Flood management in Canada at the crossroads

Abstract

Although Canadian flood management efforts have gained worldwide recognition, flood damages continue to increase. The current practice for preventing, responding to and recovering from floods in Canada is described by focusing attention on the 1997 Red River and 1996 Saguenay River floods. A set of cultures is identified that contribute to the trend of increasing flood damages. These include a culture of conflict, a culture of land development, a culture that impeded native people from easily implementing flood management programs, a culture of institutional fragmentation and a culture of dependency. These foster an inevitable cycle of increasing flood damages. The potential of recent proposals made by Emergency Preparedness Canada and the Insurance Bureau of Canada to address these cultures is assessed. While these documents represent significant progress, they continue to adopt an intermittent project rather an ongoing program perspective, fail to identify the need to adopt specific initiatives tailored for aboriginal communities, and ignore the need to enhance the operational capacity of relevant public and private participants. Addressing these requirements will further reduce future losses and vulnerability.     

Flood insurance and floodplain management: the US experience

Abstract

With over six million buildings located within the boundaries of the 100-yr floodplain, flood losses across the United States are widespread (88% of US counties experienced at least one flood disaster during the second half of the twentieth century). To deal with this problem, the federal government provides flood insurance through the National Flood Insurance Program, which was initiated by Congress in 1968 and amended significantly in 1969, 1973, and 1994. This article describes the US approach to flood insurance and notes a number of problems that have limited its effectiveness. Flood hazard identification is incomplete, and methods used are flawed. Mitigation has failed to contain increasing exposure to property damage in floods and coastal storms, and it has failed to markedly reduce exposure to loss of older buildings located in flood hazard areas. Market penetration of flood insurance is low, in spite of mandatory purchase requirements for new construction and the availability of subsidized insurance rates for older buildings located in flood-hazard areas. These problems, although serious, can be remedied through a variety of actions taken by governments at the federal, state, and local level.     

Local perception of infrequent,extreme upland flash flooding: prisoners of experience?

The United Kingdom has experienced several exceptional summer flash floods in recent years and there is growing concern about the frequency of such events and the preparedness of the population. This paper uses a case study of the upper Ryedale flash flood (2005) and questionnaire and interview data to assess local perceptions of upland flash flooding. Experience of a major flash flood may not be associated with increased flood risk perception. Despite local residents’ awareness of a trend towards wetter summers and more frequent heavy rainfall, the poor maintenance of rivers was more frequently thought to be a more significant factor influencing local flood risk than climate change. Such findings have important implications for the potential success of contemporary national flood policies, which have put greater emphasis on public responsibility for responding to flooding. This study recommends, therefore, the use of fresh participatory approaches to redistribute and raise awareness of locally‐held flood knowledge.     

Flood proneness and coping strategies: the experiences of two villages in Bangladesh

This paper explores peoples' indigenous survival strategies and assesses variations in people's ability to cope with floods in two flood‐prone villages in Bangladesh. It reveals that people continuously battle against flood vulnerability in accordance with their level of exposure and abilities, with varied strategies employed at different geophysical locations. The paper reports that people in an area with low flooding and with better socioeconomic circumstances are more likely to cope with impacts compared to people in areas with high and sudden flooding. Similarly, households' ability to cope varies depending on people's socioeconomic conditions, such as education, income and occupation. Although floods in Bangladesh generate socioeconomic misery and cause damage to the environment, health and infrastructure, people's indigenous coping strategies have helped them to reduce significantly their vulnerability. Such flood‐mitigating strategies should be well recognised and emphasised further via proper dissemination of information through an early‐warning system and subsequently external assistance.     

