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.     

Flood risks in a dynamic urban agglomeration: a conceptual and methodological assessment framework

The analysis of risk and its causes is a crucial prerequisite for the development of risk prevention and mitigation measures in the scope of disaster risk management. This paper investigates on the problem of annually occurring floods in Santiago de Chile applying a framework for risk assessment, especially developed for the usage in a large urban area. A case-specific set of variables and indicators was compiled to show the relevant components and their interrelations influencing the flood risk and to provide a tool for monitoring and evaluating their changes over time. Methods for gathering information about the three components of risk, that is, hazard, elements at risk, and vulnerability, comprise the interpretation of very high resolution satellite data, the analysis of GIS, and census data as well as household surveys and expert interviews. The work shows how the assessment framework can be applied in practice to derive a geodata-based flood risk map at the scale of the administrative unit of a building block that can be used as a local decision-making tool.     

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。     

Integrated risk assessment method of waterlog disaster in Huaihe River Basin of China

Regional waterlog disaster integrated risk system, affected by natural, social, and economic systems and its combination relationship, is a complex system with certain structure and function. Waterlog disaster integrated risk results from the combined effects of regional environment, impact factors, vulnerability, and disaster-reducing capability of flood hazards in the drainage area. Waterlog disaster integrated risk system can be divided into four subsystems of hazard, vulnerability, disaster-reducing capability, and disaster conditions. Evaluation indexes are selected using fuzzy analytic hierarchy process method, and the evaluation index system is established. Then, the waterlog disaster integrated risk evaluation model is proposed based on set pair analysis method. Taking Huaihe river in Anhui Province of China as the typical area in this study, the results show that the proposed approach is able to obtain the spatial distribution characteristics of waterlog hazard, vulnerability, mitigation capabilities, and integrated disaster risk within the study area. From the quantitative point of view, identification of the areas with high flood risk can provide a scientific basis for the flood management and technical support.

     

区域承灾体脆弱性评价指标体系研究

灾害所造成的后果是由致灾环境的危险性和承灾体的脆弱性决定的。承灾体的脆弱性对区域减灾有着极为重要的作用 ,而承灾体脆弱性指标体系的建立则成为区域脆弱性评价的关键。文章确定了承灾体脆弱性评估指标体系的功能及建立原则 ,在前人研究的基础上 ,综合反推法、信息量法等多种方法确定了基于灾前评判的承灾体脆弱性评估指标体系     

Integrated risk assessment method of waterlog disaster in Huaihe River Basin of China

Regional waterlog disaster integrated risk system, affected by natural, social, and economic systems and its combination relationship, is a complex system with certain structure and function. Waterlog disaster integrated risk results from the combined effects of regional environment, impact factors, vulnerability, and disaster-reducing capability of flood hazards in the drainage area. Waterlog disaster integrated risk system can be divided into four subsystems of hazard, vulnerability, disaster-reducing capability, and disaster conditions. Evaluation indexes are selected using fuzzy analytic hierarchy process method, and the evaluation index system is established. Then, the waterlog disaster integrated risk evaluation model is proposed based on set pair analysis method. Taking Huaihe river in Anhui Province of China as the typical area in this study, the results show that the proposed approach is able to obtain the spatial distribution characteristics of waterlog hazard, vulnerability, mitigation capabilities, and integrated disaster risk within the study area. From the quantitative point of view, identification of the areas with high flood risk can provide a scientific basis for the flood management and technical support.     

Risk assessment of rainstorm and flood disasters in China between 2004 and 2009 based on gray fixed weight cluster analysis

Rainstorm and flood disasters frequently occur in China, causing heavy losses for people’s lives and property and reducing the capability of sustainable development of the national and local economy. In this study, the risks of the rainstorm and flood disasters are assessed for the Chinese mainland, excluding Hong Kong, Macao, and Taiwan and also employ the historical data of seven indicators, including the affected area of crops, the affected population, the direct economic loss, and etc., from 2004 to 2009. Based on the large 1,302 historical sample data, the impact of rainstorm and flood disasters were analyzed using the methodology of gray fixed weight cluster analysis according to disaster losses, which were divided into the three gray classes of high, medium, and low. The regional differences of the risk assessment of the rainstorm and flood disasters are discussed, and the dynamical risk zoning map is conducted. The results show a consistent conclusion with the actual losses of rainstorm and flood disasters over each administrative district, which can provide more scientific evidence for the relevant departments of disaster prevention and mitigation.     

