Quantifying Storm Tide Risk in Cairns   总被引：6，自引：5，他引：6  

Ken Granger 《Natural Hazards》2003,30(2):165-185

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.  相似文献   

Impact of horizontal resolution on prediction of tropical cyclones over Bay of Bengal using a regional weather prediction model     

M. Mandal  U. C. Mohanty  K. V. J. Potty  A. Sarkar 《Journal of Earth System Science》2003,112(1):79-93

The present study is carried out to examine the performance of a regional atmospheric model in forecasting tropical cyclones over the Bay of Bengal and its sensitivity to horizontal resolution. Two cyclones, which formed over the Bay of Bengal during the years 1995 and 1997, are simulated using a regional weather prediction model with two horizontal resolutions of 165 km and 55 km. The model is found to perform reasonably well towards simulation of the storms. The structure, intensity and track of the cyclones are found to be better simulated by finer resolution of the model as compared to the coarse resolution. Rainfall amount and its distribution are also found to be sensitive to the model horizontal resolution. Other important fields, viz., vertical velocity, horizontal divergence and horizontal moisture flux are also found to be sensitive to model horizontal resolution and are better simulated by the model with finer horizontal grids.  相似文献   

Community Vulnerability to Tropical Cyclones: Cairns, 1996–2000     

Linda J. Anderson-Berry 《Natural Hazards》2003,30(2):209-232

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.  相似文献   

Mid-holocene climate change in Lake Bosumtwi, Ghana     

James Russell  Michael R TalbotBrian J Haskell 《Quaternary Research》2003,60(2):133-141

Lake Bosumtwi is one of the most widely studied palaeoclimate archives in West Africa. Results from numerous AMS ¹⁴C dates of samples from four piston cores from Lake Bosumtwi show that an abrupt sedimentary transition from a mid-Holocene sapropel to calcareous laminated muds occurred at about 3200 cal yr B.P. High-resolution analyses of the nitrogen isotopic composition of organic matter across this transition confirm its abrupt nature, and suggest that the change may signal a step toward increased aridity and intensified surface winds that affected western equatorial Africa from Ghana to the Congo basin. Northern and Eastern Africa experienced a similar abrupt shift toward aridity during the late Holocene, but at about 5000 cal yr B.P., a difference in timing that illustrates the regional nature of climate changes during the Holocene and the importance of feedback mechanisms in regulating Holocene climate variability. Furthermore, an abrupt change at about 3000 cal yr B.P. occurs at several sites adjacent to the tropical and subtropical Atlantic, which may hint at major changes in the surface temperatures of the tropical Atlantic and/or Pacific at this time.  相似文献   

影响韶关的热带气旋及其暴雨预报     

叶永恒 《广东气象》2003,(3):7-9

统计1965年以来影响韶关的热带气旋发现，韶关出现暴雨不仅与热带气旋的路径、强度有关，而且与大气层结稳定度或冷空气的相互作用密切相关。由此结合实况、应用数值预报产品来制作热带气旋暴雨24小时预报。  相似文献   

滞后平均法（LAF）在热带气旋路径集合预报中的应用   总被引：7，自引：8，他引：7       下载免费PDF全文

周霞琼  张秀珍  端义宏  朱永褆 《气象科学》2003,23(4):410-417

本文用-正压模式，采用滞后平均法(LAF)对2000年热带气旋进行路径集合预报试验，并与基于热带气旋初始结构扰动的集合预报方法进行了比较分析，结果表明LAF方法对热带气旋路径预报具有较好的改进作用。但LAF的集合预报效果受模式本身误差的影响，在完美模式的假设下，LAF集合预报相对于控制试验的技巧水平20～40％。  相似文献   

广东近海台风路径异常的统计特征   总被引：5，自引：0，他引：5       下载免费PDF全文

毛绍荣张东  梁健李晓娟  翁向宇 《应用气象学报》2003,14(3):348-355

对1949~2000年的52年间在广东沿海近岸转折或沿海岸移动的热带气旋异常路径进行了统计分析，同时还研究了广东沿海的地形特征。结果发现，转折点 (或靠岸点) 主要集中在有明显山脉地形的区域，同时靠岸前热带气旋有移速减慢的特征。另外还发现，转折前强度越强，则转折点离岸越近；靠岸前平均移速越小，则转折角度越大；靠岸前强度越强，则其沿海岸移动所需入射角越小。  相似文献   

