Assessing global exposure to natural hazards: Progress and future trends

Global maps of natural hazard occurrence and risk are useful tools for policy makers and international development organizations. The ranking of countries or regions by relative exposure provides a metric for prioritizing strategies for natural hazard mitigation and risk management, and for planning for response and recovery. However, the calculations underlying global natural hazard risk mapping depend on the availability and quality of geophysical and socio-economic data, which are highly variable from region to region, and may impede the application of global rankings to regional decision making. This paper summarizes a recent synthesis of natural hazard occurrence, exposure and loss data—the World Bank's “Hotspots” project—and describes the advantages and difficulties in such an approach. Several suggestions for more highly resolved, regional and sub-national analyses are made.     

Measuring vulnerability to natural hazards: a macro framework

The measurement of vulnerability—defined here as the asymmetric response of disaster occurrences to hazardous events—signifies a key step towards effective disaster risk reduction and the promotion of a culture of disaster resilience. One of the reasons for not being able to do the same in a wider context is related to conceptual, definitional, and operational issues. This paper presents an operationally feasible framework for conducting this task and measures revealed macro vulnerability as a function of disaster risk and hazard probability. The probabilities of hazard and its perceived disaster risk were obtained from past data and from probability distributions. In this paper, the corresponding analytical framework is constructed using the case study of floods in Assam, India. The proposed indicator will help policymakers to draw on available macro‐level data to identify the regions that are vulnerable to disasters, where micro‐level disaster vulnerability assessments could be performed in greater detail.     

Responses to natural and man-made hazards in Borno, Northeast Nigeria

This is a study of the responses of the people of eastern Borno to the twin hazards of drought and of an irrigation project stranded by the recent low level of Lake Chad. The environmental awareness of the people has been much influenced by access to information, particularly radio. There was a perceptual dissonance; drought is discerned as a natural act of God, but lake recession is seen as man-made. There is also a gap between responses perceived as appropriate and actual responses consequent on the constraints imposed by the process of modernization, notably the introduction of the South Chad Irrigation Project (SOP). Traditional response mechanisms involving the norm of reciprocity, the use of community resources, agricultural adaptations and sharing have become relatively insignificant in Borno. These are being replaced by emigration, lake floor cultivation and household diversification     

Small island developing states: natural disaster vulnerability and global change

Abstract

This paper sets out an examination of natural disaster amongst small island developing states (SIDS), and presents a framework for assessing the interaction of global pressures and local dynamics in the production of human vulnerability. Change at the global level is found to be a source of new opportunities as well as constraints on building local resilience to natural disaster. Much depends on the orientation of the state in global economic and political systems. The United Nations is a key global actor with relevance to shaping vulnerabilityin island states, and the impact of the UN Decade for Natural Disaster Reduction is reviewed. It is concluded that this is a critical time for SIDS which must contend with ongoing developmental pressures in addition to growing pressures from risks associated with global environmental change and economic liberalisation that threaten their physical and economic security.     

Analysis of hazardous material releases due to natural hazards in the United States

Natural hazards were the cause of approximately 16,600 hazardous material (hazmat) releases reported to the National Response Center (NRC) between 1990 and 2008-three per cent of all reported hazmat releases. Rain-induced releases were most numerous (26 per cent of the total), followed by those associated with hurricanes (20 per cent), many of which resulted from major episodes in 2005 and 2008. Winds, storms or other weather-related phenomena were responsible for another 25 per cent of hazmat releases. Large releases were most frequently due to major natural disasters. For instance, hurricane-induced releases of petroleum from storage tanks account for a large fraction of the total volume of petroleum released during 'natechs' (understood here as a natural hazard and the hazardous materials release that results). Among the most commonly released chemicals were nitrogen oxides, benzene, and polychlorinated biphenyls. Three deaths, 52 injuries, and the evacuation of at least 5,000 persons were recorded as a consequence of natech events. Overall, results suggest that the number of natechs increased over the study period (1990-2008) with potential for serious human and environmental impacts.     

