地铁系统脆弱性的建模与分析

为了揭示地铁系统脆弱性的内涵,提高地铁运营安全性与可靠性。基于工程系统脆弱性和网络拓扑脆弱性理论,采用系统建模与分析的方法,建立了地铁系统脆弱性的脆弱链模型,进行了基于功能和界面关系的脆弱性分析。结果表明:脆弱性是地铁系统的固有隐藏属性,以功能和界面关系为载体,以易感性和易损性为外部表现,并在网络化运营条件体现出分布集中性和影响扩散性;地铁系统脆弱性的脆弱链模型由脆弱源、脆弱性关联和脆弱点构成,干扰通过脆弱链实现了易感性行为向易损性后果的转化,脆弱源的易感性能、脆弱点的易损性能和脆弱性关联性能是决定上述转化过程的根本要素;地铁系统的脆弱性程度与子系统间的依赖程度和界面耦合难度正相关。     

A discussion of the potential impacts of climate change on the shorelines of the Northeastern USA

An increase in the rate of sea-level rise and potential changes in storminess represent important components of global climate change that will likely affect the extensive coasts of the Northeastern USA. Raising sea level not only increases the likelihood of coastal flooding, but changes the template for waves and tides to sculpt the coast, which can lead to land loss orders of magnitude greater than that from direct inundation alone. There is little question that sea-level rise, and in particular an increased rate of rise, will result in permanent losses of coastal land. However, quantitative predictions of these future coastal change remains difficult due in part to the complexity of coastal systems and the influence of infrequent storm events, and is further confounded by coastal science’s insufficient understanding of the behavior of coastal systems over decadal timescales. Recently, dramatic improvements in technology have greatly improved our capabilities to investigate and characterize processes and sedimentary deposits in the coastal zone, allowing us, for the first time, to address some of the over-arching problems involved in shoreline change. Despite advances in many areas of coastal geology, our fundamental understanding of shoreline change has been limited by a lack of a broad and integrated scientific focus, a lack of resources, and a lack of willingness on the part of policymakers who make crucial decisions about human activity along the coast to support basic research in this area. Although quantitative predictions remain constrained, there remains little doubt that the predicted climates changes will have profound effects upon the Northeastern coast.     

耕地转出对农民家庭贫困脆弱性的影响及其区域差异分析

关注耕地转出行为对农户贫困脆弱性的影响,对于农民家庭的持久脱贫及农村反贫困政策的制定意义重大。基于CFPS两期全国整合样本的面板数据,在对农户贫困脆弱性进行测算的基础上,运用倍差法、OLS模型及倾向得分匹配倍差法,实证检验耕地转出对农民家庭贫困脆弱性的影响及其区域差异。结果表明：（1）耕地转出行为的发生降低了农户的贫困脆弱性,是一种有效的扶贫手段,在帮助部分农户抵御收入风险上起到了积极作用;（2）耕地转出规模的扩大并未显著改善农户的贫困脆弱性状况;（3）控制变量也对农户贫困脆弱性产生了不同程度的影响,其中户主性别、户主年龄和家庭住房净资产显著正向影响农户的贫困脆弱性水平,而户主受教育程度、家庭劳动力数、健康状况、现金和存款数及当地经济发展水平等变量显著负向影响农户的贫困脆弱性水平;（4）耕地转出行为对农民家庭贫困脆弱性的影响呈现出一定的区域差异性,对东、中和东北地区农户贫困脆弱性的降低起到了显著促进作用,但对西部地区农户的减贫作用并不明显。     

A GIS-based DRASTIC vulnerability and net recharge reassessment in an aquifer of a semi-arid region (Metline-Ras Jebel-Raf Raf aquifer, Northern Tunisia)

This paper aims to elaborate new generic DRASTIC aquifer vulnerability maps of the coastal aquifer of Metline-Ras Jebel-Raf Raf (Northeast of Tunisia) using the GIS technique, making the data analyses easier to handle and providing better capabilities of dealing with large spatial data. A similar study was carried out in 1999 in the same aquifer using a method based on the soil water balance equation to determine the net recharge parameter. Unfortunately, the lack of data in the study area made the results unsatisfactory. By applying the Williams and Kissel equation and the Rao relationship, we intend to demonstrate that we could correctly evaluate the net recharge parameter. Moreover, new data related to the aquifer hydraulic conductivity, the soil cover and the vadose zone lithology have become available, and allowed us to elaborate suitable DRASTIC maps.     

