Cyclone Warning Research Articles

Public understanding of cyclone warning in India: Can wind be predicted?

In spite of meteorological warning, many human lives are lost every year to cyclone mainly because vulnerable populations were not evacuated on time to a safe shelter as per recommendation. It raises several questions, most prominently what explains people's behaviour in the face of such danger from a cyclonic storm? How do people view meteorological advisories issued for cyclone and what role they play in defining the threat? What shapes public response during such situation? This article based on an ethnographic study carried out in coastal state of Odisha, India, argues that local public recognising inherent limitations of meteorological warning, fall back on their own system of observation and forecasting. Not only are the contents of cyclone warning understood, its limitations are accommodated and explained.

Impact of Initial Condition on Prediction of Bay of Bengal Cyclone 'Viyaru' A Case Study

prediction of track and intensity of land-falling tropical cyclones is of the great importance in weather prediction in making an effective tropical cyclone warning. This study examines the impact of initial condition on real time prediction of Bay of Bengal cyclone Viyaru. For this purpose, the customized version of Advanced Research core of Weather Research and Forecasting (ARW-WRF) model with two-way interactive double nested model at 27 km and 9 km resolutions is used to predict the storm. The model initial conditions are derived from the FNL analysis and Global Forecasting System (GFS) analysis and the lateral boundary condition is provided every 3 hourly from GFS forecast. The model predicted track and intensity of the storm are compared with the India Meteorological Department (IMD) best-fit track. Results indicate that the track of the storm is reasonably well predicted by the model with both FNL and GFS initial condition. The track of the storm is better predicted by the model with FNL initial condition. It is found that in reference to the track predicted errors with GFS initial condition, the use of FNL initial analysis as condition resulted in 41%, 8%, 5% and 19% improvement respectively in 24h, 48h, 72h, and 96h forecast. This is due to less initial positional error in FNL analysis. The landfall time and location of the storm is also better predicted by the model with FNL initial condition. The trend of intensification and dissipation of the storm is also better predicted with FNL as the initial condition. The intensity of the storm in term of central sea level pressure (CSLP) and maximum surface wind (MSW) is over-predicted by the model with both initial conditions. The 24 hours accumulated precipitation around the landfall time is also better predicted by the model with FNL initial condition.

Smart cyclone alerts over the Indian subcontinent

AbstractThis article describes a first application of mobile telephony alerts for an extreme weather event ‐ the progression and landfall of cyclone Phailin. The international media picked up on the cyclone Phailin story (11th–12th October 2013) ‐ 800 000 people were evacuated within 48 h. Here we describe a novel scheme using Weather Research and Forecasting (WRF) simulations and mobile phone alerts for cyclone warnings. Cellphones have a deep penetration even in rural pockets of India and it is anticipated that the results of this commentary will inspire disaster mitigation efforts over many parts of the developing world.

Precipitation from Space: Advancing Earth System Science

Of the three primary sources of spatially contiguous precipitation observations (surface networks, ground-based radar, and satellite-based radar/radiometers), only the last is a viable source over ocean and much of the Earth's land. As recently as 15 years ago, users needing quantitative detail of precipitation on anything under a monthly time scale relied upon products derived from geostationary satellite thermal infrared (IR) indices. The Special Sensor Microwave Imager (SSMI) passive microwave (PMW) imagers originated in 1987 and continue today with the SSMI sounder (SSMIS) sensor. The fortunate longevity of the joint National Aeronautics and Space Administration (NASA) and Japan Aerospace Exploration Agency (JAXA) Tropical Rainfall Measuring Mission (TRMM) is providing the environmental science community a nearly unbroken data record (as of April 2012, over 14 years) of tropical and sub-tropical precipitation processes. TRMM was originally conceived in the mid-1980s as a climate mission with relatively modest goals, including monthly averaged precipitation. TRMM data were quickly exploited for model data assimilation and, beginning in 1999 with the availability of near real time data, for tropical cyclone warnings. To overcome the intermittently spaced revisit from these and other low Earth-orbiting satellites, many methods to merge PMW-based precipitation data and geostationary satellite observations have been developed, such as the TRMM Multisatellite Precipitation Product and the Climate Prediction Center (CPC) morphing method (CMORPH. The purpose of this article is not to provide a survey or assessment of these and other satellite-based precipitation datasets, which are well summarized in several recent articles. Rather, the intent is to demonstrate how the availability and continuity of satellite-based precipitation data records is transforming the ways that scientific and societal issues related to precipitation are addressed, in ways that would not be otherwise possible. These developments have taken place in parallel with the growth of an increasingly interconnected scientific environment. Scientists from different disciplines can easily interact with each other via information and materials they encounter online, and collaborate remotely without ever meeting each other in person. Likewise, these precipitation datasets are quickly and easily available via various data portals and are widely used. Within the framework of the NASA/JAXA Global Precipitation Measurement (GPM mission, these applications will become increasingly interconnected. We emphasize that precipitation observations by themselves provide an incomplete picture of the state of the atmosphere. For example, it is unlikely that a richer understanding of the global water cycle will be possible by standalone missions and algorithms, but must also involve some component of data, where model analyses of the physical state are constrained alongside multiple observations (e.g., precipitation, evaporation, radiation). The next section provides examples extracted from the many applications that use various high-resolution precipitation products. The final section summarizes the future system for global precipitation processing.

