建立生命的地震易损性概率矩阵初探

1966年3月8日河北省邢台地震(M_S=6.8)震害调查资料的统计分析结果表明,地震造成人员伤亡的损失程度遵从正态的概率分布,据此初步建立起土坯墙房的生命地震易损性概率矩阵P(D_0|I)。该矩阵将可应用在地震灾害生命损失的概率预测研究中。     

版纳勐养保护区鸟类及人为影响分析

切实保护和利用好西双版纳现存热带森林，是急需处理的现实问题。本文通过勐养自然保护区鸟类调查结果，揭示了西双版纳保护区管理现状。多数地区实际上未管理起来，林区居民仍滥用自然资源，对鸟类的猎捕从未停止，有的地方颇为严重；从生物多样性着眼，环境质量在下降。现已管理起来的三岔河保护区，尽管旅游开放后尚存许多问题亟待探索和改进，但鸟类保护状况已明显改善，说明自然保护区旅游在科学管理下才是可行的。就此，本文分析、评价了勐养保护区鸟类受人为影响情况，对自然保护区管理工作提出建议。     

Seismic vulnerability assessment of earthquake-prone mega-city Shillong,India using geophysical mapping and remote sensing

ABSTRACT

The concept of seismic vulnerability is a yard-stick of damage estimation from a probable earthquake considering physical cum social dimension and enables a basis for decision-makers to develop preparedness and mitigation strategies. We aim at vulnerability assessment of the typical urban system of capital city Shillong situated on hilly terrain. High-resolution satellite imagery of Shillong facilitates analysis of building footprints, communication network, and open ground. Different building typologies are identified taking into account the building’s structural configuration assessed through a rapid visual survey of more than 15% of total residential households. Slope map demarcates the landslide-prone area through discrete elevation modelling. A methodology incorporating several parameters e.g. building typology, slope angle, shear wave velocity characteristics, geomorphology, and the number of occupants in correlation with a physical measurement of vulnerability is presented and is applied to estimate the dimension of vulnerability. Additionally, MASW survey indicates lithology up to 30?m deep along with the existence of stiff soil and rocks at different depths whereas resonant frequency is identified to be in the range of 6–8?Hz through H/V ratio. Integrating all, it is observed that more than 60% of Shillong city falls under moderate to higher vulnerability and the rest is less vulnerable.     

A Probabilistic Displacement-based Vulnerability Assessment Procedure for Earthquake Loss Estimation

Earthquake loss estimation studies require predictions to be made of the proportion of a building class falling within discrete damage bands from a specified earthquake demand. These predictions should be made using methods that incorporate both computational efficiency and accuracy such that studies on regional or national levels can be effectively carried out, even when the triggering of multiple earthquake scenarios, as opposed to the use of probabilistic hazard maps and uniform hazard spectra, is employed to realistically assess seismic demand and its consequences on the built environment. Earthquake actions should be represented by a parameter that shows good correlation to damage and that accounts for the relationship between the frequency content of the ground motion and the fundamental period of the building; hence recent proposals to use displacement response spectra. A rational method is proposed herein that defines the capacity of a building class by relating its deformation potential to its fundamental period of vibration at different limit states and comparing this with a displacement response spectrum. The uncertainty in the geometrical, material and limit state properties of a building class is considered and the first-order reliability method, FORM, is used to produce an approximate joint probability density function (JPDF) of displacement capacity and period. The JPDF of capacity may be used in conjunction with the lognormal cumulative distribution function of demand in the classical reliability formula to calculate the probability of failing a given limit state. Vulnerability curves may be produced which, although not directly used in the methodology, serve to illustrate the conceptual soundness of the method and make comparisons with other methods.     

Effective Community Engagement for Sustainability: Wombat Community Forest Management Case Study

The first significant government sponsored community‐based forest management project in Australia was initiated in Central Victoria in 2002. This paper analyses the initial stage of the Wombat Community Forest Management Pilot Project. The paper develops a functional concept of ‘effective community’ for structuring community engagement in these kinds of natural resource management projects. The effective community has characteristics in common with a community of interest, adopts a bioregional perspective, embodies the values of environmental stewardship and interacts in a fully informed way as a ‘discursive community’ (Meppam 2000 Meppam, T. 2000. ‘The discursive community: evolving institutional structures for planning sustainability’, Ecological Economics, 34: 47–61.  [Google Scholar]). The paper offers general advice for organising effective community engagement in such projects and 12 recommendations for governments developing similar initiatives elsewhere.     

