The Tous dam disaster of 1982 and the origins of integrated flood risk management in Spain

The failure of the Tous dam in 1982 caused one of the most important socio-natural disasters in Spain during the twentieth century. That event triggered a paradigm change in the way disaster risks were perceived and managed, not only locally, but also at multiple levels of governance. Fifteen interviews with relevant stakeholders, content analysis of scientific literature, and review of historical and media accounts indicate that the collapse of the Tous dam had the two major effects. First, it prompted a process of institutional development, which led to the growth, and increase in complexity of the organizations involved both in vertical and horizontal communication of disaster risk reduction. Second, actions taken and experiences gained in dealing with disaster risk reduction in the Tous area were used as a benchmark to develop new strategies, as well as new mechanisms for communication and planning in other territories and other risk domains in Spain. This paper also identified the three main stages in the evolution of disaster risk reduction planning in the area: (1) After the collapse of the Tous dam, disaster risk reduction strategies in Spain focused on improving preparedness in order to reduce short-term risks. (2) Disaster management in the 1990s was strongly influenced by international initiatives, which emphasized the contextualization of risk and the importance in long-term disaster risk reduction measures such as land-use planning. (3) The European Water Framework Directive (2000) and, more recently, the Floods Directive (2007) are exerting a strong influence on the development of a new Spanish flood policy that focuses on preventive measures. However, this process is far from complete and many issues still remain unresolved: dealing with different domains of risk action, integrating concepts of ecological resilience and climate change, and promoting public awareness and effective participation.     

A Probabilistic Modelling System for Assessing Flood Risks

In order to be economically viable, flood disaster mitigation should be based on a comprehensive assessment of the flood risk. This requires the estimation of the flood hazard (i.e. runoff and associated probability) and the consequences of flooding (i.e. property damage, damage to persons, etc.). Within the “German Research Network Natural Disasters” project, the working group on “Flood Risk Analysis” investigated the complete flood disaster chain from the triggering event down to its various consequences. The working group developed complex, spatially distributed models representing the relevant meteorological, hydrological, hydraulic, geo-technical, and socio-economic processes. In order to assess flood risk these complex deterministic models were complemented by a simple probabilistic model. The latter model consists of modules each representing one process of the flood disaster chain. Each module is a simple parameterisation of the corresponding more complex model. This ensures that the two approaches (simple probabilistic and complex deterministic) are compatible at all steps of the flood disaster chain. The simple stochastic approach allows a large number of simulation runs in a Monte Carlo framework thus providing the basis for a probabilistic risk assessment. Using the proposed model, the flood risk including an estimation of the flood damage was quantified for an example area at the river Rhine. Additionally, the important influence of upstream levee breaches on the flood risk at the lower reaches was assessed. The proposed model concept is useful for the integrated assessment of flood risks in flood prone areas, for cost-benefit assessment and risk-based design of flood protection measures and as a decision support tool for flood management.     

Risk assessment of flood disaster in Shanghai based on spatial–temporal characteristics analysis from 251 to 2000

As one of the top 20 cities exposed to flood disasters, Shanghai is particularly vulnerable because it is exposed to powerful floods and poorly prepared. However, it is unclear to understand the evolution process of floods and the variation of flood risk in Shanghai during the past 1,000 years. This paper analyzed the spatial–temporal characteristics of flood disaster and evaluated the integrated risk of flood disaster in Shanghai based on the historical flood data from 251 to 2000. The results show that flood disaster in Shanghai was divided into storm surge-induced flood, rainstorm-induced flood and overbank flood. Flood disaster in Shanghai presents rising trend with time and mainly occurs in summer and autumn. Moreover, the flood disaster is dominated by rainstorm-induced flood, especially after the establishment of the People’s Republic of China in 1949. Additionally, flood risk in different areas of Shanghai between the years 251–1949 and 1950–2000 changed significantly. Shanghai urban area, Jinshan District and Chongming County belong to increased flood risk area; Baoshan, Jiading, Qingpu, Songjiang, Fengxian, Pudong and Minhang District belong to decreased flood risk area. The integrated risk of flood disaster in Shanghai has presented spatial disparities evidently at present. Shanghai urban area is most likely to suffer flood disaster; Baoshan, Jiading and Minhang District have medium flood risk rank; and Jinshan, Songjiang, Fengxian, Pudong, Qingpu and Chongming County show low flood risk at present. The combined effect of urbanization, sea-level rise, land subsidence and the poor capacity of flood prevention facilities will give rise to the risk of flood in the next several decades. These results provide very important information for the local government to improve flood risk management.     

