Dynamics and Spatial Distribution of Global Nighttime Lights

Using open source data, we observe the fascinating dynamics of nighttime light. Following a global economic regime shift, the planetary center of light can be seen moving eastwards at a pace of about 60 km per year. Introducing spatial light Gini coefficients, we find a universal pattern of human settlements across different countries and see a global centralization of light. Observing 160 different countries we document the expansion of developing countries, the growth of new agglomerations, the regression in countries suffering from demographic decline and the success of light pollution abatement programs in western countries

SPATIOTEMPORAL EVOLUTION OF THE IMBALANCED REGIONAL DEVELOPMENT IN MAINLAND CHINA USING DMSP-OLS DATA

The Defense Meteorological Satellite Programs Operational Linescan System (DMSP-OLS) nighttime lights imagery has been widely used to monitor economic activities and regional development in recent decades. In this paper, we firstly processed the nighttime light imageries of the Mainland China from 1992 to 2013 due to the radiation or geometric errors. Secondly, by dividing the Mainland China into seven regions, we found high correlation between the sum light values and GDP of each region. Thirdly, we extracted the economic centers of each region based on their nighttime light images. Through the analysis, we found the distribution of these economic centers was relatively concentrated and the migration of these economic centers showed certain directional trend or circuitous changes, which suggested the imbalanced socio-economic development of each region. Then, we calculated the Regional Development Gini of each region using the nighttime light data, which indicated that social-economic development in South China presents great imbalance while it is relatively balanced in Southwest China. This study would benefit the macroeconomic control to regional economic development and the introduction of appropriate economic policies from the national level

Avoiding overly bright future : The systems intelligence perspective on the management of light pollution

Highlights • Light pollution is a wide-spread novel environmental change. • Stringent management measures are needed to curb light pollution. • The repertoire of household level measures were identified. • Wide array actions have been employed but the problem is seen as overwhelming. • Systems intelligence may help to overcome four key issues related to light pollution.Light pollution resulting from artificial lighting is a global environmental change that profoundly alters the nocturnal environment. Various ecological and health effects are caused by the alteration of natural levels of light and disruption of cycles of light and dark. Emissions of artificial light into the night environment have increased rapidly over the last decades and this trend is likely to continue due to the introduction of new cost-efficient light sources, urban sprawl, increasing traffic, population growth, and economic growth. Efficient measures to reduce light pollution are needed. Most measures so far have been based on top-down approaches such as legislation, technical norms and guidance. Based on the results from an online survey in Finland, household-level efforts aimed at reducing light pollution are reviewed and obstacles to action based on bottom-up approach are discussed. The systems intelligence is proposed as a context sensitive approach to light pollution management. Systems intelligence emphasises personal and active involvement in socio-technological systems, characterised by complex cross-scale interactions and feedbacks

Valosaaste ympäristöongelmana – Katsaus yhteiskunnalliseen ohjaukseen

Valosaaste on häiritsevää, terveydelle haitallista tai luontohaittoja aiheuttavaa yöaikaista ulkotiloihin kohdistuvaa keinovalaistusta. Tämän raportin tarkoituksena on arvioida tarvetta yhteiskunnalliselle ohjeistukselle, jonka avulla voitaisiin vähentää valosaastetta Suomessa. Tarve tälle arvioinnille on nostettu esiin vuoden 2011 hallitusohjelmassa. Raportti kytkeytyy muuhun hallinnon ja lainsäädännön kehittämistyöhön, erityisesti maankäyttö- ja rakennuslain toimivuuden arviointiin. Raportissa esitellään lyhyesti valosaasteeseen liittyvää viimeaikaista tutkimusta, tarkastellaan olemassa olevaa kotimaista ohjeistusta ja sääntelyä, kartoitetaan tilannetta kansainvälisesti sekä arvioidaan tarvetta uuden valosaasteeseen keskittyvän ohjeistuksen ja sääntelyn kehittämiselle. Raportissa tarkastellaan erityisesti informaatio-ohjausta valosaasteen vähentämiskeinona

Light pollution in South Karelia, Finland : the public’s point of view and lighting solutions of municipalities and forest industry enterprises