Education as a Determinant of Response to Cyclone Warnings: Evidence from Coastal Zones in India

Education is often considered a means for enhancing adaptive capacity, based on the consideration that formal education is likely to improve the ability of individuals to evaluate risks and respond to warning information. We explore the relation between the level and nature of education and enhanced ability to respond to tropical cyclone risk. We make a distinction between formal school-based education and nonformal education in the form of traditional knowledge of environmental precursors and conditions that may be associated with tropical cyclone occurrence. We evaluate two possible routes through which education could lead to enhanced ability to respond to tropical cyclone risk; first, education, both formal and nonformal, may lead to a better ability to access, understand, and interpret warning information and hence lead to an appropriate response to the warning; and second, formal education may be associated with greater income levels and socioeconomic status and thus with greater resources for evacuating in response to cyclone warning. We find that the hypotheses regarding the link between formal education and adaptive capacity are actually not well supported by empirical data. On the other hand nonformal education in the form of traditional knowledge of predicting cyclones based on environmental precursors emerged as a significant determinant of the ability to understand and interpret warning information and provides a strong case for preserving and promoting a hazard-specific traditional knowledge base along with formal education.

An Evaluation of Hong Kong's Tropical Cyclone Warning System

Hong Kong is frequently exposed to the destructive wind threats of tropical cyclones from the Western-North Pacific, mainly in summer season. The Tropical Cyclone Warning System (TCWS) has been working in Hong Kong since 1884. Nevertheless, the effectiveness of the TCWS in Hong Kong has so far only been evaluated in limited aspects. This study is an exploratory attempt to evaluate holistically the performance of an existing TCWS in Hong Kong. Dennis Parker's (1999) Criteria-development Matrix was adopted as an analytical framework to identify the strengths and weaknesses of the warning system. Our findings indicate that the TCWS of Hong Kong performed quite satisfactorily. Nonetheless, weaknesses in the current system were also identified which point to the absence of weather-related legislation and failures in recognizing the local needs. Future research agendas can be extended to the evaluative application of Criteria-development Matrix onto other siren systems in Hong Kong, China or other Asian cities and countries because the natural hazard and disaster risk management research is still largely western oriented.

Factors Affecting Evacuation Behavior: The Case of 2007 Cyclone Sidr, Bangladesh*

Cyclone Sidr, a Category 4 storm, struck the southwestern coast of Bangladesh on 15 November 2007. Despite early cyclone warnings and emergency evacuation orders for coastal residents, thousands of individuals stayed in their homes. This study examines Sidr victims’ responses to cyclone warnings and evacuation orders, and explores the factors that would explain why the victims did or did not comply with the orders. Based on survey data collected from 277 Sidr survivors living in the four most severely impacted coastal districts, this study found that more than 75 percent of all respondents were aware of the cyclone warnings and evacuation orders before Sidr's landfall. Despite the efforts of the Bangladesh government, there were lapses in cyclone warnings and evacuation procedures. Field data also reveal several reasons cited by respondents for not complying with evacuation orders. Multivariate analyses of survey data show that trust in warning messages was the most important determinant in the decision to seek refuge in safer shelters, followed by distance to nearest shelter and annual level of education. Several recommendations have been made to improve cyclone warnings and the use of public shelters for similar future events.

Corruption in cyclone preparedness and relief efforts in coastal Bangladesh: Lessons for climate adaptation?

This article seeks to draw possible lessons for adaptation programmes in Bangladesh by examining whether cyclone preparedness and relief interventions are subject to corrupt practices. Based on a random sample survey of 278 households, three focus-group discussions and seven key-informant interviews, the article investigates the nature and extent of corruption in pre- and post-disaster interventions in Khulna before and after Cyclone Aila in May 2009. Ninety nine percent of households reported losses from corrupt practices. Post-disaster interventions (such as food aid and public works schemes) suffered from greater levels, and worse types, of corruption than pre-disaster interventions (such as cyclone warning systems and disaster-preparedness training). Using an asset index created using principal component analysis, the article assesses how corruption affected wealth quartiles. Ultra-poor households were affected more by corruption in pre-disaster interventions, the wealthiest quartile more in certain post-disaster interventions, in particular public works and non-governmental interventions. These findings may hold lessons for attempts to increase resilience as current adaptation measures mirror some cyclone preparedness and relief efforts.

