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81.
This Korea-China study monitored the phenomena of sandstorms and significant dustfall (SD) from 1997 to 2000. The analysis of our data included ground measurements of dust concentration, visibility, satellite imagery, aircraft and lidar observations. In addition, an estimation of atmospheric loadings and a studyon the relationship between dust concentrations and visibilitywere carried out. The movement and invasion of dust clouds toKorea were clearly identified with meteorological and satellitedata. The increasing concentrations of TSP and PM10 concurredwell with the satellite information. From case studies, weestimated that atmospheric loadings of a dust cloud were over 1million ton and that the deposition over the Korean Peninsulawas in the range from 46 000 to 86 000 tons. For SD withvisibility of 3 km, we predict TSP 659 g m-3 and PM10 493 g m-3. We recommend the issuance of an SD Watch(advisory) and an SD Warning for the general public.  相似文献   
82.
灌溉是获取作物高产的主要措施之一,灌溉减损经济效益与农民收入和生产经济效益密切相关.提出了从灌溉次数和灌溉量参数入手,根据灌溉投入和灌溉减损量来分析灌溉减损效益、减灾效益和生产经济效益;以华北冬麦区单点试验和调查结果为例,讨论了该方法在冬小麦减灾评估应用中的普适性和可行性.  相似文献   
83.
Angus Poston 《Disasters》2010,34(2):328-336
Following a major disaster, microfinance institutions (MFIs) often face high levels of bad debt, which may require the institutions to be recapitalised. This paper describes a recapitalisation programme implemented by the SANASA movement of Sri Lanka in 390 microfinance societies following the December 2004 tsunami, and highlights lessons for other similar programmes. MFI recapitalisation is a good use of funds in post‐disaster situations. To create successful programmes, donors should expect to relax some of their usual project requirements and MFIs should focus on maintaining credit discipline.  相似文献   
84.
1961-2000年干旱对我国冬小麦产量的影响   总被引:1,自引:0,他引:1  
假定在目前条件下的冬小麦作物品种、耕种措施和土壤特性不变,利用WOFOST作物模型,模拟了1961-2000年干旱对我国冬小麦产量的影响。模拟结果显示:1961-1980年干旱对我国冬小麦产量影响较为严重,干旱使整个麦区冬小麦平均减产4.6%,使北方麦区冬小麦平均减产12%。1981 -2000年,干旱对冬小麦产量的影响明显减轻。总体上,1961-2000年虽然冬小麦生育期内降水量持续减少,但干旱对冬小麦产量的影响没有加重的趋势。通过分析发现,我国北方地区冬小麦生育期内的降水和干旱与产量并没有显著相关关系,但春季降水和干旱则与产量显著相关,揭示了我国北方春季降水量对冬小麦产量影响的重要性。  相似文献   
85.
2009年2月初,我国北方冬麦区遭受了数十年未遇的严重干旱。基于野外实地考察,判断本次干旱对冬小麦造成的实际影响比气象统计与遥感监测结果要轻,同时因纬度、地貌类型、微地貌和田间管理水平的不同而呈现出明显的区域差异。在此基础上,提出应在已有的旱灾致灾指标(气象干旱)基础上,综合考虑地带性、地貌、水库等孕灾环境指标和田间管理水平等灾害适应指标来构建冬小麦旱灾风险的综合评价指标体系。并以北方冬麦区为例,选取SPI、地貌类型、DEM和水库缓冲区等指标得到的旱灾综合风险等级与实际旱情存在较高的吻合性。研究可为高风险区的冬小麦旱灾风险防范提供理论依据和案例支撑。  相似文献   
86.
The provision of humanitarian aid at times of disaster in multi-ethnic community settings may lead to conflict, tension and even the widening of the distance between various ethnic groups. That aid agencies distribute humanitarian aid directly to affected communities, to speed up recovery, may often lead to chaos and the intensification of ethnic sentiments. The new distribution mechanisms introduced for the delivery of tsunami aid in Ampara District, Sri Lanka, did not recognise local networks and the culture of the ethnically mixed community setting. This paper analyses post-tsunami aid distribution in Ampara and shows how such an extemporised effort in an ethnically cognisant context increased ethnic division, inequality and disorder, while marginalising the poor segments of the affected population. It recommends the inclusion of local networks in aid dissemination as a measure for improving ethnic neutrality and social harmony in disaster-hit multi-ethnic communities.  相似文献   
87.
The aerosol number concentration and size distribution were measured with the newly developed Wide-range Particle Spectrometer in summer and winter of 2006 at the urban site of Jinan City.Here reported the characteristics of fine particles of the different observation seasons.Relative high number concentrations for the particles in the diameter range of 10-500 nm were observed in both seasons.It was found that the dominant number distributed in particle diameter smaller than 100 nm and the percentage over the number concentration of all air particles is much higher than what has been measured in other urban sites over the world.The number mean diameter in summer was much smaller than in winter,strongly suggesting the different origin of ultrafine particles in different seasons.That is, particles in ultrafine mode mainly came from nucleation and new particle formation in summer while from traffic emission in winter. The diurnal variation also supported this point.Number concentration in the diameter range of 10-200 nm got their peak values at noontime,well correlated with the mixing ratio of SO_2 and the intensity of solar radiation in summer.While in winter,those in the same diameter range showed the main peaks during the traffic hours happened in the morning and evening.  相似文献   
88.
