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1.
Recent destructive flood events and projected increases in flood risks as a result of climate change in many regions around the world demonstrate the importance of improving flood risk management. Flood-proofing of buildings is often advocated as an effective strategy for limiting damage caused by floods. However, few empirical studies have estimated the damage that can be avoided by implementing such flood damage mitigation measures. This study estimates potential damage savings and the cost-effectiveness of specific flood damage mitigation measures that were implemented by households during major flood events in France. For this purpose, data about flood damage experienced and household flood preparedness were collected using a survey of 885 French households in three flood-prone regions that face different flood hazards. Four main conclusions can be drawn from this study. First, using regression analysis results in improved estimates of the effectiveness of mitigation measures than methods used by earlier studies that compare mean damage suffered between households who have, and who have not, taken these measures. Second, this study has provided empirical insights showing that some mitigation measures can substantially reduce damage during floods. Third, the effectiveness of the mitigation measures is very regional dependent, which can be explained by the different characteristics of the flood hazard in our sample areas that experience either slow onset river flooding or more rapid flash and coastal flooding. Fourth, the cost-efficiency of the flood damage mitigation measures depends strongly on the flood probability faced by households.  相似文献   

2.
为了开展客观定量的暴雨洪涝灾害评估,探讨了基于暴雨洪涝淹没模型的暴雨洪涝灾害损失评估业务流程,其核心环节有两部分:估算因降水造成的淹没范围和建立适用的经济损失评估模型。其中暴雨洪涝淹没模型以最大坡降算法和曼宁公式计算暴雨洪涝汇流过程,通过给定汇流时间得到研究区域的淹没面积和水深;经济损失评估模型由直接经济损失和间接经济损失构成,直接经济损失由淹没范围内各类财产的价值乘以其相应的损失率得到。以武汉市江夏区2010年7月一次暴雨洪涝灾害过程为例给出了整个评估流程的实现过程,结果表明基于暴雨洪涝淹没模型的洪涝灾害损失评估业务流程物理意义清楚,表达了暴雨-径流-洪涝灾害全过程,可用以提高洪涝灾害影响评估的定量化程度,同时也为暴雨洪涝风险管理提供一定的依据。  相似文献   

3.
Probabilistic assessment of flood risks using trivariate copulas   总被引:6,自引:2,他引:4  
In this paper, a copula-based methodology is presented for probabilistic assessment of flood risks and investigated the performance of trivariate copulas in modeling dependence structure of flood properties. The flood is a multi-attribute natural hazard and is characterized by mutually correlated flood properties peak flow, volume, and duration of flood hydrograph. For assessing flood risk, many studies have used bivariate analysis, but a more effective assessment can be possible considering all three mutually correlated flood properties simultaneously. This study adopts trivariate copulas for multivariate analysis of flood risks, and applied to a case study of flood flows of Delaware River basin at Port Jervis, NY, USA. On evaluation of various probability distributions for representation of flood variables, it is found that the flood peak flow and volumes can be best represented by Fréchet distribution, whereas flood duration by log-normal distribution. The joint distribution is modeled using four trivariate copulas, namely, three fully nested form of Archimedean copulas: Clayton, Gumbel–Hougaard, Frank copulas; and one elliptical copula: Student’s t copula. Based on distance-based performance measures, graphical tests, and tail-dependence measures, it is found that the Student’s t copula best representing the trivariate dependence structure of flood properties as compared to the other copulas. Similar results are found for bivariate copula modeling of flood variables pairs, where Student’s t copula performed better than the other copulas. The obtained copula-based joint distributions are used for multivariate analysis of flood risks, in terms of primary and secondary return periods. The resultant trivariate return periods are compared with univariate and bivariate return periods, and addressed the necessity of multivariate flood risk analysis. The study concludes that the trivariate copula-based methodology is a viable choice for effective risk assessment of floods.  相似文献   