风险分析实践的感悟

考虑到我国水资源短缺、水灾害频发和水环境恶化的情势,在水利建设和管理中,突出风险意识是非常必要的和十分及时的。我们多年从事风险分析实践的感悟是：水利风险模拟分析完全不同于建筑结构物的可靠度计算,更不是模拟设计洪水的淹没范围和水深,其真谛是在于如实模拟出当地的水旱灾害的不确定性,是对传统思维模式的重大的突破。有些传统理念也有必要作调整,如：工程水文学科的内涵,可持续发展的不确定性和风险分析的风险。     

洪水灾害风险管理广义熵智能分析的理论框架

基于洪水灾害风险管理的背景分析,提出用广义分布函数及其广义熵理论统一描述、物理解析洪水灾害风险管理系统的各种不确定性信息。基于洪水灾害风险形成机制和风险管理理论与水利科学、信息科学、智能科学综合集成途径,提出由洪水灾害孕灾环境和致灾因子危险性广义熵智能分析、承灾体易损性广义熵智能分析、承灾体灾情广义熵智能分析和风险决策广义熵智能分析组成的洪水灾害风险管理广义熵智能分析的初步理论框架及其主要研究内容,在其它灾害风险管理中具有一定的参考应用价值。     

基于风险度的青海省暴雨洪涝灾害风险评估

基于自然灾害风险原理,结合青海省气象数据、地理信息数据、社会经济数据,并利用主成分分析法、GIS自然断点法对青海省暴雨洪涝灾害致灾因子危险度、承载体易损度评估模型以及暴雨洪涝灾害风险度进行评估,结果表明：青海省不同强度降水日数均呈增多趋势,新世纪以来中雨日数及强降水日数增加趋势尤为明显;暴雨洪涝灾害致灾因子危险度呈由东南向西北降低的趋势,承载体易损度为东北部地区最高,南部以及西部地区最低;暴雨洪涝风险较高的地区主要集中在东部地区,互助、湟中、大通、西宁为高风险区,东部大部地区、环青海湖地区为较高风险区,西部地区为低风险区。该评估结果可以在气象灾害风险管理业务中进行应用,可以加强对暴雨洪涝灾害风险的影响程度及影响区域的判定,为地方防灾减灾救灾工作提供科学依据。     

Floods in Provence-Alpes-Côte d'Azur and lessons for French flood risk governance

France experiences catastrophic floods on a yearly basis, with significant societal impacts. In this study, we use multiple sources (insurance datasets, scientific articles, satellite data, and grey literature) to (1) analyze modern flood disasters in the PACA Region; (2) discuss the efficiency of French public policy instruments; (3) perform a SWOT analysis of French flood risk governance (FRG); and (4) suggest improvements to the FRG framework. Despite persistent government efforts, the impacts of flood events in the region have not lessened over time. Identical losses in the same locations are observed after repeated catastrophic events. Relative exposure to flooding has increased in France, apparently due to intense urbanization of flood-prone land. We suggest that the French FRG could benefit from the following improvements: (1) regular updates of risk prevention plans and tools; (2) the adoption of a build back better logic; (3) taking undeclared damages into account in flood risk models; (4) better communication between the actors at the different steps of each cycle (preparation, control, organization, etc.); (5) better communication between those responsible for risk prevention, emergency management, and disaster recovery; (6) an approach that extends the risk analysis outside the borders of the drainage basin; and (7) increased participation in FRG from local populations.

