基于航空影像和LiDAR数据的海地地震滑坡识别研究

快速、准确地判别滑坡灾害范围对灾情评估与救灾指挥至关重要。将高分辨率航空影像和机载LiDAR数据相结合,能充分利用滑坡体的光谱特征、几何形态与空间结构特征,提高滑坡识别的准确度。该文以海地地震诱发的滑坡识别为例,介绍了面向对象的滑坡识别思路及方法;针对海地滑坡灾害特点,选择了相应的灾害特征,并经反复试验设定了特征参数阈值;针对面向对象分类过程中特征组合与选择这一瓶颈问题,以河流沉积物和滑坡判别为例,通过特征组合试验与对比分析,发现基于NDVI与坡度特征组合的分类结果明显优于单一特征及其它组合模式的分类结果。与最大似然分类法相比,该方法的分类结果更为准确、精度更高。     

A GIS-based approach to identify the spatial variability of social vulnerability to seismic hazard in Italy

This paper argues for a multidisciplinary framework to assess the relationship between environmental processes and social sciences that can be adapted to any geographic location. This includes both physical (earthquake hazard) and human (social vulnerability) dimensions in the context of disaster risk reduction. Disasters varies drastically depending on the local context. Indeed, the probability of a natural disaster having more devastating effects in one place than in another depends on the local vulnerability components of the affected society (cultural, social and economic). Therefore, there is an important correlation between the potential risk and the social resistance and resilience of a specific place, thus the disaster response varies according to the social fabric. In this context, the evaluation of social vulnerability is a crucial point in order to understand the ability of a society (studied at individual, household or community level) to anticipate, cope with, resist and recover from the impact of natural disaster events. Within this framework, the paper discusses how it is possible to integrate social vulnerability into the seismic risk analysis in Italy. Specifically, socioeconomic indicators were used to assess and mapping social vulnerability index. Afterwards, a Geographic Information System (GIS) approach was applied to identify the spatial variability of social vulnerability to seismic hazard. Through the use of a risk matrix, the classes of a social vulnerability index map were combined with those of a seismic hazard map proposed by INGV (National Institute of Geophysics and Volcanology). Finally, a qualitative social vulnerability exposure map to an earthquake hazard was produced, highlighting areas with high seismic and social vulnerability levels. Results suggest the importance of the integration of social vulnerability studies into seismic risk mitigation policies, emergency management and territorial planning to reduce the impact of disasters.     

地震灾害死亡人口快速评估方法对比研究

中国是世界上地震活动最为频繁的国家之一,属于地震多发区。在收集分析国内外关于地震灾害死亡人口评估模型的基础上,选取10种模型以2000年以来中国典型地震灾害为案例验证其适用性。结果表明：① 对于5.7级（含）以下地震,10种模型的评估结果基本都在合理范围内,可采用各评估结果的区间值来支撑应急决策;5.7~6.6级（含）地震,10种评估方法得到的结果表现出不同程度的偏差,可采用多数评估结果指向的死亡人口数量级来支撑应急决策;6.6级以上地震,则只能采用有特定适用范围的基于结构易损性的评估结果来支撑应急决策,且也存在较大的不确定性。② 从地震灾害人员伤亡动态评估方法、地震—地质灾害死亡人口快速评估方法和快速评估软件系统方面进行了相关讨论。此研究可为地震灾害死亡人口快速评估模型的改进与发展提供借鉴。     

城市灾害社会脆弱性研究热点问题评述与展望

对城市灾害社会脆弱性研究的热点问题及趋向进行了深入的梳理和总结。研究发现,现阶段社会脆弱性研究已经成为城市灾害脆弱性的重要研究范式,但学者们在城市灾害社会脆弱性综合维度的界定、脆弱性评估方法构建、社会脆弱性与灾害种类相关性判读以及研究尺度选取等方面存在明显的争议。对这些争议进行了深入探讨,并对未来城市灾害社会脆弱性研究进行了展望,以期为中国城市防灾减灾工作提供科学参考。     

地震灾害预测和应急模拟系统的设计与应用——以永安市城市应急系统为例

城市防震减灾是地震潜在频发区提高自然灾害防治能力建设的重要方面。本文结合福建省永安市城市防震减灾信息管理系统的建设,探讨设计防震减灾数值模型,分析模型集成的关键技术,构建了地震风险评估、建筑物易损性评价、生命与财产损失估算、救援与救灾管理调度等模型和基于GIS开发的震害预测和应急模拟系统。该系统在福建省永安市的实际应用表明,通过对地震灾害预测结果的分析,可加强城市抗震中的薄弱环节,为灾区政府应急响应和制订对策提供决策支持辅助信息,从而显著提高城市防震减灾的综合能力。     

