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除水旱灾害之外,清代后期对湖南危害较大的灾种主要为虫灾,风灾、雹灾、冰冻雪灾偶有发生.本文对上述灾害的灾情进行了论述. 相似文献
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EVA KOZUBÍKOVÁ†† L. FILIPOVÁ P. KOZÁK† Z. URI‡ M.P. MARTÍN§ J. DIÉGUEZ-URIBEONDO§ B. OIDTMANN A. PETRUSEK† 《Conservation biology》2009,23(5):1204-1213
Abstract: In Central Europe invasive North American crayfishes are carriers of the oomycete Aphanomyces astaci, which causes crayfish plague. This lethal disease currently represents one of the major threats to native European crayfishes. We used molecular methods—species-specific amplification and sequencing of the pathogen DNA—to investigate the prevalence of individuals latently infected with A. astaci in 28 populations of two invasive American crayfish species (6 of the signal crayfish [ Pacifastacus leniusculus ] and 22 of the spiny-cheek crayfish [ Orconectes limosus ]) in the Czech Republic. The pathogen occurred in 17 investigated populations. We recorded a high variation in positive reactions, ranging from 0% to 100%, in populations of O. limosus . In P. leniusculus, however, only one individual out of 124 tested positive for the pathogen. There was a clear relationship between the water body type and pathogen prevalence in O. limosus . Infection ratios in isolated standing waters were usually low, whereas in running waters, pathogen prevalence often exceeded 50%. Other evaluated characteristics of potential plague pathogen carriers (size, sex, and the presence of melanized spots in the cuticle) seemed to be unrelated to infection. Our data suggest that in contrast to other European countries, O. limosus seems to be the primary reservoir of crayfish plague in the Czech Republic. Although all populations of alien American crayfishes may be potential sources of infections and should be managed as such, knowledge on the prevalence of the plague pathogen at various localities may allow managers to focus conservation efforts on the most directly endangered populations of native crayfishes. 相似文献
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基于对历史文献资料的梳理,针对1615—1619年我国发生的重大旱、蝗、涝等群发灾害,以蝗灾为主线,复原蝗灾事件的时空演化过程,解析其发生的气候背景和社会响应。结果表明:(1)蝗灾事件呈现五年的发生发展衰亡周期,县次波动明显,1616和1617年为峰值年份;(2)蝗灾以中、高等级发生为主,核心区域为黄淮海平原,热点地区为山东、河南、安徽等;空间上呈现“北密南疏”、“北方主导”的分布格局;(3)蝗与旱、涝的空间叠加显示,旱-蝗组合集中分布于黄淮海平原及其毗邻地区,涝-蝗组合则呈零星分布,旱蝗并发的频次高于涝蝗,旱蝗关系更紧密;(4)蝗灾频发与大发伴生饥荒、疫灾,体现了灾异的时空传递与承继,且次生灾害的出现存在滞后效应;(5)在寒冷期,蝗灾与温度呈现正相关,与降水呈现负相关。 相似文献
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BRETT F. EDGERTON PAULA HENTTONEN† JAPO JUSSILA†‡ ARI MANNONEN‡ PIETARI PAASONEN§ TROND TAUGBØL LENNART EDSMAN†† CATHERINE SOUTY-GROSSET‡‡ 《Conservation biology》2004,18(6):1466-1474
Abstract: Native European freshwater crayfish (Astacida, Decapoda) are under severe pressure from habitat alteration, the introduction of nonindigenous species, and epizootic disease. Crayfish plague, an acute disease of freshwater crayfish caused by the fungus-like agent Aphanomyces astaci , was introduced into Europe in the mid-nineteenth century and is responsible for ongoing widespread epizootic mortality in native European populations. We reviewed recent developments and current practices in the field of crayfish pathology. The severity of crayfish plague has