Social vulnerability assessment of natural hazards on county-scale using high spatial resolution satellite imagery: a case study in the Luogang district of Guangzhou,South China

Social vulnerability assessment of natural hazards aims to identify vulnerable populations and provide decision makers with scientific basis for their disaster prevention and mitigation decisions. A new method based on remote sensing is presented here to establish a model of social vulnerability for county-scale regions that lack of relative data. To calculate population density, which is the most important indicator in social vulnerability assessment, first, a statistical model is established to estimate the population on village level. Then a new concept defined as “population density based on land use” is created to replace the arithmetic population density. The former has taken the dynamic human distribution related to land use into account; thus, it can map the population distribution more realistically. The other two indicators are age structure and distance to hospital. The application of this method to the Luogang District of Guangzhou, South China demonstrated its capability of providing high spatial resolution and reasonable social vulnerability for social vulnerability assessment of natural hazards.     

Characterizing the spatial distribution of typical natural disaster vulnerability in China from 2010 to 2017

Natural disaster vulnerability can intuitively reflect the susceptibility of an area to environmental changes. Better understanding the spatial distribution of natural disaster vulnerability is a critical process for taking effective adaptation and management. Although significant achievements have been made in disaster vulnerability, few studies are known about natural disaster vulnerability at the national scale, especially from the typical natural disaster events in China. In this study, with normalizing selected indicators and calculating vulnerability index, we analyzed the spatial distribution of natural disasters vulnerability during 2010–2017 using the geospatial techniques. The results showed that natural disaster vulnerability has certain spatial differences, but different natural disaster can occur in the same area during the study period. Drought disaster can occur in all regions of China, especially in Inner Mongolia. Flood disaster is mainly concentrated in the middle and lower reaches of the Yangtze River and the Yellow River Basin. The wind and storm disaster is chiefly in the northern regions in China. The freezing disaster is widely distributed in China. Furthermore, the regions with low vulnerability were primarily distributed in the eastern coastal region, indicating that the rapid development of economy and technology can resist or mitigate natural disaster to a certain extent. This study offers a solution to study natural disasters and provides scientific basis for disaster prevention and mitigation actions.

     

山东暴雨洪涝灾害的风险区划与分析

根据暴雨洪涝灾害致灾因子危险性、孕灾环境敏感性、承载体易损性和防灾减灾能力4个一级因子,以山东地区为研究对象,综合考虑降雨、地形地势、河网密度、植被、人口和经济实力、道路交通信息等因子进行风险区划与分析。利用地理信息系统软件（ArcGIS）将上述因子进行归一化来获得标准化的多源栅格数据,结合层次分析法和自然断点法确定相关指标的权重,建立了暴雨洪涝灾害的风险评估模型,最后得到了山东地区暴雨洪涝灾害综合风险区划等级评估图。对研究区进行定性和定量分析后得出结论,山东地区暴雨洪涝灾害发生的高风险区在鲁中西部、鲁南及山东半岛东部沿海部分地区,此结论与历史数据基本吻合。研究结果为预防山东暴雨洪涝灾害提供了参考信息。     

太湖流域应对特大洪水防洪工程效益模拟

防洪效益评估对防洪工程投资决策与减灾对策制定具有重要意义。建立集成了与太湖流域防洪效益评估相关的系列模型和方法,包括含降雨产流与平原净雨计算的水文分析方法、由河网水动力学模型和平原区域洪水分析模型组成的大尺度水力学模型、综合流域社会经济和淹没因素的洪灾损失评估模型。模拟了太湖流域遇特大洪水的灾害损失,开展了不同防洪工程应对流域性特大洪水减灾效益的预测分析。结果表明：1999年型200年一遇降雨将会给太湖流域造成高达568.29亿元的直接经济损失,外排动力增强30%至100%的防洪效益介于26.69亿元到45.70亿元之间,新建圩区、太浦河拓宽的防洪效益依次减小,而圩区泵排能力增加30%的防洪效益仅为0.65亿元。基于研究成果提出了增设外排泵站、加强圩区科学调度、通过保险分担风险等应对特大洪水的对策措施建议,为太湖流域特大洪水的防治提供支撑和参考。     

