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Author Levin, N.; Zhang, Q.
Title (up) A global analysis of factors controlling VIIRS nighttime light levels from densely populated areas Type Journal Article
Year 2017 Publication Remote Sensing of Environment Abbreviated Journal Remote Sensing of Environment
Volume 190 Issue Pages 366-382
Keywords Remote Sensing
Abstract Remote sensing of nighttime lights has been shown as a good surrogate for estimating population and economic activity at national and sub-national scales, using DMSP satellites. However, few studies have examined the factors explaining differences in nighttime brightness of cities at a global scale. In this study, we derived quantitative estimates of nighttime lights with the new VIIRS sensor onboard the Suomi NPP satellite in January 2014 and in July 2014, with two variables: mean brightness and percent lit area. We performed a global analysis of all densely populated areas (n = 4153, mostly corresponding to metropolitan areas), which we defined using high spatial resolution Landscan population data. National GDP per capita was better in explaining nighttime brightness levels (0.60 < Rs < 0.70) than GDP density at a spatial resolution of 0.25° (0.25 < Rs < 0.43), or than a city-level measure of GDP per capita (in proportion to each city's fraction of the national population; 0.49 < Rs < 0.62). We found that in addition to GDP per capita, the nighttime brightness of densely populated areas was positively correlated with MODIS derived percent urban area (0.46 < Rs < 0.60), the density of the road network (0.51 < Rs < 0.67), and with latitude (0.31 < Rs < 0.42) at p < 0.001. NDVI values (representing vegetation cover) were found to be negatively correlated with cities' brightness in winter time (&#8722; 0.48 < Rs < &#8722; 0.22), whereas snow cover (enhancing artificial light reflectance) was found to be positively correlated with cities' brightness in winter time (0.17 < Rs < 0.35). Overall, the generalized linear model we built was able to explain > 45% of the variability in cities' nighttime brightness, when both physical and socio-economic variables were included. Within the generalized linear model, the percent of national GDP derived from income (rents) from natural gas and oil, was also found as one of the statistically significant variables. Our findings show that cities' nighttime brightness can change with the seasons as a function of vegetation and snow cover, two variables affecting surface albedo. Explaining cities' nighttime brightness is therefore affected not only by country level factors (such as GDP), but also by the built environment and by climatic factors.
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ISSN 0034-4257 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number LoNNe @ kyba @ Serial 1628
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Author Zhou, Y.; Smith, S.J.; Zhao, K.; Imhoff, M.; Thomson, A.; Bond-Lamberty, B.; Asrar, G.R.; Zhang, X.; He, C.; Elvidge, C.D.
Title (up) A global map of urban extent from nightlights Type Journal Article
Year 2015 Publication Environmental Research Letters Abbreviated Journal Environ. Res. Lett.
Volume 10 Issue 5 Pages 054011
Keywords Remote Sensing
Abstract Urbanization, a major driver of global change, profoundly impacts our physical and social world, for example, altering not just water and carbon cycling, biodiversity, and climate, but also demography, public health, and economy. Understanding these consequences for better scientific insights and effective decision-making unarguably requires accurate information on urban extent and its spatial distributions. We developed a method to map the urban extent from the defense meteorological satellite program/operational linescan system nighttime stable-light data at the global level and created a new global 1 km urban extent map for the year 2000. Our map shows that globally, urban is about 0.5% of total land area but ranges widely at the regional level, from 0.1% in Oceania to 2.3% in Europe. At the country level, urbanized land varies from about 0.01 to 10%, but is lower than 1% for most (70%) countries. Urbanization follows land mass distribution, as anticipated, with the highest concentration between 30° N and 45° N latitude and the largest longitudinal peak around 80° W. Based on a sensitivity analysis and comparison with other global urban area products, we found that our global product of urban areas provides a reliable estimate of global urban areas and offers the potential for producing a time-series of urban area maps for temporal dynamics analyses.
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ISSN 1748-9326 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number LoNNe @ christopher.kyba @ Serial 1174
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Author Pena-Garcia, A.; Nguyen, T.P.L.