Classification of cyclone hazard prone districts of India

Hazards associated with tropical cyclones are long-duration rotatory high-velocity winds, very heavy rain and storm tide. India has a coastline of about 7,516 km of which 5,400 km is along the mainland. The entire coast is affected by cyclones with varying frequency and intensity. The India Meteorological Department (IMD) is the nodal government agency that provides weather services related to cyclones in India. However, IMD has not identified cyclone-prone districts following any specific definition though the districts for which cyclone warnings are issued have been identified. On the other hand, for the purpose of better cyclone disaster management in the country, it is necessary to define cyclone proneness and identify cyclone-prone coastal districts. It is also necessary to decide degree of hazard proneness of a district by considering cyclone parameters so that mitigation measures are prioritised. In this context, an attempt has been made to prepare a list of cyclone hazard prone districts by adopting hazard criteria. Out of 96 districts under consideration, 12, 45, 31 and 08 districts are in very high, high, moderate and low categories of proneness, respectively. In general, the coastal districts of West Bengal, Orissa, Andhra Pradesh and Tamil Nadu are more prone and are in the high to very high category. The cyclone hazard proneness factor is very high for the districts of Nellore, East Godawari, and Krishna in Andhra Pradesh; Yanam in Puducherry; Balasore, Bhadrak, Kendrapara and Jagatsinghpur in Orissa; and South and North 24 Parganas, Medinipur and Kolkata in West Bengal. The results give a realistic picture of degree of cyclone hazard proneness of districts, as they represent the frequency and intensity of land falling cyclones along with all other hazards like rainfall, wind and storm surge. The categorisation of districts with degree of proneness also tallies with observed pictures. Therefore, this classification of coastal districts based on hazard may be considered for all the required purposes including coastal zone management and planning. However, the vulnerability of the place has not been taken into consideration. Therefore, composite cyclone risk of a district, which is the product of hazard and vulnerability, needs to be assessed separately through detailed study.

Measuring people's preferences for cyclone vulnerability reduction measures in Bangladesh

PurposeThis paper aims to examine people's preferences for alternative cyclone vulnerability reduction measures in cyclone prone areas of Bangladesh.Design/methodology/approachA choice experiment (CE) method has been implemented based on the pressure and release (PAR) vulnerability model. Data were collected from a sample of households in two districts of Bangladesh in winter 2008.FindingsThe results of a choice experiment (CE) method conducted in selected areas of Bangladesh prone to cyclone hazards indicated that access to resources is viewed as the most influential factor in cyclone vulnerability reduction options. Findings support the pressure and release model (PAR) of vulnerability analysis. Access to training and education and cyclone warning systems are also found to have significant impacts on households' choices of cyclone vulnerability reduction. Structural mitigation measures and access to power and decision making, though significant, were found to have the least impact.Research limitations/implicationsThe paper shows that the choice experiment method is a good technique for understanding people's preferences for vulnerability reduction measures.Practical implicationsThe paper concludes with a policy recommendation for governmental and non‐governmental agencies to focus on vulnerability reduction measures that tackle the root causes of vulnerability.Originality/valueThis is the first time that the choice experiment method has been used for cyclone vulnerability analysis, and it provides quantitative supports for the PAR model.

From dissemination to response: in search of new strategies for broadcast media in terms of cyclone warnings for Bangladesh

Media and communications technologies play a significant role in disaster management procedures in regards to the mobilization of resources in emergency situations. While the dissemination of warning messages relayed via broadcast technologies have had some positive outcomes in terms of reducing casualties in emergency situations in Bangladesh, there remain some specific problems in regards to the manner in which these messages are distributed within this developing nation. These problems are addressed within this paper. Examining the existing cyclonic warning dissemination system and the manner in which warning information is distributed and received, this study addresses citizen responses to mediated warning messages in the vulnerable coastal regions of Bangladesh. The results indicate that attitudes towards mediated warnings held by Bangladeshi citizens in these environs differ depending upon their access to media, type of dwelling and differing levels of literacy. This study also provides recommendations for media professionals and policymakers in regards to disseminating more effective warnings to the inhabitants of Bangladesh's cyclone-prone coastal belt.

