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141.
Natural disasters like floods, tornadoes, tropicalcyclones, heat and cold wavewreak havoc and cause tremendous loss ofproperty all over the world. Most ofthe natural disasters are either dueto weather or are triggered due toweather related processes.Extreme weather events claimed thousands oflives and caused damage on vastscale. Recent super cyclone which affectedOrissa in 1999, Bangladesh cyclone of1970 and Hurricane Andrew in 1992 areexamples of some of the more damagingtropical cyclones which affected developingas well as the developed world. Heatand cold waves are also extreme events,which cause enormous losses in terms oflives lost and human discomfort and ailmentsarising out of them. The heat waveof 1995 and 1998 are still fresh in the mindof the Indian public. The estimated lossof human lives due to heat wave in 1998 was morethan 15,000. Economic losses asa result of these disasters and in particular inassociation with tropical cyclones haveincreased enormously over the last three decades.During 1961–1991, total loss oflives from drought alone was 1,333,728 overthe whole world. In terms of economiclosses, there is 8–10 fold increase from thebase figure of 1960. The socio-economicimpact of natural disaster is complex dependingupon the vulnerability of the placeand mitigation strategies that are put in place.Meteorology plays a crucial role in forewarningpeople about the severe/extremeweather systems and a constant endeavour by themeteorological services worldover has gone a long way towards minimizing thelosses caused by natural disasters.The paper summarises the natural disasterstatistics over south Asia and the possibleprediction strategies for combating theirsocio-economic impacts.  相似文献   
142.
This paper is mainly concentrated on the geochemical characteristics and origin of gas of Kekeya field in the Tarim basin, NW China. This study shows that Permian mudstone is the main source rock of oil and gas. Based on the carbon isotopes of C1--C4, the carbon isotope of gas in Kekeya field is a little heavier than that in the typical marine-derived gas. The relationship between carbon isotopes of methane and ethane is coincident with Faber equation of gas derived from organic matter Ⅰ/Ⅱ. The majority of gas maturity is estimated, based on the formula, at 1.8%-2.2% besides K2 and K18 wells. In addition, the gas derived from 0.9%-1.2% Ro source rocks may also bemixture. ^40Ar/^36Ar and ^3He/^4He ratios from the gas samples also support the mixing process. Moreover, the gas in this region is mainly generated from more mature source rocks although the low mature gas exists.  相似文献   
143.
黄河流域天然径流量突变性与周期性特征   总被引:22,自引:1,他引:22  
杨志峰  李春晖 《山地学报》2004,22(2):140-146
突变性和周期性是水文时间序列的两个重要特征。黄河流域面积广阔,各区域水文水资源系统演变规律各不相同,它们的突变和周期变化及其形成的物理机制遍异,因此系统分析各区域水资源突变性和周期性特征及其影响机制具有重要意义。把黄河流域划分为15个区域,计算出各区域1951—1998年的年天然径流量系列。利用Mann-Kendall非参数检验方法检测黄河流域各区域年天然径流量的突变年份,结果表明各区域的突变年份不完全一致,主要在1953—1955年、1979—1983年、1991—1993年等发生了突变,这些突变与北半球气候突变具有一致性,且由于下垫面改变、人类活动等影响而复杂化。利用Morlet小波分析各区域年天然径流量的变化周期,发现主要存在3~4a、7~9a、11a的周期,形成这些周期的物理因子有太阳黑子、海—气相互作用和下垫面因素等。通过分析黄河流域主要产流区不同时段小波系数变化,发现20世纪80年代之后年径流量主要以短周期变化。  相似文献   
144.
1IntroductionHighway, as a kind of man-made structure, will become a part of the geographical environment and be impacted by all sorts of natural factors after it is finished. On the other hand, highway also brings some changes to the geographical environment. A highway often passes through different natural regions, so it must be adaptable to any geographical environments. On the basis of deep understanding of the geographical environment, service life and normal level of the highway can be e…  相似文献   
145.
祁连山区天然草原退化原因分析与可持续利用对策   总被引:23,自引:5,他引:23  
天然草原是畜牧业发展的重要物质基础,由于缺乏有效的制度安排和技术创新,人类无节制的赢利活动加剧了草原退化,导致了西部生态环境的恶化。论文以祁连山区的肃南县为例,通过对天然草原退化现状的调查研究,剖析了祁连山区草原生态环境保护与经济发展之间的突出问题和草原退化的深层原因,提出了天然草原永续利用的对策。  相似文献   
146.
The temperature appeared rising trend during the 20th century in China's tropics.Two cooling stages and two warming stages in the process of climatic fluctuation can be recognized.After the 1980s the climate is the warmest which corresponds to the global change,but the warmest period is the 1940s in Kunming.The climate pattern mostly appears contemporaneity of warming and humidity,which is different from the situation of whole China.The natural disasters tend to be aggravated.The number of typhoons increased.Flood damages occurred frequently in the years of more typhoons.The number of droughts and cold damages increased.It was snowed in Guangzhou.There was frost in Haikou and Yaxian.Four years of heavy snow have been recorded in Kunming.  相似文献   
147.
El Hatillo is a rural community in the Sébaco valley in Nicaragua, which suffers from an eroding resource base, high levels of poverty and malnutrition, and a high susceptibility to hazards. Structural adjustment policies have been devastating for small and subsistence farmers and have increased the level of economic, social and environmental marginalisation in rural Nicaragua. This paper explores initiatives to promote sustainable development in Nicaragua in the context of structural adjustment and environmental degradation. Drawing on qualitative research conducted in El Hatillo, it outlines the ways in which women in this community are attempting to address the multiple challenges of rural poverty and environmental risk and considers the potential of these strategies for gender equality.  相似文献   
148.
This paper identifies contrasting environmental discourses on bushfire from the public debate that followed the Victorian fires of 2002–03. Submissions to the inquiry into the 2002–03 Victorian bushfires provide a particularly rich source of documentation. It is argued that environmental events such as bushfire only become political issues, or problems, when they are constituted as such through environmental discourse. Through the analysis, three contrasting discourses on bushfire are identified—here labelled the ‘conservationist’, ‘ruralist’ and ‘wise use’ discourses. In examining how different ‘constructions’ of bushfire have led to conflict, each discourse is shown to consist of a range of actors who draw on shared storylines. Having established a better understanding of the different attitudes, beliefs, interests and values that underpin debates about bushfire, the paper concludes with a brief discussion of the prospects for compromise among the discourses and the potential for improved land and fire management outcomes.  相似文献   
149.
利用太原地区发生的798个地质灾害个例和汛期降水资料,从地质环境背景着手,在地理信息系统(MAPGIS)支持下,对太原地质灾害危险性区划和诱发因素进行了系统研究。提出了精细的地质环境概率量化评价方法,得出了地质灾害影响因素的重要结论。建立了地质灾害预报模型,制定了预报等级标准和预报规则。经业务试验,预报结果与实况基本吻合。  相似文献   
150.
2003年2月14日新疆石河子南发生了5.0和5.4级地震。地震发生在北天山石场东南高山区内,位于亚马特断裂与斜切天山的博罗科努断裂所夹持断块的南缘。地震仅对石河子南山矿区所属的红沟煤矿、小沟煤矿与沙湾县煤矿等50、60年代建造的部分危房造成了轻微的破坏,大部分地区的房屋基本完好。造成地震灾害减轻的主要原因为多条断裂的隔震作用与居民点位于山区较平缓地带、场地条件较好等因素。  相似文献   
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