Lightning Disaster Research Articles

The Determination of Lightning Disaster Hazard Index Using Analytical Hierarchy Process

In order to minimize the losses caused by lightning, a lightning disaster management system is compulsory. It should provide lightning disaster information in an area to get the risk values of lightning strikes. One way is to establish a lightning disaster risk map. The disaster risk map consists of hazard map, vulnerability map and capacity map. However, lightning yet has not been included in the regulation guiding the establishment of risk map for several disasters in Indonesia. This study is conducted to develop a process to determine general hazard index for lightning disaster.

Lightning Risk: An Under-Valued Disaster?

<div><p><em>Lightning is a very common natural phenomenon which primarily solicits little attention. In this climate – allied innate localized activity, high electric charges are generated which cause disastrous outcomes, both physically and economically. Many lives are burnt and severe losses are suffered due to this natural disaster. But, it is often doubted that the deaths and economic losses due to lightening are under reported. Many reasons are cited as difficult in getting authentic figures, inadequacy of the government rules in the reporting areas etc. Disaster relief is also outside the sphere of such calamity. Comparison between the loss figures due to lightning with other disaster loss figures also reveals that the former ranks higher than the latter. Still, many of the lightning disasters are not properly accounted and recompensed by National Calamity and Relief Fund or any other such Relief Funds. The article is an attempt to see the depth of such an issue and major challenges faced by the victims to get the compensation from the authorities. Also, suggestions are sought to arrive at a satisfying solution to such an unnoticed problem.</em></p></div>

Temperature distribution and evolution characteristic in lightning return stroke channel

According to the time-resolved spectra of four lightning return strokes, the temperatures of arc core channel and the peripheral optical channel surrounding the arc core are investigated by different methods; the temperature distribution along the radial direction of channel on the peak current stage is discussed. The results show that a temperature gradient is formed along the radial direction of channel during the discharge process. With the increasing of the radius, the temperature decreases gradually. The temperature of arc core channel is about 4000–5000K higher than that of the peripheral optical channel. The time evolution of channel temperature shows that the falling of the temperature is very slow compared with the decreasing of the current after their peak values. After the peak current, the channel temperature is still maintained at around 20,000K up to 200–400μs. The heat effect resulting from such a long-time high temperature is the main source of most direct lightning disasters.

Research on C5.0 Algorithm Improvement and the Test in Lightning Disaster Statistics

After analysis the importance of continuous attributes in the C5.0 algorithm processing, and consider the shortcomings of discretization method of C5 algorithm, this paper proposes a new method based on Rough set theory- information entropy- discernible matrix discretization (RSIEDM). The method uses rough, information entropy and Discernible matrix that can be more reasonable and more accurately to continuously attribute discretization, and making created decision tree have better accuracy. In the application of optimization of lightning disaster statistics and evaluation result of lightning disaster, the algorithm which has obtained a better effect.

Analysis about Influence on Surrounding Lightning Environment of Communication Base Station Based on One Lightning Disaster

With the lightning position data in recent years of Jiangsu, satellite and live data on 3rd,July,2012, the reasons for the damage to office room equipment beside a communication base station in Wujin District, Changzhou were analyzed, and reasonable suggestions were given. Based on the lightning accident, this paper analyzed the reasons of lightning strike to buildings near communication base station from weather, lightning strike probability, the validity of lightning protection device and potential. It is mainly because of lightning electromagnetic pulse. Base station can protect the buildings inside the protective area from direct strike, but which increased the possibility of damage to equipment from lightning impulse, at the same time, direct lightning strike probability in the scattered strike zone may increase. Therefore communication base station should be sufficiently far away from the building, when it cant meet a safe distance, not only the direct lightning protection measures should be taken to protect the station and buildings, but also protection measures against lightning electromagnetic pulse for equipment in buildings around are needed.

A digital lightning prototype system: DLPS/HUST

Digital lightning is an important thematic branch of the digital earth. Lightning data are complex, momentary, discrete, dynamic and spatio-temporal in nature. Hence, making great progress in their management, analysis and service is challenging. Many studies have been directed towards this field all over the world. Some different relevant systems are currently available. However, most of them focus on a single or a few aspects of lightning applications, rather than taking an overall account of lightning detection, management, analysis and service from the strategic perspective of the digital earth. Lightning disaster also demands a better developed spatial information technology in this field than at present. The idea of the digital earth offers a reasonable scheme to address these issues. Based on reviews of the concept, development and progress of the digital earth, an integrated technical framework of a digital lightning prototype system (DLPS) is proposed, including its data, functions and implementation of subsystems, which aims at the facilitation, management, accessing, visualisation, application, release and sharing of lightning data. Some key technologies are also carefully discussed to facilitate the construction of the DLPS. This framework could provide a helpful guide to future lightning research and hazard mitigation, as well as enrich connotation on the digital earth. So far, there are still many difficulties in multi-level grid construction that need to be solved.