试析洪水灾害增长的社会因素

自然灾害的本质属性是社会问题。社会的发展,环境的改变以至防洪工程的兴建都影响以至增大灾害的损失。因此,减轻洪水灾害的有效途径,一方面要尽可能控制自然态洪水的泛滥,另一方面则应调整社会的发展布局、有关的对策和实践活动以适应洪水。我国的防洪方针应进一步从单纯注重调动工程手段去控制洪水,向工程与非工程防洪相结合的方向发展,动员全社会投入,从而有效地提高防洪减灾的能力。     

Trauma and short-fuse weather warning perceptions

The purpose of this research was to assess the importance of psychological trauma in understanding reactions to short lead time weather warnings. The research consisted of two case studies, one in Denver, Colorado and the other in Austin, Texas. A total of 61 individuals with 9 or greater traumas were compared to 281 non-trauma exposed individuals. Results demonstrated significant differences on questions related to general beliefs about flash floods and warning perceptions as well as reported anticipated actions during a flash flood at home. Results suggest high trauma exposure may lead to more threat sensitivity and a higher probability of initiated action in a home-based flash flood.     

Trauma and short-fuse weather warning perceptions

The purpose of this research was to assess the importance of psychological trauma in understanding reactions to short lead time weather warnings. The research consisted of two case studies, one in Denver, Colorado and the other in Austin, Texas. A total of 61 individuals with 9 or greater traumas were compared to 281 non-trauma exposed individuals. Results demonstrated significant differences on questions related to general beliefs about flash floods and warning perceptions as well as reported anticipated actions during a flash flood at home. Results suggest high trauma exposure may lead to more threat sensitivity and a higher probability of initiated action in a home-based flash flood.     

Environmental knowledge and human experience: using a historical analysis of flooding in Ireland to challenge contemporary risk narratives and develop creative policy alternatives

Focusing on three of the largest coastal cities in the Republic of Ireland, this paper highlights the importance of a historical analysis of flood hazards in contextualising current events and potential future risks. Over the last decade, the cities of Dublin, Cork and Galway have experienced several major coastal, river and pluvial floods. In the aftermath of these floods, two distinct but related narratives have dominated public discourse and official responses. The first narrative presents recent floods as unprecedented and as possible evidence of climate change. The second constructs floods primarily as natural events and assumes that the optimal means of reducing flood losses is to prevent flood events. In this paper, I suggest that these narratives are not supported by a historical analysis of exposure and vulnerability to flood hazards in Irish cities. This paper draws primarily on newspaper archives to construct a record of past flooding that challenges these narratives in several ways and in doing so offers lessons for similar cities in other countries. I contend that these narratives are perpetuated by a narrow form of knowledge production (quantitative risk assessment) and a narrow range of data (numeric instrumental records). Incorporating a broader range of sources and data types into risk and vulnerability assessments may illuminate more creative strategies for reducing both contemporary and future flood losses.     

Effects of the 2008 flood on economic performance and food security in Yemen: a simulation analysis

Extreme weather events such as floods and droughts can have devastating consequences for individual well being and economic development, in particular in poor societies with limited availability of coping mechanisms. Combining a dynamic computable general equilibrium model of the Yemeni economy with a household‐level calorie consumption simulation model, this paper assesses the economy‐wide, agricultural and food security effects of the 2008 tropical storm and flash flood that hit the Hadramout and Al‐Mahrah governorates. The estimation results suggest that agricultural value added, farm household incomes and rural food security deteriorated long term in the flood‐affected areas. Due to economic spillover effects, significant income losses and increases in food insecurity also occurred in areas that were unaffected by flooding. This finding suggests that while most relief efforts are typically concentrated in directly affected areas, future efforts should also consider surrounding areas and indirectly affected people.     