     

ICL Latin-American Network: on the road to landslide reduction capacity building

There is a clear need for integrated research on landslide disaster risk. Landslide disasters have major impacts in developing countries due to the increasing social vulnerability of both rural and urban communities. In recent decades, landslide disasters in Latin America triggered by both precipitation and earthquakes have also increased considerably. Thus, scientific contributions based on integrated risk research are quite urgent for improving the knowledge base for reducing the vulnerability of exposed communities to landslides. Thus, there is a parallel necessity to promote capacity building for young scientists in Latin America by considering the shift of disaster paradigm to recognize the “unnaturalness” of disasters. Under such a framework, there are particular goals to be pursued including: (1) Development of landslide regional networks with a commitment for understanding risk as a socially constructed process; (2) Engagement of young scientists in integrated landslide risk research; (3) Inducing a scientific multi- and transdisciplinary approach for integrated landslide risk research; (4) Development and implementation of capacity building; (5) Contributing to the dissemination and application of common methodologies on landslide disasters investigations; and (6) Strengthening collaboration on integrated landslide disaster risk research in Latin America. In this paper, we present one of the main activities of the ICL Latin-American network in terms of capacity building carried out in 2013; to that end, the first international workshop on forensic investigations of disasters associated with landslides was held in the University of Sciences and Arts of Chiapas in the city of Tuxtla Gutierrez, Chiapas, Mexico, from June 26th to July 4th, 2013.     

中国城市主要自然灾害风险评价研究

本文依据灾害系统理论和中国自然灾害数据库,构建了反映城市承灾体的综合城市化水平（CL）指标,并在此基础上得到城市脆弱性水平指数。考虑对城市具有结构性破坏和易于造成交通灾情的主要灾种,即水灾、地震、滑坡—泥石流、台风、沙尘暴,构建了反映城市主要致灾因子的综合自然灾害强度（QC）指标,并得到城市综合自然灾害强度指数。据此,在定性分析的基础上,通过半定量计算,将中国城市主要自然灾害风险划分为高风险、较高风险、中等风险、较低风险、低风险5个等级,编制了中国城市自然灾害风险评价图,并对灾害链的综合风险评价作了进一步的探讨。     

基于最大熵原理和属性区间识别理论的洪水灾害风险分析

针对复杂洪水灾害系统中随机、模糊、灰色等各种不确定性,结合洪水灾害风险管理广义熵智能分析的理论框架,以最大熵原理和属性区间识别理论为基础,建立了基于最大熵原理的洪水灾害风险属性区间识别模型(AIRM-POME),利用梯形模糊数和层次分析法相结合的方法确定评价指标权重,采用均化系数综合AIRM-POME计算得到的属性测度区间,由置信度准则和特征值公式对各评价单元进行危险、易损等级的评定和排序,并根据联合国对自然灾害风险的定义及其定量表达式给出风险等级。将模型应用到荆江分洪区洪水灾害风险分析中,实例研究表明,模型合理可靠,深层次地刻画了各种不确定性,是一种风险分析新方法,可推广应用到其他自然灾害的风险分析中。     

Integrated risk assessment of flood disaster based on improved set pair analysis and the variable fuzzy set theory in central Liaoning Province,China

This study presents the methodology and procedure for risk assessment of flood disasters in central Liaoning Province, which was supported by geographical information systems (GIS) and technology of natural disaster risk assessment. On the basis of the standard formulation of natural disaster risk and flood disaster risk index, of which weights were developed using combined weights of entropy, the relative membership degree functions of variable fuzzy set (VFS) theory were calculated using improved set pair analysis, while level values were calculated using VFSs, including hazard levels, exposure levels, vulnerability levels and restorability levels, and the flood risk level for each assessment unit was obtained using the natural disaster index method. Consequently, integrated flood risk map was carried out by GIS spatial analysis technique. The results show that the southwestern and central parts of the study area possess higher risk, while the northwestern and southeastern parts possess lower risk. The results got by the assessment model fits the area of historical flood data; this study offer new insights and possibility to carry out an efficient way for flood disaster prevention and mitigation. The study also provides scientific reference in flood risk management for local and national governmental agencies.     

