共查询到20条相似文献,搜索用时 525 毫秒
1.
我国小麦白粉病发生流行的长期气象预测研究 总被引:16,自引:0,他引:16
确定了影响我国小麦白粉病发病流行的9项关键环流特征因子指标,其中4项较好地表征了我国小麦白粉病发病面积轻、偏轻、偏重、重4个级别的气候特征.以关键环流特征因子距平为预测因子,建立的上年10月初、当年4月初制作预报的2个全国小麦白粉病发病面积距平预测模式历史拟合效果较好,对2004年的外延预报准确率分别达87.5%和98.2%.通过分析关键大气环流特征因子对我国小麦白粉病发生流行的可能影响机制,发现前期关键环流特征因子对我国小麦白粉病的发生流行具有很好的气候背景指示效应. 相似文献
2.
近年来陕西省小麦条锈病流行规律及其与气象条件的关系 总被引:1,自引:0,他引:1
《灾害学》2019,(3)
对陕西省小麦条锈病的发病规律和影响因素进行分析,为陕西省小麦条锈病预报预警、综合防治提供科学依据。基于陕西省2010-2017小麦条锈病调查资料和温度、降水等气象要素资料,利用DPS数据处理系统,采用相关分析法,分析小麦条锈病发生流行监测指标与气象因子的关系,筛选关键时段和气象因子;采用线性回归、非线性回归和逐步回归分析方法,研究陕西省小麦条锈病发生流行规律,建立小麦条锈病发生流行监测指标与气象因子的关系模型。结果表明:近年来,关中、陕南地区条锈病平均始见期分别为4月18日和1月30日,两地区始见期时间顺序都为由西向东逐步推迟,全省条锈病始见期具有提早的趋势。研究期内陕西省小麦条锈病发病程度变化趋势不明显,秋田发病面积具有逐年减少的趋势,而最终病田面积具有逐年增加的趋势。条锈病发生面积扩展过程可用逻辑斯蒂(Logistic)生长曲线来模拟。小麦条锈病始见期的早晚对最终发生面积具有极显著影响,始见期越早最终病田面积越大,始见期越晚最终病田面积越小。冬前条锈病发生面积与最终发生面积的关系不大,初春发生病面积与最终发生面积具有极显著的相关关系。陕西小麦主产区条锈病流行取决于春季菌源传入时间和数量。反映小麦条锈病的指标(始见期、流行速率、发病面积、发病程度)与冬季温度、初春降水量关系密切。冬季温度高,有利于条锈病孢子越冬;初春降水多,空气湿度大有利于条锈病滋生、蔓延和流行。暖冬、初春降水多等有利气象条件是陕西省小麦条锈病流行的外因。 相似文献
3.
基于多种预测模型的玉米低温冷害预测集成模型 总被引:2,自引:0,他引:2
引入大气环流特征量因子、500hPa高度场因子、太平洋海温因子以及预报量本身的均值周期因子等四类因子的低温冷害预测子模型来建立玉米低温冷害预测集成模型。利用该集成模型预报下一年温度等级时,将上一年的实况资料输入预测模型,滚动预测,克服了统计模型预报时效短的缺点,且试报准确性高,无错报。 相似文献
4.
5.
6.
东北区夏季低温冷害的长期预报 总被引:2,自引:1,他引:2
利用东北区三大站(沈阳、长春、哈尔滨)50年(1951-2000年)夏季平均气温、前冬和夏季500hPa高度场、距平场及副高面积指数和海温场资料,对东北夏季低温冷害的环流特征进行了分析,建立了东北区夏季低温冷害预报模式;用春季高度距平平均场建立了夏季低温冷害天气预报模型。结果表明,东北区低温冷害与冬季副高面积指数及500 hPa乌拉尔山附近的高度值呈正相关,与冬季西风漂流区附近(40°~45°N,160°~150°N)海温场呈反相关;所建方程及模式预报拟合率和预报准确率都比较高,且可提前3个月左右进行预报。 相似文献
7.
