影响广西两次低温灾害及物理机制对比分析

利用常规观测资料、NCEP再分析资料对比分析了2016年1月23-28日和2008年1月13日至2月5日影响广西的两次强冷空气的灾害特征、环流形势,动力机制。分析表明:2016年强冷空气过程阻塞高压比2008年冷空气过程的高压异常偏强。2016年1月冷空气过程中高纬度环流为两槽一脊型,强冷空气沿西路迅速南下,导致广西近50年最南雪线。而2008年1月强冷空气天气过程,中高纬度维持稳定的东高西低形势,冷空气东路南下影响,导致广西近50年最长期的冻雨和冰冻天气。负涡度往乌拉尔山东部高压内部持续输送,支持了2008年1月阻塞高压不断重建、维持。2008年冷空气过程因为孟加拉湾水汽持续输送,维持了长期冻雨和冰冻天气,2016年冷空气过程由于水汽不足,导致少量降雪过后迅速转晴天。     

黑龙江省雷电活动气候特征分析

利用黑龙江省闪电定位网在2005年4月至2006年间得到的285347次地闪资料,分析了雷电参数的月变化、年变化及其空间分布的气候特征,结果显示,正闪占总闪的比例仅为5.84%和7%,地闪密度的高值中心分别在(127.3°E,46.3°N)和(123.5°E,52.9°N)附近;总体日变化特征明显,呈一峰一谷态势,分别为18时和10时;一年中雷电活动主要出现在7,8月份,正云地闪的平均强度明显大于负云地闪.云地闪主要集中在两个区域的分布表明雷电活动特征可以基本揭示该地区天气活动的时空分布规律.     

黑龙江省夏季干旱气候特征及成因分析

利用1954-2009年气候实测资料,分析了黑龙江省干旱发生的气候特征。结果表明,20世纪70年代与21世纪初的近10年为干旱盛行时期,尤其是2000年后至今,平均每2年发生一次干旱。大部分年份的干旱发生在拉尼娜事件或赤道东太平洋为冷水位相,副高较弱及偏东和北界偏北。从500hPa环流特点表明,东亚区盛行-、+、-距平场型式;冷空气偏向乌拉尔北部泰米尔至新地岛,黑龙江处在西风带高脊或高脊与副高结合体控制之下,维持高温少雨造成干旱。选取副高强、厄尔尼诺发生的年份的干旱典型年2004年。恰与过去年份发生的低温多雨形势相反,盛行-、+、-距平场型式,造成干旱。从旱年的水汽输送环境来看,来自欧亚大陆40°～50°N与孟加拉弯和南海的水汽输送通道,明显减弱或消失。     

2021/2022年云南冬季异常气候特征及成因分析

基于云南省124个站点逐月气温和降水资料以及美国国家环境预报中心和国家大气研究中心(NCEP/NCAR)再分析资料,运用数理统计方法,分析了2021/2022年冬季云南气候异常的成因,得到(1)2021/2022年冬季,中低纬度地区维持北非槽、阿拉伯半岛脊、孟加拉湾槽的波列,有利于阿拉伯海、孟加拉湾、西太平洋和南海的水汽向云南境内输送,造成云南整个冬季降水偏多。(2)前(后)冬中高纬度的环流变化是造成冬季气温前暖后冷的直接原因。从前冬到后冬中高纬度欧洲大陆槽明显减弱北抬,西西伯利亚附近的脊增强,易形成阻塞高压;地面西伯利亚高压增强,东亚冬季风也明显增强。相应地冷空气从少而弱到频发并偏强,气温从明显偏高到显著偏低。(3)2021年12月到2022年2月东亚副热带急流从偏弱逐渐变为偏强,而极锋急流从偏强逐渐变为偏弱,导致冬季风逐渐增强,影响南下冷空气,致使云南冬季气温发生了前暖后冷的季节内异常变化。(4)云南上空整个冬季皆存在异常水汽辐合,水汽辐合抬升有利于降水生成。两个主要水汽输送通道一个是从阿拉伯海经孟加拉湾进入云南;另一个是从西太平洋海域经南海、中南半岛和孟加拉湾进入云南。     

广西多雨年6月环流和V分量特征

2008年6月中上旬,广西出现了大范围持续性暴雨或特大暴雨天气,持续性强降雨使得广西6月降雨量显著偏多。对比分析了2008年6月和广西多雨年同期500hPa高度场和距平场,及主导环流型和V分量特征,结果表明:(1)2008年6月和广西多雨年同期6月亚欧中高纬同为两脊一槽型,青藏高原西侧和亚洲东岸均为持续稳定的高压脊,贝加尔湖及其以北为持续稳定的低压槽,青藏高原东部和孟加拉湾附近低压槽活动频繁;西太平洋副热带高压在华东、华南沿海一带持续稳定;(2)广西及附近区域500hPa环流W型和SLP环流C型与广西6月降雨量存在显著的正相关关系,2008年6月主要为这2种环流型控制;(3)当在垂直3层高度上广西东南部维持一条深厚的偏南风区域带、西北部维持一条深厚的偏北风区域带,且在广东中东部附近海面和中南半岛附近南风分量偏强,青藏高原东部北风分量偏强或为弱南风分量时,则广西6月降雨量明显偏多,2008年6月垂直3层高度上V分量符合广西6月多雨年的特征。     

