Vertical evacuation in hurricanes: An urgent policy problem for coastal managers

Abstract

Evacuation inland ("horizontal evacuation") is the traditional method of saving life in areas forecast as the site of hurricane landfall. But “high confidence”; warning time is only 12 hours, while some coastal areas are now so densely populated that twice that time is required for evacuation. Coastal managers must therefore risk the ire of local citizens “unnecessarily”; evacuated early, and the associated risk that several false alarms will reduce citizen compliance, or the risk that evacuation will be too long delayed.

The alternative of vertical evacuation (going upstairs in hurricane‐proof buildings) is resisted by planners who are concerned that its risks are too high and that partial acceptance of the concept would vitiate compliance with the horizontal component. But in some areas there may no longer be a choice: prudent coastal managers must determine the potential need and capability for vertical evacuation in their areas. Effective integration of both vertical and horizontal evacuation will require development of new plans and policies.     

A review of the sea state generated by hurricanes

Data from four studies of waves generated by hurricanes are reviewed and compared. The combined dataset presents a consistent picture of the wave field within a hurricane. The wave field is more asymmetric than the corresponding wind field, mainly due to the “extended fetch” which exists to the right of a translating hurricane. This concept leads to the specification of an equivalent fetch for a hurricane which enables the use of fetch limited growth relations for the prediction of the significant wave height within a hurricane. Examination of spectra recorded within hurricanes indicates that they are remarkably similar to fetch limited forms. Relationships for the parameters defining fetch limited spectra are found to also be valid for hurricane conditions. The reason for the similarity of hurricane and fetch limited spectra is attributed to the shape stabilizing effect of non-linear wave–wave interactions, which continually reshape the spectrum to conform to the standard JONSWAP-like form. Although the wind speeds within hurricanes are very high, the spectra generated are mature, with values of non-dimensional peak frequency typical of fully-developed seas. The analysis develops a set of standard relationships which can be used to define the wave field and spectral form for use in design of offshore fixed and floating structures.     

Have tropical marine protected areas worked? An initial analysis of their success

A multinomial choice framework was used to analyze data from hypothetical storm forecast scenarios administered via mail survey to a random sample of U.S. Gulf Coast residents. Results indicate that the issuance of a mandatory evacuation notice and the presence of higher wind speeds had the largest influence on increasing the likelihood of evacuation. Age, race, disability, distance, and education were significant in explaining one's decision to wait relative to choosing to evacuate. Blacks and disabled individuals were strictly less likely to wait and more likely to make an immediate evacuation decision. Hurricane Katrina evacuees and those with an evacuation destination identified were also more likely to decide to evacuate, but were also more likely to wait before deciding. Results indicate that residents of mobile homes were more likely to either evacuate or wait before making a decision, but strictly less likely not to evacuate. Respondents very confident in being rescued were strictly more likely not to evacuate. Results indicate that not having an evacuation destination identified was the most influential factor regarding the likelihood of not knowing what choice to make.     

飓风极值波浪数值模拟

飓风浪对于船舶航行、海洋和海岸结构物的安全意义重大,分析工程区设计波要素需要考虑飓风引起的大浪。采用YoungSobey风场模型建立飓风风场,以飓风风场作为第三代波浪模型MIKE 21 SW的驱动场,对发生在大西洋的飓风IRENE引起的飓风浪进行模拟,并将模拟结果与实测浮标数据进行对比。对比结果显示,MIKE 21 SW可以很好地模拟飓风引起的极值波浪要素。     

Surfer and Beachgoer Responsiveness to Coastal Water Quality Warnings

Fecal contamination of coastal waters has led local public health agencies to issue tens of thousands of beach advisories annually and to advise against ocean swimming and surfing for 72 hours following a rain. The responsiveness of recreationists to beach advisories and the “72 hour rule” is estimated by merging four years of multi-daily surfer and beachgoer counts at one beach in Southern California with hourly data on beach advisories, recent precipitation, meteorological conditions, and the UCSB academic calendar. Both surfing and beach-going decreased significantly following rainfall in response to the 72 hour rule, showing that recreationists are willing to engage in health risk-reducing avoiding behavior. However, neither surfing nor beach-going decreased significantly during beach advisories. Surfers were significantly more responsive to beach advisories during dry periods than during wet periods, consistent with the hypothesis that recreationists are most likely to respond to a risk warning that they believe provides accurate and additional health risk information beyond what they can observe personally. Additional studies of beach advisories elsewhere could clarify whether responsiveness to beach advisories varies by recreationist demographic, recreational activity, frequency of advisories, or frequency of repeat visitation. Increasing the accuracy and additional information provided by beach advisories, as proposed by numerous authors, could lead to increased responsiveness.     