The increasing exposure of cities to the effects of volcanic eruptions: a global survey

Abstract

The most dynamic demographic process of the past 250 years has been the movement of people from rural areas to cities. For most of this period urbanisation has been concentrated in economically more developed parts of the world, but during the last 50 years the focus has shifted to economically less developed regions. Urbanisation, particularly in developing countries, has led to increasing global exposure to a variety of natural hazards, not the least of which are risks posed to large cities by volcanoes. In this paper we monitor these demographic changes and detail the various types of volcanic hazard to which cities are exposed. A major eruption affecting a city in a developing country could cause widespread loss of life and regional disruption. Effective response, however, might minimise casualties in a city within a developed nation affected by a major eruption, but the economic impact could have global consequences. We argue that global hazard exposure is often subtle and involves not only the size of a city and the types of volcanic product that may occur, but also the strategic position of the threatened city within the economy of a country and/or region and the fact that volcano-induced tsunami and other consequences of eruptions, such as climatic change, may affect cities far removed from a given eruption site. Mitigation measures informed by both specifc prediction (surveillance) and general prediction (hazard mapping) are providing the potential to reduce hazard exposure. The paper concludes with a consideration of ongoing research, in particular the emphasis currently being placed on conflating hazard analysis with studies of place, economy, society and culture.     

长江三角洲地区人类生命体多自然灾害综合风险度评估

自然灾害综合风险评估是当前灾害研究领域的主要难点之一。以经济发达、灾害频繁的长三角地区为研究区,选取县级行政区域为基本分析单元,以人类生命体作为受灾对象,尝试进行了区域多灾种综合风险度分析。致灾因子方面选取地震、台风、洪水;选择性别比例、年龄结构、交通状况、通信设施和医疗状况等构建脆弱性评价指标,以人口密度作为承灾体暴露性指标。以历史上各致灾因子造成的年均死亡人数为权重依据,将各致灾因子进行加和得到多致灾因子的危险度指数;使用熵值法对脆弱性的各相关指标进行分析计算,得出脆弱性指数。将得到的多致灾因子危险度指数、承灾体脆弱性指数和暴露性指数合并,得出各县的人类生命多灾种综合风险度指数。结果表明:高风险度地区主要分布在上海市中心区域、台州市的南部。所得风险度指数反映了长三角区域内各县区人口受到多灾种综合影响的相对强度。     

自然灾害发生时间序列的分形特征及R/S分析

统计了公元960年到1979年我国地震、洪涝和台风风暴潮灾害发生的时间及死亡人数,以分形几何中的Cantor集合为模型,发现我国自然灾害发生时间序列的分布呈现出明显的分形特征,并采用Smalley方法分别计算了不同灾害发生时间序列分布的分维值,它们均在0.5左右,同严格意义上的数学分形Cantor集合相比分维较小,说明我国地震等自然灾害发生发展的自组织程度还有进一步发展的趋势,其危害程度将可能进一步提高;在自然灾害发生时间序列的分形特征的基础上,通过R/S分析,得出3种自然灾害发生时间序列的H指数均在0.28左右,同日斑指数、树木年轮、湖泊水位变化等自然现象相比较小,说明自然灾害的发生具有短程相关性,其发生规律没有日斑指数等自然现象明显.该研究对于进一步认识和研究我国地震等自然灾害的发生规律和发展趋势等具有一定意义.     

中国沿海风暴潮灾害的历史变化及未来趋向

中国是全球少数几个同时受台风风暴潮和温带风暴潮危害的国家之一,风暴潮灾一年四季,从面到北均可发生,本文基于中国沿海近５０年风暴潮灾时间变化和空间分布特点的分析,着重探讨了近５００年全国及长江、黄河、珠江三角洲的历史记录和近５０年实测风暴潮灾发生频次的变化及其与气候波动的关系,并对未来全球变化背景下,中国沿海风暴潮灾的变化趋向进行了讨论。结果表明：近５００年来,中国沿海的风暴潮灾的气温较高的偏暖时段     

Australia's organized response to natural disaster: Background and theoretical analysis

An analysis of organizations involved in response to disaster within Australia is offered. The location of these key organizations within the existing institutional framework, and a discussion of the functions of each, together with the relationships between them is provided. Particular emphasis is placed on the location and role of the State and Territory Emergency Service organizations (S/TES's) within this organizational network. The paper suggests there are a number of constraints that operate upon the S/TES's which prejudice both the effectiveness of this organizational type and that of the entire organizational network. These constraints are analyzed in terms of power and influence variables. The outcome of this discussion is the development of a taxonomy of Australia's counter-disaster organizations that is based on: (1) the ability of individual organizations within the network to determine the role which it will perform; and (2) the potential of the organization to influence the direction of the network.     

