青藏铁路隧道内有害气体浓度标准探讨

摘《铁路隧道运营通风设计规范》（TBl0068—2000）中规定“内燃机车通过隧道后15min内,氮氧化物（换算成NO2）浓度小于10mg／m^3”。此规定对于平原地区是适用的。然而青藏铁路建于高海拔地区,低气压、低氧、低温等严酷的自然条件对人体健康和劳动能力带来更为恶劣的影响。为了保障青藏铁路相关人群的健康生存和正常工作,本文结合青藏地区的特殊高原气候对人体造成影响的因素和气态污染物的衡量方式对青藏铁路运营隧道内宜采用的N02控制浓度进行了探讨。     

Analysis and Potential Alternatives for the Disputed South China Sea from Ocean Governance in the Polar Regions

Sovereignty claims over insular features and maritime jurisdiction in the South China Sea have been disputed for decades, and a governance regime to address ocean-related issues is urgently needed. This article first introduces the notion of a regime, and examines details of cooperation mechanisms in the Polar Regions. Lessons that can be applied to the South China Sea include that both soft and hard law regimes work to bring States concerned together to cooperate on the “commons” issues even when military conflicts or sovereignty disputes still exist. Consensus among bordering States would be necessary to make the South China Sea a “zone of peace.” Mechanisms that accommodate the various sovereignty claims and freeze existing and new claims to, as well as to prohibit military activities in, the South China Sea are recommended. Lastly, if a cooperative mechanism were to be established in the future, the Arctic regime would be more applicable to the South China Sea than the Antarctic regime due to their geographic nature. Thus, only States bordering the South China Sea should have voting and decision-making rights in the cooperative mechanism. As always, the political will of all parties is paramount to the success of such an endeavor.     

Improvement actions for reducing transport’s impact on climate: A shipper’s perspective

The purpose of this paper is to compare improvement actions for reducing transport’s impact on climate from the shipper’s perspective. To that end, it introduces an evaluation tool for comparing improvement actions in transport systems in terms of transport costs, impact on climate, and barriers to implementation. Within the context of five international flows involving a food producer, three actions—namely, engaging intermodal transport, increasing load factors by double-stacking pallets, and using high-capacity vehicles—were evaluated. Shipment data were collected to calculate reductions in transport costs and impact on climate, whereas interviews with the food producer were conducted to identify barriers. Results showed that reductions in transport costs and impact on climate attributed to the improvement actions differed among the five flows. Engaging intermodal transport reduced the system’s impact on climate by 27–53%, double-stacking pallets by 0–23%, and using high-capacity vehicles by 7–15%, with differences primarily due to different freight densities. Concerning barriers to implementation, the improvement actions also varied by flow. Altogether, unlike other papers, which have examined improvement actions separately, this paper offers an evaluation tool for comparing several improvement actions at once, as applied to a particular empirical case. Shippers with multiple flows and several possible improvement actions can use the evaluation tool to efficiently reduce their systems’ impact on climate.     

Merging Socioeconomic Imperatives with Geospatial Data: A Non-Negotiable for Coastal Risk Management in South Africa

The current approach to coastal development set-back delineation in South Africa is producing high-tech empirical methodologies that attempt to pinpoint areas at risk from physical coastal processes and the subsequent positioning of set-backs in relation to these risk areas. Experience in the Western Cape province of South Africa has shown that this approach contributes only partially to coastal risk management. In the context of an urban and peri-urban environment, and bearing in mind that set-backs have significant socioeconomic implications, the development of a set-back line at the local scale requires an expansion beyond just relying on the numerical modeling of physical coastal processes. This research reveals that such an approach is parochial and socially detached and a more inclusive and integrated approach grounded in and spanning localized social, cultural, economic, political, and ecological intricacies of the coastal space is required. Fundamental to achieving this is a re-consideration of the broader project management processes applied in the development of set-backs. The article concludes with a set of principles and guidelines for determining set-backs in complex coastal contexts at the local scale.     

