共查询到20条相似文献，搜索用时 125 毫秒
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很多城市缺乏洪灾灾情资料,导致缺少洪灾损失量化的有效手段。为满足城市洪涝日益严峻的风险管理需求,亟需缺灾情资料城市的洪灾损失定量评估方法。提出了"因子变异-动态比拟-目标驱动-情景拟合"的缺灾情资料洪灾损失率函数构建方法:借鉴等比例替代思想,采用多引用对象和多特征指标构建变异比拟因子;建立以变差系数最小为目标的动态比拟方法,形成移植样本矩阵;以Beta分布概率最大为驱动目标,确定水深-损失率拟合序列;设置多拟合情景,以拟合相关系数最大为准则,优选洪灾损失率函数。以郑州市为例,模拟4种土地利用类型的洪灾损失率函数,结果表明,本文提出的缺资料城市洪灾损失率函数构建方法可行,特征组合指标呈现动态变化性,多种函数组合拟合效果最优。 相似文献
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如何快速,有效地进行投保户洪涝灾害损失评估是保险行业急需解决的一个重要课题.从洪涝灾害的成灾机理出发,针对保险公司对具体受灾体理赔需求,提出了计算每个投保户洪灾损失率方法,建立基于遥感(RS)和地理信息系统(GIS)的城市财产保险洪涝灾害损失评估模型.建模时较全面地考虑了与投保物性质有关的承灾体易损度和与投保物所处环境有关的地基承载力等因素,并使用RS/GIS将其定量化提取.最后使用广东省深圳市洪灾数据进行模型检验.验证结果表明,模型对于各个投保户均能得到较好的精度. 相似文献
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新疆洪灾时间序列突变及其气候原因分析 总被引：6，自引：2，他引：4
利用统计方法对新疆农田洪灾成灾面积和洪灾次数时间序列进行了非参数突变检验, 发现新疆农田洪灾成灾面积和洪灾次数时间序列在1980年代中后期发生了明显的突变.突变现象在洪灾直接经济损失上也有明显表现, 主要表现为洪灾直接经济损失在1980年代中后期出现了明显的差异, 即1980年代中后期以前损失较低, 之后急剧增大.在分析了洪灾序列和降水序列的相关关系的基础上, 认为1980年代中后期新疆洪灾损失突变的主要原因之一是此时期新疆气候发生了由干到湿的转折. 相似文献
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吉林省乃我国产粮大省之一，然洪灾频临，损失重大，为减少洪灾损失，本文从工程措施；非工程措施；增强灾害意识；树立正确的防兴指导思想等方面，提出了具体的对策，以地减轻洪灾损失有所裨益。 相似文献
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为充分理解全球洪涝灾害的时空演变规律,基于长时间序列全球历史洪灾数据,运用数理统计和GIS空间分析方法,在不同空间尺度和年代际、年际的时间尺度上,全面分析了1980—2020年重大洪涝灾害的时空特征。结果表明：(1)全球洪灾次数在21世纪前10 a达到峰值,死亡和影响人口在1990s达到峰值,累计经济损失在2010s达到峰值,次均经济损失在1990s和2010s最高;(2)洪灾发生次数及造成的经济损失在1980—2020年期间呈显著上升趋势,每次洪灾造成的人口损失呈现下降趋势;(3)亚洲洪涝灾害严重,洪灾的发生次数、死亡人数、影响人口及经济损失的累计值分别占全球总数的41%、68%、95%和63%,然而包括中国在内的亚洲诸多国家的洪灾人口损失呈下降趋势;(4)全球重大洪灾呈东西向分布,灾害重心有南移趋势,洪灾由集中趋于分散,影响区域逐渐变广。 相似文献
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山洪灾害来势凶猛、预见期短、破坏性大,如何获得较长的预见期,最大程度减小洪灾损失十分重要。雨量预警指标也可叫临界雨量(强)就是解决山洪灾害预报、增加洪灾预见期的基础指标。通过对乡宁县地质、地貌、历史洪灾、暴雨等资料的分析整理,采用水利部规定的计算方法,结合乡宁县现状实际,确定了全县21处小流域山洪灾害防治雨量预警指标,为今后山洪灾害防治群策群防提供科学决策依据。 相似文献
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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。 相似文献
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Balqis M. Rehan 《Natural Hazards》2018,91(3):1039-1057
Economic damage assessment for flood risk estimation is established in many countries, but attentions have been focused on macro- or meso-scale approaches and less on micro-scale approaches. Whilst the macro- or meso-scale approaches of flood damage assessment are suitable for regional- or national-oriented studies, micro-scale approaches are more suitable for cost–benefit analysis of engineered protection measures. Furthermore, there remains lack of systematic and automated approaches to estimate economic flood damage for multiple flood scenarios for the purpose of flood risk assessment. Studies on flood risk have also been driven by the assumption of stationary characteristic of flood hazard, hence the stationary-oriented vulnerability assessment. This study proposes a novel approach to assess vulnerability and flood risk and accounts for adaptability of the approach to nonstationary conditions of flood hazard. The approach is innovative in which an automated concurrent estimation of economic flood damage for a range of flood events on the basis of a micro-scale flood risk assessment is made possible. It accounts for the heterogeneous distribution of residential buildings of a community exposed to flood hazard. The feasibility of the methodology was tested using real historical flow records and spatial information of Teddington, London. Vulnerability curves and residual risk associated with a number of alternative extents of property-level protection adoptions are estimated by the application of the proposed methodology. It is found that the methodology has the capacity to provide valuable information on vulnerability and flood risk that can be integrated in a practical decision-making process for a reliable cost–benefit analysis of flood risk reduction options. 相似文献
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Recent flood events in Switzerland and Western Austria in 2005 were characterised by an increase in impacts and associated
losses due to the transport of woody material. As a consequence, protection measures and bridges suffered considerable damages.