长江荆江分蓄洪区历史演变、前景和风险管理

依据社会经济统计数据、水文资料、遥感影像信息和实地调查资料，分析了荆江分蓄洪区在历史演变过程中形成的分洪与发展的矛盾及其在未来长江流域防洪体系中的重要作用，指出其风险管理的必要性。运用基于GIS栅格数据的二维水动力洪水动态演进模型，对荆江分蓄洪区1954年的分洪过程进行了模拟和验证，模拟了不同分洪规划方案下的洪水淹没范围，水深和水位，并结合现阶段社会经济发展情况，定量估算了农户和农业的分洪可能损失。在分洪损失评估基础上提出了荆江分蓄洪区引导人口合理发展、促进土地有效利用、开展防洪教育、实施洪水保险和确保安全运用预案等减轻洪水损失提高运用机率的洪水风险管理初步方案。     

The 1934 floods in Tabriz, N. W. Iran

The disastrous floods of July 1934 in Tabriz are examined in the context of the history of floodinginthe city, which is crossed by a dry stream bed liable to sudden Inundation by mountain torrents from the southeast. Few details of past events have survived, suggesting that relatively little significance has been attached to them. Typically, flood dykes were inadequately maintained. This neglect, combined with a radical alteration in urban topography after 1925, when broad straight avenues were constructed through the old heart of the city, led to serious losses from flooding twice in 1929 and again in 1934. Enhanced perception of the flood risk finally found expression in the adoption of large scale engineering measures to mitigate future events, including strengthening protective dykes and widening the river channel through the city. These works have reduced vulnerability to flooding from river overflow. No long-term detrimental Impact of the 1934 flood has been observed. Some of the physical and social parameters that have influenced the vulnerability of Tabrizinthe past continue to be present both there and elsewhere in Iran, and they may be characteristic also of other regions with comparable natural environments or in a similar stage of socio-economic development.     

How to get there? Assessing motorists’ flash flood risk perception on daily itineraries

Flash floods are characterized by their suddenness, fast and violent movement, rarity, small scale but high level of damage. They are particularly difficult to forecast accurately and there is little lead time for warning. This makes motorists especially vulnerable. Assuming that these flash flood hazard specificities may be the significant factors leading to difficulties for drivers to perceive danger, we used cognitive mapping combined with GIS data processing to assess motorists’ flash flood risk perception on their daily itineraries. The analysis of 200 mental maps collected allows planners to have maps highlighting dangerous areas where risk perception is weak and to identify reasons for this.     

How to get there? Assessing motorists' flash flood risk perception on daily itineraries

Flash floods are characterized by their suddenness, fast and violent movement, rarity, small scale but high level of damage. They are particularly difficult to forecast accurately and there is little lead time for warning. This makes motorists especially vulnerable. Assuming that these flash flood hazard specificities may be the significant factors leading to difficulties for drivers to perceive danger, we used cognitive mapping combined with GIS data processing to assess motorists' flash flood risk perception on their daily itineraries. The analysis of 200 mental maps collected allows planners to have maps highlighting dangerous areas where risk perception is weak and to identify reasons for this.     

Floods on opposite German borders

Abstract

The Rhine and the Oder rivers have many similarities. Both are subject to comparable hydroclimate regimes, are flood prone, are international waterways and have been extensively modified by humans over many hundreds of years. Yet the recent history of flooding on the German sections of these rivers is distinctively different. Most communities along the Rhine seem to take floods in stride whereas along the Oder they have been highly disruptive. The disruption has provided a mechanism for helping to integrate disparate parts of the newly reunified German states emergency management system and has highlighted continuing differences between Polish and German flood experiences.     

水灾害治理对种植业生产的影响

为了应对水灾对我国种植业生产的破坏，国家每年要投入大量资金用于防灾减灾工作，在对1980年以来我国种植业生产、自然灾害和水利建设的统计数据进行描述性分析的基础上，通过建立模型，定量分析了26年来我国救灾工作和各种防灾水利建设对种植业增长所起的作用，为我国进一步制定科学有效的国家防灾减灾政策提供参考。     

福建省主要流域的暴雨洪涝特征

利用1989-1999年近11年的水文、气象资料分析了福建省6个主要流域主控站水位与降水量的关系和洪涝的时间变化规律,进而分析了暴雨致洪的特征,结果表明:(1)福建省6个主要流域洪峰水位与上游有关气象站前期平均总降水量相关显著,暴雨是福建省洪涝发生的主要原因;(2)根据闽江(竹歧站)、九龙江(浦南)、交溪(白塔)、木兰溪(濑溪)4个站的达警戒水位或危险水位的降水指标,可利用暴雨预报作为洪涝预警预测的依据。(3)上世纪80年代后,洪水的高低变化有增大的趋势,应进一步完善抗洪防洪预警系统,提高抗洪防洪的应变能力。     