东北区夏季低温冷害的长期预报方法研究 总被引:7,自引:4,他引:7
利用东北区三大站(沈阳、长春、哈尔滨)50年(1951~2000年)夏季平均气温、前冬和夏季500hPa高度场、距平场及副高面积指数、海温场资料,对东北夏季低温冷害的环流特征进行了分析,建立了东北区夏季低温冷害预报模式;用春季高度距平平均场建立了夏季低温冷害天气预报模型.结果表明,东北区低温冷害与冬季副高面积指数及500hPa乌拉尔山附近的高度值呈正相关关系,与冬季西风漂流区附近(40°~45°N,160°~150°N)海温场呈反相关关系.所建方程及模式预报拟合率和预报准确率都比较高,可提前三个月左右做出预报. 相似文献
8.
高森林火险天气形势及其前期气候特征与预报 总被引:2,自引:0,他引:2
利用1980-2006年27年间黑龙江省林区发生的37次特大森林火灾资料,针对高空500hPa温压场的结构,将着火前3天短期时段内的天气形势分为4类8型,在此基础上对相对湿度与气温等因子的变化进行了分析,并对高火险日数及前期气候与大气环流特征进行了预报. 相似文献
9.
基于自然正交展开的神经网络长期预报模型 总被引:6,自引:0,他引:6
对月降水量的前期500hPa高度场、海温场相关预报因子进行E0F展开,并取其中与预报量相关程度较高的主成分,结合人工神经网络技术,建立了一种新的短期气候预测模型。将这种新的预报模型与同样根据这些预报因子建立的回归预报模型进行了对比分析。结果表明,这种新的短期气候预测模型由于集中了众多预报因子的预报信息,并有效地利用了神经网络方法的非线性映射能力,因此比传统预报方法的预报精度显著提高,并且稳定性好,具有很好的应用前景。 相似文献
10.
11.
Malholland K 《Disasters》1985,9(4):247-258
In 1985 cholera has been a serious problem in the horn of Africa, particularly affecting the many famine victims and refugees in that region. In this paper the history of cholera in Africa is briefly summarized, as is the background to the current refugee situation in eastern Sudan. A cholera epidemic involving 1,175 cases in two adjacent refugee camps in eastern Sudan is described. In this epidemic there were thirteen inpatient deaths and thirty-eight known home deaths from cholera. The management of the epidemic is described in detail. Overall an average of 8 1. of intravenous fluid was used per case, a higher figure than was anticipated, probably because of the unexpected degree of vomiting and the shortage of trained nursing staff.
The relationship between cholera and malnutrition is explored and hypochlorhydria is suggested as the main reason for the increased susceptibility to cholera among malnourished populations. It was observed that severely malnourished adults and children appeared to nave less severe diarrhoea with their cholera, presumably because of reduced mucosal surface area and poor enterocyte function. Finally possible means of aborting cholera epidemics are discussed. 相似文献
The relationship between cholera and malnutrition is explored and hypochlorhydria is suggested as the main reason for the increased susceptibility to cholera among malnourished populations. It was observed that severely malnourished adults and children appeared to nave less severe diarrhoea with their cholera, presumably because of reduced mucosal surface area and poor enterocyte function. Finally possible means of aborting cholera epidemics are discussed. 相似文献
12.
The land borders of Evros, Greece, have been a common entry point for undocumented migrants on their way to Europe through Turkey. Adverse conditions, however, have resulted in many human casualties over the years. On the Greek side, 334 cadavers were retrieved between 2000 and 2014. This study provides a detailed forensic account of the humanitarian disaster in Evros to create an official scientific record of the situation. It showcases the gravity of the global issue of migration relating to health and mortality, and encourages communication and continual improvement of the approach and patterns of practices surrounding the subject. A retrospective statistical research review was conducted of border‐related fatalities between 2000 and 2014, assessing the age and gender of victims, the cause of death, the location of bodies, identification rates, and country of origin. Age ranged generally from 24 to 29 years, but infants and children were among the deceased. 相似文献
13.
Darfur farming and pastoralist livelihoods are both adaptations to the environmental variability that characterises the region. This article describes this adaptation and the longer‐term transformation of these specialised livelihoods from the perspective of local communities. Over several decades farmers and herders have experienced a continuous stream of climate, conflict and other shocks, which, combined with wider processes of change, have transformed livelihoods and undermined livelihood institutions. Their well‐rehearsed specialist strategies are now combined with new strategies to cope. These responses help people get by in the short term but risk antagonising not only their specialist strategies but also those of others. A combination of factors has undermined the former integration between farming and pastoralism and their livelihood institutions. Efforts to build resilience in similar contexts must take a long‐term view of livelihood adaptation as a specialisation, and consider the implications of new strategies for the continuity and integration of livelihood specialisations. 相似文献
14.