广西春旱的时空分布特征及成因分析

利用广西具有气候代表性的32个站点1961-2007年逐日降水量资料,引入季节无雨日作为划分干旱的标准,采用EOF分析等方法,分析了广西春旱的时空分布特征;并用NCEP再分析资料、NOAA海温资料、国家气候中心的74项环流特征量资料等,对广西春旱的成因进行了分析。结果表明:从时间变化看,广西春旱的趋势变化不明显,主要以年际、年代际变化为主,从空间分布看,广西春旱以全区一致性型为主要空间分布型;在春旱年,广西上空对流层低层出现偏南-西南气流距平强辐散异常,伴随有明显的水汽通量辐散异常,同时东亚大槽偏弱,阿留申低压明显减弱,中纬度大陆高压减弱,中高纬环流平直,不利于冷空气南下华南;广西春旱年前冬阿留申低压明显增强,大陆高压也增强,冷空气活动频繁,当前冬印缅槽偏弱时,广西春季发生干旱的可能性较大。     

华北暴雨云和降水的中/微尺度结构特征(Ⅰ)——一次暴雨的天气背景研究

为研究华北暴雨形成时的中尺度与微尺度的结构特征,选取发生于2005年7月22-24日的一次华北暴雨过程为研究对象,利用1°×1°的NCEP再分析资料和0.05°×0.05°的FY2C红外TBB资料,对此次暴雨过程发生时的天气形势、水汽输送、大气稳定度、云场特征进行了分析.结果表明:此次暴雨过程是在登陆台风和西风槽的共同影响下产生的,高空槽后的西风急流入侵到华北北部,低层副高西侧的东南急流位于华北东部,使得华北地区上空形成了有利于触发对流的低层辐合和高层辐散的天气形势.低层印度季风与我国南海夏季风对水汽的北上有重要作用,还有一部分水汽系来自副高西侧的东南风急流输送;高层水汽主要是由偏东气流经副高西侧向西,然后转向北输送到华北;华北地区的低层存在较强的水汽辐合,高层存在相对较弱的水汽辐散区,这为暴雨发生提供了必要的水汽条件.     

湖南短时强降水时空分布及相关环境参数统计分析

为探讨湖南不同区域短时强降水气候规律及相关环境参数特征,利用2002-2018年1 h雨量资料,对湖南5个区域短时强降水时空分布特征进行了统计分析。同时,利用NCEP1°×1°再分析资料,对5个相关环境参数进行了计算分析。研究结果表明:短时强降水主要出现在4-9月,以夏季最多,呈单峰型分布;不同月份也有一定差异,4-5月夜雨出现较多,而6-7月对流降水频繁,8-9月则各时段都可能出现短时强降水;湖南5个区域短时强降水日变化也有较大差异,洞庭湖地区日变化较小,湘西北和湘中地区在夜间和傍晚有两次峰值,湘西南有夜雨特征,湘东南在午后达峰值;地形对短时降水有一定影响,武陵山脉、雪峰山、南岭与罗霄山附近是短时强降水高发区。各月短时强降水发生时环境条件存在差异,热力不稳定参数百分位变化存在南高于北,且暖季高于冷季特征,水汽参数亦南高于北,动力不稳定参数冷季高于暖季,尤其在湘东南无论在水汽、动力、热力及不稳定参数都高于其他区域。     

两种类型的厄尔尼诺事件对大气环流及黑龙江省低温洪涝灾害的影响

厄尔尼诺事件按发生时间可分为：春季型和秋季型,按发生源地又可分为东部型和西部型。它们都有在春季阿留申低槽发展向西摆动,到夏季控制我国东北地区的特征。这种形势下,对黑龙江省灾害天气的影响主要看副高的变化。春季型副高弱,北界偏南脊点偏东则有低温发生;副高强,北界偏北脊点西伸则有高温洪涝灾害。秋季型由于乌拉尔低槽和阿留申低槽于夏季在东北汇合加强,易造成低温多雨。东部型的天气过程与秋季型基本相似,也易发生低温。西部型天气过程与其它型差异较大,在夏季东亚区维持一脊一槽型,如副高强脊点偏西有洪涝;如副高北界偏南则低温多雨,副高偏北则高温洪涝。由此,利用厄尔尼诺的类型及大气环流变化就可提前预报低温洪涝灾害。     