太湖流域应对特大洪水防洪工程效益模拟

防洪效益评估对防洪工程投资决策与减灾对策制定具有重要意义。建立集成了与太湖流域防洪效益评估相关的系列模型和方法,包括含降雨产流与平原净雨计算的水文分析方法、由河网水动力学模型和平原区域洪水分析模型组成的大尺度水力学模型、综合流域社会经济和淹没因素的洪灾损失评估模型。模拟了太湖流域遇特大洪水的灾害损失,开展了不同防洪工程应对流域性特大洪水减灾效益的预测分析。结果表明:1999年型200年一遇降雨将会给太湖流域造成高达568.29亿元的直接经济损失,外排动力增强30%至100%的防洪效益介于26.69亿元到45.70亿元之间,新建圩区、太浦河拓宽的防洪效益依次减小,而圩区泵排能力增加30%的防洪效益仅为0.65亿元。基于研究成果提出了增设外排泵站、加强圩区科学调度、通过保险分担风险等应对特大洪水的对策措施建议,为太湖流域特大洪水的防治提供支撑和参考。     

洪涝灾害风险评估与分区研究进展

在全球气候变化和城市化进程不断加快的背景下,城市洪涝灾害频发,造成严重的经济损失和人员伤亡问题。对近年来中国典型城市洪涝灾害进行系统整理介绍,说明洪涝灾害带来的人员伤亡和经济损失巨大。风险评估作为一种非工程性防洪措施,是城市洪涝风险管理的首要工作,精确、高效的把握洪灾过程等特征可以为防灾减灾工作提供科学依据。对城市洪涝风险评估与分区的概念和内容进行系统梳理,常用的风险评估方法有数理统计法、不确定性分析法、遥感影像评估法、指标体系评估法、情景模拟评估法；风险分区常用方法有阈值法、经验公式法和物理机制法。论述了城市洪涝风险评估与分区常用方法的应用范围、优缺点及其发展前景。     

GIS-based flood risk assessment in suburban areas: a case study of the Fangshan District,Beijing

Suburban areas have become rapid development zones during China’s current urbanization. Generally, these areas are also regional precipitation centers that are prone to flood disasters. Therefore, it is important to assess the flood risk in suburban areas. In this study, flood risk was defined as the product of hazard and vulnerability based on disaster risk theory. A risk assessment index system was established, and the analytic hierarchy process method was used to determine the index weight. The Fangshan District in Beijing, China, which is an example of a typical suburban area undergoing rapid urbanization, was selected for this study. Six factors were considered in relation to hazard, and three factors were considered for vulnerability. Each indicator was discretized, standardized, weighted, and then combined to obtain the final flood risk map in a geographical information system environment. The results showed that the high and very high risk zones in the Fangshan District were primarily concentrated on Yingfeng Street, Xingcheng Street, Xincheng Street, and Chengguanzhen Street. The comparison to an actual flood disaster suggested that the method was effective and practical. The method can quantitatively reflect the relative magnitude and spatial distribution patterns of flood risk in a region. The method can be applied easily to most suburban areas in China for land use planning and flood risk management.     

GIS-based multi-dimensional risk assessment of the grassland fire in northern China

This study presents a methodology for risk analysis and assessment to manage grassland fire in northern China based on the Geographical Information Systems from the viewpoints of climatology, geography, disaster science, and environmental science and so on. Using natural disaster and risk assessment theory, a multi-dimensional grassland fire risk index (MGFRI) was proposed by integrating weighted comprehensive method, analytic hierarchy process, and fuzzy gamma method into natural disaster risk index. The developed MGFRI will be an easily understandable tool to manage grassland fire by comparing the risk of regions in the northern China and relative contributions of various factors, for example, hazard, exposure, vulnerability, and management ability. A scale of one to five was derived to measure the risk degree. It shows that 4.4?% of grassland falls in the category of ??very high?? risk, followed by 9.6, 19.1, 60.9, and 5.9?%, respectively, in the categories ??high??, ??middle??, ??low??, and ??very low??. The assessment results show reliability by test. The results in this study are intended to support local, provincial, and national government agencies to: (1) make resource allocation decisions; (2) make high-level planning decisions; and (3) raise public awareness of grassland fire risk, its causes, and ways to manage it.     