Poverty, vulnerability and the impact of flooding in the Limpopo Province, South Africa

The article evaluates household vulnerability after the 2000 flood in two poor communities of the Limpopo Province, South Africa. The study analyses the forms of vulnerability which disasters such as floods present. Using data gathered from a survey of households, the study presents the impacts, coping and adapting strategies of households after the 2000 flood. The article argues that beyond the concern over socio-economic circumstances as the major determinant of household vulnerability, the management of the disaster can serve to perpetuate vulnerability.     

Resilient capacity assessment for geological failure areas: examples from communities affected by debris flow disaster

This study establishes a novel method for assessing the community resilient capacity of debris flow disasters with appropriate parameters, such as responding, monitoring and communication capabilities. This study adopts eight communities in Taiwan, namely Nangang, Tongfu, Jhongyang, Laiyuan, Chingfu, Sinsheng, Shangan and Jyunkeng, as examples. First, the Analytic Hierarchy Process was applied to establish the framework of the community resiliency capacity, including the community’s resources for disaster resilience and resident capabilities. The community’s resources for disaster resilience are identified by surveying the community leaders via checklists. Resident capabilities are determined using questionnaires. The community resilient capacity refers to the sum of the results from these two investigations. The two investigations have similar weights, indicating that they are equally significant when evaluating community resilient capacity. Second, FLO-2D software is utilized for hazard analysis by simulation results of deposited areas for debris flows, and then these areas were categorized according to hazard degrees. Finally, the vulnerability of communities is classified based on the land use type. In summary, the values of capacity, hazard and vulnerability are integrated to determine the risk of debris flow for each community. A risk map is then generated.     

Integrated methodology for flood risk assessment and application in urban communities of Pakistan

Flood disasters and its consequent damages are on the rise globally. Pakistan has been experiencing an increase in flood frequency and severity along with resultant damages in the past. In addition to the regular practices of loss and damage estimation, current focus is on risk assessment of hazard-prone communities. Risk measurement is complex as scholars engaged in disaster science and management use different quantitative models with diverse interpretations. This study tries to provide clarity in conceptualizing disaster risk and proposes a risk assessment methodology with constituent components such as hazard, vulnerability (exposure and sensitivity) and coping/adaptive capacity. Three communities from different urban centers in Pakistan have been selected based on high flood frequency and intensity. A primary survey was conducted in selected urban communities to capture data on a number of variables relating to flood hazard, vulnerability and capacity to compute flood risk index. Households were categorized into different risk levels, such as can manage risk, can survive and cope, and cannot cope. It was found that risk levels varied significantly across the households of the three communities. Metropolitan city was found to be highly vulnerable as compared to smaller cities due to weak capacity. Households living in medium town had devised coping mechanisms to manage risk. The proposed methodology is tested and found operational for risk assessment of flood-prone areas and communities irrespective of locations and countries.     

An analysis on disasters management system in China

This paper introduced the principle, institutional framework, and legal construction of Chinese disaster management system, and operating mechanisms of disaster management departments in pre-disaster, response and post-disaster phases were also demonstrated. Although China has basically built the disaster management system, formed national emergency plan system, and gained achievements in some aspects, the disasters management system is still a segmental model and is not an integrated management system. This article analyzes problems of Chinese disaster management system, and puts forward some suggestions for improving and optimizing this system. This can make Chinese disaster management system better respond and handle to disasters risk, and reduce the social and economic losses of disasters caused.     

Beyond Modelling: Linking Models with GIS for Flood Risk Management

Spatially explicit hydrodynamic flood models can play animportant role in natural hazard risk reduction. A key element of these models that make them suitable for riskreduction is the ability to provide time-series inundation information about the onset, duration and passingof a hazard event. Such information can be critical for landuse planning, for mapping evacuation egress routes,and for locating suitable emergency shelters to name only a few risk treatments. This research contends that abarrier to effective risk reduction is providing disaster managers with access to model results in a structured andflexible framework that allows consequences of different hazard scenarios to be assessed and mapped. Toaddress these limitations, a framework has been developed that links a commercial relational databasemanagement system with a GIS-based decision support system. The framework utilises industry standard dataexchange protocols and results in efficient time-series hazard data management. A case study based in Cairns,in far-north coastal Australia is presented to illustrate how the system has been developed. Results show that theframework reduces data volumes significantly, while making pre-run modelled inundation results rapidly accessibleto disaster managers. Of note is the ability of the framework to present results in terms of risk to buildings,roads and other spatial features in urban regions, and to provide answers to relatively complex risk questions.     

