Tropical Cyclone Hazard Research Articles

Tropical cyclone hazards analysis based on tropical cyclone potential impact index

Tropical cyclone, a high energy destructive meteorological system with heavy rainfall and gale triggered massive landslides and windstorms, poses a significant threat to coastal areas. In this paper we have developed a Tropical Cyclone Potential Impact Index (TCPI) based on the air mass trajectories, disaster information, intensity, duration, and frequency of tropical cyclones. We analyzed the spatial pattern and interannual variation of the TCPI over the period 1949–2009, and taking the Super Typhoon Saomai as an example have examined the relationship between the TCPI and direct economic losses, total rainfall, and maximum wind speed. The results reveal that China’s TCPI appears to be a weak decreasing trend over the period, which is not significant overall, but significant in some periods. Over the past 20 years, the TCPI decreased in the southern China coastal provinces of Hainan, Guangdong and Guangxi, while it increased in the southeastern coastal provinces of Zhejiang, Fujian and Taiwan. The highest values of TCPI are mainly observed in Taiwan, Hainan, the coastal areas of Guangdong and Fujian and Zhejiang’s southern coast. The TCPI has a good correlation (P=0.01) with direct economic loss, rainfall, and maximum wind speed.

Tropical Cyclone Hazards in the USA

Coastal development, population, and hurricane activity are all projected to increase in the near future. Thus, the USA has a tropical cyclone problem that requires interdisciplinary solutions from physical and social scientists. In this article, we review topics that summarize the current state of hurricane hazards in the USA. A review of meteorological hurricane hazard literature is broken into sections discussing wind and water hazards associated with land-falling tropical cyclones. This section is followed by a review of societal impact literature such as mortality and morbidity, hazard perception, communication, evacuation, and risk. Ideas are presented which introduce suggestions on how to possibly change processes and promote cross-dialog that may alleviate both the physical and societal impacts of tropical cyclones in the USA.

Analysis and prediction of hazard risks caused by tropical cyclones in Southern China with fuzzy mathematical and grey models

A hazard-risk assessment model and a grey hazard-year prediction model (GHYPM) are constructed by integrating recent advances in the fuzzy mathematics, grey theory and information spread technique, and then applied to 17-year tropical cyclones (TCs) hazards in Southern China. In constructing the models, a genetic fuzzy mathematical algorithm is first developed to calculate the categorical and ranking weights of TC hazard impact and cause indicators, from which their combined weights are obtained after optimization. The hazard impact and cause index series are then found by coupling the combined weights with their corresponding down-scaled indicators. A two-dimensional normal-spread technique is employed to create a primitive information matrix and a fuzzy relation matrix in order to make fuzzy rough inference of hazard risks with the factorial space theory. An exceeded probability model is developed to assess the possibility of exceeding any given hazard-year category. Results from the GHYPM show that the simulated hazard risk values are more or less consistent with the hazard-impact index series, with more than 60% probability of exceeding a moderate hazard year in Southern China. Results also show small relative errors of the GHYPM, indicating its applicability to the prediction of TC hazard-years up to 20 years.

Role of exposure in projected residential building cyclone risk for the Australian region

The paper presents a methodology to analyse the direct impact of tropical cyclone hazard on communities in northern Australia. The study focuses on the maximum potential intensity (MPI) of the cyclonic wind hazard, and location. Storm surge impacts were developed using a simple relationship between intensity and storm surge height and mid-point sea-level rise projections. The impact on residential building stock of severe wind and storm surge hazards associated with IPCC climate change scenarios is considered. Changes in residential building stock, for over 500 coastal statistical local areas (SLAs) from Southeast Queensland anticlockwise to Perth, were estimated using Australian Bureau of Statistics population projections through to 2100. A Probable Maximum Loss (PML) curve was derived, and the average annual cost across a 5000 year period (or "annualised loss") was evaluated for each region. The projected population growth and the drift to coastal locations are significant elements in determining the damage associated with possible future cyclone threat.

Tropical cyclone strikes at the coastal cities of China from 1949 to 2008

The spatiotemporal features of tropical cyclone strikes from 1949 to 2008 at 49 coastal cities of China are investigated in this study. The cities in Hainan, Guangdong, and Taiwan have high strike frequencies, with the severest and most frequent average strikes found in Taiwan. In Hainan, strike clusters appear in the mid-1950s, the early 1960s and 1970s, and the late 1980s, with relative inactive frequencies from the mid-1990s to 2008, and the clusters of strikes in Guangdong are found during the 1970s. In Taiwan, the most active strikes are found during the period 1956–1963. The return periods for all typhoons are either 1 or 2 years at the coastal cities of Taiwan in contrast to 2–5 and 4–8 years at the cities of Guangdong and Fujian, respectively. Super typhoons affect Taiwan with a frequency of once every 12–30 years on average. A tropical cyclone hazard index is also created to investigate the vulnerability at these cities.