东北地区湿地的水文景观分类及其对气候变化的脆弱性

湿地对气候变化的脆弱性取决于湿地在水文景观中所处的位置.笔者简单介绍了水文景观的基本理论,从水文景观视角对东北地区的典型湿地进行了分类,并依据水文景观特征将东北地区的湿地所发育的景观分为冰蚀地貌、山地沟谷、河口三角洲、滨海低洼地、河漫滩、阶地洼地和古河道洼地、山前洼地、湖泊及其湖泊边缘洼地和半干旱、半湿润平原低湿洼地等类型,并将发育于各类景观中的湿地对气候变化的脆弱性划分出低度脆弱性、低-中度脆弱性、中-高度脆弱性、高度脆弱性和极度脆弱性.      

南方丘陵区农业水资源脆弱性概念与评价

论文旨在探讨中国南方丘陵区农业水资源脆弱性的概念及内涵,构建脆弱性评价指标体系并进行定量评价实证研究。首先,在了解资源环境科学领域有关脆弱性研究相关成果的基础上,结合中国南方丘陵区农业水资源系统的特点,给出了农业水资源脆弱性的概念,并分析了其脆弱性内涵。然后,以衡阳盆地为例构建了一个包括自然脆弱性、人为脆弱性、承载脆弱性3个方面12个具体指标的评价指标体系。最后,运用模糊物元模型对衡阳盆地7个县(市)的农业水资源脆弱度进行评判,发现祁东县、衡阳县、衡南县、衡东县和耒阳市农业水资源脆弱度为强脆弱度等级,常宁市、衡山县为微脆弱等级。经验证,评价结果与评价区水资源脆弱性的实际表现比较吻合。     

Humanitarian information systems and emergencies in the Greater Horn of Africa: logical components and logical linkages

Natural and man-made emergencies are regular occurrences in the Greater Horn of Africa region. The underlying impoverishment of whole populations is increasing, making it more difficult to distinguish between humanitarian crises triggered by shocks and those resulting from chronic poverty. Shocks and hazards can no longer be seen as one-off events that trigger a one-time response. In countries that are both poor and exposed to frequent episodes of debilitating drought or chronic conflict, information needs tend to be different from the straightforward early warning/commodity accounting models of information systems that have proven reliable in past emergencies. This paper describes the interdependent components of a humanitarian information system appropriate for this kind of complex environment, noting the analytical links between the components and operational links to programme and policy. By examining a series of case studies from the Greater Horn region, the paper demonstrates that systems lacking one or more of these components will fail to provide adequate information--and thus incur humanitarian costs. While information always comes with a cost, the price of poor information--or none--is higher. And in situations of chronic vulnerability, in which development interventions are likely to be interspersed with both safety nets and emergency interventions on a recurrent basis, investment in improved information is a good investment from both a humanitarian and a financial viewpoint.     

Applying assessments of adaptive capacity to inform natural-resource management in a changing climate

Adaptive capacity (AC)—the ability of a species to cope with or accommodate climate change—is a critical determinant of species vulnerability. Using information on species’ AC in conservation planning is key to ensuring successful outcomes. We identified connections between a list of species’ attributes (e.g., traits, population metrics, and behaviors) that were recently proposed for assessing species’ AC and management actions that may enhance AC for species at risk of extinction. Management actions were identified based on evidence from the literature, a review of actions used in other climate adaptation guidance, and our collective experience in diverse fields of global-change ecology and climate adaptation. Selected management actions support the general AC pathways of persist in place or shift in space, in response to contemporary climate change. Some actions, such as genetic manipulations, can be used to directly alter the ability of species to cope with climate change, whereas other actions can indirectly enhance AC by addressing ecological or anthropogenic constraints on the expression of a species’ innate abilities to adapt. Ours is the first synthesis of potential management actions directly linked to AC. Focusing on AC attributes helps improve understanding of how and why aspects of climate are affecting organisms, as well as the mechanisms by which management interventions affect a species’ AC and climate change vulnerability. Adaptive-capacity-informed climate adaptation is needed to build connections among the causes of vulnerability, AC, and proposed management actions that can facilitate AC and reduce vulnerability in support of evolving conservation paradigms.     

基于GIS的城镇建筑物易损性分析与应用研究

利用城镇地籍数据信息,基于GIS软件进行建筑物易损性和居民安全风险分析与应用研究。通过对某县城中最具代表性的一个街坊建筑物的易损性分析和居民安全风险分析实例应用研究,重点讨论并实现了利用现有数字化地籍图、城镇地籍数据库及土地调查记录等信息;并结合建筑物震害损失评估模型和人员伤亡预测方法,完成不同结构类型的建筑物在不同地震烈度条件下的破坏造成的经济损失评估和人员伤亡程度的预测,对城市防灾减灾进行辅助决策支持与评估。