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1.
In 2011, the National Oceanic and Atmospheric Administration (NOAA) reported that the coastal population of the US that lives within 50 miles of the shoreline exceeded 50 % for the first time in history in spite of a high level of exposure to hurricanes and related flooding. Hurricane Andrew (1992), Mitch (1998), Ivan (2004), Katrina (2005), and Sandy (2012) are recent reminders of both the financial and human toll that result from hurricanes. Generally, hurricanes bring with them torrential rains and storm surges which enable destructive flooding inland and at the coastal (land–sea) interface and cause extensive and severe damages to residential structures and fatalities. An improved understanding of hurricanes and its interactive effects on the built environment will significantly reduce structural and non-structural damage and loss of life. This paper presents the method and results of a study that focused on application of a hybrid loss model which combines structural and non-structural damage vulnerabilities to quantify the damage and subsequent loss as a result of hurricanes, but particularly the extension to the community level. The methodology presented in this paper will help enable designers and/or planners to assess the change in anticipated losses at the community level as a result of one or more mitigation strategies as well as provide insight into land use planning.  相似文献   

2.
In the United States, mitigating the adverse impacts of flooding has increasingly become the responsibility of local decision makers. Despite the importance of understanding why flood mitigation techniques are implemented at the local level, few empirical studies have been conducted over the last decade. Our study addresses this lack of research by examining the factors influencing local communities to adopt both structural and non-structural flood mitigation strategies. We use statistical models to predict multiple flood mitigation techniques implemented by cities and counties based on a survey of floodplain administrators and planning officials across Texas and Florida. Particular attention is paid to the role of organizational capacity to address floods in addition to various local geophysical and socioeconomic characteristics. Results indicate that organizational capacity is a significant factor contributing to the implementation of both structural and non-structural flood mitigation techniques, even when controlling for contextual characteristics.  相似文献   

3.
Sea level rise threatens to increase the impacts of future storms and hurricanes on coastal communities. However, many coastal hazard mitigation plans do not consider sea level rise when assessing storm surge risk. Here we apply a GIS-based approach to quantify potential changes in storm surge risk due to sea level rise on Long Island, New York. We demonstrate a method for combining hazard exposure and community vulnerability to spatially characterize risk for both present and future sea level conditions using commonly available national data sets. Our results show that sea level rise will likely increase risk in many coastal areas and will potentially create risk where it was not before. We find that even modest and probable sea level rise (.5 m by 2080) vastly increases the numbers of people (47% increase) and property loss (73% increase) impacted by storm surge. In addition, the resulting maps of hazard exposure and community vulnerability provide a clear and useful example of the visual representation of the spatial distribution of the components of risk that can be helpful for developing targeted hazard mitigation and climate change adaptation strategies. Our results suggest that coastal agencies tasked with managing storm surge risk must consider the effects of sea level rise if they are to ensure safe and sustainable coastal communities in the future.  相似文献   

4.
In the last decade, attention has been devoted to the southern part of the Egyptian Red Sea coast due to the large touristic and mining activities. Egypt spares no effort to develop it, to build new urban communities, and to create new job opportunities. Many comprehensive planning studies have been conducted. Many luxurious tourist spots, airports, and harbors have been constructed. These areas are subjected to flash floods, which represent a frequent threat to these urbanization activities that may cause losses in livelihood. By analyzing the geomorphologic features of the study area, intense stream networks are detected that, with the available metrological data, require flood management and analysis to mitigate the possible negative effects and to benefit from the estimation of flood water. Rahbaa basin is a sub-catchment of wadi Hodin. Flash floods within this area threaten the Red Sea coastal plain as well as the main coastal roads. It also directly drained out to the sea, which leads to a loss of huge amounts of flood water that is useful for arid regions. Using geographic information system and remote-sensing tools with the application of a comprehensive graphical modeling (watershed modeling system) supports the hydrological modeling of HEC-1. The total amount of runoff is calculated and the hydrograph of the 50-year return period is computed using rainfall historical data.  相似文献   

5.
Nigel W. Arnell 《Geoforum》1984,15(4):525-542
The National Flood Insurance Program (NFIP) both provides flood insurance to floodplain occupants and encourages local communities to adopt floodplain land-use regulations. As well as providing the core of the federal non-structural flood hazard management effort, the NFIP is a central element in both state and local activities. A major issue influencing the success of the NFIP in curbing flood damages is its treatment of properties built before the adoption of floodplain regulations. The potential for using the NFIP to encourage floodproofing and influence post-flood hazard mitigation must be fully explored.  相似文献   

