Exploring the effect of air pollution on settlement intentions from migrants: Evidence from China

Based on the China Migrants Dynamic Survey (CMDS) from 2015 to 2017, this paper uses IV-Probit model to investigate the effects of air pollution on migrants' settlement intentions in China. The results show that: First, air pollution has a significant and negative effect on intentions in settling down of the migrants. Specifically, when the concentration of PM_2.5 increases by 1 μg/m³, the probability of migrants settling down in the city which they have moved to for work or business will significantly decrease by 1.89%. Second, there is heterogeneity in the effects of air pollution on migrants' settlement intentions. In detail, the sensitivity to air pollution is higher among female groups, who have higher education levels and prefer better air quality in the living place to settle down, and there is an inverted U-shaped relationship between age and settlement intentions. On the one hand, the conclusion of this paper enriches the relevant theoretical achievements of air pollution and migration. On the other hand, it also has a high reference value for developing more reasonable policies related to urban environmental governance and labor mobility.     

Emerging conservation challenges and prospects in an era of offshore hydrocarbon exploration and exploitation

Globally, extensive marine areas important for biodiversity conservation and ecosystem functioning are undergoing exploration and extraction of oil and natural gas resources. Such operations are expanding to previously inaccessible deep waters and other frontier regions, while conservation‐related legislation and planning is often lacking. Conservation challenges arising from offshore hydrocarbon development are wide‐ranging. These challenges include threats to ecosystems and marine species from oil spills, negative impacts on native biodiversity from invasive species colonizing drilling infrastructure, and increased political conflicts that can delay conservation actions. With mounting offshore operations, conservationists need to urgently consider some possible opportunities that could be leveraged for conservation. Leveraging options, as part of multi‐billion dollar marine hydrocarbon operations, include the use of facilities and costly equipment of the deep and ultra‐deep hydrocarbon industry for deep‐sea conservation research and monitoring and establishing new conservation research, practice, and monitoring funds and environmental offsetting schemes. The conservation community, including conservation scientists, should become more involved in the earliest planning and exploration phases and remain involved throughout the operations so as to influence decision making and promote continuous monitoring of biodiversity and ecosystems. A prompt response by conservation professionals to offshore oil and gas developments can mitigate impacts of future decisions and actions of the industry and governments. New environmental decision support tools can be used to explicitly incorporate the impacts of hydrocarbon operations on biodiversity into marine spatial and conservation plans and thus allow for optimum trade‐offs among multiple objectives, costs, and risks.     

广东省雾霾天气能见度的时空特征分析Ⅰ:季节变化

雾霾已经成为一种新的气象及环境灾害性现象,分析雾霾天气下低能见度的时空分布特征,对掌握雾霾的发生规律和减灾预报具有重要意义。文章利用1980—2003年广东省沿海地区26个地面气象观测站23年的气象观测资料,分析了广东省雾霾天气下能见度的时空分布特征。分析结果发现,1980—2003年广东地区雾霾天气下能见度的季节变化规律与雾天气时能见度的季节变化规律大体一致,即广东地区低能见度天气主要受雾天气的影响;另一方面,雾、霾天气时能见度的季节变化规律有很大不同,雾天气时能见度观测值在冬、春两季相对较高,最低值出现在3月份,最高值出现在9月份,其年变化表现为峰—谷型、稳定型和不规则波动型三种变化;霾天气时能见度的值在秋、冬两季相对较高,最低值出现在6月份,而且在5、6、7三个月中能见度值都很低;受广东沿海地形特征影响,雾天能见度的空间分布从西到东呈低—高—低—高的波列状分布,而霾天气时能见度的空间分布则没有明显的区域差异。     

Can best competitors avoid extinction as habitat destruction?

A nonlinear n-population metapopulation model, which can describe the nonlinear relationship between one species and other species or between one species and the habitat, is presented in this paper. By simulation and mathematics analysis, we discover that species possess an ability to control or avoid extinction during habitat destruction. Any species in n-population metapopulation can increase (decrease) the influence of habitat destruction if it agrees (disagrees) with the environment, and it also can increase (decrease) the proportion of sites occupied by all species by harmonizing (not harmonizing) with the other species.     

Continuous monitoring of conventional parameters to assess receiving water quality in support of combined sewer overflow abatement plans.

As part of its long-term control plan for combined sewer overflow (CSO) abatement, the city of Buffalo, New York, maintained a network of Hydrolab Datasondes (Hydrolab-Hach Company, Loveland, Colorado) to assess receiving water-quality effects by continuously logging dissolved oxygen, pH, temperature, conductivity, and turbidity. Although the effect of individual CSOs could be visualized, turbidity levels entering the Buffalo River from the upper watershed often were greater than from CSO discharges. Turbidity data showed that the Buffalo River was a net-sediment sink. Low dissolved oxygen levels were observed in the summer during dry weather, baseflow, and watershed-wide storms and CSO events. Some CSOs did not produce dissolved oxygen sags in the receiving waters, but others did. This information, together with the sampling done for organic and inorganic contaminants, can aid the decisionmaking process when prioritizing outfalls for abatement work and provides a baseline against which receiving water-quality improvements can be measured.     

