Light Pollution Levels Research Articles

Light Pollution Index System Model Based on Markov Random Field

Light pollution is one of the environmental pollution problems facing the world. The research on the measurement standard of light pollution is not perfect at present. In this paper, we proposed a Markov random field model to determine the light pollution risk level of a site. Firstly, the specific data of 12 indicators of 5 typical cities were collected, and 10-factor indicators were screened using the R-type clustering algorithm. Then, the entropy weight method was used to determine the weight, and the light pollution measurement method of the Markov random field was established. The model was tested by five different data sets, and the test results show that the model is very effective. Three kinds of potential effects were proposed, and the relationship between the factor index and potential effects was established by using the partial least square method. Three possible intervention strategies for solving the problem of light pollution are pointed out: road lighting system planning, increasing vegetation coverage, and building system planning. Finally, a simulated annealing algorithm was used to determine the best intervention strategy, concluding that using strategy 1 in urban neighborhood 2 was the most effective measure, reducing the risk level of light pollution by 17.2%.

Influence of Illumination Parameters on Night Sky Observation in Rural Areas

Currently, there are concerns about the significant increase in the level of night-time light pollution, which has become more dramatic in recent years. This causes several environmental problems and makes it impossible to observe the starry night sky, especially in rural areas where observatories are often located. Incorrect orientation and arrangement of lighting are often responsible for this pollution. This study quantified the level of interference of lighting parameters in the night sky. The influence of other environmental factors which may interfere with observation was also evaluated. A predictive model was developed to determine the level of darkness in rural areas. It was concluded that the distance from the emission point to the observation site is critical for sky observation. A series of guidelines were proposed for designing the lighting around observatories, which could help reduce light pollution and increase the stars’ perception. The conclusions and guidelines obtained could also be applied to designing the lighting in other areas, such as protected natural areas, historical monuments, urban lighting, and computer tools used for lighting. Globally, the results obtained in this study could help to reduce the level of night-time light pollution in rural areas, leading to improvements in the environment and in the observation of the night sky. This finding is of great relevance for astronomical observatories, which are spread around the world in strategic positions for sky observation, usually in rural areas.

Illuminating the threat: a decade-long analysis of light pollanálisis de una década de contaminacio´n lumínica en los principales centros urbanos de Colombia mediante imágenes satelitalesution in Colombian main urban centers through satellite imagery

Light pollution is a form of environmental degradation present throughout the world that affects the natural environment, flora, fauna, and various aspects of human life. Despite the growing concern about this problem, its study in Colombia is still minimal. Here we present a comprehensive analysis of the expansion of artificial nighttime lighting in the main Colombian cities between 2012 and 2022. According to the analysis, light pollution levels in the urban areas of Bogotá, Barranquilla, and Cartagena increased, while in Medellín, Cali, and Bucaramanga, they decreased. However, all the cities evaluated experienced an expansion in the coverage of illuminated areas revealing an evident spatial increase of the problem. In the case of Bogotá, the phenomenon was studied at the locality level. Additionally, we used external data to analyze the relationship between increased light pollution and the installation of new luminaires, the change to LED technologies, and the growing population density and gross domestic product (GDP) in the city. Our results provide valuable information on the threat of light pollution in Colombia and the need to take measures to help control the associated environmental degradation.

The Bats in Churches project : What building professionals need to know about working with bats in English churches

With one quarter of Britain’s mammals in serious decline and one-third of those most under threat being our more elusive bats, people who own, manage or access a variety of buildings are playing an ever more vital role in helping to conserve wildlife, often without even realising it. Buildings have become important roosting sites for bats, including houses, bridges, barns, mines, and historic buildings and churches. As older structures that have escaped modernisation, churches can provide ideal habitats for bats. In small numbers, bats in churches often go unnoticed, but where they roost in large numbers, or where multiple species use the same church, a conflict can arise between the wildlife and the community using the building and caring for the artefacts inside. In contrast to residential and commercial buildings, where bats and people are separated by a ceiling, churches often have open-roof architecture. This means that bat droppings and urine can damage historic items, the fabric and interior of the church, and create an unmanageable cleaning burden for the church community. This is why the Bats in Churches project is so important. This partnership between the Church of England, Historic England, Natural England, Bat Conservation Trust and Churches Conservation Trust was granted funding by the National Lottery Heritage Fund in 2018 and runs through 2023. The project brings together ecologists, church architects and heritage experts to trial and implement systems to manage the issues created by bats in churches, through a specially designed licence. The UK has 17 breeding bat species. Sadly, the loss of natural roosting sites coupled with factors such as intensive agriculture and urbanisation, including increasing levels of light pollution, have all had a dramatic impact on bat populations, which have seen serious declines in the last century. As well as making up a significant proportion of Britain’s mammal biodiversity, bats are indicator species. This means changes to our bat populations can reveal wider changes to local wildlife populations signalling the health of the environment upon which we all ultimately depend. This is why all species of bat in the UK and their roosts are protected by law. This means it is illegal to damage, destroy or disturb any bats or their roosts without having taken the necessary precautions and sought the correct advice from the Statutory Nature Conservation Organisation (SNCO) for your country. In England, this is Natural England, via the Bat Conservation Trust. This does not mean, however, that building work, roof repairs and other maintenance works cannot take place. It is entirely possible to carry out works alongside resident bats, but it requires careful planning and consideration of timings. This paper will discuss the law relating to bats and building works. It will cover how bats use churches and other buildings, and the impact they can have on church interiors and communities. It will consider the practicalities of surveys and licensing and will describe some interventions and mitigation solutions created by the Bats in Churches project.