4.
C. S. Joy 《Climatic change》1993,25(3-4):335-351
Four surveys were conducted to assess the cost of direct and indirect flood damage to the New South Wales town of Nyngan, which was inundated in the 4–6 hour period after its flood protection levees were breached on 23 April 1990. A survey of flood damage to 24 residential properties, 14 commercial properties and 6 public authority properties was made by personal inspection. Surveys of flood damage to other public properties, of the worth of the volunteer effort in the evacuation, clean-up and recovery phases of the disaster, and of the value of donated goods and money were made by telephone and letter. The results of all surveys are presented and discussed. The use of a computer model to estimate property damage throughout the flooded area is described. Finally, the total cost of flood damage in Nyngan ($47.3 million) is dissected by type of damage, property sector and community sector.  相似文献   

5.
D. I. Smith 《Climatic change》1993,25(3-4):319-333
Most scenarios of greenhouse climate change are obtained from general circulation models. These provide poor information on changes to extreme events. It is therefore, difficult to convert changes of flood frequency into their impact on flood damages. The procedures for estimating urban flood losses are outlined. Australian case studies illustrate the possible effects of greenhouse-induced changes in comparison to the variability under current climate; changes in urban flood losses for small and large catchments; and the implications for dam design. In all cases, relatively small increases in flood frequency would cause significant increases in loss. The policy implications are outlined, it must not be assumed that the availability of more precise data on future flood frequencies will be matched by policy response in the field of flood plain management.  相似文献   

6.
Modeling flood event characteristics using D-vine structures   总被引:1,自引:0,他引:1  
The authors investigate the use of drawable (D-)vine structures to model the dependences existing among the main characteristics of a flood event, i.e., flood volume, flood peak, duration, and peak time. Firstly, different three- and four-dimensional probability distributions were built considering all the permutations of the conditioning variables. The Frank copula was used to model the dependence of each pair of variables. Then, the appropriate D-vine structures were selected using information criteria and a goodness-of-fit test. The influence of varying the data length on the selected D-vine structure was also investigated. Finally, flood event characteristics were simulated using the four-dimensional D-vine structure.  相似文献   

7.
山西是水资源缺乏省份之一。为了较准确掌握旱涝成因,本文对气候旱涝与农业旱涝的不同意义作了分析,并对几种旱涝指标及气候与农业旱涝的差别进行了简述,以进一步发展节水农业,促进水资源的合理利用。  相似文献   

8.
Fluvial flood risk in Europe in present and future climates   总被引:2,自引:0,他引:2  
In this work we evaluate the implications of climate change for future fluvial flood risk in Europe, considering climate developments under the SRES A2 (high emission) and B2 (low emission) scenario. We define flood risk as the product of flood probability (or hazard), exposure of capital and population, and vulnerability to the effect of flooding. From the European flood hazard simulations of Dankers and Feyen (J Geophys Res 114:D16108. doi:, 2009) discharges with return periods of 2, 5, 10, 20, 50, 100, 250 and 500 years were extracted and converted into flood inundation extents and depths using a planar approximation approach. Flood inundation extents and depths were transformed into direct monetary damage using country specific flood depth-damage functions and land use information. Population exposure was assessed by overlaying the flood inundation information with data on population density. By linearly interpolating damages and population exposed between the different return periods, we constructed damage and population exposure probability functions under present and future climate. From the latter expected annual damages (EAD) and expected annual population exposed (EAP) were calculated. To account for flood protection the damage and population exposure probability functions were truncated at design return periods based on the country GDP/capita. Results indicate that flood damages are projected to rise across much of Western Europe. Decreases in flood damage are consistently projected for north-eastern parts of Europe. For EU27 as a whole, current EAD of approximately €6.4 billion is projected to amount to €14–21.5 billion (in constant prices of 2006) by the end of this century, depending on the scenario. The number of people affected by flooding is projected to rise by approximately 250,000 to 400,000. Notwithstanding these numbers are subject to uncertainty, they provide an indication of potential future developments in flood risk in a changing climate.  相似文献   