Keinovaloa, jolla on jonkinlaisia haitallisia vaikutuksia, kutsutaan valosaasteeksi. Valosaaste on vasta suhteellisen vähän aikaa tunnettu ympäristöongelma, joka aiheuttaa monia haittoja eliöille ja ekosysteemeille sekä ihmisten terveydelle ja hyvinvoinnille. Tämän tutkimuksen tarkoituksena on yhdistää kaksi valosaasteen näkökulmasta vähän tutkittua teemaa: yksityisten ihmisten näkemykset ja kokemukset sekä kuntien ja yritysten valaistusratkaisut. Nämä teemat yhdistyvät toisiinsa valaistusolosuhteen käsitteen kautta. Tässä valaistusolosuhteilla tarkoitetaan kolmea aluetta, joiden valaistukset eroavat toisistaan merkittävästi: kaupunkikeskustoja, metsäteollisuuden tuotantolaitoksia ympäristöineen sekä maaseutua. Tutkimusalueet sijaitsivat Etelä-Karjalassa ja tutkimus oli kaksiosainen. Yksityishenkilöitä käsittelevän osan tavoitteena oli selvittää sekä yleisellä tasolla että eri valaistusolosuhteissa asuvien eteläkarjalaisten suhtautumista keinovalovalojen vaikutuksiin sekä häiritsevyyteen. Lisäksi tarkoituksena oli löytää muita heidän mielipiteidensä taustalla vaikuttavia tekijöitä. Kuntia ja metsäteollisuusyrityksiä käsittelevän osan tavoitteena taas oli kartoittaa tutkimuskuntien ja -yritysten valaistuksen suunnittelua ja toteutusta sekä valosaasteen roolia näissä. Molemmissa tutkimuksen osioissa menetelmänä oli haastattelu. Yksityishenkilöitä häiritsivät eri valosaasteen lähteistä eniten valaistut mainostaulut sekä autojen valot, ja valosaasteen tyypeistä häiriötä aiheuttivat erityisesti voimakkaat valot sekä häikäisy. Keinovalojen hyödyistä korostettiin niiden turvallisuutta lisäävää, rikollisuutta ehkäisevää sekä mielialaa kohentavaa vaikutusta. Tähtitaivaan näkemisen ja luonnollisen pimeyden kokemisen vaikeutuminen taas koettiin suurimmiksi keinovalojen haitoiksi. Myös eri valaistusolosuhteiden vaikutus oli nähtävissä: Maaseudulla asuvat eivät tunteneet turvattomuutta pimeillä alueilla kaupunkien ulkopuolella tai pitäneet runsasta valaistusta viihtyisänä, mutta pitivät luonnollisen pimeyden kokemista tärkeänä. Muista taustamuuttujista erityisen voimakkaasti vastaajien näkemyksiin vaikuttivat luontosuuntautuminen, valoherkkyys, ympäristöasenne sekä sukupuoli. Kunnissa ja metsäteollisuusyrityksissä valaistuksen suunnittelu keskittyi alueellisiin suunnitelmiin. Kaikissa kunnissa ja yrityksissä yhtä lukuun ottamatta oli jollain tavalla huomioitu valosaaste, mutta huomioinnin muodot ja keinot vaihtelivat. Tulevaisuudessa sekä kunnat että metsäteollisuusyritykset tulevat panostamaan LED-valojen entistä laajempaan käyttöön. Tulokset osoittivat, että keinovalot voivat aiheuttaa haittaa myös sellaisille ihmisille, jotka asuivat kirkkaasti valaistujen alueiden ulkopuolella, ja jotka eivät olleet erityisen kiinnostuneita valosaasteesta. Häiritsevyyden ja haitan kokemisen taustalla olivat ennen kaikkea vastaajien tottumus ja kokemukset sekä heidän arvonsa ja asenteensa. Kuntien ja yritysten toiminnassa valosaasteen näkökulmasta oli parannettavaa, ja niiden pitäisi panostaa mm. valaistussuunnitteluun, ylivalaisun välttämiseen sekä miellyttäväksi koettujen ja ympäristölle vain vähän haitallisten natriumlamppujen suosimiseen. Jatkossa olisi tärkeä selvittää ihmisten mielipiteitä ja kartoittaa valomaisemaa paikallisella tasolla, mikä helpottaisi alueellisesti soveltuvimpien valaistusratkaisujen löytämisessä. Mielipidetutkimuksissa olisi syytä myös tarkastella subjektiivisten ominaisuuksien vaikutusta ihmisten näkemysten taustalla. Kuntia ja yrityksiä koskevaa tutkimusta tulisi suunnata niille alueille, joissa valosaastetta ei säännellä, jotta saataisiin tietoa vapaaehtoisten valosaastetta vähentävien toimien motivaatiosta ja toteutuksesta.Artificial light that produces some adverse effects is called light pollution. Light pollution has only recently been recognized as an environmental problem – it has been noticed to have adverse effects to organisms, ecosystems, human health and their well-being. The purpose of this study is to combine two aspects of light pollution that have so far gained little attention: the public’s point of view and the lighting solutions of municipalities and forest industry enterprises. These two aspects can be connected to each other through a concept called condition of lighting. Here the conditions of lighting consist of three areas with notable differences in lighting: city centers, countryside and forest industry production plants along with their surroundings. The study was conducted in South Karelia, Finland, and it was divided into two sections. The first section dealt with the public’s point of view on light pollution. The objective was to find out how South Karelians perceive the effects and obtrusiveness of artificial light both generally and also within areas of differing conditions of lighting. In addition, the intention was to uncover other factors that might influence the opinions of people. The second section of the study concerned the lighting solutions of municipalities and forest industry enterprises. The objective was to examine their lighting planning and implementation as well as the role of light pollution in the process. Interview was selected as the method of research in both sections of the study. The public considered electronic billboards and car headlights as the most obtrusive sources of light pollution. Bright lights and glare, on the other hand, were considered the most obtrusive types of light pollution. Most valued benefits of artificial light were its influence on safety, crime prevention and its positive effect on mood. Not being able to see the stars or experience natural darkness were considered as the biggest disadvantages of artificial light. The conditions of lighting in different areas also influenced the respondents’ experiences: people living in the countryside did not feel insecure in dark places outside the cities and did not consider abundant lighting pleasant. They also felt that being able to experience natural darkness was important. Among other factors, nature orientedness, light sensitivity, environmental attitudes and gender strongly affected the views of the respondents. In the municipalities and forest industry enterprises, the lighting planning concentrated on territorial plans. All but one of the municipalities and enterprises had taken light pollution into consideration at some level at least, but the forms and means varied. In the future both municipalities and forest industry enterprises will invest more in LED technology. The results show that artificial light can cause inconvenience to people who live outside the brightly lighted areas and who were not particularly interested in light pollution. Behind the inconvenience and disturbance were mostly the experiences, habits, values and attitudes of the respondents. The municipalities and enterprises have a lot to improve when it comes to light pollution. They should, for example, invest in comprehensive lighting planning, avoid over-illumination and pay attention to suitable direction and positioning of the light fixtures. In the future, it is important to examine the public’s opinion and to map the landscape of lights at a local scale. This would help in finding the most suitable lighting solutions for different areas. In the opinion polls, the subjective characteristics affecting the views of the respondents should be taken into consideration. Research regarding the municipalities and enterprises should be directed to the areas where light pollution is not regulated, in order to gather information on motivation and implementation of the voluntary activities reducing light pollution