Introducing a methodology to define the negative effects of upward façade lighting in historical buildings.

Light pollution is a phenomenon that affects both humans and the environment negatively. Currently there are no established means to calculate light pollution. This work proposes a method for calculating the levels of light pollution on the facades of buildings, specifically historical buildings, which are the most difficult to light, using simulation techniques. The proposed methodology tested different simulation grid densities and concluded that the highest density produces most accurate results, since lower densities are prone to software errors. Moreover, this research proves that the visual perception of a lit façade is the wrong way to determine if a lighting design produces light pollution and that the comprehensive methodology proposed should be used to determine the percentage of light that spills into the environment.

Impact of urban air pollutants on the night sky brightness and color in Hohhot

This study investigated the impact of urban air pollutants on the brightness and color of the night sky in Hohhot, China. The study used correlation analysis to determine the relationship between air pollutant concentrations and night sky brightness. Observations were conducted using a charge-coupled device(CCD) camera and an unmanned aerial vehicle (UAV) to assess changes in night sky brightness, color, and their spatial distribution before and after the aggravation of air pollution. The results revealed that particulate matter (PM) had the strongest correlation with night sky brightness among urban air pollutants, while the correlation between gaseous pollutants (except O3) and night sky brightness needs to be cautiously interpreted. The CCD camera observations showed that the night sky shifted toward red as the concentration of urban air pollutants increased. Meanwhile, the UAV observations demonstrated that the brightness of the night sky decreased with height above ground, and the area of night sky glow increased with higher urban air pollutant concentrations. Based on the research findings, controlling air pollutant emissions may have a positive impact on reducing the level and area of light pollution in the night sky, and thus promote sustainable urban environment development.

A study of light pollution risk level assessment based on multiple linear regression

Light pollution is affecting modern people’s lives, and it may damage people’s health and safety. To develop an applicable metric to identify the light pollution risk level of a location, this paper first analyzes the correlation of factors affecting light pollution, and obtains that the correlation coefficient with light pollution mainly includes population density, per capita income, GDP, green coverage, the proportion of the tertiary industry and employment rate. Select these explanatory variables which have high linear correlation with the degree of light pollution to establish a multiple linear regression model. Then, carry out heteroscedasticity and multicollinearity tests on the model, and next, after removing the three variables of population density, per capita income and the proportion of tertiary industry, the optimal linear regression model is determined through OSL. Finally, different levels of light pollution are classified by DN value, which represents the night light of a location, to achieve the assessment of light pollution risk level.

Study on the risk level of light pollution based on satellite remote sensing image data

Light pollution caused by artificial lighting at night (ALAN) is attracting more and more attention. In order to develop a widely applicable light pollution risk level measurement standard and accurately assess the local light pollution risk level, this paper establishes a RIM model, proposes a light pollution risk score based on satellite remote sensing image data to measure the light pollution risk level in an arbitrary area, and visualizes the model solution results by Matlab. Specifically, this paper selects the "satellite remote sensing-environmental measurement" method to obtain the data, and adopts the double difference robust regression algorithm to reduce the influence of outliers on the model and improve the validity of the model. By iterating over a large amount of data, a cubic polynomial regression equation between the independent variable and illumination was determined. Finally, the established model was applied to measure the light pollution risk levels of four types of sites.