Ian Davis 《Disasters》2019,43(Z1):S61-S82
This reflection, based on a keynote address to celebrate the fortieth anniversary of Disasters on 14 September 2017, begins by considering some of the prevailing assumptions that existed at the time of the journal's creation. Next is a summary of significant milestones during the past 40 years, covering major global trends, changing disaster impacts, and key developments in disaster risk management. Contrasting approaches in the first and fourth decade of the journal's history are then followed by examples of changes in terminology in the disaster field as an indication of shifting values. The paper goes on to explore the context of 2017, with observations of problem areas such as the loss of knowledge, failures to tackle the root causes of disasters, shortfalls in international assistance, and some negative attitudes. It closes by evaluating some current positive occurrences, including a reduction in casualties, sharing of experience, technological advances, and dramatic improvements in disaster warning. 相似文献
15.
Joseph Chung 《Disasters》1987,11(1):40-48
Tropical cyclones and hurricanes have a severe impact on the social and economic activities of affected communities. For small island nations in the Pacific region, the effects can be devastating because of their smallness. FQi and several other countries in the region are vulnerable to such disasters as they are situated in the zone where cyclones occur frequently.
During the last decade, the frequency of natural disasters and their adverse impact on die economic and social development of small nations like Fiji, has aroused awareness mat relief efforts must go beyond immediate "mopping up" operations to those which contribute to attaining longer term benefits through reconstruction and rehabilitation.
The paper outlines the 1985 agricultural rehabilitation program and discusses related issues and problems. 相似文献
During the last decade, the frequency of natural disasters and their adverse impact on die economic and social development of small nations like Fiji, has aroused awareness mat relief efforts must go beyond immediate "mopping up" operations to those which contribute to attaining longer term benefits through reconstruction and rehabilitation.
The paper outlines the 1985 agricultural rehabilitation program and discusses related issues and problems. 相似文献
16.
Natural disasters are inevitably the outcome of cultural agonisms. The cultural politics of natural disasters are shaped by competing claims and conceptions of ‘nature’. Recent disasters in Indonesia are directly linked to these contending conceptions and the ways in which different social groups imagine risk and reward. The Sidoarjo volcanic mudflow of 2006 represents a volatile and violent exemplar of contending cultural and economic claims. Like other disasters in Indonesia and elsewhere in the developing world, this ‘natural’ disaster is characterised by differing conceptions of ‘nature’ as cultural tradition, divine force, and natural resource. A new extractive project in East Java is exhibiting similar economic and cultural agonisms, particularly around the notion of development, environment, self‐determination, and tradition. This paper examines the ‘disputes over meaning’ associated with natural disasters in contemporary societies, and the ways in which they are related to human culture, social organisation, and hierarchical systems of violence. 相似文献
17.
This paper presents the results of primary research with 40 survivors of the 2004 Indian Ocean tsunami in two communities: Khao Lak (n=20) and Koh Phi Phi Don (n=20), Thailand. It traces tsunami survivors' perceptions of vulnerability, determines whether residents felt that the tsunami affected different communities differently, identifies the populations and sub-community groups that survivors distinguished as being more vulnerable than others, highlights community-generated ideas about vulnerability reduction, and pinpoints a range of additional vulnerability reduction actions. Tsunami survivors most consistently identified the 'most vulnerable' community sub-populations as women, children, the elderly, foreigners, and the poor. In Khao Lak, however, respondents added 'Burmese migrants' to this list, whereas in Koh Phi Phi Don, they added 'Thai Muslims'. Results suggest that the two case study communities, both small, coastal, tourism-dominated communities no more than 100 kilometres apart, have differing vulnerable sub-groups and environmental vulnerabilities, requiring different post-disaster vulnerability reduction efforts. 相似文献
18.
19.
中国内陆自然环境的干旱化与未来趋势 总被引:5,自引:2,他引:3
根据中国内陆陕西、甘肃部分地区509a旱涝资料和主要测站气象、水文实测数据,应用Word97图形处理系统,证明在526a序列中目前处在11a、50a滑动的干旱期。近46a气温上升了0.3℃,年降水减少了80mm,径流量减少了0.78%,出现了明显的干旱化,环境变化趋势不容乐观。 相似文献