9.
洪水再生稻高产栽培技术研究   总被引:1,自引:0,他引:1       下载免费PDF全文
2007年7月8—9目,四川省泸县发生了特大洪涝灾害,嘉明和福集2镇洪水淹没面积多达8000hm^2,淹没时间为60-92h,处于不同生育期的水稻受到了不同程度的生长抑制。通过野外追踪调查和示范区比较试验,提出在洪灾后结合水稻生育期、淹没时间、淹水深度、植株长势等指标判断水稻受害程度,并以各指标为依据果断采取相应的抗灾、减灾对策。初步分析认为,蓄留洪水再生稻是行之有效的灾后生产自救措施,同时揭示了早割低留桩、晚割高留桩、早割多施肥、晚割少施肥、保持浅水层和防治病虫害是蓄留洪水再生稻的关键技术。  相似文献   

10.
通过Z指数法和降水资料对昌吉地区8个国家级气象观测站37a(1971—2007年)的旱涝变化趋势和时空分布特征研究,发现昌吉州各地降水和旱涝变化具有一致性.20世纪70年代以来,各地具有由偏旱转为偏涝的趋势,其中,西部地区的偏涝速度最快,东部地区的偏涝速度最慢.各地出现干旱的频率高于雨涝的频率,其中,西部出现干旱频率最大,东部最小;相反,西部出现雨涝的频率最小,东部最大.  相似文献   

11.
Extreme flood on the Danube River in 2006   总被引:2,自引:0,他引:2  
Causes and features of an extreme flood on the Danube River in spring and summer 2006 are considered. The water levels at some gauge stations on the Middle Danube and at most gauge stations on the Lower Danube exceeded maxima observed during previous 100–130 years. The flood on the Lower Danube lasted from March to July and led to widespread inundations and damage. The flood was caused by melt of large amounts of snow accumulated in the river basin during winter, very warm spring, and abundant rains. In recent decades, the occurrence frequency of extreme hydrological events on the Danube River (large spring-summer floods and catastrophic rainfall freshets) has increased.  相似文献   

12.
Abstract

Floods are major natural disasters in Canada and worldwide. Although technology has reduced the flood hazard in many areas, the world death toll from floods in recent decades still has averaged 4680 per year. During the summer of 1993, flooding in the U.S.A. caused an estimated $12 billion damage. These statistics confirm that floods are a major natural disaster.

This paper reviews the hydrometeorological aspects of the hazard associated with rainstorm, urban, ice‐jam, and snowmelt floods. The hazard element is highest for floods with rapid onsets such as rainstorm, urban, and ice‐jam floods. Although snowmelt floods are common throughout Canada, their slower onset times reduce their risk potential.

To reduce the risk of the flood hazard, society must have access to statistical information for adequate planning and design, and forecasts for issuing warnings and implementing evacuation strategies. Flood design statistics and forecast models are discussed relative to each major flood type. The paper also describes historical flood frequency trends and discusses the implications of climatic warming for future floods. The paper concludes with a brief discussion of some knowledge gaps and research needs.  相似文献   

13.
In this study, we investigated the spatial and temporal characteristics of precipitation heterogeneity and meteorological drought/flood in China based on the precipitation-concentration degree (PCD) and the integrated meteorological drought index. We also studied the corresponding relationship between precipitation heterogeneity and meteorological drought/flood in China by using Spearman correlation analysis and canonical correlation analysis. The results show that: (1) The severity of meteorological drought/flood exhibited a spatial pattern of gradual change from Northwest to Southeast China. (2) With a higher PCD and a delayed precipitation-concentration period (PCP), the drought severity was higher but the flood severity was lower. In contrast, with a lower PCD and an early PCP, the drought severity was lower and the flood severity was higher. (3) The correlation between meteorological drought/flood and PCD was significant. The higher the PCD, the longer the duration of drought and more frequently, the droughts occurred, and vice versa. It is concluded that PCD and PCP were significantly correlated with meteorological drought/flood in China.  相似文献   

