城市供水的二次污染原因及治理

自来水经过一定的处理工艺,然后经过配送管网输送至各户。水在配送管网中流动的过程中,往往会受到管网、供水管道及附属设备的影响,造成二次污染。因此,要切实做好城市供水二次污染的防治工作,提高人们的生活质量。基于此,本文提出了城市供水二次污染的几点原因和一般性的治理对策。     

The cost of unconventional gas extraction: A hedonic analysis

We focus on identification and estimation of potentially negative environmental impacts of unconventional natural gas extraction on property values in the United States and advance previous research by contributing new data and new identification strategies for isolating these potential impacts. Our study area consists of two counties in Pennsylvania that are home to large amounts of unconventional natural gas extraction but are otherwise isolated from other resource extraction industries or large urban areas. We deploy parametric, semi-parametric, and matching hedonic regression models that include recent quasi-experimental methods and, in contrast to previous research and much popular intuition, we fail to find robust significance that negative environmental externalities of natural gas extraction are manifested in nearby property values. While there may be plausible risks associated with unconventional natural gas extraction, we do not find consistent evidence to suggest that these risks significantly affect nearby property values.     

Firm performance in dynamic environments: The role of operational slack and operational scope

This study examines the effects of operational scope (breadth of product offering, extent of geographical diversification, and extent to which production processes can effectively meet varying demand) and operational slack (resources in excess of what is required to fulfill expected demand) on firm performance, contingent on two components of a firm's dynamic environment, unpredictability and instability. We collate quarterly data on 3857 publicly traded firms in 19 industries from the years 1991 to 2013 (representing 99,559 firm-quarter observations). Using panel data analysis, we find that narrow product offerings, low geographical diversification, low levels of excess capacity, and low inventory slack are each positively associated with firm performance. More importantly though, we find that operational scope is associated with improved performance in unpredictable environments, whereas operational slack is associated with improved performance in unstable environments. These findings contribute to the research on operations strategy by identifying the industry-specific environmental conditions under which operational slack and operational scope are associated with firm performance.     

Tourism at Costalegre,Mexico: An ecosystem services-based exploration of current challenges and alternative futures

Tourism, as all human activities, is dependent on the natural environment and its respective ecosystem services (ES). Different user groups manage and consume these touristic ES differently, resulting in discrepancies and potential conflicts. Despite the urgency to find inclusive local approaches for sustainable development, tourism studies still analyze socio-economic and ecological impacts separately and lack integrated social–ecological approaches to improve foresight in tourism planning. Based on a growing concern regarding the future of Costalegre on the Jalisco coast of Western Mexico, we analyze through interviews, surveys, and participant observation the dependence of tourism on specific ecosystem services and conduct a scenario analysis which shows present and future implications for the social–ecological system. Furthermore, this analysis shows in detail how different scenarios change ES provision and people's livelihoods. Key findings include identifying freshwater provision and cultural ES as the most important touristic ES. At a regional scale, peasants in ejidos are the main ES stewards, whereas high-class tourism facilities constitute important local stewards. Benefits, mainly access to freshwater and the beach, are unequally distributed, provoking conflicts among different ES user groups that may escalate in the near future. Improved communication between all user groups and strengthening of key political actors seem to be the most immediate recommendations to ensure the long term sustainability of this particular region. This work may contribute to improved planning and decision-making as our ES based scenarios are a first step to integrate social–ecological knowledge into improved decision-making. At a local scale, the study reveals the most likely future development options and their social and ecological consequences. It could also serve as a baseline for informed policy making.     

Long term effects of an intervention in the outdoor environment—a comparison of older people’s perception in two residential areas,in one of which accessibility improvements were introduced

Walking and participating in activities outdoors in old age can be restricted both by the physical capacity of the individual and by the maintenance and/or the design of the outdoor environment. The purpose of this paper is to compare frequency of walking and frequency of activity outside the home, reported environmental barriers and valuation of the outdoor environment between two areas, in one of which there was an intervention in the outdoor environment 5–8 years prior to this study. The paper is based on a questionnaire sent out in 2011, to all residents 65 years and older in two different areas, the Study Area, an area with an intervention, and the Reference Area. The results show that reports on functional limitations, use of mobility devices and walking difficulties were similar in both areas. Despite that, respondents in the Study Area had a significantly higher frequency of walking and they also participated to a higher degree in activities than respondents in the Reference Area, even though they reported more environmental barriers. The valuation of the outdoor environment was, however, similar in both areas. The results indicate that older people benefit from interventions in the outdoor environment. However, the results also emphasize the importance of good maintenance of the environment.     

