广州-茂名铁路换碴施工技术

文章介绍了有关在广州-茂名铁路运用大型养路机械进行更换石碴施工的技术和经验。     

试论研究环境问题的三种理论框架

本文认为,对环境问题的理论研究大致分三种脉络:外部性与社会福利、公地的悲剧与环境产权、物质平衡模型与可持续发展规划。依据这三种理论框架,解决环境问题的对策措施需要同时从市场机制建设、人类社会发展目标确定与技术途径三个方面展开。     

Integrating ecosystem services into conservation assessments: A review

A call has been made for conservation planners to include ecosystem services into their assessments of conservation priority areas. The need to develop an integrated approach to meeting different conservation objectives and a shift in focus towards human wellbeing are some of the motivations behind this call. There is currently no widely accepted approach to planning for ecosystem services. This study contributes towards the development of this approach through a review of conservation assessments and the extent to which they include ecosystem services. Of the 476 conservation assessments identified by a set of search terms on the Web of Science, 100 were randomly selected for this review. Of these only seven had included ecosystem services, while another 13 had referred to ecosystem services as a rationale for conservation without including them in the assessment. The majority of assessments were based on biodiversity pattern data while 19 used data on ecological processes. A total of 11 of these 19 assessments used processes, which could be linked to services. Ecosystem services have witnessed an increase in attention received in conservation assessments since the year 2000, however trends were not apparent beyond this date. In order to assess which types of ecosystem services and how they have been accounted for in conservation assessments, we extended our review to include an additional nine conservation assessments which included ecosystem services. The majority included cultural ecosystem services, followed by regulatory, provisioning and supporting services respectively. We conclude with an analysis of the constraints and opportunities for the integration of ecosystem services into conservation assessments and highlight the urgent need for an appropriate framework for planning for ecosystem services.     

Theory and practice of monetary policy

Summary. We consider an optimally managed renewable resource with stochastic non-concave growth function. We characterize the conditions under which the optimal policy leads to global extinction, global conservation and the existence of a safe standard of conservation. Our conditions are specified in terms of the economic and ecological primitives of the model: the biological growth function, the welfare function, the distribution of shocks and the discount rate. Our results indicate that, unlike deterministic models, extinction and conservation in stochastic models are not determined by a simple comparison of the growth rate and the discount rate; the welfare function plays an important role.Received: 20 October 2004, Revised: 28 February 2005, JEL Classification Numbers: D90, O11, O41, Q32.Santanu Roy: Correspondence toResearch on this paper was completed when the second author visited Cornell University in July, 2003. We thank the Center for Analytic Economics and the Department of Economics at Cornell University for making this research visit possible. The current version has gained considerably from the comments made by an anonymous referee.     

“连接自然与文化” ① ：西方哲学背景下 的全球议题

文化遗产保护是动态发展的概念，总结了文化景观 的3类意义：1)文化景观作为物质实体；2)文化景观作为概念 和过程；3)文化景观作为方法和工具。指出当前世界遗产及 文化景观保护中存在的自然和文化分离现象，揭示了西方哲学 的二元两分法的背景根源。介绍了IUCN和ICOMOS为融合 自然与文化而进行的“连接实践项目”和“自然文化之旅”2 个项目，推广他们在不同地理和文化背景下，为更好地连接自 然与文化遗产的治理和管理实践所作出的杰出贡献和引领作 用，主张非西方原住民社区、地方社区应该在推进“自然文化 之旅”工作中占有核心地位。     

我国西南地区水土治理及西部大开发的实证研究

无论是从问题的实质,还是方法论的角度来讲,水土治理都是西南地区经济开发中的一项战略性工程。通过对云南省红河州具体的水土流失现状、危害和治理的紧迫性和治理中存在的主要问题的分析,提出了西南地区水土治理的总体战略设想和具体的治理措施。     

北京饮用水源保护的实践与思考

密云、怀柔水库是北京城市、生活用水的重要水源，饮用水源保护是北京市城市总体建设的重要组成部分，本文通过分析饮用水源保护区的自然、地理、经济条件，回顾总结过去实施饮用水源保护的有效措施，提出了面向21世纪，加大饮用水源保护的具体措施和重点。     

河湖普查山地河流平均比降校核方法的探讨

2010—2012年第一次全国水利普查是新中国成立以来第一次全面的水利调查。普查共分8个专项,其中河湖普查开展最早,河湖普查是国务院第一次全国水利普查的主要任务,也是其他水利专项普查的基础。流域水系自然特征校核是河湖特征一项重要的工作,其中对于国普办提取的河流平均比降数据进行校核是一项重要的工作。     

三峡枢纽排漂孔及泄洪孔过流面检修装备方案研究

针对三峡工程排漂孔及泄洪孔过流面墙壁的检修分别提出了多种专用检修装备方案。经过分析比较,得出安全合理的检修装备方案。排漂孔检修方案:闸室段侧墙用升降台车,斜坡段侧墙采用单梁吊篮,排漂孔底板采用双侧单台车;泄洪深孔检修方案:闸室段和斜坡段侧墙采用升降台车检修,底面与排漂孔检修方案相同。     

深港联合治理深圳河工程的水土保持与生态建设

深港联合治理深圳河工程以环境管理为核心,始终将水土保持融入到环境保护和生态修复中,将生态建设作为工程建设的重要内容,在工程的不同阶段,采取不同的策略和措施,不断深化、丰富水土保持及生态建设的内容,不断践行生态治河及生态文明施工的理念。本文系统简要介绍了该工程在建设过程中开展水土保持及生态保护的主要措施和经验。