14.
华北汛期降水的年代际减少,一直是气候学领域关心的重要课题之一。本文扼要回顾了华北汛期旱涝研究的最新代表性成果,主要包括华北汛期起讫的客观识别、华北汛期降水多时间尺度的变化特征、华北汛期降水变化与大气遥相关型的关系,以及华北汛期降水量增多趋势的停滞等。在此基础之上,归纳和总结了该领域需要继续深入研究的问题,如:华北汛期起讫时间的统一性;在华北汛期降水年代际变少的归因分析中,其年际振荡成分衰减的物理原因;华北汛期降水年代际变多趋势停滞的原因;华北汛期降水何时恢复增多等科学问题。  相似文献   

15.
利用1961—2020年江西省逐日降水资料,基于Z指数分析确定了适用于江西省的旱涝指标。运用M-K检验、小波分析和EOF等方法分析了江西省旱涝时空分布特征。结果表明,1961—2020年江西省降水量年际变化大,20世纪90年代出现突变,但未出现显著的持续增加或减少。江西省干旱、雨涝事件存在准20 a主周期,从90年代开始偏涝年份明显增多,且雨涝呈增强的趋势。江西省旱涝主要存在4种空间分布型,分别为全区型、北涝(旱)南旱(涝)型、西涝(旱)东旱(涝)型、中心涝(旱)南北旱(涝)型,累计贡献率为83.61%。Z指数作为表征江西省旱涝指标的方法具有一定的适用性。  相似文献   

16.
气候变化情景下澜沧江流域极端洪水事件研究   总被引:1,自引:0,他引:1  
以澜沧江流域为研究对象,基于ISIMIP2b协议中提供的GFDL-ESM2M、HadGEM2-ES、IPSL-CM5A-LR、MIROC5这4种全球气候模式,通过4种模式的输出数据耦合VIC模型,分析4种模式在历史时期(1961—2005年)对洪峰洪量极值(年最大洪峰流量、3 d最大洪量)、极端洪水的模拟能力,比较RCR2.6和RCP6.0两种情景下未来时期(2021—2050年)年均径流量较基准期(1971—2000年)的变化情况,并结合P-III型分布曲线预估了澜沧江流域在两种情景下未来时期极端洪水的强度变化情况。结果表明:VIC模型在该流域能够较好地模拟极端洪水;HadGEM2-ES和MIROC5两种气候模式的输出数据在澜沧江流域有较好的径流模拟适用性;在RCP2.6情景下,澜沧江流域未来时期年均径流量没有明显变化,可能会有略微的增加,而在RCP6.0情景下,未来时期年均径流量有较大可能增加;澜沧江流域未来时期极端洪水较基准期,在RCP2.6情景下无明显变化,而在RCP6.0情景下,洪峰、洪量增加的可能性较大,极端洪水频率和强度也较大可能增加。  相似文献   

17.
Floodplain restoration offers an opportunity to enhance communities’ resilience to flooding. However, the degree to which these interventions mitigate damages is often unknown, and identifying the best locations for implementation is a challenge. Further, the extent to which the benefits of flood mitigation are equitably distributed within communities is rarely considered in restoration projects. Here, we develop a novel framework to optimize investments in floodplain restoration that maximizes the utility of avoided damages from flood inundation for a range of budgetary constraints. We estimate the expected reduction in flood damages from restoration interventions by integrating a hydraulic flood model and an economic damage cost model. Using equity-weighted utility functions, we explicitly evaluate how the value of reduction in flood damages varies for different property owners. We demonstrate the potential of this approach in the Lewis Creek watershed, located in Vermont, USA. Under all optimal scenarios, the benefits of avoided flood damages over a 100-year time period outweigh the costs of restoration by at least 5-to-1. Floodplain restoration has the potential to reduce the present value of damages by up to $400,000, a 5% decrease from the baseline, at a cost of only $75,000. We also show that the equity-weighted utility of flood mitigation increase when restoration interventions protect the lowest-income property owners, particularly those who live in mobile homes. Together, our results illuminate the importance of evaluating the distribution of benefits and costs associated with alternative restoration strategies, as well as underscore the capacity for floodplain restoration to build resilience to flooding.  相似文献   