6.
More than 518 km2 (200 mi2) of prime lands in Jamaica lay on Karstic material where sinkholes are the natural outlet of important streams. Due to increasing social pressure, the lands are inappropriately managed and as a consequence, vegetal debris and silting have plugged the sinkholes which have thus lost their capacity to drain the runoff produced during heavy rainfalls. One of these areas is Cave Valley, which during the last 36 years, has been affected by at least six floodings, some of which have produced losses of life and property, in a sector of the Jamaican population which is already under severe economic hardship. A flood prevention and mitigation project is being implemented including watershed management, river training and community preparedness. A geologic, hydrologic, and hydraulic analysis are also part of this study. All these measures are expected to reduce future losses. This article is not an official World Meteorological Organization document and WMO does not necessarily share the views expressed in it.  相似文献   

7.
Gupta  Sujata  Javed  Akram  Datt  Divya 《Natural Hazards》2003,28(1):199-210
The peculiar rainfall pattern in Indiarenders the country highly vulnerable to floods. Forty million hectares of land, roughlyone-eighth of the country's geographical area, is prone to floods. Each year, floods cause extensive damage to life and property, losses being exacerbated by rapid population growth, unplanned development and unchecked environmental degradation. The country has been tackling the problem through structural and non-structural measures. While non-structural measures like flood forecasting aim at improving the preparedness to floods by seeking to keep people away from floodwaters, structural measures involve the construction of physical structures like embankments, dams, drainage channels, and reservoirs that prevent floodwaters from reaching potential damage centres. Almost 48% of the vulnerable area has been provided with reasonable protection, though floods continue to cause widespread losses year after year. This paper examines the incidence of floods and the trends in consequent losses in the eastern region of the country – one of the most vulnerable – with the objective of studying the efficacy of flood protection measures in the region. Based on a simple regression exercise for three highly vulnerable states in the region, the paper argues that flood protection measures have been inadequate in controlling losses and reducing vulnerability. Regressions for the three states over the period 1971 to 1996 indicate that the level of protection is an insignificant explanatory variable in explaining the number of people (adjusted for increases in density) affected by floods; while area affected, as an indicator of the intensity of floods remains the main loss-determining factor.  相似文献   

8.
Semarang is one of the biggest cities in Indonesia and is nowadays suffering from coastal flooding. Land subsidences, high water tide, and inadequate structural measures play important roles in the coastal inundations. Structural and non-structural methods for controlling coastal flooding including dykes, drainage systems, pump stations, polder systems, coastal-land reclamations, coastal planning and management, public education, as well as the establishment of an institutional framework for disaster management have been implemented in the Semarang coastal area. Although some improvements have been made, the current flood management system has generally failed to address a wide range of coastal inundation problems. Some improvement actions have been proposed including stakeholders involvement on the disaster mitigation. For a long period coastal management, accelerated sea level rises due to global warming should also be taken into account.  相似文献   

9.
The level of damage of flood events does not solely depend on exposure to flood waters. Vulnerabilities due to various socio-economic factors such as population at risk, public awareness, and presence of early warning systems, etc. should also be taken into account. Federal and state agencies, watershed management coalitions, insurance companies, need reliable decision support system to evaluate flood risk, to plan and design flood damage assessment and mitigation systems. In current practice, flood damage evaluations are generally carried out based on results obtained from one dimensional (1D) numerical simulations. In some cases, however, 1D simulation is not able to accurately capture the dynamics of the flood events. The present study describes a decision support system, which is based on 2D flood simulation results obtained with CCHE2D-FLOOD. The 2D computational results are complemented with information from various resources, such as census block layer, detailed survey data, and remote sensing images, to estimate loss of life and direct damages (meso or micro scale) to property under uncertainty. Flood damage calculations consider damages to residential, commercial, and industrial buildings in urban areas, and damages to crops in rural areas. The decision support system takes advantage of fast raster layer operations in a GIS platform to generate flood hazard maps based on various user-defined criteria. Monte Carlo method based on an event tree analysis is introduced to account for uncertainties in various parameters. A case study illustrates the uses of the proposed decision support system. The results show that the proposed decision support system allows stake holders to have a better appreciation of the consequences of the flood. It can also be used for planning, design, and evaluation of future flood mitigation measures.  相似文献   