Tropical cyclone hazard assessment using model-based track simulation

A method is introduced for assessing the probabilities and intensities of tropical cyclones at landfall and applied to data from the North Atlantic. First, a recently developed model for the basin-wide Monte-Carlo simulation of tropical cyclone tracks is enhanced and transferred to the North Atlantic basin. Subsequently, a large number of synthetic tracks is generated by means of an implementation of this model. This synthetic data is far more comprehensive than the available historical data, while exhibiting the same basic characteristics. It, thus, creates a more sound basis for assessing landfall probabilities than previously available, especially in areas with a low historical landfall frequency.

Methodology for identifying vulnerability hotspots to tropical cyclone hazard in India

Methodology for identifying vulnerability hotspots to tropical cyclone hazard in India

Methodology for identifying vulnerability hotspots to tropical cyclone hazard in India

Vulnerability indices are commonly used for characterizing the impacts on a region or comparing relative vulnerability across regions. Such indices are usually computed as a composite/aggregate across different components of vulnerability. Though such a single numerical value can be useful in many situations, a major disadvantage is that it leads to loss of information about how the different factors that went into making the composite index interact with each other, and contribute to making a place vulnerable. In this paper we develop an alternative approach for identifying hotspots, based on cluster analysis that seeks to address this problem by considering the different components of vulnerability separately. We compute different indices for each of the components of vulnerability. Cluster analysis helps in identifying the most vulnerable districts based on different combinations of the components of vulnerability. In addition to being methodologically more robust than the index approach, the clustering approach may have greater policy-relevance as it provides information about which aspects of vulnerability, policy needs to address in the most vulnerable districts.

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.

The tropical cyclone hazard over the South China Sea 1970–1989: Annual spatial and temporal characteristics

An assessment of the spatial dimension of tropical cyclone hazard potential in the South China Sea is based on an analysis of gridded tropical cyclone frequency data, covering the period 1970–1989. Analysis reveals that the inter-annual variations in the areal extent and spatial dispersion of tropical cyclone activity can be used as an index of tropical cyclone hazard potential in the South China Sea. Perturbations in the tropical ocean-atmosphere system, as manifest by the occurrence of El Niño-Southern Oscillation events through their control on the synoptic atmospheric circulation environment, are also shown to have marked impacts on the spatio-temporal characteristics of tropical cyclones. Implications for the general assessment of the tropical cyclone hazard potential in the South China Sea are discussed.

Tropical cyclone hazards and warning and disaster mitigation systems in India

The main features of a cyclone that cause death and destruction are: (1) Storm surge, a rapid increase in sea level along the coast, primarily caused by the strong surface wind field of the cyclone as it approaches the coast, (2) the violent sustained wind and wind gusts and cyclone-spawned tornadoes, and (3) the heavy rain and consequent flooding. The paper describes the structure of a tropical cyclone of hurricane intensity and its damage potential, cyclone detection, tracking, forecasting and warning systems. It concludes that with over a hundred years of research and operational experience on cyclones available with the meteorological community and with theinsat and cyclone detection radar network, India has now an efficient cyclone warning system. This system would however benefit from further sophistication notably the use of Doppler Radars for cyclone wind field monitoring and an aircraft reconnaissance facility for probing cyclones. Research is needed to develop techniques for better forecasting of the tracks of cyclones more than a day ahead and also their intensity changes. Cyclone disaster mitigation arrangements were organised in the maritime states of India only during the last 25 years. This relatively young field requires more developmental work, particularly in coastal area planning to reduce property losses, and exploration of alternative approaches to large-scale evacuation of the coastal population threatened by cyclones to distant temporary shelters.

Disasters and Development in Historical Context: Tropical Cyclone Response in the Banks Islands, Northern Vanuatu

The Banks Islands in northern Vanuatu are prone to tropical cyclones. While a thriving population appears to have coped with these events prior to European contact, since then a smaller population has struggled to maintain its food security following tropical cyclone events. A number of social, economic, political and resource management changes have led to a set of disaster pre-conditions which result in dependence on external food relief following tropical cyclones. Most of these changes have taken place in the intervening years between disasters and have occurred independent of the tropical cyclone hazard. However, one set of changes, the provision of food relief itself, has provided the catalyst for the other changes to occur.

Physical hazard and risk assessment in Jamaica, West Indies

Abstract Jamaica is prone to both earthquakes and hurricanes. The cities of Port Royal and Kingston respectively were destroyed by earthquakes in 1692 and 1907, whilst the island lies within the Caribbean hurricane belt with recent devastation being caused by a tropical depression in 1979 and Hurricane Allen in 1981. The Geological Survey of Jamaica has been actively involved in land use planning for many years. The recent contributions are briefly reviewed, particularly with respect to natural hazards such as landslips and flooding. The problems of preparing risk assessment maps from a weak data base are discussed. Preliminary Earthquake and Tropical Cyclone hazard maps which were prepared for the Office of Disaster Preparedness and Mitigation are presented as examples of the approach taken. The method, of necessity, was based on largely subjective assessments of ground materials and levels of risk. The preliminary maps were intended to provide general guidelines for planning and development and to prepare the way for further studies. The preparation of detailed engineering design guides was regarded as the logical development of this work and, to illustrate this, some initial results of a subsequent hydrological study of flood flow characteristics and flood prediction techniques are presented.