Quantifying Storm Tide Risk in Cairns

The United Nations International Decade for Natural Disaster Reduction (IDNDR)gave rise to an increasing level of attention to the risks posed by a range of naturalhazards and the development of strategies by which to reduce those risks. It waswidely recognised that in order to evaluate risk treatment strategies it was necessaryto `measure' the level of risk that already existed and the level of risk that would beencountered with the treatment strategy(s) in place.This paper outlines the methodology developed under the AGSO (now GeoscienceAustralia) Cities Project to quantify the risk associated with storm tide inundation. It includes the methodology for `measuring' the level of community exposure to storm tide hazards and the methodology for `measuring' community vulnerability. The Far North Queensland city of Cairns is used as the case study to demonstrate the application of these methods.     

Community Vulnerability to Tropical Cyclones: Cairns, 1996–2000

This paper is a partial discussion of a four-year study that investigated the vulnerability of the people living in the Cairns region to the tropical cyclone hazard. The longitudinal case study, focussing on the Cairns Northern Beaches area, was unique in that it included a social and societal `pre-cyclone impact' evaluation of various resident communities within the region, and then two consecutive `post-cyclone impact' studies. The primary research method supported an inductive qualitative approach to the collection and analysis of survey data. Some quantitative methods were invoked to support qualitative research findings. Survey data was collected in five separate questionnaire-based social surveys that were administered between 1996 and 2000. During the study, residents experiencedthe direct impact of two land-falling tropical cyclones. In addition to this, targeted andfocussed tropical cyclone awareness education was made increasingly available withinthe community. The social and demographic attributes that influence the individual'sperception of risk and contribute to our understanding of community vulnerability were examined and evaluated. Changes in the residents' attitudes, cyclone preparednessbehaviours and willingness to respond to cyclone warnings were monitored and measured. Analysis of early survey data indicated that community residents generally had some knowledge of cyclones but a limited understanding of cyclone processes and very little direct personal experience of the cyclone hazard. Individually and collectively, residents frequently demonstrated a biased perception of the risks associated with cyclones. The resident community was shown to be fragmented, with limited support being available to individual households. Initially, residents were found to be poorly prepared for cyclones and unlikely to respond to warnings appropriately. It appeared that, in the event of a land-falling tropical cyclone impacting the area, the community was highly vulnerable to unnecessary loss of property, livelihood and – in extreme circumstances – life. By 2000, Cairns community residents were somewhat better informed about cyclones and certainly more experienced. This paper provides some insight into how cyclone experience and education may synergisticly have contributed to a change in risk perceptions and a reduction in the vulnerability of Cairns residents to the tropical cyclone and storm surge hazards.     

2001年7月27日临汾区域性暴雨天气过程分析

本文应用数值预报产品，常规天气图，卫星云图及大气探测等资料，对2001年7月27日临汾区域性暴雨天气过程产生的环流形势，水汽和热力条件及动力机制进行了分析和研究，进一步揭示临汾市暴雨发生的环境流场和物理量场的特征。     

影响广西的孟湾风暴

统计分析了1973年以来影响广西的孟湾风暴天气气候情况及环流特征,总结出该类天气演变的一般规律及预报着眼点,为提高天气预报准确率提供有益参考。     

登陆热带气旋的大暴雨天气与一般暴雨对比分析及其雨强增幅原因的初探

本文以９０１５号热带气旋登陆后造成的省淮以南大暴雨天气为例，与８闪一般暴雨天气的热力动力条件进行对比，分析它们之间的异同点，并利用二维点尺度力学模式对地面中尺度锋区引起民环流进行模拟试验，结果表明，在热带气旋伸向东北部一条辐合线的偏北旗帜的中尺度锋区驱动扰动涡旋，在涡旋的上升部位可对大暴雨有增幅作用。     