风暴潮灾害脆弱性研究综述

脆弱性是自然灾害风险研究的热点,风暴潮灾害脆弱性与风暴潮自然过程强度以及沿海社会经济、人口、自然环境等因素相关。本文从风暴潮灾害脆弱性定义出发,对国内外风暴潮灾害社会脆弱性和物理脆弱性进行了回顾,重点对人口、海堤、房屋等风暴潮灾害典型承灾体物理脆弱性研究进展进行了论述,分析了风暴潮灾害脆弱性评价中存在的不确定性,探讨了风暴潮灾害脆弱性在灾害损失评估、保险及再保险、防灾减灾决策支持等领域的应用,对未来风暴潮灾害脆弱性研究提出了以下展望：①开发符合中国沿海区域风暴潮灾害特征和承灾体分布的定量化、精细化脆弱性曲线,拓展风暴潮脆弱性评价结果在保险理赔、灾害损失评估等领域应用;②气候变化背景下中国沿海面临风暴潮巨灾风险,迫切需要建立科学的基于灾害实地踏勘以及物模实验、数值模拟相结合的风暴潮灾害典型承灾体脆弱性评估方法模型。     

小城镇灾害易损性熵权与可变模糊集评估方法研究

为了客观评估小城镇的灾害易损性,提出一种熵权和可变模糊集组合评估方法.采用熵值法确定小城镇灾害易损性评估指标的权重,采用可变模糊集理论建立小城镇灾害易损性评估模型,并以湖南省小城镇为例,进行了相关研究.研究表明:熵值法通过挖掘统计数据的熵来确定评估指标的熵权,所确定的权重是客观的;可变模糊集通过相对隶属度和相对差异函数确定综合相对隶属度,并通过参数组合变换验证了评估方法的可靠性.因而熵权和可变模糊集组合评估是小城镇灾害易损性评估的一种有效方法.     

自然灾害综合研究的新进展--脆弱性研究

文章对脆弱性概念、研究内容、脆弱性的形成和影响因素以及减轻脆弱性、减少灾害影响和损失的途径进行了综述,并讨论了从灾害孕育发生的各个环节降低脆弱性,以最大限度减轻灾害及影响意义.     

基于GIS的中国地震灾害人口风险性分析

中国地震灾害发生频繁,因此进行有关地震灾害风险性分析十分必要。本文在分析地震灾害形成的各主要因子的基础上,结合1900-2009 年地震灾害数据,建立了地震灾害风险评估模型,定量确定了各风险性影响因子。最后利用ArcMap 软件的栅格计算功能,对于地震灾害中最重要的人口因素进行了分析,形成了中国地震灾害人口风险性分布图,并划分出了人口高风险区。     

京津冀地区县域单元地质灾害风险评估

以京津冀地区为例,探索县域单元的地质灾害风险评估方法。通过测算地质灾害危险性与承灾体易损性,以定性综合评估的方式实现县域单元地质灾害风险评估。实际评估中,将承灾体易损性分为人口安全易损性与资产易损性,分别用因灾死亡人口比与因灾直接经济损失比加以表征;再以国土资源部2001-2015年地质灾害灾情数据为基础,参考1950-2000年灾情数据,提出人口安全易损性与资产易损性的分级标准,并在京津冀地区进行了评估。结果表明：研究区整体地质灾害风险低,204个评估单元中仅有6个为中风险区,包括河北省涞源县、涞水县、武安市、青龙满族自治县、北京石景山区、延庆区,其余198个为低风险区,与实际情况相符。此方法快捷简便、数据可连续获取,符合建立资源环境承载能力监测预警机制要求。空间差异化评估结果可为主动防灾减灾、国土空间管理提供支撑。     