Geographical variations in hurricane risk and legislative response

Abstract

Risk from the “natural event system”; of hurricanes varies greatly along the U.S. coastline, and so do the property and lives at risk. Damage potential from storm surge in the Miami area is less than a third that of the Tampa area. However, damage potential from winds in the Boston and New York areas exceeds that of either the Miami or Tampa areas. Passage of time since the great hurricane disasters near the turn of the century and improvements in the warning system may make coastal dwellers underestimate the likelihood of a hurricane catastrophe. But population growth near the coast has been more than three times the national average, and 10 of 58 coastal segments 50 miles in width more than doubled in population between 1960 and 1970. Twenty‐two segments increased by more than 25,000 people with six increasing by 150,000. Legislative response to the growing hazard has varied as widely as risk but is not clearly correlated with risk.     

Coastal Zone Management: Using No-Build Areas to Protect the Shorefront

Five coastal counties in Florida were studied to assess the effect of state-mandated local comprehensive plan policies on hurricane evacuation clearance times and public shelter demand. Numbers of residential units in 2002 and at the time of plan approval were estimated from property parcel data. Abbreviated transportation models were used to calculate 2002 evacuation times and shelter demand and to ascertain the impacts of post-plan residential growth within hurricane hazard areas. Calculated increases in clearance times and shelter demand are not in concert with the state's mandate to maintain or reduce clearance times. State law currently limits the leverage of the state planning agency to compel local governments to implement the required comprehensive plan policies. We recommend a concurrency management strategy that parallels the state's requirement to provide adequate transportation facilities to accommodate the impacts of future residential growth. Such a policy could be employed in other states as well.     

A maritime safety on-board decision support system to enhance emergency evacuation on ferryboats

Planning emergency evacuation operations in a proactive manner in public marine transportation systems is a critical success factor for passenger and crew safety. Despite the fact that there is a growing attention on safety issues for marine transportation systems, providing a real-time decision support for evacuation planning under different emergency conditions has not yet been addressed. In this context, this paper contributes to the related literature by providing a comprehensive methodology including simulation and statistical analysis along with a three-module decision support system (DSS) for ferryboat emergency evacuation. Emergency evacuation and fire environment are simulated via Maritime EXODUS V5.1 and SMARTFIRE V4.3, respectively. The methodology is applied to a real-life Ro-Ro ferry, and the results not only revealed significant factors on emergency evacuation performance, but also demonstrated the validity of the developed decision support system.     

Concept for a risk based Navigation Decision Assistant

A concept for a risk based decision support system for navigation of ships that face degrading weather conditions and dangers of damages to a ship at its cargo is outlined. Similar systems exist in various forms, mostly as prototypes, and are based on different ideas of how decision parameters should be communicated to a master as improved basis for decision making. The paper advocates that it is possible to develop a system that systematically is built on risk assessment approaches with the intention of being applicable for a specific ship with a specific loading situation in a real-time environment. The concept is based on modern reliability methodology and relies on state-of-the-art hydrodynamics software and information sources relating to the environment. Based on the various consequences that may occur, the study suggests a selection of limit states and shows how they can be integrated in the decision support system described. The paper presents the risk based concept only while testing of the concept is still in progress.     

The Causal Effects of Place Attachment and Tourism Development on Coastal Residents' Environmentally Responsible Behavior

Coastal areas are generally known as high-usage areas for residential, recreational, and tourism purposes. Coastal residents, as well as local visitors, therefore, can play an important role in protecting coastal resources. The purpose of this study was to identify important factors that could promote residents' environmentally responsible behavior (ERB). The two concepts, place attachment and attitudes toward tourism development (ATTD), were included to verify causal relationships of ERB. For data analysis, confirmatory factor analysis (CFA) and structural equation modeling (SEM) were conducted. Study results showed that place identity fully mediated the relationship between place dependence and ERB. With respect to the two dimensions of ATTD, there was a positive relationship between perceived benefits and ERB, while perceived concerns mediated this relationship. To promote ERB, the study emphasized the importance of developing place identity by providing diverse economical, socio-cultural, and recreational coastal benefits. In addition, involving those residents, who are positively and negatively impacted by tourism development, in the process of sustainable tourism development will develop more effective sustainable development strategies by reflecting local residents' opinions and preferences.     