The evaluation model of light pollution degree based on Topsis method

Light pollution is an environmental problem that arises along with the economic development of modern society. To explore the influencing factors of light pollution degree, firstly, the evaluation indicator system was constructed. The system modified by factor analysis, then entropy weight method and multiple linear regression are used to calculate the weight values of factors respectively, and the comprehensive score index of 271 prefecture-level cities in China is obtained by substituting into TOPSIS. And K-Means++ clustering is performed on the scores to derive the grade classification boundary values, thus dividing the degree of light pollution into five criteria. Then the 271 prefecture-level cities in China are divided and visualized by the two rating systems, and the advantages and disadvantages are analyzed by comparing with satellite images. And the DN values were calculated with the composite score series derived from the two models separately to calculate the spearman coefficients, and the results showed a better fit of the multivariate linear TOPSIS. This article applies the superiority rating system of the previous work, selects four representative areas from each of the four scenarios with different levels of light pollution, calculates their comprehensive score index, and adopts the light pollution level classification and cause analysis. The results show that light pollution is very low in conservation land locations, low in rural communities, medium in suburban communities, and high in urban communities.

Study on the Selection of Light Pollution Interventions Based on Goal Planning Model

With the continuous development of economy and technology, light pollution has become a new form of environmental pollution affecting human health and ecosystem. To assess the level of light pollution risk in a place, we used the HALOEN model to analyze the local light pollution situation, taking into account the health level of the local population, economic energy consumption, light pollution index, natural environment and urban planning. Using this model, we evaluated and ranked the risk levels of light pollution in four types of areas: protected land, rural communities, suburban communities and urban communities. Quantified according to the data of urban areas in Hubei Province, a total of 20 eligible cities in Hubei Province were selected as samples. Finally, the result of risk level is protected land < rural community < suburban community < urban community. Second, we designed specific interventions to address the problem of light pollution. Our team proposed specific actions in terms of lighting facilities, humanities education and urban planning, and explained the potential impact of these actions on light pollution. Finally, the causes of light pollution in Wuhan and Rio de Janeiro are analyzed, relevant intervention measures are proposed, and the effectiveness of their combination is calculated.

Evaluation System of Light Pollution Risk Index Based on Entropy Weight Method

In recent years, the issue of light pollution has garnered widespread attention. To address this concern, the state of California in the United States has developed a grading format to regulate lighting areas for light pollution protection. In order to further study this problem, we have selected six factors related to light pollution, namely population density, per capita gross regional product, total passenger transport, industrial electricity consumption, real estate development investment, and green area of built-up areas in different years in each prefecture-level city in China. Based on the VIKOR model, we have established a light pollution risk assessment system using the obtained compromise value as an assessment index for light pollution levels in different regions. The results have been analyzed using VIIRS satellite remote sensing images, and the average error is 5.24%, indicating good sensitivity to the system. Finally, we have analyzed the assessment results to show that over-development of areas can seriously exacerbate the risk level of light pollution. Therefore, development should be planned rationally to reduce the impact of light pollution.

Study on optimal intervention strategy of light pollution based on DSP model

Light pollution is a new type of environmental pollution, which has attracted the attention of many countries in the world and become a global environmental issue.In order to measure the impact of light pollution quantitatively and solve the problem of light pollution more pertinately, we established the light pollution risk level hierarchical model (RLG) to assess the risk level of light pollution in a region widely.Based on this, in order to more effectively control light pollution in a specific location, we construct a prediction model (DSP) based on different strategies introduced impact factors and apply it to two specific areas. The two sites are scored by combining the RLG model, and verify that the model can determine the optimal intervention strategy for a specific location and provide inspiration for local light pollution control. The results show that: (1) The risk level of light pollution is not only affected by the total amount of light pollution, but also affected by the development level, population level, ecological level, geography and climate. (2) We derived the formula that the above factors affect the classification of light pollution risk level. (3) A DSP model was established to determine the optimal light pollution intervention strategy for a specific location.

A Computer Vision Milky Way Compass

The Milky Way is used by nocturnal flying and walking insects for maintaining heading while navigating. In this study, we have explored the feasibility of the method for machine vision systems on autonomous vehicles by measuring the visual features and characteristics of the Milky Way. We also consider the conditions under which the Milky Way is used by insects and the sensory systems that support their detection of the Milky Way. Using a combination of simulated and real Milky Way imagery, we demonstrate that appropriate computer vision methods are capable of reliably and accurately extracting the orientation of the Milky Way under an unobstructed night sky. The technique presented achieves angular accuracy of better then ±2° under moderate light pollution conditions but also demonstrates that higher light pollution levels will adversely effect orientation estimates by systems depending on the Milky Way for navigation.