18.
Estimates of future flood hazards made under the assumption of stationary mean sea level are biased low due to sea-level rise (SLR). However, adjustments to flood return levels made assuming fixed increases of sea level are also inadequate when applied to sea level that is rising over time at an uncertain rate. SLR allowances—the height adjustment from historic flood levels that maintain under uncertainty the annual expected probability of flooding—are typically estimated independently of individual decision-makers’ preferences, such as time horizon, risk tolerance, and confidence in SLR projections. We provide a framework of SLR allowances that employs complete probability distributions of local SLR and a range of user-defined flood risk management preferences. Given non-stationary and uncertain sea-level rise, these metrics provide estimates of flood protection heights and offsets for different planning horizons in coastal areas. We illustrate the calculation of various allowance types for a set of long-duration tide gauges along U.S. coastlines.  相似文献   

19.
中国南方旱涝时空分布特征分析   总被引:16,自引:5,他引:11  
郭锐  智协飞 《气象科学》2009,29(5):598-605
用1955-2001年我国南方81个测站全年逐月降水量资料,利用Z指数确定单站旱涝等级.结果表明,春季华中地区和两广交界处更易发生干旱,湖南与华南沿海地区降水偏多,出现洪涝的几率较大;夏秋两季106~115 °E,23~32 °N区域和四川西北部地区出现干旱的频率较高,洪涝频率较高地区主要集中在长江流域,同时四川南部、云南中部、华南沿海出现大涝的频率较高;冬季南方大部分地区发生旱涝的频率较小,干旱多发区主要集中在云南中部以及江苏、安徽两省,西南部出现降水偏多的频率较高.通过对降水资料的EOF分析发现,我国南方春季降水主要为南旱北涝、南涝北旱两种分布型.夏季降水区域主要分为长江流域与华南沿海地区、云南两个区域,而秋、冬季南方降水分布比较均匀,表现为南方一致旱或涝.  相似文献   

20.
Flooding is the most costly natural hazard in Europe. Climatic and socioeconomic change are expected to further increase the amount of loss in the future. To counteract this development, policymaking, and adaptation planning need reliable large-scale risk assessments and an improved understanding of potential risk drivers.In this study, recent datasets for hazard and flood protection standards are combined with high resolution exposure projections and attributes of vulnerability derived from open data sources. The independent and combined influence of exposure change and climate scenarios rcp45 and rcp85 on fluvial flood risk are evaluated for three future periods centered around 2025, 2055 and 2085. Scenarios with improved and neglected private precaution are examined for their influence on flood risk using a probabilistic, multivariable flood loss model — BN-FLEMOps — to estimate fluvial flood losses for residential buildings in Europe.The results on NUTS-3 level reveal that urban centers and their surrounding regions are the hotspots of flood risk in Europe. Flood risk is projected to increase in the British Isles and Central Europe throughout the 21st century, while risk in many regions of Scandinavia and the Mediterranean will stagnate or decline. Under the combined effects of exposure change and climate scenarios rcp45, rcp85, fluvial flood risk in Europe is estimated to increase seven-fold and ten-fold respectively until the end of the century. Our results confirm the dominance of socioeconomic change over climate change on increasing risk. Improved private precautionary measures would reduce flood risk in Europe on an average by 15%. The quantification of future flood risk in Europe by integrating climate, socioeconomic and private precaution scenarios provides an overview of risk drivers, trends, and hotspots. This large-scale comprehensive assessment at a regional level resolution is valuable for multi-scale risk-based adaptation planning.  相似文献   

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