Furthermore, cross-sectional obstructions due to woody material entrapment caused unexpected flood plain inundations resulting
in severe damage to elements at risk. Until now, the transport of woody material is neither sufficiently taken into account
nor systematically considered, leading to prediction inaccuracies during the procedure of hazard mapping. To close this gap,
we propose a modelling approach that (1) allows the estimation of woody material recruitment from wood-covered banks and flood
plains; (2) allows the evaluation of the disposition for woody material entrainment and transport to selected critical configurations
along the stream and that (3) enables the delineation of hazard process patterns at these critical configurations. Results
from a case study suggest the general applicability of the concept. This contribution to woody material transport analysis
refines flood hazard assessments due to the consideration of woody material transport scenarios. 相似文献
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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. 相似文献
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A Probabilistic Modelling System for Assessing Flood Risks 总被引：4，自引：2，他引：4
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. 相似文献
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Public perception of flood hazard and flood risk in Iceland: a case study in a watershed prone to ice-jam floods 总被引：1，自引：1，他引：0
Understanding and improving the public perception has become an important element in the management of flood risk worldwide.
In Iceland, studying perception of flood hazard and flood risk is, however, in its early stages. This paper presents a case
study on the public perception of flood hazard and flood risk in an Icelandic town prone to ice-jam floods. Awareness of the
population regarding historical inundations, self estimation of flood risk and worry is considered. The factual knowledge
of the residents is deconstructed in flood hazard parameters accessible to the lay population: number of events, dates, genesis
and boundaries. The performance of the respondents is rated for each parameter and the influence of several predictors evaluated.
The research shows three significant patterns: there is poor awareness and little worry about historical inundations in the
area; experience of the past flooding events in town is the most effective source of knowledge; awareness, risk estimation
and worry are not correlated. 相似文献
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The production of flood hazard assessment maps is an important component of flood risk assessment. This study analyses flood hazard using flood mark data. The chosen case study is the 2013 flood event in Quang Nam, Vietnam. The impacts of this event included 17 deaths, 230 injuries, 91,739 flooded properties, 11,530 ha of submerged and damaged agricultural land, 85,080 animals killed and widespread damage to roads, canals, dykes and embankments. The flood mark data include flood depth and flood duration. Analytic hierarchy process method is used to assess the criteria and sub-criteria of the flood hazard. The weights of criteria and sub-criteria are generated based on the judgements of decision-makers using this method. This assessment is combined into a single map using weighted linear combination, integrated with GIS to produce a flood hazard map. Previous research has usually not considered flood duration in flood hazard assessment maps. This factor has a rather strong influence on the livelihood of local communities in Quang Nam, with most agricultural land within the floodplain. A more comprehensive flood hazard assessment mapping process, with the additional consideration of flood duration, can make a significant contribution to flood risk management activities in Vietnam. 相似文献
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The frequency in occurrence and severity of floods has increased globally. However, many regions around the globe, especially in developing countries, lack the necessary field monitoring data to characterize flood hazard risk. This paper puts forward methodology for developing flood hazard maps that define flood hazard risk, using a remote sensing and GIS-based flood hazard index (FHI), for the Nyamwamba watershed in western Uganda. The FHI was compiled using analytical hierarchy process and considered slope, flow accumulation, drainage network density, distance from drainage channel, geology, land use/cover and rainfall intensity as the flood causative factors. These factors were derived from Landsat, SRTM and PERSIANN remote sensing data products, except for geology that requires field data. The resultant composite FHI yielded a flood hazard map pointing out that over 11 and 18% of the study area was very highly and highly susceptible to flooding, respectively, while the remaining area ranged from medium to very low risk. The resulting flood hazard map was further verified using inundation area of a historical flood event in the study area. The proposed methodology was effective in producing a flood hazard map at the watershed local scale, in a data-scarce region, useful in devising flood mitigation measures. 相似文献