Performance of Coastal Structures during Cyclone Sidr

On November 15, 2007, Bangladesh was hit by the category 4 storm Severe Cyclonic Storm Sidr. At least 3,447 deaths were reported in coastal areas of Bangladesh, mainly owing to the storm surge, which was >5 m. A study team of several faculty members of Bangladesh University of Engineering and Technology (BUET) was formed to visit areas affected by Sidr, two months after the storm. It was found that cyclone shelter capacities were inadequate for the population of the service area. Without shelters, many livestock animals died during the disaster. Many people neglected cyclone warnings, which resulted in many deaths. To improve cyclone shelter performance, this study makes many recommendations, including building more cyclone shelters, providing shelters for livestock, and improvement of warning systems.

Hazard Warnings and Responses to Evacuation Orders: the Case of Bangladesh's Cyclone Sidr*

On 15 November 2007 Cyclone Sidr, a category 4 storm, struck the southwestern coast of Bangladesh. Despite early cyclone warnings and evacuation orders for coastal residents, thousands of individuals stayed in their homes. This study examines dissemination of the warning, assesses the warning responses, and explores the reasons why many residents did not evacuate. Field data collected from 257 Sidr survivors in four severely affected coastal districts revealed that more than three‐fourths of all respondents were aware of the cyclone warnings and evacuation orders. Despite the sincere efforts of the Bangladesh government, however, lapses in cyclone warnings and evacuation procedures occurred. Field data also revealed several reasons why evacuation orders were not followed. The reasons fell into three broad groups: those involving shelter characteristics; the attributes of the warning message itself; and the respondents' characteristics. Based on our findings, we recommend improved cyclone warnings and utilization of public shelters for similar events in the future.

Dynamics of cyclone evacuation behavior among southwestern coastal residents in Bangladesh: A case study of cyclone Sidr

Cyclone Sidr struck the southwestern coast of Bangladesh on November 15, 2007, resulting in 3,406 deaths and damaged properties of about US $1.7 billion. Despite the government’s sincere efforts, thousands of coastal residents did not comply with the evacuation orders. This article attempts to identify the sociodemographic factors affecting evacuation choices during the cyclone. Following systematic random sampling technique, a total of 384 heads of household was surveyed in the southwestern coast of Bangladesh. The bivariate results indicate that single women, older residents, people with small possessions, and people with higher level of education and occupation are more likely to evacuate. Moreover, level of education, household’s status of food security, trust in cyclone warning, and perceived severity of cyclone are also found as significant predictors of evacuation choice. Trust in cyclone warning has been found as the single best predictor. This article recommends improvement in the cyclone warning system, establishment of more public cyclone shelters, and implementation of different campaigns in coastal areas to increase the use of public shelters.

Critical time requirements for operational use of deterministic and ensemble tropical cyclone track forecasts

Tropical cyclone track forecasts have been improved, and forecast intervals have been extended to five days, owing to improved global and regional numerical model guidance. Critical time requirements that must be met for operational use of the deterministic model track forecasts are summarized for the U.S. and other selected non-U.S. tropical cyclone warning centers. One of the most accurate deterministic model forecasts from the European Center for Medium-range Weather Forecasts arrives too late to be used with other models at the + 6 h warning time, and thus is at least 12 h old before it can be operationally used. The time-critical nature of the tropical cyclone warning system is a major obstacle to operational use of single-model, or proposed multi-model, ensemble prediction system (EPS) mean and spread information, which is 12 h (or 18 h) delayed. This EPS mean and spread must also be superior to the mean and spread of the consensus of deterministic models that are available six hours earlier. These requirements must be met before the EPS tropical cyclone tracks will be operationally useful in specifying the uncertainty in the official track forecasts, which is the next challenge in tropical cyclone track warnings.

Cyclone evacuation in Bangladesh: Tropical cyclones Gorky (1991) vs. Sidr (2007)

Based on two separate post-cyclone pilot surveys on evacuation behaviour during two category 4 tropical cyclones in Bangladesh—Gorky in 1991 and Sidr in 2007—this study attempts to explain why the overwhelming majority of cyclone victims did not participate in evacuation initiatives, irrespective of significant changes in cyclone preparedness in Bangladesh following 1991. Although the two surveys were conducted in different time horizons—one about 10 years following the catastrophic event (Gorky) and the other in the immediate aftermath of the event (Sidr)—the cyclone victims cited similar reasons for their lack of evacuation to designated cyclone shelters. Despite recent improvements in cyclone warning systems and a major expansion of public cyclone shelters in coastal Bangladesh, which are clearly reflected in significant increases in formal evacuation, from only 3 per cent of the Gorky respondents to 33 per cent of the Sidr respondents, the lack of adequate numbers of shelters and problems with the cyclone warning systems have been attributed by the respondents as the principal deterrents of evacuation to the designated shelters. Most of the other factors, such as problems with logistics, gender issues, anxiety about the security of possessions left at home, and respondents' perceptions and experience of the cyclone hazards, are consistent with the findings of previous studies on the Gorky event, in particular, and other studies on cyclone/hurricane evacuation, more generally.