Distribution Characteristics, Ecological Risks, and Source Identification of Heavy Metals in Cultivated Land Under Non-grain Production

The purpose of this study was to explore the distribution characteristics and potential ecological risks of soil heavy metal pollution of cultivated land under non-grain production. Taking a typical area around Hangzhou Bay as an example, 254 topsoil samples (0-20 cm) of cultivated land were collected, and the content of eight soil heavy metals in four different cultivated land use types, including grain, seedlings, vegetables, and fruits, was analyzed. The ecological risk was assessed by the Nemerow pollution index and the potential ecological risk index, and the PMF model was used to identify the source of soil heavy metals in the study area. The results showed that the average contents of As, Cr, Cd, Cu, Hg, Ni, and Zn were all higher than the soil background value, except for Pb, but were lower than the national risk control standard for soil contamination of agricultural land. Non-grain production had a significant impact on the accumulation of heavy metals in soil. The content of heavy metals in nurseries and orchards was relatively high, followed by vegetable fields, and the lowest in grain fields. The Nemerow index showed that the cultivated land in the study area was in a light pollution level as a whole, and the single-factor pollution risks of Hg, Cd, and As were relatively high. The potential ecological risk levels of heavy metals in different cultivated land use types were:nurseries>orchards>vegetable fields>grain fields. The PMF results showed that the main sources of soil heavy metals in the study area were mixed sources of industrial emissions (36.8%), natural parent material sources (28.4%), atmospheric deposition sources (21.4%), and agricultural activity sources (13.4%). In conclusion, the increase in the application of chemical fertilizers and pesticides was the direct reason for the increase in soil heavy metal content caused by non-grain production of the cultivated land, whereas the industrial and mining emissions and atmospheric deposition accelerated the increase in soil heavy metal content in the study area.

Study on the risk assessment of light pollution based on entropy weight method-TOPSIS model

In the process of rapid human development, artificial light has gradually increased. People use artificial light more consider light to bring us benefits, but light pollution and the use of light at the same time harm human beings, even to the point of endangering human health and affecting the ecological environment. The problems caused by light pollution are waiting to be solved by us and all human beings together. In this paper, regional vulnerability (e.g., regional development level, population, biodiversity, etc.) is considered. Together with the intensity of pollution sources (e.g. road glare level, light hours, light violation level, etc.), the risk level of light pollution is determined. The risk level model of light pollution was established by calculating the weights of each index using TOPSIS entropy weighting method and hierarchical analysis method. The natural interruption point method was used to classify the risk level of light pollution into level I, level II, level III, level IV, and level v. The risk level model of light pollution was applied to four regions. We derived the risk level as level IV for urban communities, level II for protected land and suburban communities, and level II for rural communities.

The Impact of Environment Situation on Fireflies and the Contribution of Fireflies on Environment Situation

Firefly is an adorable insect which is often seen in our daily life as virtual characters or mascots due to its beautiful appearance. It is famous for its glowing abdomen. It can be colorful but mostly yellow and green. The biological light is rare which attracts lots of scholars and artists to study. However, after taking research on this specie, people start to ignore it. With the technology developing and land extension, they are suffering from land losing and different kind of pollution. There are countable studies on firefly protecting that lead the population of this cute creature decline steeply. The topic of this paper is about the factors which influence a lot on the population of firefly. There concentrates information from some papers related to firefly, environment pollution and bioindicator. Wishfully, this paper will be helpful to those who want to protect fireflies and those who can explore the application of fireflies. After researching, the results are about the impact of environment situation on fireflies and the contribution of fireflies on environment situation. Firefly is threatened by three aspects which are land loss, light pollution and water pollution. Land loss is due to the commercial district and residential district building of urbanization. Light pollution will disturb fireflies to find their companion and mate. Water pollution and land pollution such as insecticide will kill firefly larvae and adults directly in chemical ways. Those above are about how people gradually pushing fireflies to distinct. Its not fair of the way people treat wild fireflies. They have a lot of contribution down for people. They have controlled the number of ampullaria gigas which is a horribly threatening invasive species that confuses people for long. It is also a bioindicator which can test the level of light pollution with a relatively low cost. The biological fluorescence is pretty in the night. It has enlightened quite a few literature and art composers to create many excellent works. It is used to educate children and to witness love when wedding. Thus, the value of fireflies can be seen from this paper and how significant it is to protect wild fireflies.

