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101.
We statistically analyze the tropical typhoon forming in the South China Sea and use TC (Tropical
Cyclone) for short in the following) by typhoon yearbook. The typhoon quantity is very different in different
months and years. TC appears in all months except March, and the most TC quantity in a year is 11, the least is 1
and 6.2 on average. The most TC quantity in a month is 5 and the least is 0. TC lands most in August and no TC
lands on Chinese continent from December to the following April. The primary landing area is between Shantou
and Hainan Island. The sustaining period of TC is usually between 4 days to 7days, and the longest is 19 days.
Only 15% of the TC forming in the South China Sea can intensify to typhoon, and they all form in the ocean area
deeper than 150m. The South China Sea is the ocean area over which the TC occurs frequently. 相似文献
102.
Local knowledge has played an active role in the lives of rural communities in virtually every part of the world. In Jamaica, traditional cropping systems based on local informal knowledge have been practiced since the days of slavery and play a vital role in meeting food security. Yet, some negative attitudes remain about the legitimacy and relevance of small-scale farmers' local and traditional knowledge. This paper discusses some conceptual and empirical issues related to the application of local knowledge among small-scale food farmers in central Jamaica. The paper argues that contextually speaking, local and traditional knowledge is valuable, adaptable and necessary in coping with risk and uncertainty in a changing world, while cautioning against a misguided notion of traditional knowledge as a panacea to all the ills of local agriculture. 相似文献
103.
104.
Bellie Sivakumar 《地球表面变化过程与地形》2007,32(7):969-979
Whether or not river flow exhibits nonlinear determinism remains an unresolved question. While studies on the use of nonlinear deterministic methods for modeling and prediction of river flow series are on the rise and the outcomes are encouraging, suspicions and criticisms of such studies continue to exist as well. An important reason for this situation is that the correlation dimension method, used as a nonlinear determinism identification tool in most of those studies, may possess certain limitations when applied to real river flow series, which are always finite and often short and also contaminated with noise (e.g. measurement error). In view of this, the present study addresses the issue of nonlinear determinism in river flow series using prediction as a possible indicator. This is done by (1) reviewing studies that have employed nonlinear deterministic methods (coupling phase‐space reconstruction and local approximation techniques) for river flow predictions and (2) identifying nonlinear determinism (or linear stochasticity) based on the level of prediction accuracy in general, and on the prediction accuracy against the phase‐space reconstruction parameters in particular (termed as the ‘inverse approach’). The results not only provide possible indications to the presence of nonlinear determinism in the river flow series studied, but also support, both qualitatively and quantitatively, the low correlation dimensions reported for such. Therefore, nonlinear deterministic methods are a viable complement to linear stochastic ones for studying river flow dynamics, if sufficient caution is exercised in their applications and in interpreting the outcomes. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
105.
2000年我国主要天气气候特点为:全国大部地区降水偏少或接近常年,出现全国性干旱,特别是北方地区春夏季遭遇多年来罕见的特大干旱,汛期未发生大范围的暴雨洪涝灾害,秋季黄淮以南地区出现持续连阴雨天气,全国大部分气温接近常年成偏高,持续暖冬态势发生转折,夏季高温酷热,春季北方扬沙和沙尘暴天气异常频繁,登陆我国台风个数偏少,风雹等强对流天气明显偏少。 相似文献
106.
Two kinds of observational data,fluctuation and mean profile measurements,from a 325 m meteorological tower in Beijing,China,are used to evaluate local scales of velocity and temperature for higher heights by flux-gradient mean profiles and eddy-correlation techniques.A comparison of these methods each other was made in terms of vertical turbulence fluxes for momentum and beat at the same heigbt.The vertical profiles of non-dimensional second moments.such as vertical turbulent fluxes of momentum and heat.velocity and temperature standard deviations,were derived by local similarity theory.The local similarity relations expressed that the vertical distributions of non-dimensional second moment variables were found to be functions of z/Λ and z/h in the stable boundary layer and the function of z/Zi for the convective boundary layer,where A the local Monin Obukhov(M-O) length. h the height of stable boundary layer and Zi the height of mixed-layer.These relations are shown to agree well with the observational data. 相似文献
107.
108.
王健 《地震学报(英文版)》2001,14(5):589-595
Introduction The Tangshan earthquake sequence in 1976 is one of most important events in North China. Although nearly thirty years passed and there are some researches on its cause, it is far from the end. Here we introduce two explanations for the cause of Tangshan earthquakes and point out their defects. One is that there is a diamond block in NEE direction in Tangshan region, which is shaped by cutting action of NingheChangli fault, FengtaiYejituo fault, Luanxian fault and Jiyunhe fau… 相似文献
109.
This paper provides new insights into girls' use of recreational spaces within rural areas. We draw upon data from in-depth discussion work with 10–14 year old girls undertaken in rural Northamptonshire to show how conflict between adults and children, rival groups of children, and boys and girls influences the social ownership of recreational spaces. In contrast to the rural childhood myth, we disclose geographies of anxiety, tension anddisharmony. 相似文献
110.
东莞PC相关制造业地方产业群的发展演变 总被引:27,自引:2,他引:27
从地方产业群理论出发,探讨全球联系和本地联系对地方产业群内部企业网络发展的影响,并结合对东莞3镇的PC相关制造业的实地考察,指出随着中国沿海改革开放的不断深入,逐渐形成一些外向型制造业地方产业群,其发展过程中,本地生产网络与全球生产网络格局已经发生了转变,原来为“三来一补”的出口加工贸易服务的制度设计在实践中逐渐变成了地方产业群进一步发展的制度瓶颈。区域持续发展有赖于不断的制度创新,以充分发挥本地已经形成的产业集聚优势。 相似文献