pedestrian paths in Campbell County Kentucky were evaluated using a ranking criteria developed by the Walking and Bicycling Suitability Assessment (WABSA) project at the University of North Carolina School of Public Health. A pedestrian path Geographic Information System (GIS) data-layer was created, and mobile GIS units were used to assess the sidewalk segments using the ranking. Data from sidewalk surveys were compared with Census 2000 block group information on age of housing, population density, and household transportation characteristics to examine the correlation between these factors and sidewalk presence and quality. The analysis explored the use of census data to predict walkability factors and looked for trends in quality and availability of pedestrian paths over time.Results:Results showed higher overall scores for older urban areas adjacent to the Ohio River and Cincinnati. Housing built in the 1970s and 1980s showed the lowest scores, while more recent housing showed improvement over earlier decades. Age of housing was determined to be a useful predictor, while economic and population density attributes showed no correlation with walkability factors.Conclusion:Census housing age data are the most useful predictor of walkability demonstrating clear trends over time. The study shows improvements in walkways availability over the past few decades; however, infrastructure improvements are needed to provide more extensive pedestrian walkways and linkages between existing walkways in Campbell County.

Cold Nights, City Lights: Artificial Light at Night Reduces Photoperiodically Induced Diapause in Urban and Rural Populations of Aedes albopictus (Diptera: Culicidae)

2020 ◽  
Vol 57 (6) ◽  
pp. 1694-1699 ◽  
Author(s):  
Katie M Westby ◽  
Kim A Medley
Keyword(s):  
Local Adaptation ◽  
Aedes Albopictus ◽  
Rural Areas ◽  
Urban Areas ◽  
Activity Patterns ◽  
Rapid Evolution ◽  
Egg Laying ◽  
Artificial Light ◽  
Light At Night ◽  
Diapause Incidence

Abstract As the planet becomes increasingly urbanized, it is imperative that we understand the ecological and evolutionary consequences of urbanization on species. One common attribute of urbanization that differs from rural areas is the prevalence of artificial light at night (ALAN). For many species, light is one of the most important and reliable environmental cues, largely governing the timing of daily and seasonal activity patterns. Recently, it has been shown that ALAN can alter behavioral, phenological, and physiological traits in diverse taxa. For temperate insects, diapause is an essential trait for winter survival and commences in response to declining daylight hours in the fall. Diapause is under strong selection pressure in the mosquito, Aedes albopictus (Skuse); local adaptation and rapid evolution has been observed along a latitudinal cline. It is unknown how ALAN affects this photosensitive trait or if local adaptation has occurred along an urbanization gradient. Using a common garden experiment, we experimentally demonstrated that simulated ALAN reduces diapause incidence in this species by as much as 40%. There was no difference, however, between urban and rural demes. We also calculated diapause incidence from wild demes in urban areas to determine whether wild populations exhibited lower than predicted incidence compared to estimates from total nocturnal darkness. In early fall, lower than predicted diapause incidence was recorded, but all demes reached nearly 100% diapause before terminating egg laying. It is possible that nocturnal resting behavior in vegetation limits the amount of ALAN exposure this species experiences potentially limiting local adaptation.

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