Research on the Lightning Information Management System Based on GIS

Lightning disaster has caused billions of dollars of property and infrastructure damages, unexpected disruption to socioeconomic activities and tragic loss of human beings each year. Considerable work has been done on lightning mechanism and its detection approach. However, little work was concerned about the effective management of lightning. In this paper, both a geographic information science (GIS) and a database management system (DBMS) were used to manage the lightning spatial data and provide service products in the proposed system. Some of the basic methods and strategies such as architecture design, function dividing and database classification were outlined. The lightning spatial database comprises data on lightning thematic, fundamental geographic and other raster imagery data, readily providing information for further development of lightning relevant applications. The proposed system was exemplified in Hainan area. As the system runs stable and provides a valuable tool for the further study on lightning, it can be recommended to a national level of China.

Lightning casualties and damages in China from 1997 to 2009

Lightning-related fatalities, injuries and property damages reported in China from 1997 to 2009 are summarized by using the National Lightning Hazards Database. Therefore, characteristics of the incidents including 5,033 deaths, 4,670 injuries and 61,614 damage reports are analyzed. For the spatial distribution of lightning disasters in China, the eastern costal and southern areas have more frequent lightning disasters than the western areas. Lightning disasters mainly occur in summer months from July to September, while fewer damages occur in winter months from October to March, which correlate significantly with the temporal variability of lightning frequency in China. Lightning-related casualties and damages in China have increased for the period of 1997 to 2007 and then began to decrease since 2008. The national fatalities and injuries per million people per year are 0.31 and 0.28, respectively. Rural people account for 51 and 29% of all lightning fatalities and injuries, which makes residents in agricultural and rural area the major lightning victims. Characteristics of lightning disasters and correlative factors are also studied, including hazard-affected industries and locations. The results show that civil industry has the worst property loss and farmland is the largest category in lightning-caused casualty locations.

Investigations into Mechanisms of Involvement of Objects and Personnel in Lightning Disasters

Cloud to ground lightning causes damage to objects and injures people by different mechanisms like direct hit, contact voltage, side flash, step voltage etc. Understanding the different ways of involvement of objects and personnel in lightning disasters is helpful in deciding the type and level of external protection. Details of investigations conducted in 47 lightning disasters spread over several years are presented. The different types of mechanisms of involvement of objects and personnel in these incidents are discussed. All the incidents investigated were from Kerala, India which is a region of relatively high vegetation density. In 51% of the cases objects and personnel were found to have got involved by ground conduction of lightning energy into dwellings. Some of the cases of ground conduction involvements are unusual. The high degree of damage in some of the unusual cases is attributed to the continuing current component. The role of metal objects in charge collection and dissipation is also discussed. The relative importance of ring conductor to the lightning conductor in places of high vegetation density is brought out.

Analysis of Lightning Disasters in China and Their Correlative Factors

In order to obtain a better reveal of the spatial and temporal distribution and formation mechanism of lightning disasters in China,this paper establishes a national lightning disaster database and gives statistic analysis of lightning disaster data from 1997 to 2006,in combination with the analysis of satellite-based Optical Transient Detector and Lightning Imaging Sensor lightning detecting data from 1995 to 2005 over China.Characteristics of lightning disasters and correlative factors are studied,including lightning exposure,hazard formative environment,hazard,hazard affected bodies and their interactions.The results are as follows.(1) The frequency of lightning disasters and lightning-related casualties correlate with hazard(lightning activities) and hazard affected bodies(population and economic development) in different areas of China.Taking area into consideration,lightning casualties correlate with lightning density,population density and the average GDP,but in negative correlation with rural population proportion and area.Various types of lightning exposure are closely related to various types of hazard affected bodies(proportion of urban population to rural population and economic development).Casualties from lightning disasters rate higher where rural population proportion is higher,while cities mainly suffer property loss from lightning disasters.(2) The annual and diurnal variations in the lightning casualties and the lightning damage correlate significantly with that of the lightning rate.Compared with lightning damages,lightning casualties are affected by people's life routines and habits.(3) Different hazard formative environment causes different ways of lightning casualties and damages.The most proportion lightning fatalities occur on farmland,while the most proportion lightning injuries occur in buildings.(4) 80% of lightning casualties incidents only involve one or two victim,while 61% of the cases involve one victim and 19% involve two victims.Lightning disasters with one death account for 83% of all lightning disasters involving death,while lightning disasters with two death accounts for 12%.(5) Major lightning casualties are directly related to vulnerability of hazard affected bodies.54% of major lightning casualties happen in rural buildings and constructions,in most of which lightning protection appliances are not installed.21% happen in sites with danger of explosion and fire,while 13% and 8% happen in classrooms and tourist sites respectively.

Adolescents' perceived risk and personal experience with natural disasters: An evaluation of cognitive heuristics

Elevated risk judgments for negative life events have been linked to personal experience with events. We tested the hypothesis that cognitive heuristics are the underlying cognitive mechanism for this relation. The availability (i.e., memory for incidents) and simulation (i.e., imagery) heuristics were evaluated as possible mediators for the relation between personal experience and risk estimates for fatal weather events. Adolescents who had experienced weather disasters estimated their personal risk for weather events. Support was obtained for the simulation heuristic (imagery) as a mediator for the relation. Availability for lightning disaster experience was also found to be a mediator for the relation between personal lightning disaster experience and risk estimate for future events. The implications for risk perception research are discussed.