南方多雨地区石灰土施工实践研究

石灰土强度形成受气候等条件影响,特别在南方多雨地区,地下水位较高,土含水量大,石灰土施工中合理的控制措施非常重要。该文结合上海市中环线浦东段道路工程中石灰土的施工,在对上海地区气候条件分析的基础上,对石灰土施工的准备阶段、施工阶段、养护阶段等环节的控制要点进行了系统总结,可为南方地区石灰土施工提供参考。     

高寒地区道路翻浆发育机理研究

笔者基于对新疆国道 2 18线和省道 313线道路翻浆的长期现场观测和研究 ,比较客观地构筑了道路翻浆发生的物质环境 ,即路床中 4 0 %左右的粘土含量和 2 5 %左右的含水量 .道路翻浆可以分为气候翻浆和动力翻浆两大类型 ,路床中存在粘土透镜是翻浆发育的必备条件 .翻浆鼓丘是道路翻浆的直观体现 .翻浆鼓丘呈椭圆形及圆形 ,椭圆形鼓丘主要出现在平直公路段 ,圆形鼓丘主要出现在弯曲公路段 .路基中道路翻浆通常发生在路面基层以下 30— 4 0cm的路床范围内 .根据鼓丘龟裂纹可以反演翻浆类型 ,并判识粘土透镜的位置 .     

气温升高对多年冻土地区路基稳定性影响

为了分析在气温升高的状况下冻土退化对东北多年冻土地区路基稳定性的影响,假设气温年增长率为0.05℃,通过ANSYS有限元软件计算了不同地表状况和不同含冰量情况下,多年冻土最大季节融化深度变化,根据不同土质、不同含冰量的融沉系数,计算得到不同含冰量冻土的沉降量.结果表明:在气温逐年升高的状况下,含冰量大的土层沉降量大于含...     

山区高速公路设计及其交通安全问题

与普通高速公路相比,山区高速公路的交通安全问题更为突出.鉴于此,分析现阶段山区高速公路事故多发的原因,研究山区高速公路的线形设计、视觉和气候等方面的因素对交通安全的影响,探讨减少山区高速公路交通事故的具体措施,以达到加强安全管理、降低交通事故率、减少经济损失的目的.     

Climate Change and Coastal Management Decisions: Insights from Christchurch Bay,UK

The integration of climate change adaptation considerations into management of the coast poses major challenges for decision makers. This article reports on a case study undertaken in Christchurch Bay, UK, examining local capacity for strategic response to climate risks, with a particular focus on issues surrounding coastal defense. Drawing primarily on qualitative research with local and regional stakeholders, the analysis identifies fundamental disjunctures between generic concerns over climate change and the adaptive capacity of local management institutions. Closely linked with issues of scale, the problems highlighted here are likely to have broad and continuing relevance for future coastal management elsewhere.     

Clean Water Act Section 404 and Coastal Marsh Sustainability

The “no net wetland loss” goal has not been met in urban coastal regions where conditions continue to exacerbate wetland losses. Under the Clean Water Act (Section 404) the U.S. Army Corps of Engineers and U. S. Environmental Protection Agency share responsibility for regulating placement of fill material in wetlands. The `no discharge of fill' rules threaten coastal wetlands with continuing losses due to effects of changing climate, including rising sea levels, higher storm surges, and flooding. Where inland migration is limited by development, or where sediment accretion rates are lower than the rate of sea level rise, urban wetlands will be lost unless marsh topography is elevated. We explored regulatory and design approaches in recent Hudson-Raritan Estuary (HRE), San Francisco Bay Estuary and coastal Louisiana restorations, including creation of new marshland using dredge material. Questions related to sea level rise, ecological position within the landscape, or potential effects of extreme storm events were not addressed in the HRE restoration designs; these concerns were taken into account in other regions. We suggest benefits of marsh `replenishment' should be acknowledged in Federal regulatory policy and that consistent policies supportive of low-lying coastal marsh preservation in all regions should be enacted.