Mobility due to natural disaster: theoretical considerations and preliminary analyses

Relatively little of the work on natural disasters has focused on people who do not return to their pre-disaster homes. This study uses Annual Housing Survey data from 1974 through 1981 to examine moving households who attribute their moves to a natural disaster. The focus is on three issues: the characteristics of the movers and their recovery; a comparison with other involuntary movers (i.e., public and private displacees); and the amount of innovating or conserving behavior shown by different groups of movers and the impact of these behaviors on each group's recovery after the move. The paper compares disaster movers to all movers and to other forced movers. Distinct differences between the groups in their characteristics and housing recovery exist. The paper concludes with suggestions for continued analysis and policy implications.     

Economic resilience to natural and man-made disasters: Multidisciplinary origins and contextual dimensions

Economic resilience is a major way to reduce losses from disasters. Its effectiveness would be further enhanced if it could be precisely defined and measured. This paper distinguishes static economic resilience—efficient allocation of existing resources—from dynamic economic resilience—speeding recovery through repair and reconstruction of the capital stock. Operational definitions are put forth that incorporate this important distinction. The consistency of the definitions is examined in relation to antecedents from several disciplines. The effectiveness of economic resilience is evaluated on the basis of recent empirical studies. In addition, its potential to be enhanced and eroded is analyzed in various contexts.     

Economic resilience to natural and man-made disasters: Multidisciplinary origins and contextual dimensions

Economic resilience is a major way to reduce losses from disasters. Its effectiveness would be further enhanced if it could be precisely defined and measured. This paper distinguishes static economic resilience—efficient allocation of existing resources—from dynamic economic resilience—speeding recovery through repair and reconstruction of the capital stock. Operational definitions are put forth that incorporate this important distinction. The consistency of the definitions is examined in relation to antecedents from several disciplines. The effectiveness of economic resilience is evaluated on the basis of recent empirical studies. In addition, its potential to be enhanced and eroded is analyzed in various contexts.     

Permanent post-disaster housing in honduras: aspects of vulnerability to future disasters

To some degree it is unfair to evaluate a post-disaster housing program as to its effectiveness in decreasing vulnerability and preventing future disasters. As Burton states, "With rare exceptions, administrators and techniques have been trained to cope with disaster rather than to prevent it" [reference (2), p.197]. These were certainly not goals articulated by the agency responsible for constructing housing after Fifi. However, the authors feel that failure to evaluate specific projects by persons knowledgeable of the projects functioning, will only forestall the shift which Cuny calls for, "… from disaster response to disaster mitigation and prevention" [reference (4), p.123). In doing this we hope to add some specific case study data to the growing literature on disaster mitigation and prevention. Disaster vulnerability in Honduras is overwhelmingly related to flooding. More crucial than the materials and construction of housing is the issue of siting. If appropriately sited, houses made of bajarique, wood, or concrete block are able to withstand the heavy rains associated with a hurricane. Regarding the siting of the projects, the Honduras Project clearly has one positive and one negative accomplishment in the cases of Santa Rica and Flores, respectively. San Jose is less clear but is certainly a much safer site than those formerly occupied by the residents, in that there is no danger of flooding. The present site was not flooded during Fifi nor did it experience mudslides. However, the future is not so clear regarding the latter. Within the village proper a large amount of vegetation has been added which will tend to stabilise the soil on the steeper slopes. The streets, however, are seriously eroded and probably can not be maintained for vehicle usage, which does not pose a serious problem to the residents as none possess automobiles or trucks. One large gully bisects the village and receives run-off from the adjacent hills. It has been expanding, which would suggest that the slopes above the village could prove problematic in case of a Fifi-sized storm. Flores is located on a very poor site in reference to prevention and mitigation. It is located in a portion of the Sula Valley which is prone to flooding and, as mentioned before, was inundated by over 2m of water during hurricane Fifi. No prevention techniques were possible by NAEA/HEA and the houses were built on earthen mounds barely adequate to keep water out during the rainy season. The nearby dike which could possibly provide protection is non-functional due to poor maintainance. Given a storm of Fifi's magnitude, or possibly smaller, this site will again be flooded. Santa Rica is clearly well sited concerning flooding: it did not experience flooding during Fifi and is not flood prone. However, houses did experience some wall damage due to earthquakes following and associated with the Guatemalan quake of 1976. Due to the size and nature of the latter much "re-adjustment" occurred in the neighbouring fault system; however, damage to the houses was all superficial. We feel the residents were vocal about their concern due to the severity of the Guatemalan disaster and their lack of experience with concrete block houses. That the two sites (particularly Flores and partially San Jose) are vulnerable to future disasters cannot be considered solely the fault of an outside agency without local knowledge and understanding. In the engineering report issued during the construction it was explicitly stated that in Flores, "Future flooding remains a danger," [reference (6), p.49]. The future residents of Flores had gained access to the land from the National Agrarian Institute and were anxious to receive assistance in building homes. In fact, CARE, which had previously given these people tin roofing for houses, was threatening to take it back since the people had not yet started building. NAEA/HEA were responding to people in a rather desperate situation. But, on the other hand, they were responding to people who had been promised (not given) land by an agency of the Honduran national government which would be cognizant of the potential flooding at this site. Likewise, in San Jose, where mudslides and erosion remain a threat, the land was provided by a local government agency, the municipality. Although our goal in this discussion has not been to establish blame, we feel it imperative to mention the sequence of events that resulted in the questionable siting of Flores and San Jose. It is very easy and often accurate to place blame on outsiders who lack sophistication and knowledge about such matters. In this case local input did not result in post-disaster planning that is actually precautionary. This, we feel, illustrates the extreme complexity of cross-cultural aid, especially in the post-disaster period. It also points to the need for precautionary planning with reference to permanent post-disaster reconstruction.     

