借鉴国际经验助推我国汞污染场地修复

汞污染问题已经成为国内外关注的环境热点问题。我国是汞的生产、使用和排放大国,涉汞行业众多,汞污染场地问题突出。发达国家在汞污染场地治理方面有着丰富的经验。本文通过借鉴美国和英国的相关经验,从完善法规标准、健全管理制度、增强科技支撑和完善投融资政策四个方面为我国未来开展汞污染场地修复工作提出政策建议。     

Ecological Feasibility Studies in Restoration Decision Making

The restoration of degraded systems is essential for maintaining the provision of valuable ecosystem services, including the maintenance of aesthetic values. However, restoration projects often fail to reach desired goals for a variety of ecologic, financial, and social reasons. Feasibility studies that evaluate whether a restoration effort should even be attempted can enhance restoration success by highlighting potential pitfalls and gaps in knowledge before the design phase of a restoration. Feasibility studies also can bring stakeholders together before a restoration project is designed to discuss potential disagreements. For these reasons, a feasibility study was conducted to evaluate the efficacy of restoring a tidal freshwater marsh in the Potomac River near Alexandria, Virginia. The study focused on science rather than engineering questions, and thus differed in approach from other feasibility studies that are mostly engineering driven. The authors report the framework they used to conduct a feasibility study to inform other potential restoration projects with similar goals. The seven steps of the framework encompass (1) initiation of a feasibility study, (2) compilation of existing data, (3) collection of current site information, (4) examination of case studies, (5) synthesis of information in a handbook, (6) meeting with selected stakeholders, and (7) evaluation of meeting outcomes. By conducting a feasibility study using the seven-step framework, the authors set the stage for conducting future compliance studies and enhancing the chance of a successful restoration.     

ENVIRONMENTAL IMPACT OF STREAM CHANNELIZATION1

ABSTRACT Geologic, engineering, and biological investigations of six Pennsylvania coldwater streams were undertaken to determine the impact of channel modifications instituted both prior to and following Hurricane Agnes. The primary focus of the study was on the ecological changes brought about by stream channelization. No long-term deleterious effects on water quality, attached algae, benthic fauna, or forage fish populations were found. Trout, however, were found to be greater in numbers and weight in natural than in channelized stream reaches. Lack of suitable physical habitat appears to be the primary cause of reduced trout populations in stream reaches which have been channelized.     

The decline of a regional fishing nation: The case of Ghana and West Africa

Inadequate trade policies, globalization of the fishing industry, dominance of Europe's distant water fleets, declarations of exclusive economic zones (EEZs) by neighbouring West African nations, overfishing and a lack of good governance contributed to the decline of Ghana as a regional fishing nation, a position it had held since the 18^th century. The prohibitive cost of access arrangements limited Ghana's access to distant waters. The country's marine environments have been impacted by overexploitation of stocks and the use of destructive methods. Subsistence fishing has become the sole means of survival for many fishers. The decline of the fishing sector has limited the country's ability to meet domestic demand and threatened the economic and food security of many Ghanaians. The article traces the early history of Ghana's fisheries, their gradual decline during the last four decades, and outlines recommendations for policy changes to address the situation and steer the nation on a course towards sustainable fisheries.     

国际环境制度对能源安全战略的重大影响

能源安全一直是国际政治和经济领域的重大问题。在追求可持续发展和全球化不断推进的2l世纪,国际环境制度的逐步形成为能源安全赋予了新的涵义,生态安全已经成为能源安全的重要组成部分。以保障能源供应为主要出发点的传统能源安全观逐渐向着涵盖能源供应、经济竞争力和环境质量三大要素的“综合能源安全观”的方向发展。     

全球经济一体化中的环境壁垒与我国环境和贸易政策选择

本文纵观全球经济贸易格局和环境问题特点,指出了环境壁垒是影响全球贸易和环境的重要因素,分析了环境壁垒产生的本质,提出了国际贸易的新形势下我国如何实现可持续经济发展的贸易和环境政策。     

Proliferating Principles; Or How to Sup with the Devil without Getting Eaten

The international humanitarian system is seen by many to be in crisis. The reasons for this are complex but include the perception held by many that there is an increasing ambivalence on the part of powerful states to invest military, political and financial resources in upholding humanitarian principles, and a growing feeling that much humanitarian action both ignores human rights issues and can prolong conflict. As a result, much attention has focused on the notion of 'humanitarian principles' and there has been a proliferation of statements and initiatives on this topic in recent years.     

ENVIRONMENTAL FACTORS INFLUENCING SUSPENDED SOLIDS IN THE LOXAIIATCHEE ESTUARY,FLORIDA1

ABSTRACT: A study was initiated to examine the effects of wind speed, wind direction, freshwater inflow, and tide height on suspended solid concentration and distribution in the Loxahatchee estuary, Florida. Recent efforts to increase freshwater flows in this system raised concerns that suspended solid concentrations would increase as well, which might result in negative impacts for the estuary. The data indicated that total suspended solids (TSS) in the estuary are derived primarily from the inlet and not from freshwater tributaries. In addition, total suspended solids and volatile suspended solids were correlated strongly with salinity, suggesting that suspended sediments act conservatively throughout this system. No one environmental factor had an overwhelming influence on suspended solid concentration throughout the estuary; different regions of the estuary were influenced by different factors. Freshwater inflow was negatively related to TSS in the upper reaches of the estuary but was positively related to TSS in the central embayment region of the estuary. We attribute this latter finding to the fact that extremely high inflows both prevented the normal transport upstream of tidal borne suspended sediments and promoted mixing when the freshwater front moving downstream confronted the tidal front moving upstream. Wind speed, wind direction, and tide height had relatively small effects on TSS concentration but were most influential in reaches upstream of the central embayment, where tidal velocity begins to diminish.