分米波仪表着陆系统虚假下滑道的分析与仿真

分米波仪表着陆系统虚假下滑道的存在会导致飞机得到错误的导航信息。从下滑天线的原理出发,分析了其空间合成信号的特性,并通过数学推导分别研究了理想下滑面及虚假下滑面上、下1300Hz和2100Hz信号的变化规律。最后采用MatrixX软件开发平台对推导结果进行了仿真验证。     

South Carolina's diked tidal wetlands: The presisting dilemmas

Abstract

South Carolina has a significant stock of diked coastal wetlands, dating from the days of rice culture before the Civil War. A survey of those controlling these sites along the entire South Carolina coast reveals that many continue to be used for waterfowl hunting, with management practices becoming more intensive than they were when partial data were gathered a decade ago. It also suggests that most of the acreage involved is located in large fields, where management is more difficult and mosquito control problems are more likely. This survey also indicates that public access is limited, but that there is evidence of continuing conflict over ownership. This situation creates a persisting dilemma for coastal zone management, shaping conflicts between alternative strategies for the use of natural systems.     

Ecological sustainability of the South Australian coastal aquaculture management policies

Coastal aquaculture in South Australia has been going through a period of unprecedented growth during the past seven years. The value of the South Australian aqua‐culture industry has increased from US$1.3 million in 1990–1991 to an estimated US$31 million in 1996–1997. This growth has led to the implementation of planning and management policies by the state government. South Australian coastal waters have been divided into regions, and regional aquaculture management plans have been prepared. These management policies have generated concerns among interest groups and the community. The recent coastal aquaculture planning and management policies are described and analyzed, focusing on their contribution to the development of an ecologically sustainable industry. The need for an integrated approach to management is emphasized, especially given the great interest of the state government on the development of the industry.     

深远海设施人员应急撤离路径优化模型

针对深远海设施人员应急撤离路线优化问题,基于深水半潜式支持平台船体实际环境信息,考虑各可撤离路径的通行能力,引入拥挤度和撤离时间来计算人员路阻函数,构建人员撤离路径优化模型.以一个小型多源多汇拓扑网络的人员撤离方案为例,分别求解人员撤离路径优化模型和传统最短撤离路径模型,并对计算结果进行对比分析,验证人员撤离路径优化模型的有效性.     

X2检验方法和DF方法抗距离拖引干扰的性能比较

利用Monte Carlo方法，对X^2检验方法和分解融合(DF)方法在有虚警测量的环境下抗距离拖引干扰的性能进行了分析和比较。研究表明，在既有虚警测量又有距离后拖(Rcpo)干扰的情况下，采用DF方法可以有效地抗距离后拖欺骗干扰，实现对目标的跟踪，相对于X^2检验方法有一定的优越性。     

基于BP算法的减弱复杂电磁环境对炮兵侦察影响的研究

从剖析实战面临的复杂电磁环境的特点以及对炮兵作战的影响入手,提出运用BP算法的收敛性,对不同的侦察工具的信息可信度确立合适的权值,消除由于复杂电磁环境对炮兵侦察和传递信息时所产生的误差甚至是错误的影响。     

Visual Communication of Climate Change: Local Framing and Place Attachment

To examine the effects of local versus global message framing concerning climate change, data were gathered from 114 undergraduate students at a Southern US coastal university. The experiment accounted for participants' perceived attachment to their environments (place attachment) to observe whether it related to increased engagement and risk perceptions. Messages were most effective in eliciting environmental action when local effects of climate change were emphasized. Those reporting more connection to their local environments perceived more risks and intended more mitigating actions. The results may assist practitioners, researchers, and decision makers in developing more effective approaches to climate change mitigation.     

基于组合赋权法的船型方案模糊综合评判

为了提高船型方案决策结果的客观性与可靠性,文中分析了主观赋权和客观赋权的优劣,提出r一种新的组合赋权方法。该方法通过专家评分法、层次分析法、信息熵法、变异系数法这四种单一的主客观赋权方法问建立相关系数的概念。该评判方法原理简单、可解释性强,并同时充分利用客观信息,兼顾号家主观偏好,因此,决策方案更加合理、可信、这种综合方法也能推广应用于船舶决策的相关领域。     

琼州海峡客滚船的人员撤离分析

随着海上人员运输和旅游业的发展,以及对生命财产安全关注度的提高,乘客的紧急撤离作为船舶安全的最后一道保障,获得高度重视。以海安会通函MSC/Circ.1033为依据,对琼州海峡950m车道/999客海口-海安航线客滚船的脱险通道,在优化布置的基础上,考虑夜晚和白天两种工况,详细地计算和评估其撤离逃生性能,并对客船撤离系统前期的设计要点进行总结归纳。     

Household attitudes toward environmental quality in a coastal South Carolina County

Abstract

This paper presents an analysis of the findings of a survey of a sample of Beaufort county, South Carolina, households which was conducted to ascertain preferences for environmental quality. These preferences were approximated from survey responses on willingness to pay for environmental amenities and the size of payments households would require to forfeit them. A scale was developed and used to rank these responses ordinally, and the matrices of scaled responses for each of eight household annual‐income classes were subjected to factor analyses.