Variability of NO₂ in different environments at a moderately polluted island over the southwestern Indian Ocean     

Chatrapatty Bhugwant  Jean-Luc Hoareau 《Atmospheric Research》2003,66(4):241-259

This work presents the temporal evolution and spatial distribution of nitrogen dioxide (NO₂) measured with the help of passive diffusion tubes in different environments: rural, sub-urban, urban, at La Réunion Island in December 1997 and November 2000 (austral spring), respectively. NO₂ concentration exhibits notable enhancement from 1997 to 2000. For instance, its mean concentration was 16 and 20 μg/m³ in December 1997 and November 2000, respectively, at La Réunion Island, especially in inhabited regions due to increase of local anthropogenic activities, mainly traffic circulation, in the absence of house heating and biomass burning. We also observe a net increase of pollutant levels by a factor two in rural/remote areas within 3 years, which is tied to the extension of inhabited areas and air-flows from enhanced local sources. The increase of atmospheric pollutants is mainly due to enhancement of anthropogenic activities (traffic) since the 1990s at La Réunion Island, which results from a constant increase of population and consequently, from a higher number of vehicles in circulation. Importantly, in cities like Saint-Denis, where traffic network has been subject to notable improvement (e.g. single to double lanes, etc.), pollutant levels exhibit little variability as in temperate continental latitudes. Semi-continuous NO₂ concentration measured in parallel with ozone in November 2000 also showed that daytime photochemical ozone production is influenced by pollutant and precursor (NO₂) levels at Saint-Denis, while nighttime ozone increase is mainly tied to dynamical processes. The November 2000 ozone diurnal pattern is notably different from that observed in September 1995, during which a daytime ozone loss was observed, pointing out that atmospheric conditions have been subject to notable changes, i.e., clean to moderately polluted, within a few years at La Réunion Island. The results presented here point out that the ‘source enhancement effect’ is superimposed on dynamical and photochemical processes to influence pollutants variability and hence atmospheric chemistry, in a quite ‘pristine’ tropical oceanic region.  相似文献   

用卡尔曼滤波预报南海热带气旋路径的试验   总被引：2，自引：0，他引：2  

刘春霞  周家斌 《热带气象学报》1997,13(4):359-356

利用卡尔曼滤波方法预报南海热带气旋路径，发现采用卡尔曼滤波可以大大地降低预报误差，提高预测模型的预报能力。  相似文献   

ANALYSIS OF COMPOSITE DIAGNOSIS OF OCEANIC EXPLOSIVE CYCLONES^*          下载免费PDF全文

WANG Jinsong  DING Zhiying  ZHAI Zhaofeng 《Acta Meteorologica Sinica》2004,18(3):327-346

Using the data of ECMWF (European Center for Medium-range Weather Forecasts) to undertake composite diagnoses of 16 explosive cyclones occurring at the Atlantic and the Pacific Oceans,it is found that there are a lot of obvious discrepancies on the basic fields between these strong and weak explosive cyclones.The major reasons why the explosive cyclones over the Atlantic are stronger than those over the Pacific Ocean are that the non-zonal upper jet and the low-level warm moist flow over the Atlantic are stronger.The non-zonal upper jet offers stronger divergence,baroclinicity and baroclinic instability fields for explosive cyclones.Anticyclonic curvature at the high level of strong explosive cyclones is easy to make the inertia-gravitational wave developing at the moment of northward transfer of energy and stimulate the cyclones deepening quickly.Warm advection and diabatic heating can cause the upper isobaric surface lifting,as a result,the anticyclone curvature of cyclones enlarges,and wave energy develops easily as well.The most powerful period of the development of explosive cyclones is just the time when the positive vorticity advection center is located over the low vortex.At the upper level,when the distribution of potential vorticity contours changes suddenly from rareness to denseness,and the large values of the potential vorticity both in the west and north sides of cyclones extend downwards together,then cyclones are easy to explosively develop.The formation of strong explosive cyclones is closely related with the non-zonality of upper jet and the anticyclonic curvature.  相似文献