“93.5”黑风暴发展期中尺度期热量和水汽收支诊断

１９９３年５月４—６日（“９３．５”）在我国西北地区发生了一次极具破坏力的“黑风暴”。为了诊断这次黑风暴发展期的热量和水汽收支，使用了具有高分辨ＰＢＬ参数化及４０ｋｍ细网络的ＭＭ４对该例控制模拟的输出资料和热量与水汽收支方程。对视热源（Ｑ１）和视水汽汇（Ｑ２）的诊断结果指出，Ｑ１的垂直积分在黑风暴的前部和后部分别呈现一条显著的加热带和冷却带。在黑风暴区，Ｑ１和Ｑ２的区域平均垂直廓线揭示，黑风暴的Ｑ１加热主要发生在对流层的上部，而其中部加热主要出现在发展初期；与Ｑ１相应，Ｑ２在低空和中空分别发生明显的增湿变冷和变干加热。这些结果不仅与因黑风暴过程而观测到的强剧强降温率一致，而且也为改进和发展用于模拟和预报黑风暴的中尺度数值模式提供了一些物理依据     

澳大利亚东南部持续性降水的成因

利用热带天气图，日本ＧＭＳ卫星云图，ＥＣＭＷＦ格点风场资料，对澳大利亚东南部持续性降水的两类主要天气过程，热带云涌－冷锋尾流气旋锋生过程和阻塞反气旋北侧回流降水过程进行了分析，从云型演变，环流形热，热带流场等方面揭示了澳大利亚东南部持续性降水天气过程的基本特征、为业务预报提供参考。     

东亚冬季风的演变特征

文章主要讨论了东亚冬季风和冷涌的演变特征，并与南亚作了对比，发现在东亚地区，冬季风演变主要表现为10月中旬经向环流的突变及9月初、11月中旬和1月末对流层低层温度的3次突变；而在南亚地区，经向环流的变化不如东亚地区明显，而且高层要先于低层变化，对流层低层温度存在2次突变。在整个冬季，东亚地区冷涌的演变过程，主要表现为南海地区冷涌在12月份出现最高频率，而西太平洋冷涌在1月份出现最高频率；南亚地区冷涌在12月份出现最高频率，但远小于东亚地区且衰减速度很快。另一个不同点是东亚地区的冷涌强度是往上衰减的，而南亚地区的冷涌强度则是往上增强的。这说明东亚冬季风和南亚冬季风的性质有较大的区别。     

中国西北部“4.5”沙尘暴过程中尺度低压的数值模拟

利用改进型ＰＳＵ／ＮＣＡＲ中尺度数值模式（ＭＭ４标准版），取模式水平格距４０ｋｍ，４６×６１网格，垂直方向ａ取１５层，即从地面到模式顶（１００ｈＰａ），σ＝０．０、０．１、０．２、０．３、０．４、０．５、０．６、０．７、０．７８、０．８４、０．８９、０．９３、０．９６、０．９８、０．９９、１．００，采用ＮＣＡＲ的３０＇×３０＇地形资料，以常规观测资料作为初始场，较好地模拟了此次沙尘暴过程的海平面气压的演变和分布，特别是张掖、柴达本盆地以及敦煌附近的三个中低压。同时，模拟了张掖中低压与蒙古冷高压之间的甘肃河西沙尘暴东大风。敏感性试验表明，沙尘暴中低压的形成发展主要是受于物理过程制约；沙尘暴中尺度系统的研究与暴雨中尺度系统的研究是有区别的，积云对流参数化并不是特别重要，在设计研究沙尘暴的数值模式中，应当合理地处理其他的热力、动力过程及大气外强迫源的作用。模式水平格距、地形真实程度对模拟中低压的位置、中心强度有重要贡献；下垫面变化中低压强度有一定影响。张掖热低压的形成发展主要是在有利的环境形势下，特殊地势起了重要作用，表现为直接动力强迫和间接热力强迫。     

国内外PMP/PMF的发展和实践

对20世纪80年代以来PMP／PMF在国内外的发展和实践情况作了简要的介绍和评论。内容包括PMP／PMF定义、估算方法、成果合理性检查和概率。PMP估算方法包括概化估算法、当地暴雨放大、暴雨移置、暴雨组合、推理模式和统计估算法。PMF估算着重介绍了由PMP转化为PMF的产流和汇流特点，以及目前在南非和法语非洲国家广泛应用的经验公式。