Title (up) A Global Perspective for Sustainable Highway Tunnel Lighting Regulations: Greater Road Safety with a Lower Environmental Impact Type Journal Article
Year 2018 Publication International Journal of Environmental Research and Public Health Abbreviated Journal Int J Environ Res Public Health
Volume 15 Issue 12 Pages
Keywords Lighting
Abstract Tunnel lighting installations function 24 h a day, 365 days a year. These infrastructures have increased exponentially and now connect quite distant locations, even on different continents. This has led European administrations and international regulatory bodies to establish regulations for tunnel safety with the lowest environmental impact. However, until now, these regulations have almost exclusively focused on traffic safety, and relegated sustainability to the background. Even though they recognize the need to reduce energy consumption, they do not propose any tools for doing so. Given the impact of these installations and the lack of a specific regulatory framework, Asian countries will soon be forced either to update previous standards for tunnel lighting or elaborate new ones. A better understanding of the weaknesses of European regulations combined with a willingness to embrace innovation could position Asia as a world leader in the regulation of more sustainable road tunnels. The objective of this research was to improve the sustainability of tunnel lighting installations through new regulations or amendments to existing ones, without impairing the mental well-being of users, who could potentially be affected by energy-saving measures. Accordingly, this paper presents and analyzes a broad proposal for formulating tunnel lighting regulations. The originality of this proposal lies in the fact that it integrates road safety, lower environmental impact, and user well-being. Furthermore, it is expected to broaden the perspective of regulatory bodies and public administrations with regard to tunnel installations, which would ultimately enhance their sustainability.
Address Department of Development and Sustainability, School of Environment, Resources and Development, Asian Institute of Technology, 12120 Pathumthani, Thailand. phuoclai@ait.asia
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Language English Summary Language Original Title
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ISSN 1660-4601 ISBN Medium
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Notes PMID:30486333 Approved no
Call Number GFZ @ kyba @ Serial 2119
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Author Elvidge, C.D.; Sutton, P.C.; Ghosh, T.; Tuttle, B.T.; Baugh, K.E.; Bhaduri, B.; Bright, E.
Title (up) A global poverty map derived from satellite data Type Journal Article
Year 2009 Publication Computers & Geosciences Abbreviated Journal Computers & Geosciences
Volume 35 Issue 8 Pages 1652-1660
Keywords Poverty; DMSP; Nighttime lights; World development indicators; light pollution
Abstract A global poverty map has been produced at 30 arcsec resolution using a poverty index calculated by dividing population count (LandScan 2004) by the brightness of satellite observed lighting (DMSP nighttime lights). Inputs to the LandScan product include satellite-derived land cover and topography, plus human settlement outlines derived from high-resolution imagery. The poverty estimates have been calibrated using national level poverty data from the World Development Indicators (WDI) 2006 edition. The total estimate of the numbers of individuals living in poverty is 2.2 billion, slightly under the WDI estimate of 2.6 billion. We have demonstrated a new class of poverty map that should improve over time through the inclusion of new reference data for calibration of poverty estimates and as improvements are made in the satellite observation of human activities related to economic activity and technology access.
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ISSN 0098-3004 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 123
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Author Walch, O.J.; Cochran, A.; Forger, D.B.
Title (up) A global quantification of “normal” sleep schedules using smartphone data Type Journal Article
Year 2016 Publication Science Advances Abbreviated Journal Science Advances
Volume 2 Issue 5 Pages e1501705-e1501705
Keywords Human Health; Sleep; *Circadian Rhythm; smartphone; society
Abstract The influence of the circadian clock on sleep scheduling has been studied extensively in the laboratory; however, the effects of society on sleep remain largely unquantified. We show how a smartphone app that we have developed, ENTRAIN, accurately collects data on sleep habits around the world. Through mathematical modeling and statistics, we find that social pressures weaken and/or conceal biological drives in the evening, leading individuals to delay their bedtime and shorten their sleep. A country’s average bedtime, but not average wake time, predicts sleep duration. We further show that mathematical models based on controlled laboratory experiments predict qualitative trends in sunrise, sunset, and light level; however, these effects are attenuated in the real world around bedtime. Additionally, we find that women schedule more sleep than men and that users reporting that they are typically exposed to outdoor light go to sleep earlier and sleep more than those reporting indoor light. Finally, we find that age is the primary determinant of sleep timing, and that age plays an important role in the variability of population-level sleep habits. This work better defines and personalizes “normal” sleep, produces hypotheses for future testing in the laboratory, and suggests important ways to counteract the global sleep crisis.
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ISSN 2375-2548 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number LoNNe @ kyba @ Serial 1440
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