10.
Severe storms in desert regions, especially along the coastal area of the Chilean desert, produce very destructive mud flows that last a few hours and constitute the only surface run-off in these events. To date, there is no simple or practical methodology for assessing such mud flows. Given the settlement of mining fields and creation of desert campgrounds, it is increasingly necessary to understand how these water and/or mud flows behave in order to develop structural and non-structural mitigation plans. Thus, herein, we present software known as PVCS, which provides a system for calculating mud volumes after a strong storm. This hydrological and computer tool allows us to calculate the structure and volume of mud passing through the mouth of a hydrographic watershed after a desert rainstorm. To use this software, it is necessary to know the hydrological, meteorological, and morphometric parameters of the watershed under study. These data are entered into a model that estimates the amount of mud that will pass through the mouth with each hour of rain. Simulations can be done with historical data or data designed for future events, thereby allowing the preparation of measures to protect people and property. We use the watershed Quebrada La Cadena to exemplify the use of this software. This drainage basin is located on the western slope of the Chilean Coastal Range in Antofagasta, a city in northern Chile. Here, rain in June 1991 produced a destructive flood that killed nearly one hundred people living at the main mouth of the watershed and caused huge economic losses. Data from this catastrophe have significantly improved the understanding of such flows, and this has been incorporated into the software. The principal value of PVCS lies in its ability to forecast the volume of mud that will result from a storm and hourly outflows that will pass through a specific populated area, mining camp, or industrial plant located in the mouth of a watershed of any size. This information is used to determine the most critical moment, i.e., the time of the largest outflows, which can then be used to organize timely evacuations to safe places for people, animals, and machines. Moreover, the program is methodologically valuable since, in order to implement PVCS, the user must structure information in a hydrological way. In summary, this program simulates different rain scenarios, thereby allowing us to design structural mitigation projects and contingency plans.  相似文献   

11.
The increasing natural disasters, especially floods during the last quarter century, are raising the economic losses in Taiwan. The most severe hazard in Taiwan is flooding induced by typhoons and storms in summer and autumn. By comparing the rivers around the world, the ones in Taiwan have the steepest slopes, the largest discharge per unit drainage area, and the shortest time of concentrations. Rapid urbanization without proper land uses managements usually worsen the flood problems. Consequently, flood hazards mitigation has become the most essential task for Taiwan to deal with. Although the government keeps improving flood defense structures, the flood damage grows continuously. In this article, possible flood mitigation strategies are identified for coping with complex environmental and social decisions with flood risk involved.  相似文献   

12.
Implementation of structural and non-structural flood control measures in flood-prone watersheds is on increasing demand. Different watershed areas are not necessarily hydrologically similar and impose variable effects on the outlet flow hydrograph. Meanwhile, prioritization of watershed areas in terms of flood generation is essential for economic flood control planning. Previous works have focused on the definition of a flood index that quantifies the contribution of each subwatershed unit or grid cell to the outlet flood hydrograph through the application of unit flood response (UFR) approach. In the present research, for the first time, the effect of spatial pattern of storm events on the flood index variation was assessed via a Monte Carlo uncertainty analysis. To do so, the UFR approach was carried out for a large number of randomly generated rainfall spatial pattern. The proposed methodology was adopted to the Tangrah watershed in northern Iran. The watershed is frequently hit by floods that have historically caused loss of life and properties. The results indicated that for the more frequent flood events, the flood index is quite sensitive to the spatial distribution of rainfall such that for the highest ranked subwatershed (SW6), the standardized variation of the flood index values (i.e., the uncertainty range) decreases from 1.0 to 0.5 when the rainfall depth increases from 20 to 150 mm, respectively. The results further revealed that increasing the rainfall depth from 20 to 150 mm would cause the effect of rainfall spatial distribution on subwatersheds’ flood indices to diminish. The implications are that if flood control measures are designed for more frequent floods with lower return periods, an uncertainty analysis is required to identify the range of flood index variations.  相似文献   