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.     

矿井水害防控远程服务云平台构建与应用

煤矿水害严重制约煤炭资源安全高效开发。针对我国煤矿开采面临的典型顶板、底板和老空水害问题,现阶段矿井水害防治主要开展水害危险性评价、涌水量预测、水害监测预警及水害探查与治理等工作,智能化程度不高。为了解决煤矿企业现场水害防治不同阶段研究与决策的智能化需求,通过将煤矿水害防治与“大数据”“数字化矿山”“互联网+”“云服务平台”等新理念、新技术进行融合,设计开发了基于多源数据融合的矿井水害防控远程服务云平台,实现水文地质信息管理、水害风险分析评价、水害防治方案设计、水害监测数据分析与智能预警、水灾事故辅助决策以及随时随地多部门多端协同,构建形成“互联网+水害防治智慧服务”新模式。矿井水害防控远程服务云平台实现了煤矿水害防治方案的科学、快速、精准制定,提高了矿井水害防治技术工作管理水平,为煤矿安全高效开采提供可靠的技术平台支撑。      

中国旱灾农业承灾体脆弱性诊断与评价

旱灾是世界上影响面最广、造成农业损失最大的自然灾害类型，世界近一半的国家干旱严重。中国旱灾频繁，每年旱灾损失占各种自然灾害损失的15%以上，随着人口和农业的快速发展，农业承灾体脆弱性对灾情的放大也在增加。基于灾害系统理论，从致灾因子和耕地承灾体的区域组合角度，在旱灾频发高值区，选择雨养农业、灌溉农业和水田农业为主要承灾体类型，构建了农业旱灾脆弱性生产压力和生活压力，灾前—灾中易损性和灾中—灾后适应性等农业旱灾承灾体脆弱性诊断指标体系。提出脆弱性评价的区域模型，即：雨养农业的易损—适应模型（兴和）、灌溉农业的生产—生活压力模型（邢台）和水田农业的需水—灌水模型（鼎城）。基于农业承灾体脆弱性评价，提出制定适应降水变化的波动土地利用结构调整区域政策、建立农业生态—生产范式、建立“水银行”管理机制、建立用水效益和开源节流的评估体系以及加强“截水—抽水—控水”为一体的灌溉系统工程建设，提高灌溉应急能力等对策，以期为农业旱灾的防御和区域粮食安全决策提供科学依据。     

An approach for measuring social vulnerability in context: The case of flood hazards in Muzarabani district,Zimbabwe

Understanding the complexity of vulnerability to disasters, including those triggered by floods, droughts and epidemics is at the heart of disaster risk reduction. Despite its importance in disaster risk reduction, there remains a paucity of approaches that contribute to our understanding of social vulnerability that is hidden in dynamic contextual conditions. The study demonstrates an accessible means to assessing the spatial variation of social vulnerability to flood hazards and related for the context of Muzarabani district in northeast Zimbabwe. The study facilitated local identification with residents of variables contributing to social vulnerability and used the principal component analysis (PCA) technique to develop a social vulnerability index (SoVI). Using ArcMap10.2 geographic information systems (GIS) tool, the study mapped composite SoVI at the ward level. The results showed that Muzarabani district is socially vulnerable to hazards. The social vulnerability is influenced by a variety of economic, social and institutional factors that vary across the wards. Quantifying and visualising social vulnerability in Muzarabani provides useful information for decision makers to support disaster preparedness and mitigation programmes. The approach shows how spatially distributed multivariate vulnerability, as grounded in interpretations at local level, can be quantitatively derived for contexts such as those of Muzarabani. The study findings can inform disaster risk reduction communities and cognate disciplines on quantitative assessments for managing hazard vulnerability where these have hitherto not been developed.     

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.