Geostatistical characterization of nitrogen dioxide concentration in an urban area: Part II: Time component of the estimation error

The temporal component of the estimation error is usually neglected in calculation of the variance of the error associated with the mapping of annual nitrogen dioxide (NO₂) concentration. However, under realistic hypotheses, adding a temporal term to the spatial estimation variance is convenient enough. In a survey using passive diffusion samplers, which was carried out in 2001 on the Mulhouse area, the two measurement phases do not allow calculation of variance of the temporal error. But this error is accessible by means of the few fixed analyzers that continuously measure NO₂ concentrations. The statistics of the experimental temporal error are examined and the temporal variogram is calculated. Experimental quadratic error is then compared to the theoretical estimation variance, deduced from the temporal variogram.The fixed analyzers available in Alsace are then used to “optimize” empirically the duration and the date of the beginning of the temporary measurement phases.Without increasing the cost of the temporary survey, it is then possible to improve the precision of the maps of annual NO₂ concentration, by combining the spatial optimization presented in Part I of the paper, and the temporal optimization presented here.     

Risk governance guidelines for bioenergy policies

These Notes from the Field summarise the governance guidelines developed by the International Risk Governance Council (IRGC) to address the key challenges that policy-makers face when designing and implementing policies and regulations for the increasing production, trade and use of bioenergy.The guidelines comprise an integrated and coherent set of policy recommendations and practical actions to help policy-makers and industry account for the various trade-offs presented by bioenergy and develop sustainable bioenergy production for domestic use and international trade. They include land-use policies, full life-cycle assessments, as well as sustainability standards and certification criteria.     

An in-depth analysis of self-reported cycling injuries in single and multiparty bicycle crashes in Denmark

Introduction: Cycling is one of the main forms of transportation in Denmark. However, while the number of traffic crash fatalities in the country has decreased over the past decade, the frequency of cyclists killed or seriously injured has increased. The high rate of serious injuries and fatalities associated with cycling emphasizes the increasing need for mitigating the severity of such crashes. Method: This study conducted an in-depth analysis of cyclist injury severity resulting from single and multiparty bicycle-involved crashes. Detailed information was collected using self-reporting data undertaken in Denmark for a 12-month period between 1 November 2012 and 31 October 2013. Separate multilevel logistic (MLL) regression models were applied to estimate cyclist injury severity for single and multiparty crashes. The goodness-of-fit measures favored the MLL models over the standard logistic models, capturing the intercorrelation among bicycle crashes that occurred in the same geographical area. Results: The results also showed that single bicycle-involved crashes resulted in more serious outcomes when compared to multiparty crashes. For both single and multiparty bicycle crash categories, non-urban areas were associated with more serious injury outcomes. For the single crashes, wet surface condition, autumn and summer seasons, evening and night periods, non-adverse weather conditions, cyclists aged between 45 and 64 years, male sex, riding for the purpose of work or educational activities, and bicycles with light turned-off were associated with severe injuries. For the multiparty crashes, intersections, bicycle paths, non-winter season, not being employed or retired, lower personal car ownership, and race bicycles were directly related to severe injury consequences. Practical Applications: The findings of this study demonstrated that the best way to promote cycling safety is the combination of improving the design and maintenance of cycling facilities, encouraging safe cycling behavior, and intensifying enforcement efforts.     

The characterization and comparison of ozone exposure indices used in assessing the response of loblolly pine to ozone

Using the 1988 and 1989 experimental results obtained for two loblolly pine half-sibling families (GAKR 15–23 and GAKR 15–91) at the Auburn University intensive field research site, we: (1) explored the performance of a set of exposure indices; (2) characterized the ambient air and charcoal-filtered air treatments at Auburn and compared the values of the O₃ exposure indices with those values calculated for ambient O₃ monitors for a select set of sites; (3) identified and characterized O₃ treatments in the Auburn open-top exposure chambers where an adverse effect was noted; and (4) identified where such experimental exposure regimes occurred under ambient conditions. We found that the SUMO exposure index did not perform adequately. We were unable to distinguish among the performances of the SUM06, W126, and SUM08 exposure indices. The results of the analyses of six estimated logistic parameters for a model of diameter² × height (d²h) vs time indicated O₃ effects for both families. At pH 4.3 (near ambient conditions), a response to O₃ was detected in the NF × 2.5 treatments for both families for t₂, the approximate time of maximum growth during the second year. Using ln (final d²h), family 23 did not show O₃ effects. A comparison of the exposures experienced in the NF × 2.5 treatments with those occurring under ambient conditions at other locations showed that in 1983 and 1986, the San Bernardino County (CA) site experienced O₃ exposures similar to those values experienced at the NF × 2.5 treatments in 1989.