13.
Coastal towns along the coast of Africa are among the most vulnerable to climate change impacts such as flooding and sea level rise. Yet, because coastal conditions in many parts of the region are poorly understood, knowledge on which population groups are at the most risk is less known, particularly in the Greater Accra Metropolitan Area (GAMA) of Ghana, where the capital city Accra is located. Without adequate information about the risk levels and why, the implementation of locally appropriate adaptation plans may be less effective. This study enriches our understanding of the levels of flood risks along the coast of GAMA and contributes knowledge to improve understanding of place-specific adaptation plans. The study uses data from a 300-household survey, stakeholder meetings, and interviews with local community leaders to construct an integrated vulnerability index. The index includes seven components made up of: dwelling type; house and house environment; household socioeconomic characteristics; experience and perception of flood risk; household and community flood adaptation strategies; house location, and physical characteristics. Our findings show that exposure to floods, particularly from local flash floods is relatively high in all communities. However, significant differences in sensitivity and adaptive capacity of the communities were observed due to differences in location, socioeconomic characteristics, and perception of risks to flooding and sea level rise. The complexity of factors involved in the determination of local-level vulnerability requires that the implementation of adaptation strategies needs to involve cross-sectorial partnerships, involving local communities, in building a comprehensive multi-risk adaptation strategy.  相似文献   

14.
In this investigation, four scenarios were used to quantify the balance between the benefits of levees for flood protection and their potential to increase flood risk using Hazards U.S. Multi-Hazard flood-loss software and hydraulic modeling of the Middle Mississippi River (MMR). The goals of this study were (1) to quantify the flood exposure under different flood-control configurations and (2) to assess the relative contributions of various engineered structures and flood-loss strategies to potential flood losses. Removing all the flood-control structures along the MMR, without buyouts or other mitigation, reduced the average flood stages between 2.3 m (100-year flood) and 2.5 m (500-year), but increased the potential flood losses by $4.3–6.7 billion. Removing the agricultural levees downstream of St. Louis decreased the flood stages through the metro region by ~1.0 m for the 100- and 500-year events; flood losses, without buyouts or other mitigation, were increased by $4.3–6.7 billion. Removing the agricultural levees downstream of St. Louis decreased the flood stages through the metro region by ~1.0 m for the 100- and 500-year events; flood losses, without buyouts or other mitigation, were increased by 155 million for the 100-year flood, but were decreased by $109 million for the 500-year flood. Thus, agricultural levees along the MMR protect against small- to medium-size floods (up to the ~100-year flood level) but cause more damage than they prevent during large floods such as the 500-year flood. Buyout costs for the all the buildings within the 500-year floodplain downstream of urban flood-control structures near St. Louis are ~40% less than the cost of repairing the buildings damaged by the 500-year flood. This suggests large-scale buyouts could be the most cost-effective option for flood loss mitigation for properties currently protected by agricultural levees.  相似文献   

15.
Flood events have the highest damage costs and losses among natural hazards. There are different types of measures to mitigate flood damage costs and their negative consequences. Application of flood-control reservoirs or detention dams, as one of the main measures, may decrease devastating flood effects or even may cause to intensify flood damages in the watershed by a poor design with tremendous construction costs. Optimal design of a flood-control multi-reservoir system can simultaneously minimize investment costs of constructions and potential flood damage costs. This study proposes a simulation-based optimization approach to optimize the design of multi-reservoirs for flood control in the watershed by coupling the MIKE-11 hydrodynamic model and the NSGA-II multi-objective optimization model. The present approach provides the Pareto optimal solutions between two conflict objectives of minimizing total investment costs and the expected flood damage costs in the watershed. Application of the proposed model for a small watershed in central part of Iran as a case study shows that optimal designs of multi-reservoir systems can efficiently reduce construction costs, flood peaks and their corresponding damage costs at the downstream reaches of the basin.  相似文献   

16.
The structural measure was the major solution for flood defense in Taiwan. However, the measure is always limited to the design standard and cannot prevent the damages when floods exceed certain scale. Therefore, non-structural measures for flood mitigation are the indispensable complements to structural solutions. The study introduces the establishment of inundation potential database that provides required information for the non-structural measures in Taiwan. The database was built by numerical simulations, based on different rainfall scenarios, and has been applied by the local governments of Taiwan for land use managements, flood warning systems, emergency responses, and flood insurance programs to reduce the flood damages and impacts.  相似文献   