Participatory methods of incorporating scientific with traditional knowledge for volcanic hazard management on Ambae Island,Vanuatu

Ambae Island is the largest of Vanuatus active volcanoes. It is also one of the nations potentially most dangerous, with 60 million m³ of lake-water perched at over 1340 m in the summit caldera and over the active vent. In 1995, small phreatic explosions, earthquake swarms and heightened gas release led to calls for evacuation preparation and community volcanic hazard awareness programs for the ~9500 inhabitants. Differences in perspective or world-view between the island dwellers adhering to traditional beliefs (Kastom) and external scientists and emergency managers led to a climate of distrust following this crisis. In an attempt to address these issues, rebuild dialogue and respect between communities, outside scientists and administrators, and move forward in volcanic hazard education and planning for Ambae, we adapted and applied Participatory Rural Appraisal (PRA) approaches. Initial gender-segregated PRA exercises from two representative communities provided a mechanism for cataloguing local traditional viewpoints and hazard perceptions. Ultimately, by combining elements of these viewpoints and perceptions with science-based management structures, we derived volcanic hazard management guidelines, supported by an alert system and map that were more readily accepted by the test communities than the earlier top-down plans imposed by outside governmental and scientific agencies. The strength of PRA approaches is that they permit scientists to understand important local perspective issues, including visualisations of volcanic hazards, weaknesses in internal and external communication systems, and gender and hierarchy conflicts, all of which can hinder community emergency management. The approach we describe has much to offer both developing and industrialised communities that wish to improve their awareness programs and mitigative planning. This approach should also enhance communication and understanding between volcanologists and the communities they serve.     

Economic Hotspots: Visualizing Vulnerability to Flooding

We simulate a large-scale flooding in the province of South-Holland in the economic centre of the Netherlands. In traditional research, damage due to flooding is computed with a unit loss method coupling land use information to depth-damage functions. Normally only direct costs are incorporated as an estimate of damage to infrastructure, property and business disruption. We extend this damage concept with the indirect economic effects on the rest of the regional and national economy on basis of a bi-regional input output table.We broaden this damage estimation to the concept of vulnerability. Vulnerability is defined as a function of dependence, redundancy and susceptibility. Susceptibility is the probability and extent of flooding. Dependency is the degree to which an activity relates to other economic activities in the rest of the country. Input–output multipliers form representations of this dependency. Redundancy is the ability of an economic activity to respond to a disaster by deferring, using substitutes or relocating. We measure redundancy as the degree of centrality of an economic activity in a network. The more central an activity is, the less it encounters possibilities to transfer production and the more vulnerable it is for flooding. Vulnerability of economic activities is then visualized in a GIS. Kernel density estimation is applied to generalize point information on inundated firms to sectoral information in space. We apply spatial interpolation techniques for the whole of the province of South-Holland. Combining information of sectoral data on dependency and redundancy, we are able to create maps of economic hotspots. Our simulation of a flood in the centre of Holland reveals the vulnerability of a densely populated delta.     

Agricultural performance on marginal land in Eastern Inner Mongolia,China – Development in the pre- and post-1978 reform periods

Rapid economic development in the aftermath of the Chinese post-1978 reforms has resulted in a shrinking of grain grown area in the southern and eastern regions of the country which in turn is believed to have put the marginal northern regions under increased pressure. This paper examines key indicators of agricultural performance as well as cultivated land area development of the pre- and post-1978 reform periods focusing on the agro-pastoral Tongliao City Prefecture, eastern Inner Mongolia. The results are related to the village level development through a case study as well as to the provincial level. Average annual grain per capita production increased from about 400 kg in the late 1970s to more then 1000 kg in the late 1990s. This was achieved through a combination of intensification and reclamation of cropland, with the latter restricted to pastoral classified counties. Production variability, in particular for the low producing counties, has also increased possibly as an effect of the substitution of traditional mixed pattern of crops with HYV monocultures. Average living standards have improved but have been accompanied by widening income gaps. Poor farmers’ livelihoods continue to be insecure, particularly during dry years. Concern is raised regarding the sustainability of the rapid agricultural development; an increased use of costly fertilisers constrains poorer farmer’s economy and may lead to deteriorating water quality while increasing irrigation depletes water resources.     

Claiming space and community: rural women’s strategies for living with, and beyond, fear

Following the well-established literature on women’s fear in urban contexts, a small but important literature has also begun to document accounts of boldness, fearlessness and empowerment. We extend this work by considering ways in which women live with, and beyond, experiences of fear. We argue that fear and fearlessness are not discrete and separate states, but rather they are often simultaneous conditions that women negotiate in complex ways. Moving away from a sense of victims and passivity, we suggest that women have spatial and social strategies that can be adopted when they face fear or take up forms of action that might be termed ‘bold’ or ‘courageous’. Consequently, this work draws on Koskela’s [Gender, Place and Culture 4 (1997) 301] previous discussion of ‘bold women’ in Finland to develop a notion of agency and highlight strategies that some rural women adopt in New Zealand.     

Responding to the coffee crisis: a pilot study of farmers' adaptations in Mexico, Guatemala and Honduras

This article explores the impacts of market shocks and institutional change on smallholder livelihoods, and the challenge of adaptation in Mexico, Guatemala and Honduras. The rapid decline in coffee prices since the dissolution of the International Coffee Agreement in 1989 has had widespread and profound impacts across coffee-producing regions. The data collected in the three case studies of this project confirm the severity of the impact, particularly in the Mexican and Guatemalan communities. They also illustrate the importance of the historical relationship between farmers and public institutions in defining farmers' perception of risk, their awareness of the nature of the changes they face, and thus the flexibility of their responses to present and future uncertainty. The project's findings indicate that the existence and development of local networks among farmers, service providers and information sources may be critical for facilitating adaptation, particularly in the context of economic liberalization and globalized agriculture.