西北太平洋热带气旋的时空分布特征分析

西北太平洋是世界上热带气旋(TC)发生频率最高、强度最强的一个海区,因此对西北太平洋TC进行气候分析是很有意义的.根据1945-2006年JTWC的数据资料对西北太平洋的热带气旋时空分布特征进行了统计分析,得到TC活动的一些最新概况.从时间分布特征上来看:TC频数呈增加趋势,有两个上升阶段,两个下降阶段;台风和强台风与TC的变化趋势大致相同,但自2000年至今有上升趋势;在季节上分布上,热带气旋,台风和强台风频数存在时间上的延迟现象.从空间分布特征来看:TC源地在0°～30°N范围内,纬向发生高频区轴线位于12.6°N,经向对应于南海海区和菲律宾以东及关岛附近洋面有两个峰值;TC强度越强,其发生高频区纬向轴线向赤道方向移动,而经向轴线向东移动;南海海区不是强台风的高发区;台风和强台风源地高频区经向轴线在145°～155°E之间移动;纬向轴线在6°～14°E之间移动,强台风的源地高频区经向轴线始终位于台风轴线的东侧,而纬向轴线位于其南侧.     

Cholera in Sudan: An account of an epidemic in a refugee camp in eastern Sudan, May-June 1985

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.     

A retrospective statistical review of deaths owing to migration through the southeasternmost land borders of the European Union,Greece 2000–14

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.     

Complexity,continuity and change: livelihood resilience in the Darfur region of Sudan

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.     

Fiji, land of tropical cyclones and hurricanes: A case study of agricultural rehabilitation

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.     

火灾场景中玻璃破裂行为研究综述

建筑物在火场中的结构响应问题中,门窗玻璃在火场中的热响应特性及破裂脱落是影响火灾发展的重要因素之一。通过事故案例分析了火灾场景中玻璃破裂脱落的危害性,指出了研究火灾场景中玻璃受热破裂脱落的意义,并对目前火灾场景中玻璃受热破裂过程和主要形态、玻璃的破裂机理和判据等的研究现状进行了详细的分析,总结了目前实验和计算机模拟的最新研究进展和不足,为今后进一步开展玻璃受热破裂脱落研究提出了若干建议。     

中国内陆自然环境的干旱化与未来趋势

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。     

美国的洪泛平原管理

美国开展洪泛平原管理已有约40年历史，洪水保险计划是美国泛平原管理的主要措施。了解并借鉴他们的思路与具体策略，将有助于我国洪泛平原管理政策的制定。     

A general assessment of the environmental impact of refugees in Somalia with attention to the refugee agricultural programme

This paper attempts to examine the broad features of Somalia's harsh physical environment into which several hundreds of thousands of refugees, with mainly a nomadic or semi-nomadic life style and culture, dramatically descended six years ago. The thirty-six rural camps in which at least half of them live are described as is the refugee agricultural programme which is training several thousand families so that they may be "self-supporting." The four regions where the camps are located are each briefly summarized in terms of their soils, their climates, their natural vegetation, and the type of agriculture which the refugee farmers practice. A more detailed analysis is then given on the following critical environmental concerns: Vegetation and erosion on refugee farms, the growing problem of refugee livestock, the destruction of trees, and irrigation practices and salinity on refugee farms. The paper concludes with an argument to preserve Somalia's environment from careless and destructive exploitation, which is leading towards desertification, and calls for an in-depth study of the situation.     

30年来我国农业气象灾害变化趋势和分布特征

利用1979-2008年的统计数据分析了我国近30年来农业气象灾害的时间变化趋势和空间分布特征。结果表明:(1)1979-2008期间,我国农业气象灾害的灾情日趋严重,农业气象灾害总成灾面积和成灾比率都呈增加趋势;各类灾害中,旱灾和霜冻成灾面积和成灾比率呈增加趋势,风雹成灾面积和成灾比率变化不大呈略微下降趋势,而1989-1998年段水灾严重。(2)旱灾成灾面积在总成灾面积中所占比例最大(约占总成灾面积的1/2),其次是水灾(约占总成灾面积的1/4),再次是风雹,而霜冻成灾面积最小。(3)在区域分布方面,旱灾灾情华北地区最为严重,其次是东北,再次是西北;水灾和旱灾的轻重程度往往是一个此消彼长的关系,华中的水灾最严重,其次为华东、华南和西南;风雹灾情的轻重程度在我国的分布也有较强的区域性,华北、西北和东北是风雹的重灾区;霜冻分布各区域差异较小,西北和华中的灾情相对较重。     

Does money work? Cash transfers to ex-combatants in disarmament, demobilisation and reintegration processes

This paper analyses the relevance and potential of cash transfers as part of the disarmament, demobilisation and reintegration (DDR) assistance packages provided to ex-combatants in transitions from war to peace. To this end, a theoretical framework is established that permits the identification of the advantages and disadvantages of using cash in DDR. Subsequently, an empirical analysis is carried out to compare selected theoretical assumptions on the use of cash with the reality of lessons learned from recent experience in Sierra Leone and other African countries. The study shows that some theoretical drawbacks commonly associated with the use of cash in DDR processes may indeed bear out in practice. At the same time, though, the paper argues that the utility of cash transfers in DDR is affected by a variety of factors that go far beyond the simple choice of employing cash, most notably decisions on payment location, eligibility criteria and targeting.