Control Light Pollution by Genetic Algorithms

Based on Light pollution, the team first investigated the important factors that may lead to light pollution, and is divided into three factors, respectively, they are cultural factors, geographical factors and development factors, each and there are several secondary factors, they are GDP, air pollution, river coverage, vegetation coverage, residential coverage, industrial coverage, population quality and other factors. After obtaining these key factors affecting light pollution, our group conducted quantitative modeling based on the two-level AHP hierarchical analysis and derived the weights of these key factors. Noted that because the AHP model largely depends on expert opinion, has a lot of subjectivity, so our group further introduced the grey correlation analysis to more accurately and our assessment results and actual situation is very well, such as protection areas, rural areas for almost no light pollution or light pollution, and urban areas or urban areas are severe or moderate light pollution. Based on the above work, our group adopted the multi-target gene optimization method to obtain the optimal set of strategies, and greatly reduced the light pollution level under the premise that it did not affect the development.

Vertical Pollution Characteristics and Source Analysis of Soil PAHs in Different Land Use Types

In order to study the vertical pollution characteristics of polycyclic aromatic hydrocarbons (PAHs) in soils of different land use types in suburban areas of Nanjing, 15 types of controlled PAHs were studied in each section (0-100 cm) of soils from six different land use types, including a vegetable field, forestland, residential area, urban land, paddy field, and industrial area. The vertical distribution and composition characteristics, influencing factors, and sources of PAHs were analyzed. The results showed that:the total concentrations of Σ15PAHs in the six sampling site profiles were as follows:vegetable field (69.3-299.2 μg·kg-1), forestland (20.8-128.3 μg·kg-1), residential area (30.7-142.1 μg·kg-1), urban land (185.6-1728.7 μg·kg-1), paddy field (208.3-693.0 μg·kg-1), and industrial area (165.6-739.2 μg·kg-1). There was no pollution in the residential area or forestland and a light pollution level in the vegetable field, medium pollution level in the paddy field and industrial area, and more serious pollution in the urban land. Soil PAHs were mainly distributed in the surface or subsurface layer, except in the residential area and urban land; however, they were still detected in the deep layers, and high-molecular-weight PAHs were dominant in most depths and sampling sites. The vertical distribution and migration of PAHs in soils were affected by molecular characteristics and component concentrations of PAHs, soil physical and chemical properties, and land use types. PMF source analysis indicated that coke sources, traffic sources, and coal combustion sources from human activities were the main sources of PAHs in this study region.

Aerosol impact on light pollution in cities and their environment

Measurements of artificial light at night represent an incredible challenge as the optical state of the atmosphere is highly unstable thus making both long-term trend analyses and inter-comparison of multiple observations difficult. Variations of atmospheric parameters, caused by either natural or anthropogenic processes, can massively influence the level of resulting night sky brightness caused by light pollution. Focusing on six parameters, either from aerosol optics or emission properties of light sources, this work literarily and numerically examines defined variations in aerosol optical depth, asymmetry parameter, single scattering albedo, ground surface reflectance, direct uplight ratio, and aerosol scale height. For each individual element the effect size and angular reliance is investigated, with results indicating that besides the aerosol scale height all play non-negligible roles in forming skyglow and environmental impact. Especially variations in aerosol optical depth and city emission function displayed severe discrepancies in consequential light pollution level. Hence, future improvement on atmospheric condition, i.e., air quality, focusing particularly on discussed elements indicates to positively influence the level of environmental impact caused by artificial light at night. We underline the need of inclusion of our outcomes to urban development and civil engineering processes in order to create or protect habitable areas for humans, wildlife and nature.

Assessment of light pollution risk level

Artificial light has both positive and negative effects, affecting different sites in different ways. The level of light pollution is influenced by the level of local development, population, biodiversity, geography and climate. Therefore, it is important to assess the risk level of light pollution and to study the impact of different interventions to reduce light pollution in different locations. In this paper, four different types of representative locations in China were selected for calculation using the LPRL assessment model. Protected land locations have the lowest L1 values. Urban communities have the highest LPRL of L7. Rural and urban communities have LPRLs of L2 and L5, respectively. the results show that for rural communities, SI works best. It increased LPRL from L2 to L1. however, SII and SIII had no effect on LPRL. For urban communities, SIII had a significant effect in that it increased LPRL from L7 to L5. Therefore, it was necessary to focus on this aspect to develop the most effective intervention strategy for an urban community in Hangzhou, and a 1-page flyer was created to promote the strategy at this site.