Background, Aim and Scope Acid deposition has become a concern in south China in recent years. This phenomenon has increased to a dramatic extent with the large use of cars and coal- fueled power plants. As a consequence, soils are becoming acidified and their element dynamics will change. A decrease in the nutrient availability will lead to slower plant growth and maybe to a change in the forest type with current species being replaced by new ones with less nutrient requirements. Because of these reasons, it is important to understand how the dynamics of elements will change and what mechanism is part of the process. This knowledge is important for modeling the acidification process and either finding ways to counter it or to predict its consequences. The primary purpose of this study was to provide information about how the dynamics of K, Na, Ca, Mg and P are affected by acid deposition in a typical forest in southern China. Materials and Methods: Experimental soils and saplings were collected directly from the monsoon evergreen broad-leaved forest in Dinghushan. All saplings were transplanted individually into ceramic pots in August 2000 and placed in an open area near their origin site. Pot soils were treated weekly from October, 2000 to July, 2002 with an acidic solution at pH 3.05, pH 3.52, pH 4.00 or pH 4.40, or with tap water as a control. The concentrations of SO42-, NO3-, K+, Na+, Ca2+, Mg2+ and available P and the pH were measured in soil and leachate samples taken at different times. The sapling leaves were collected and their element concentrations were measured at the end of the experiment. Results: Concentrations of soil exchangeable Ca and Mg decreased quickly over time, although only Ca showed changes with the acidic solution treatment and soil exchangeable K was stable because of soil weathering. Leaching of K, Mg and Ca was dependent upon the treatment acidity. Soil available P decreased slowly without any correlation with the acidity of the treatment. All the NO3- added by the treatment was taken up by the plants, but the SO42- added accumulated in the soil. Discussion: Amongst the plant species, Schima superba was little affected by the treatment, the leaf P content was affected in Acmena acuminatissima plants and Cryptocarya concinna was the most susceptible species to soil acidification, with a marked decrease of the leaf K, Ca and Mg concentrations when the treatment acidity increased. Conclusions: Simulated acid deposition affected the dynamics of K, Ca and Mg in the monsoon evergreen broad-leaved forest. The dynamics of Ca in the soil and of K, Mg and Ca in the soil leachates were affected by the acidic solution treatment. If such a soil acidification occurs, Cryptocarya concinna will be amongst the first affected species, but Schima superba will be able to sustain a good growth and mineral nutrition. Recommendations and Perspectives: Acid deposition will lead to imbalance the nutrient elements in the evergreen broad-leaved forest because of accelerated leaching losses of soil exchangeable Ca and Mg. Measures should be developed to slow down soil acidification or nutrient decrease.  相似文献   
89.
冬小麦抗霜性与抗冻性的关系   总被引:3,自引:0,他引:3  
拔节期霜冻害是制约冬小麦生产的主要因素之一。然而关于冬小麦拔节期抗霜性的鉴定工作,国内外的研究报导还很少。选取了13个起源地和春化特性不同的小麦品种,通过利用人工霜箱模拟田间自然霜冻发生过程的试验方法,在小麦幼穗分化进程中的低温敏感期——药隔期进行抗霜性鉴定。同时,对这13个小麦品种越冬期间的抗冻性进行了鉴定。最后对冬小麦品种的抗冻性与抗霜性之间的相关性进行了分析。结果表明:抗霜性与抗冻性之间不存在显著的相关关系。抗冻力较强的冬性品种,抗春霜冻的能力不一定就强;相反,抗冻力较低、发育进程快的早熟品种也可能具有较强的抗霜性。  相似文献   
90.
The habitats, relative occurrence, and distribution of the white whale in the White Sea and the southeastern Barents sea in every month of the ice season have been studied using the results of an aerial ice survey along standard routes from 1970–1991. In these seas, white whales have been found in each month of the ice season, with single animals, groups, schools or gams, herds, and large congregations of several hundred animals accounting for 10, 22.8, 47.2, 12.9, and 7% of all aggregations of white whales observed, respectively. The relative occurrence of white whales in the White Sea is higher in March and May (32.5 and 30%, respectively) and lower in February, January, and November (15, 10, and 7.5%, respectively); in December and April, the whales are observed very seldom (2.5% in both months). In the southeastern Barents Sea, the relative occurrence of white whales is highest in May (53.3%) and considerably lower in December and February (16.7 and 10%); only a few animals are found during the remaining ice season. Regarding different habitats, the relative occurrences of white whales in open water, in water openings in the ice, near the edge of pack ice, and in ice packs with different degrees of closeness are 21.5, 11.4, 45.7, and 21.4%, respectively.  相似文献   
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