气候变暖背景下黄河流域干旱灾害风险空间特征

黄河流域是中国重要的经济带和经济增长极,也是人口密集暴露、特色农业种植和重点生态承载区。在全球变暖和极端降水事件频发的气候背景下,近年来黄河流域干旱灾害变化特征异常突出,新形势下该流域的干旱灾害风险及其对气候变化的响应机制需进一步深入认识。本文利用1960年以来黄河流域122个国家气象站逐日气象数据,结合遥感、社会统计和地理信息数据与技术,基于灾害风险理论,建立致灾因子危险性、孕灾环境脆弱性、承灾体易损性和防灾减灾能力可靠性4个因子的干旱灾害风险指标体系和模型,详细分析了黄河流域干旱灾害风险变化特征和区域差异性及其气候变化的影响机制。结果表明：黄河流域干旱灾害风险分布格局具有明显的地带性和复杂性,流域区域差异显著,总体是中下游风险高于上游,高风险区主要位于黄河流域中下游,致灾因子危险性是黄河流域干旱灾害风险的主导因子,其次是孕灾环境脆弱性和防灾减灾能力可靠性,而承灾体易损性贡献量相对最小。干旱灾害风险影响机制的区域差异也很显著,上游是孕灾环境脆弱性和防灾减灾能力可靠性的影响大于致灾因子和易损性,中游则是致灾因子、易损性和防灾减灾能力对干旱灾害风险的贡献度大,下游是干旱致灾因子起主导作用,致灾因子危险性和承灾体易损性控制了风险总体格局。黄河流域干旱灾害风险变化规律以及对气候变化的响应异常复杂,流域干旱灾害风险主要受季风气候和复杂地形的影响,还受社会经济发展水平、人口暴露度和水资源供需矛盾等多种要素的影响。该研究对黄河流域生态文明建设,粮食安全保障和国家发展战略具有重要意义。     

‘Prosperity beyond belief’: The interaction between a potato crop boom,vulnerability and volcanic hazard in Central Java,Indonesia

This article examines the interaction between conditions of vulnerability and a potato crop boom in Central Java's highlands. While partaking in agricultural endeavours on volcanic slopes can bring substantial economic rewards, the local benefits associated with these livelihood activities are often overlooked by disaster scholarship. Drawing on a period of fieldwork conducted in the Dieng Plateau, a region characterized by a series of craters that periodically erupt mud and poisonous gas, this article demonstrates how a potato crop boom has evolved despite, and in part because of, the underlying volcanic hazard. By integrating the sustainable livelihood and agrarian change literatures, the article concludes that the potato boom has provided significant economic opportunity, and through this, a means to reduce vulnerability. Yet, despite these economic gains, the agrarian shift described herein has also introduced new vulnerabilities as farmers have become dependent on a resource intensive crop. These findings demonstrate how theories of agrarian transformation can complement livelihood perspectives in disaster research, and provide greater detail into the local and regional processes that encourage people to often-profitably farm hazardous land.     

地震灾害宏观分析研究*

运用对致灾因素及灾害发生机制的已有认识,根据50个历史的典型震例,建立地震烈度、人口密度、单位面积工农业产值等因素与反映灾害程度的人员伤亡、经济损失的估算模型;以减少灾害研究对历史资料的依赖.用两个历史震例检验模型,结果其精度满足宏观分析的要求.     

区域人地耦合系统脆弱性及其评价指标体系

从概念界定与目标定位入手,以气候变化和系统结构要素为分析框架,建立了包括敏感性、暴露性和适应性等三类指标要素和本底脆弱性、潜在脆弱性和现实脆弱性等三个评价层次的区域脆弱性评价系统,并以南方丘陵地区为例,针对泥石流、滑坡、干旱与洪涝等区域自然灾害,构建了水土流失敏感区的人地耦合系统脆弱性评价指标体系。作者认为,区域人地耦合系统脆弱性主要是针对全球气候变化扰动下与自然灾害有关的脆弱性,敏感性与易损性是其脆弱性的本质属性,敏感性、暴露性和适应性是脆弱性的系统要素。自然灾害频率指标可以作为反映灾害空间集聚性的区位暴露性指标,现实灾害度可以提供脆弱性评价因子厘定、指标权重确定、模型建立与阈值分析的结果验证。     

A fuzzy multiple-attribute decision-making modelling for vulnerability analysis on the basis of population information for disaster management

Research activity and published literature on the reliability and vulnerability analysis of urban areas for disaster management has grown tremendously in the recent past. Population information has played the most important role during the entire disaster management process. In this article, population information was used as the evaluation criterion, and a fuzzy multiple-attribute decision-making (MADM) approach was used to support a vulnerability analysis of the Helsinki area for disaster management. A kernel density map was produced as a result that showed the vulnerable spatial locations in the event of a disaster. Model results were first validated against the original population information kernel density maps. In the second step, the model was validated by using fuzzy set accuracy assessment and the actual domain knowledge of the rescue experts. This is a novel approach to validation, which makes it possible to see how and if computer decision-making models compare to a real decision-making process in disaster management. The validation results showed that the fuzzy model has produced a reasonably accurate result. By using fuzzy modelling, the number of vulnerable areas was reduced to a reasonable scale and compares to the actual human assessment of these areas, which allows resources to be optimised during the rescue planning and operation.     