Statistical inference of the relations among air temperature, land-use change, and rockfall hazard

Climate change has widespread impacts on human and natural systems worldwide. The pronounced air temperature warming detected worldwide could explain unusual events, as for example the increment of extreme precipitation events, increased incidence of summer heatwaves and slope instability. The possible presence of non-climatic forcings affecting temperature records, as for example land-use and land-cover changes, could introduce significant bias in the records and uncertainty on global overall temperature trends. This could somehow alterate, on the one hand, the perception of global warming, and on the other hand, all temperature-related analyses and models. Nevertheless, a robust assessment of climate warming patterns entails not only the analysis of all climate variables involved, but also the full understanding of the impacts on the natural systems, as for example the cryosphere, that could be used as terrestrial indicators of climate change. Chapter 1 shed light on the main scientific question investigated in the thesis, presenting the proposed investigation strategy, and the techniques applied. After an introduction on the issue of increasing air temperature vaiability in the current context of climate change, the two macrotopics of the thesis are presented and briefly outlined (Chapter 2 and 3). In Chapter 2, we investigate the nexus between temperature variations and urbanization trends, by analysing data recorded from weather instruments worldwide. After an extended introduction on the Urban Heat Island effect and its implications for climate warming trends at regional and global scale, we propose several methods to investigate the presence of a possible relation between air temperature variations and urbanizations dynamics with time, based on nightlights satellite measurements as proxy of urbanization. We applied a global scale analysis on more than 5000 temperature stations from the Berkeley Earth dataset in the period 1992-2013. Results highlight the tendency of urbanization to affect temperature trend at continental and regional scales. Significant positive concordant trends in temperature and nightlights variations have been detected, especially in developing and emerging regions, where the effects of growing urbanization are more evident. In Chapter 3 we turn to investigate the effects of air temperature variations on the hydrogeological hazard risk in those environments that are among the most sensitive to climate change, i.e. the high elevation sites. In alpine areas, and in particular in high mountain areas, the potential effects of environmental changes on air temperature data are minimum, since these areas are only slightly affected by urbanization dynamics and land-use changes. More in detail, in Chapter 3, we propose a statistical-based tool for the detection of the role of temperature, in association with other climate-related variables (as precipitation), in the triggering of slope stability. This approach is aimed to point out the potential climatic triggering climate factors for the slope failure. It has thought up as a tool for a better comprehension of the possible effects of air temperature variations on environmental dynamics, also in the presence of sparse and poor-quality data. We performed this method on a catalogue of 41 rockfalls in the Italian Alps, focusing on the role of temperature on slope instability preparation and initiation, and on cryosphere-related dynamics. The final purpose is detecting a possible linkage between slope failures and meteorological anomalies, and results suggest a major role of temperature as a preparatory/triggering factor. Rockfalls occurred in association with significant temperature anomalies in 83% of our case studies, and different regional patterns emerge from the data. Based on these results, temperature can be considered as a key factor contributing to slope failure occurrence in different ways, in presence of both warm and cool temperature anomalies. Chapter 4 presents a critical analysis in terms of how much it could be really answered of the main scientific questions with this work, what are the limitations encountered, which questions remain open and the possible further developments