'All hazards approach' to disaster management: the role of information and knowledge management, Boyd's OODA Loop, and network-centricity

The ever-increasing complexity of disasters demands utilisation of knowledge that exists outside domains traditionally drawn upon in disaster management. To be operationally useful, such knowledge must he extracted, combined with information generated by the disaster itself, and transformed into actionable knowledge. The process, though, is hampered by existing, business-oriented approaches to knowledge management, by technical issues related to access to relevant, multi-domain information/knowledge, and by executive decision-making processes based predominantly on historical knowledge. Consequently, as shown by many recent incidents, the management of large-scale (mega) disasters is often inefficient and exceedingly costly. This paper demonstrates that the integration of modified information and knowledge management into the concepts of network-centric operations and network-enabled capabilities, and the employment of Boyd's OODA (Observe, Orient, Decide, and Act) Loop-based decision-making in unpredictable and dynamically changing environments, may address some of these problems.     

Knowing better and losing even more: the use of knowledge in hazards management

Abstract

Although loss of life from natural hazards has been declining, the property losses from those causes have been increasing. At the same time the volume of research on natural hazards and the books reviewing findings on the subject have also increased. Several major changes have occurred in the topics addressed. Emphasis has shifted from hazards to disasters. There has been increasing attention to vulnerability. Views of causation have changed. Four possible explanations are examined for the situation in which more is lost while more is known: (1) knowledge continues to be flawed by areas of ignorance; (2) knowledge is available but not used effectively; (3) knowledge is used effectively but takes a long time to have effect; and (4) knowledge is used effectively in some respects but is overwhelmed by increases in vulnerability and in population, wealth, and poverty.     

Risk transference and related trends: driving forces towards more mega-disasters

Abstract

In recent decades, the global cost of natural disasters has increased substantially. There are several trends in society and nature that suggest this pattern may continue, with more frequent mega-disasters occurring in the future. In particular, risk perception that is at odds with the “reala” risk underlies the process of risk transference which encourages development that increases long-term vulnerability.     

Medical aspects of volcanic disasters: An outline of the hazards and emergency response measures

The health and safety hazards posed by volcanic eruptions are outlined with special reference to experience gained from the eruptions of Mount St. Helens in 1980. The ability of volcanologists to predict the timing and the impact on local communities of an impending eruption are limited, some recent devastating eruptions having occurred without apparent warning. With the expansion of world populations into hazardous volcanic areas there is a growing need to develop appropriate emergency response measures. This paper describes the main preventive public and occupational health measures that are now a necessary part in dealing with volcanic emergencies.