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Effect of uncertainty in land use, damage models and inundation depth on flood damage estimates 总被引：8，自引：2，他引：6
With the recent transition to a more risk-based approach in flood management, flood risk models—being a key component in flood
risk management—are becoming increasingly important. Such models combine information from four components: (1) the flood hazard
(mostly inundation depth), (2) the exposure (e.g. land use), (3) the value of elements at risk and (4) the susceptibility
of the elements at risk to hydrologic conditions (e.g. depth–damage curves). All these components contain, however, a certain
degree of uncertainty which propagates through the calculation and accumulates in the final damage estimate. In this study,
an effort has been made to assess the influence of uncertainty in these four components on the final damage estimate. Different
land-use data sets and damage models have been used to represent the uncertainties in the exposure, value and susceptibility
components. For the flood hazard component, inundation depth has been varied systematically to estimate the sensitivity of
flood damage estimations to this component. The results indicate that, assuming the uncertainty in inundation depth is about
25 cm (about 15% of the mean inundation depth), the total uncertainty surrounding the final damage estimate in the case study
area can amount to a factor 5–6. The value of elements at risk and depth–damage curves are the most important sources of uncertainty
in flood damage estimates and can both introduce about a factor 2 of uncertainty in the final damage estimates. Very large
uncertainties in inundation depth would be necessary to have a similar effect on the uncertainty of the final damage estimate,
which seem highly unrealistic. Hence, in order to reduce the uncertainties surrounding potential flood damage estimates, these
components deserve prioritisation in future flood damage research. While absolute estimates of flood damage exhibit considerable
uncertainty (the above-mentioned factor 5–6), estimates for proportional changes in flood damages (defined as the change in
flood damages as a percentage of a base situation) are much more robust. 相似文献
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Flooding in urban area is a major natural hazard causing loss of life and damage to property and infrastructure. The major causes of urban floods include increase in precipitation due to climate change effect, drastic change in land use–land cover (LULC) and related hydrological impacts. In this study, the change in LULC between the years 1966 and 2009 is estimated from the toposheets and satellite images for the catchment of Poisar River in Mumbai, India. The delineated catchment area of the Poisar River is 20.19 km2. For the study area, there is an increase in built-up area from 16.64 to 44.08% and reduction in open space from 43.09 to 7.38% with reference to total catchment area between the years 1966 and 2009. For the flood assessment, an integrated approach of Hydrological Engineering Centre-Hydrological Modeling System (HEC-HMS), HEC-GeoHMS and HEC-River analysis system (HEC-RAS) with HEC-GeoRAS has been used. These models are integrated with geographic information system (GIS) and remote sensing data to develop a regional model for the estimation of flood plain extent and flood hazard analysis. The impact of LULC change and effects of detention ponds on surface runoff as well as flood plain extent for different return periods have been analyzed, and flood plain maps are developed. From the analysis, it is observed that there is an increase in peak discharge from 2.6 to 20.9% for LULC change between the years 1966 and 2009 for the return periods of 200, 100, 50, 25, 10 and 2 years. For the LULC of year 2009, there is a decrease in peak discharge from 10.7% for 2-year return period to 34.5% for 200-year return period due to provision of detention ponds. There is also an increase in flood plain extent from 14.22 to 42.5% for return periods of 10, 25, 50 and 100 years for LULC change between the year 1966 and year 2009. There is decrease in flood extent from 4.5% for 25-year return period to 7.7% for 100-year return period and decrease in total flood hazard area by 14.9% due to provisions of detention pond for LULC of year 2009. The results indicate that for low return period rainfall events, the hydrological impacts are higher due to geographic characteristics of the region. The provision of detention ponds reduces the peak discharge as well as the extent of the flooded area, flood depth and flood hazard considerably. The flood plain maps and flood hazard maps generated in this study can be used by the Municipal Corporation for flood disaster and mitigation planning. The integration of available software models with GIS and remote sensing proves to be very effective for flood disaster and mitigation management planning and measures. 相似文献