Assessment of land use compatibility and noise pollution at Imam Khomeini International Airport

This study aimed to investigate land use planning around airports, by employing Remote Sensing (RS) and Geographic Information Systems (GIS), in conjunction with an optimization algorithm using an Integrated Noise Model (INM) software, to establish the potential effects of aircraft noise at Imam Khomeini International Airport (IKIA) in Tehran. We also checked for land use compatibility with the noise levels around IKIA and the residents' reaction to the noise. The research was carried out in three stages: a) the establishment of Strategic Noise Map (SNM) scenarios of the airport operation in the years 2011, 2020 and 2030 using the INM software; b) the assessment of the results with emphasis on the study area land uses and application of RS and GIS and the exposure of residents at different levels of environmental noise; and c) the assessment of the intensity of aircraft noise annoyance at various times of day and night. The results indicated that developing IKIA together with the residential development will increase airport noise. Hence proper management and control of noise at IKIA is essential.     

Voluntary carbon offsetting: Who does it?

Voluntary carbon offsetting was popularised during the last decade, particularly by airlines, as a tool to ‘neutralise’ emissions associated with travel. Although there is a wide range of carbon offsetting schemes for tourism, the uptake of these programs has been reportedly low. Regardless, little research has explored the visitor segments who voluntarily undertake carbon offsetting. Consequently, this research investigates the prevalence of carbon offsetting amongst international tourists to Australia between 2008 and 2010 and, using cluster analysis, segments the carbon offsetters into three distinct markets. Findings reveal a stable carbon offsetting market, despite a Global Financial Crisis occurring during the reference period. Further, travellers from the United Kingdom/Europe were more likely to carbon offset, while those from Asia were less likely to participate in the schemes. Thus, this could indicate that the social marketing, public discourse and substantial media coverage in the United Kingdom/Europe had enhanced climate change mitigation behaviours.     

Management of petroleum hydrocarbon contaminated sites in Nigeria: Current challenges and future direction

Sites affected by petroleum hydrocarbons from oil exploitation activities have been identified as a major environmental and socio-economic problem in the Niger Delta region of Nigeria. The current Nigerian regulatory instruments to manage these contaminated sites are fragmented and the roles and responsibilities of government agencies, such as the Department for Petroleum Resources (DPR), and the National Oil Spill Detection and Response Agency (NOSDRA), are not well defined. This lack of coordination has led to ineffective land contamination policy and poor enforcement more generally. Appropriate, risk-based policy instruments are needed to improve regulatory capacity, and to enhance the regulator's ability to manage new and existing petroleum hydrocarbons contaminated sites. Lessons can be learned from countries like the United Kingdom (UK) and the United States America (USA) that have experience with the management and clean up of historically contaminated land. In this paper, we review the status of petroleum hydrocarbon contaminated sites management in Nigeria and identify the gaps in existing policy and regulation. We review the contaminated land policies and regulation from the UK and the USA, and identify lessons that could be transferred to the Nigerian system. Finally, we provide a series of recommendations (e.g. source – pathway-receptor approach, soil screening criteria, clean-up funding, liability) that could enhance contaminated land legislation in Nigeria.     

中国突发性环境污染事件的走势及其治理

水污染、大气污染和固体废物污染是中国突发性环境污染事件的主要构成部分,中国突发性环境污染事件的发生频次呈现出直线下降的趋势,说明我国的环境保护确已取得了显著成效,但这也是建立在大量经济投入与付出的基础之上的。中国突发性环境污染事件的环保经济效益却是直线式地越来越差,不过,环保人本效益却无大幅度的扩增,此外,新型的海洋污染之类的事件也不容忽视。最后,针对治污问题,提出了相应的举措。     

环境不确定下企业孵化网络治理机制对治理绩效影响研究

从企业孵化网络本身以及环境视角分析了企业孵化网络治理绩效的影响因素,通过企业孵化网络治理机制对治理绩效关系的实证分析,验证了环境不确定下企业孵化网络的契约治理机制、管理治理机制对治理绩效的影响。结果表明:企业孵化网络治理机制中的契约治理机制、关系治理机制对治理绩效具有正向调节作用;环境不确定性会扩大或缩小治理机制对治理绩效的作用强度。企业孵化网络在高市场不确定性环境下,采用关系治理机制的绩效较好;在高技术不确定性环境下,采用契约治理机制的绩效较好。