探讨自动气象站的雷电防护措施

随着社会的进步,科学技术的不断发展,气象事业也在越来越快的发展。自动气象站是大气探测地基系统的重要组成部分,采用自动气象站对气象信息进行观测,能够节省很多的人力,为偏远地区的测量提供方便,然而部分自动气象站的仪器要求放置在室外,容易遭受雷击。基于此,文章针对于自动气象站防雷防护做一些初步的探索,希望能给大家以启发。     

Lightning whelk natural history and a new sourcing method

Artifacts made from sinistral (left-handed) whelk shells are commonly found at inland archaeological sites in eastern North America. Past attempts to source the coast of origin of these marine shells based on chemical analyses have provided tentative results. A knowledge of sinistral whelk natural history is essential before attempting shell sourcing studies. The common occurrence of sinistral whelks in the Gulf of Mexico and their uncommon occurrence along both the South Atlantic and Mid-Atlantic bights are documented. Critical biogeographical and morphological information is presented, as well as a new method of sourcing artifacts based on spire-angle measurements. Sinistral whelk artifacts from Spiro, East St. Louis, and Cahokia probably came from the eastern Gulf of Mexico.     

Lightning return stroke electric fields above ground

The vertical and horizontal field wave shapes derived from the Liènard-Wiechert potentials for a lightning return stroke are presented. The calculations were performed for ranges from 50 m to 5 km and altitudes from ground level up to 10 km, assuming a finitely conducting ground. It was found that the finite ground conductivity affects the fields at close ranges and lower altitudes. It was also found that the effect introduced by considering the Liènard-Wiechert potentials is to increase the initial field peaks and the time to peak. The maximum deviation in peak fields observed due to this effect is 40%.     

Health hazards of floods: hospital admissions for Lismore

Severe unprecedented flooding of unprepared and inexperienced communities adversely affects community health, but the effect of severe flooding on well-prepared and experienced communities is less certain. An answer was sought for the New South Wales coastal town of Lismore. Parts are flooded every year with the last major flood occurring in 1974. Hospital admission and death certificates were analysed for the years before and after that flood. Using this data and information from an earlier survey two types of analysis were undertaken: a comparison of mortality and hospital admissions before and after the flood; and a comparison of health effects between different levels of flooding, including residents whose properties were located outside the flood plain. Although the flood did not appear to increase the number of hospital admissions or deaths, the ratio of male to female admissions showed a significant change. For those severely flooded, male admissions doubled while female admissions halved. Analysis of the data in relation to flood risk showed that for both pre-and post-flood periods hospital admissions were closely related to the degree of flood risk. Those whose dwellings were subject to a metre or more offloodwater over floor level are twice as likely to be admitted to hospital as residents of the flood free areas.     

Natural hazards and religion in New Orleans: Coping strategies and interpretations

Socially disadvantaged people are more vulnerable and exposed to the effects of extreme natural events and the social disasters which follow. This article presents the coping strategies and cultural creativity of the most vulnerable (non‐conformist African American religious/spiritual) communities in New Orleans today and in the aftermath of Katrina. Rituals and religious practices play an important role in resilience‐building and for relief and recovery from disasters. Case studies are presented to demonstrate how these devotions, and the community‐building and mutual support that take place as a result (as well as individual practices), have assisted practitioners in their struggle for survival during Katrina and the yearly hurricane season. The article also examines how natural hazards are perceived and reflected in religious explanations and expressions, as well as in spiritual arts, and how they lead to change and adaptations. Here, affected people are not regarded as ‘passive victims’ but as creative and active agents.     

Vulnerability to climate change hazards and risks: crop and flood insurance

This paper reviews the widely used concepts of risk and vulnerability as they relate to climate and weather hazards, re‐conceptualizes these terms in the context of climate change and illustrates this development using crop and flood insurance as examples. Government subsidization of insurance against risks associated with adverse climatic conditions and weather events, such as flood damage and crop loss, may lead to individual decisions that actually increase the susceptibility of people, property and economic activities to those risks. The processes that give rise to this phenomenon are important in understanding the vulnerability of human populations to climate change. In many regions, existing conditions that give rise to flooding or crop failure are likely to be exacerbated by climate change over coming decades. In the climate change field, vulnerability has been conceptualised as a function of exposure to risk and as an ability to adapt to the effects. In this context, crop and flood insurance are possible adaptive measures. This treatment of vulnerability compares with similar concepts in insurance and risk management whereby events that cause loss are known as perils, and physical conditions, such as climate change, that increase the likelihood of a peril occurring, are known as physical hazards. Human behaviour that increases the exposure of individuals to potential perils is known as morale hazard or moral hazard, depending on the intentions of the person. Vulnerability consequently becomes a function of hazard and responses taken to reduce risk. Examples of crop and flood insurance programs from Canada, New Zealand and the U.S. are used to show how subsidized insurance might create a morale hazard in addition to physical hazards such as short‐term weather events and long‐term climate change, resulting in a higher level of vulnerability than would otherwise exist. These findings demonstrate that human behaviour affects the formation of both exposure and adaptive capacity in the context of vulnerability to climate change. Responses taken to increase adaptive capacity may in some cases be offset by individual behaviour that increases exposure.