基于灰色理论的黑龙江省暴雨洪涝特征分析及灾变预测

基于灰色理论和气象灾害普查资料对黑龙江省暴雨洪涝灾害时空分布特征进行了分析并进行了灾变预测。黑龙江省暴雨洪涝灾害主要发生在5-9月,其中7月损失最大;1990年以来暴雨次数虽然有所减少,但暴雨洪涝造成的损失却明显增加;黑龙江省暴雨洪涝灾害可划分为严重洪涝区、重洪涝区、中洪涝区和轻洪涝区,严重洪涝区位于松花江及其支流沿岸的大庆市、伊春市、齐齐哈尔市、佳木斯市和哈尔滨市。根据灰色灾变预测理论预测2013年出现严重暴雨洪涝灾害(全省农作物受灾面积≥500 000 hm2、可比经济损失≥50 000万元)的可能性最大,其次是2016年。     

Normalised insurance losses from Australian natural disasters: 1966–2017

ABSTRACT

The paper updates normalisation of the Insurance Council of Australia’s Disaster List in the light of debate about the contribution of global warming to the rising cost of natural disasters. Normalisation estimates losses from historical events in a common year, here ‘season’ 2017 defined as the 12-month period from 1 July 2017. The number and nominal cost of new residential dwellings are key normalising factors and post-1974 improvements in construction standards in tropical cyclone-prone parts of the country are explicitly allowed for. 94% of the normalised losses arise from weather-related perils – bushfires, tropical cyclones, floods and severe storms – with the 1999 Sydney hailstorm the most costly single event (AUD5.6 billion). When aggregated by season, there is no trend in normalised losses from weather-related perils; in other words, after we normalise for changes we know to have taken place, no residual signal remains to be explained by changes in the occurrence of extreme weather events, regardless of cause. In sum, the rising cost of natural disasters is being driven by where and how we chose to live and with more people living in vulnerable locations with more to lose, natural disasters remain an important problem irrespective of a warming climate.     

Flood vulnerability and commercial activities: the case of the city of Girona, Spain

This paper is based on a case study of the city of Girona in Catalonia, Spain, and analyses the vulnerability of commercial establishments to floods caused by the Onyar River. A mapping and statistical approach (cluster analysis) was applied to the information obtained from 568 questionnaires answered by the shops and the workshops located in the flood risk area. The results obtained allowed the authors to determine five different flood vulnerability profiles of the commercial establishments analysed. These profiles paint a picture of little individual adaptation to the risk and the possibility of suffering, sooner or later, large economic losses due to overflowing of the Onyar River. The authors established a methodology for carrying out a detailed multidimensional analysis of the flood vulnerability of the city's commercial establishments in order to provide the foundations for local government policies and for strategies for shop owners to reduce flood vulnerability.     

Commuting patterns of Czech households exposed to flood risk from the Bečva river

Using unique data collected in October–December 2012 we estimate the link between commuting for work and level of individual exposure to floods. We find that commuters on average have higher earnings than non-commuters. Individuals affected by one flood commute by 11.2% more than unaffected individuals. We conjecture that the increase is linked to intentions to cover flood-related losses, decrease households' vulnerability to flood risk or out-migrate from the risk areas. Individuals affected by at least two floods are by 20.2% less likely to commute relative to those unaffected. We explain this non-linear effect by the fact that many households out-migrate after the first flood. Stayers commute less, because they are different from non-stayers in some underlying characteristics related to education, employment and family circumstances, which strongly affect commuting behaviour. We further find that in a commuting family an individual is by 53.8% more likely to commence commuting relative to a non-commuting family. Choice of commuting destination is often similar to that of other family members.