resulted in an overemphasis on it. Diagnostic methods for detecting fungi and fungal-like agents, and sometimes culturing them, are frequently the sole techniques used to investigate disease outbreaks in European freshwater crayfish. Consequently, the causes of a significant proportion of outbreaks are undetermined. Pathogen groups well known for causing disease in other crustaceans, such as viruses and rickettsia-like organisms, are poorly understood or unknown in European freshwater crayfish. Moreover, the pathogenic significance of some long-known pathogens of European freshwater crayfish remains obscure. For effective management of this culturally significant and threatened resource, there is an urgent need for researchers, diagnosticians, and resource managers to address the issue of disease in European freshwater crayfish from a broader perspective than has been applied previously. 相似文献
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《Environmental Hazards》2013,12(2):161-180
The 1994 outbreak of pneumonic plague in Surat, India is revisited and analyzed using the pressure and release (PAR) model. Overviews of the outbreak, of India's experience with plague, and of the disease are provided and the PAR model is used to trace the production of vulnerability via root causes, dynamic pressures, and unsafe conditions and to explain the why, when, and where of the epidemic. The emergence of plague in Surat was an unfortunate amalgam of prior hazard events and of factors generating vulnerability. Root causes include the country's colonial legacy and a complex and pervasive social hierarchy promoting caste and class interests over the common good. Dynamic pressures include: a curative-focused healthcare system; a weak civil society; misplaced spending priorities; and public and private corruption that deprived public health programs of needed funds and which compelled workers to live and labor in unhealthy environments. Unhealthy public, residential and workplace environments; fragile economic conditions; and a lack of surveillance and preparation are immediately linked to the outbreak and to the transmission of pneumonic plague. 相似文献
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全面系统地总结了<中华人民共和国鼠疫与环境图集>的设计思想、研制方法和原则以及图集所揭示的内容和规律首次利用图集的方式进行空间分析,研究我国鼠疫的流行、防治和疫源地特性及其与环境的关系.图集主要由序图组、环境背景图组、世界鼠疫流行及疫源地背景图组、自然疫源地与环境图组、流行图组、宿主分布图组、媒介蚤图组、鼠疫菌生物型图组、防治机构图组和防治效果图组组成.在鼠疫病情数据的处理和病情图的制作、环境背景图的制作和疫源地特征图制作等方面,都力求多层次、多角度和多种方式地表达鼠疫与环境的关系.它客观、科学地反映和阐述了我国200多年来鼠疫流行的空间和时间特征,揭示了我国鼠疫疫源地的分类和分布以及鼠疫菌的质粒组合和生化特性的地域分异规律,并发现鼠疫疫源地的分布和形成与地球化学环境密切相关. 相似文献
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历史时期瘟疫的研究对现代瘟疫的防治具有重要的意义。本文选取陕西省为研究区域,在大量收集历史文献资料的基础上,初步考察了康熙三十至三十一年(1691—1692年)陕西瘟疫发生的情况,并着重分析了这次瘟疫爆发的相关原因。结果表明,干旱灾害、社会风俗、治疫政策等是瘟疫爆发的主要诱因。 相似文献
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从历史地理学的角度,对明代277年的山西蝗灾进行数据统计分析。结果表明:从时间上看,明代山西蝗灾每4~5年发生一次;在季节上,主要集中在夏秋两季,其中秋季危害最重,具有明显季节差异;在月份上,主要集中在阴历6月;从地域上看,泽州和平阳府蝗灾分布具有普遍性,同时也是蝗灾发生最为频繁的地区,大同府和汾州府蝗灾分布较集中,辽州和汾州府发生蝗灾次数最少,明代山西蝗灾主要沿河分布,主要集中在晋南区,具有明显的地域差异。 相似文献
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河南省1942—1943年旱,风,蝗灾害略考 总被引:2,自引:0,他引:2
有史以来,河南水旱灾害频繁,不绝于书。1942~1943年河南又出现了特大旱灾,其灾情之重,范围之广,为近代史罕见。加上蝗蝻为患,干热风肆虐,造成麦秋绝大部分绝收,灾民饿死达数百万人。根据当时的有关资料,初步探讨,提供历史借鉴。 相似文献