Assessing adaptive capacity to tropical cyclones in the East coast of India: a pilot study of public response to cyclone warning information

Ability to respond positively to climate hazards (also called adaptive capacity) first requires a perception of the risk due to that hazard and then formulation, evaluation and implementation of response by the exposed units with the view to reducing impacts. From a policy perspective, facilitating the process of perception of risk (and sometimes formulation, evaluation and implementation of response) often requires some kind of generation and communication of information for use by the exposed units. For example, the cyclone early warning system is a policy intervention which aims to generate and communicate information to the people about a possible cyclone occurrence, so as to facilitate timely and appropriate response such as evacuating the risk prone areas and/or taking refuge in a cyclone shelter by the people in danger. Anecdotal evidence suggests that many a time the cyclone warning message is not able to generate the desired response from the target audience. An understanding of the factors underlying the process of perception, formulation, evaluation and response by the exposed units to manage cyclone risk is required to close the gap between the desired response and the actual response by the exposed units to the warning information. In this paper we attempt to identify such factors in the Indian context. We conducted an exploratory study on the East coast of India to identify the factors that affect the perceptual and evaluative processes underlying the ‘warning-response’ process i.e. evacuation behavior of the exposed units once they have received the cyclone warning. The findings highlight some important factors that could be addressed to improve the warning-response process and hence enhance the ability of people to respond to cyclone risk.

Why relatively fewer people died? The case of Bangladesh’s Cyclone Sidr

Cyclone Sidr, a Category IV storm, struck the southwestern coast of Bangladesh on November 15, 2007 killing 3,406 people. Despite a similar magnitude, Sidr claimed far fewer lives than Cyclone Gorky, also a Category IV storm, which struck Bangladesh in 1991 causing an estimated 140,000 fatalities. The relatively low number of deaths experienced with Sidr is widely considered the result of Bangladesh government’s efforts to provide timely cyclone forecasting and early warnings, and successful evacuation of coastal residents from the projected path of Cyclone Sidr. Using information collected from both primary and secondary sources, this study identified several other reasons for the unexpectedly lower mortality associated with Cyclone Sidr relative to Cyclone Gorky. Fewer casualties may be attributed to a number of physical characteristics of Cyclone Sidr, such as duration of the storm and storm surge, landfall time and site, varied coastal ecology, and coastal embankment. This article recommends improvements to the cyclone warning systems, establishment of more public cyclone shelters, and implementation of an education campaign in coastal areas to increase the utilization of public shelters for future cyclone events.

The effects of cyclones, tsunami and earthquakes on built environments and strategies for reduced damage

There is a general belief that Sri Lanka is in a disaster free zone. However, frequent cyclone warnings and earthquake tremors over the past few decades and the December 2004 Tsunami show that this belief may no longer be valid for Sri Lanka. The Tsunami of 26th December 2004, which devastated a 800 km stretch of costal area of Sri Lanka killed more than 36,000 unwary people and displaced more than 800,000. It was the worst ever disaster in the history of Sri Lanka. Due to inadequate attention paid to these events in construction practice, the damages caused are enormous both to human life and to the built environment. There is no guarantee that this kind of natural disaster will not happen again. They could repeat in the future, may be with lower magnitudes or intensity. This indicates that some kind of disaster preparedness is of great importance today. This paper deals with few natural disasters which could affect the built environment, and suggests some simple and useful guidelines to improve the disaster resistance of low rise buildings. Keywords: Built environments, disaster resistance, natural disasters doi:10.4038/jnsfsr.v36i1.128 Journal of the National Science Foundation of Sri Lanka 36 (1) 3-14

２００７年サイクロン「シドル」によるバングラデシュの高潮災害

Cyclone Sidr passed on the southwestern part of Bangladesh and induced storm surge disasters affecting 8.9 million people in November 15, 2007. From the point of disaster mitigation on storm surges, we surveyed damages of this disaster and assistance needs for recovery in damaged areas. Long stretch of river embankments was eroded by overflowing during the storm surge. Cyclone warning was transmitted to many people through the system based on Cyclone Preparedness Program. Continuous disaster education and succession of disaster experiences are important as well as improvement of river embankments.