Highway flood disaster risk evaluation and management in China

Flood disaster has become one of the most damaging natural disasters for the highway transportation all around the world, especially its destructive effects on highway infrastructures. In order to better understand the ruinous influence of flood disaster on highway transportation in China, this paper proposes an alternative evaluation index of highway flood disaster risk from three aspects, namely the disaster-causing factors, disaster-inducing environment, and disaster-bearing subjects. This paper also puts forward some targeted suggestions for the risk management, including two aspects: physical protection measurement and organization and management measurement. Moreover, this paper develops a highway flood disaster risk management system by using the ArcGIS technology.

     

吉林省重大暴雨过程灾害损失风险预评估

利用吉林省50县市1951-2013年逐日降水资料、暴雨灾情损失数据,1：5万DEM数据、水系、TM遥感卫星影像资料以及GDP、人口等数据,探讨了吉林省重大暴雨过程灾害损失风险的主要影响因素,确立了各因素的权重系数,构建了吉林省重大暴雨过程灾害损失风险评估模型.利用过程预报降雨量对2013年8月14-17日的重大暴雨过程灾害损失风险进行了预评估.结果表明：重大暴雨过程灾害损失综合风险的高值区分布在四平、辽源大部以及长春、吉林、通化城区附近,风险偏高区位于中南部,西部地区和东北部地区为中低风险区.灾害损失风险评估模型预评估效果良好,可在实际的暴雨过程灾害损失风险预评估业务中使用,由于通过该模型的评估结果可迅速圈定各级洪涝风险区,对提高重大暴雨过程应对能力、减少灾害损失以及防灾减灾意义重大.     

Highway flood disaster risk evaluation and management in China

Flood disaster has become one of the most damaging natural disasters for the highway transportation all around the world, especially its destructive effects on highway infrastructures. In order to better understand the ruinous influence of flood disaster on highway transportation in China, this paper proposes an alternative evaluation index of highway flood disaster risk from three aspects, namely the disaster-causing factors, disaster-inducing environment, and disaster-bearing subjects. This paper also puts forward some targeted suggestions for the risk management, including two aspects: physical protection measurement and organization and management measurement. Moreover, this paper develops a highway flood disaster risk management system by using the ArcGIS technology.     

Risk analysis and influencing factors of drought and flood disasters in China

The risk analysis of flood and drought disasters and the study of their influencing factors enhance our understanding of the temporal and spatial variation law of disasters and help identify the main factors affecting disasters. This paper uses the provincial administrative region of China as the research area. The proportion of the disaster area represents the degree of the disaster. The statistical distribution of the proportions was optimized from 10 alternative distributions based on a KS test, and the disaster risk was analyzed. Thirty-five indicators were selected from nature, agriculture and the social economy as alternative factors. The main factors affecting flood and drought disasters were selected by Pearson, Spearman and Kendall correlation coefficient test. The results demonstrated that the distribution of floods and drought is right-skewed, and the gamma distribution is the best statistical distribution for fitting disasters. In terms of time, the risk of flood and drought disasters in all regions showed a downward trend. Economic development and the enhancement of the ability to resist disasters were the main reasons for the change in disasters. Spatially, the areas with high drought risk were mainly distributed in Northeast and North China, and the areas with high flood risk were mainly distributed in the south, especially in Hubei, Hunan, Jiangxi and Anhui. The distribution of floods and drought disasters was consistent with the distribution characteristics of precipitation and water resources in China. Among the natural factors, precipitation was the main factor causing changes in floods and drought disasters. Among the agricultural and socioeconomic factors, the indicators reflecting the disaster resistance ability and regional economic development level were closely related to flood and drought disasters. The research results have reference significance for disaster classification, disaster formation mechanisms and flood and drought resistance.