17.
Australia is currently experiencing climate change effects in the form of higher temperatures and more frequent extreme events, such as floods. Floods are its costliest form of natural disaster accounting for losses estimated at over $300 million per annum. This article presents an historical case study of climate adaptation of an Australian town that is subject to frequent flooding. Charleville is a small, inland rural town in Queensland situated on an extensive flood plain, with no significant elevated areas available for relocation. The study aimed to gain an understanding of the vulnerability, resilience and adaptive capacity of this community by studying the 2008 flood event. Structured questionnaires were administered in personal interviews in February 2010 to householders and businesses affected by the 2008 flood, and to institutional personnel servicing the region (n = 91). Data were analysed using appropriate quantitative and qualitative techniques. Charleville was found to be staunchly resilient, with high levels of organisation and cooperation, and well-developed and functioning social and institutional networks. The community is committed to remaining in the town despite the prospect of continued future flooding. Its main vulnerabilities included low levels of insurance cover (32% residents, 43% businesses had cover) and limited monitoring data to warn of impending flooding. Detailed flood modelling and additional river height gauging stations are needed to enable more targeted evacuations. Further mitigation works (e.g., investigate desilting Bradley’s Gully and carry out an engineering assessment) and more affordable insurance products are needed. Regular information on how residents can prepare for floods and the roles different organisations play are suggested. A key finding was that residents believe they have a personal responsibility for preparation and personal mitigation activities, and these activities contribute substantially to Charleville’s ability to respond to and cope with flood events. More research into the psychological impacts of floods is recommended. Charleville is a valuable representation of climate change adaptation and how communities facing natural disasters should organise and operate.  相似文献   

18.
Structure and temporal variability in nekton communities were examined for four small brackish creeks along a major tributary (Adams Creek) of the Neuse River estuary, North Carolina during May–September 1994. An inverse salinity gradient was observed along Adams Creek with highest values in the most upstream creek due to a manmade channel connecting the creek to the Newport River estuary. The nekton communities of the four tributaries were similar with some differences in relative abundance of individual species and timing of recruitment and migrations. Bay anchovies (67%), spot (19%), and brown shrimp (6%) were the most abundant species, with the top ten species accounting for 98% of the total catch. The transport of high salinity water (and presumably nekton larvae) into the headwaters of Adams Creek via the canal appeared to have a strong influence on the nekton community; the nekton community present in the Adams Creek system resembled communities in mesohaline waters closer to the outer banks rather than those in an adjacent creek along the Neuse River estuary (South River estuary). Cluster analysis indicated nekton in the creeks could be grouped into early and late season assemblages. Canonical correspondence analysis suggested that neither the creeks nor the dominant species were strongly related to any measured environmental variables indicating habitat suitability was similar regardless of the differences in watershed activities among the four creeks.  相似文献   

19.
Flood mitigation involves the management and control of floodwater movement, such as redirecting flood runoff through the use of floodwalls and flood gates, rather than trying to prevent floods altogether. The prevention and mitigation of flooding can be studied on three levels: on individual properties, small communities, and whole towns or cities. The current study area is located in Hurghada on the Red Sea, which is considered an important area for coastal tourism. The study area is located at distance 7.50 km from El Gouna city along the Red Sea and east of Hurghada–Al Ismaileya road. The aim of this research is to derive the runoff flow paths across the study area and their flow magnitudes under different rainfall events of 10, 25, 50, and 100 year return periods in order to design the flood mitigation measures to protect such important areas. Field data (e.g., topographic data and rainfall intensities) were collected for the study area. The results indicated that the site is exposed to high flash flood risk and protection work is required. In order to protect the area from flood risks, locations of number of drainage channels and dams were selected and designed based on flood quantity and direction. The proposed mitigation system is capable of protecting this crucial area from flood risks and increases the national income from tourism. This study can be applied in different areas of Egypt and the world.  相似文献   

20.
对未来防洪减灾形势和对策的一些思考   总被引：2，自引：0，他引：2       下载免费PDF全文
徐乾清 《水科学进展》1999,10(3):235-241
简要介绍了20世纪90年代我国大江大河的防洪形势。重点指出:河道萎缩,江河泄洪能力下降,行洪水位抬高,城市水灾突出,洪涝矛盾加重和水灾损失急剧增加的特点。探讨了防洪减灾的目标和标准,在进行防洪策略历史回顾的基础上,阐述了防洪减灾对策和基本措施方向。  相似文献   

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