汶川地震灾区滑坡空间特征变化分析

“5.12”汶川大地震触发了大量滑坡,给人民群众生命财产和社会经济发展造成了巨大损失。基于GIS空间分析方法,结合震前和震后的滑坡编目数据,对滑坡与坡度、坡向、高程、岩土类型、道路、河流和断裂带等7个孕灾环境因素的空间分布关系进行统计分析。结果表明：滑坡与孕灾环境因素的空间分布关系受地震的影响比较大。相比于震前,震后滑坡发生的优势坡度、优势岩土类型、优势距离缓冲区等均发生了很大的变化;并且坡向、距道路距离、距河流距离等因素对滑坡有明显地趋势性影响。     

Participatory 3-dimension mapping: A tool for encouraging multi-caste collaboration to climate change adaptation and disaster risk reduction

This article reflects upon the use of participatory 3-dimensional mapping (P3DM) for facilitating the collaboration of different castes in disaster risk reduction (DRR) and climate change adaptation (CCA). Unequal power relationships amongst upper and lower castes has indeed been identified has a major driver of people's vulnerability to natural hazards, including the negative effects of climate change, in Nepal and elsewhere in South Asia. However, this does not prevent the members of all these castes, including the lowest untouchables, to display significant capacities in facing these natural hazards and changes in climate patterns. It is therefore similarly important to harness those capacities and address the unequal power relationships underpinning vulnerability. Achieving these goals requires fostering dialogue amongst upper and lower castes as well as with other stakeholders of DRR and CCA, e.g. scientists, NGOs, government agencies, which often tend to work with a single caste because it is easier. P3DM provides a platform for such a dialogue as it makes the knowledge of every caste tangible and credible to others. This proves essential in both assessing and planning for reducing the risk of disasters and adapting to climate change. This article particularly documents activities conducted in a small village of the Terai plain of Nepal frequently affected by flooding.     

Using spatial analysis and Bayesian network to model the vulnerability and make insurance pricing of catastrophic risk

Vulnerability refers to the degree of an individual subject to the damage arising from a catastrophic disaster. It is affected by multiple indicators that include hazard intensity, environment, and individual characteristics. The traditional area aggregate approach does not differentiate the individuals exposed to the disaster. In this article, we propose a new solution of modeling vulnerability. Our strategy is to use spatial analysis and Bayesian network (BN) to model vulnerability and make insurance pricing in a spatially explicit manner. Spatial analysis is employed to preprocess the data, for example kernel density analysis (KDA) is employed to quantify the influence of geo-features on catastrophic risk and relate such influence to spatial distance. BN provides a consistent platform to integrate a variety of indicators including those extracted by spatial analysis techniques to model uncertainty of vulnerability. Our approach can differentiate attributes of different individuals at a finer scale, integrate quantitative indicators from multiple-sources, and evaluate the vulnerability even with missing data. In the pilot study case of seismic risk, our approach obtains a spatially located result of vulnerability and makes an insurance price at a finer scale for the insured buildings. The result obtained with our method is informative for decision-makers to make a spatially located planning of buildings and allocation of resources before, during, and after the disasters.     

汶川地震灾区滑坡空间特征变化分析简

“5.12”汶川大地震触发了大量滑坡,给人民群众生命财产和社会经济发展造成了巨大损失。基于GIS空间分析方法,结合震前和震后的滑坡编目数据,对滑坡与坡度、坡向、高程、岩土类型、道路、河流和断裂带等7个孕灾环境因素的空间分布关系进行统计分析。结果表明：滑坡与孕灾环境因素的空间分布关系受地震的影响比较大。相比于震前,震后滑坡发生的优势坡度、优势岩土类型、优势距离缓冲区等均发生了很大的变化;并且坡向、距道路距离、距河流距离等因素对滑坡有明显地趋势性影响。     

Dynamic process-based risk assessment of debris flow on a local scale

After the Wenchuan earthquake in China, debris flows have been more frequent. Multiple debris flows commonly occur in earthquake-affected areas during heavy rainfall, often causing losses of lives and property. We analyzed the dynamic movement of debris flows and proposed a quantitative method of debris flow hazard assessment, based on kinetic energy. Validated using field study of an actual debris flow disaster, these analyzes help determine the type, quantity, distribution, economic worth, and susceptibility of elements at risk. We established a method to determine vulnerability of elements at risk and we propose a systematic and quantitative method for local risk analysis of debris flows. We applied the proposed method to a debris flow in Qipan gully, which caused serious damages for Duwen Highway and Qipan settlements of Sichuan Province in 2013. With the support of a debris-flow movement numerical simulation, remote sensing, and GIS techniques, the proposed method analyzed disaster effects and divided the hazardous areas into three risk zones. Calculated risk zones coincided with the actual distribution and severity of damage of the event, suggesting that the risk assessment generated by the proposed method is consistent with results from the actual disaster.