中国西北大旱年发生概率的统计推断   总被引：6，自引：7，他引：6  

栗珂  赵东  杨碧轩  郭宏武  高炬 《高原气象》2001,20(1):66-70

根据中国西北近500a旱涝等级资料，用Bernoulli试验等理论模式，对大旱年发生的概率特征进行了研究，得出大旱年发生的统计规律。在全球气候变暖的大背景下，给出了21世纪中国西北大旱年发生概率的统计推断结果。  相似文献   

The High Concentration Tails Of The Probability Density Function Of A Dispersing Scalar In The Atmosphere   总被引：1，自引：0，他引：1  

R. J. Munro  P. C. Chatwin  N. Mole 《Boundary-Layer Meteorology》2001,98(2):315-339

The distribution function for concentrations of a scalar pollutant dispersing in the turbulent atmosphere has a finite domain that is bounded above and below. Three methods, based on extreme value statistics, are used to obtainestimates for the upper bound and to describe the high concentration tailbehaviour of the distribution; all three methods are applied to concentrationdata obtained from experimental atmospheric releases. Quantile quantile (QQ)plots are used to assess the goodness of fit of the resulting estimates of thedistribution, and also to compare the performance of the three methods. Thepredicted values for the upper bound are orders of magnitude less than thesource concentration, illustrating that molecular diffusion has a large effecton the high concentrations.  相似文献   

非洲、澳洲、南美洲的连环拼合与成因探讨     

李维渡 《地球物理学进展》2001,16(1):56-61

通过对非洲、澳大利亚、南美洲彼此之间的大陆架边界线相似的概率分析，指出巧合是不可能的，地球在过去几十亿年间一定发生了大规模的膨胀。  相似文献   

震源耦合的等效物理模型     

薄景山  廖振鹏 《地震工程与工程振动》1996,16(3):11-21

本文提出了考虑各潜在震源相互耦合的等效物理模型，系统地建立了通过拟合各潜在震源地震序列来确定不同时间段内活断层形速率的方法，给出了预报各潜在震源未来一定年限内发生震级在不同震级段的概率模型。  相似文献   

中国大陆强地震时间间隔的概率          下载免费PDF全文

于利民  李钦祖  刁桂苓  孙佩卿  陈敬伟 《地球物理学报》1996,39(4):493-499

以东经１０８°线为界，把中国大陆分为东、西两部，东部取震级Ｍ≥６的地震、西部取Ｍ≥７的地震为强地震．利用有史以来全部地震资料，针对不同情况和不同时期，系统地研究了相继两次强地震之间的时间间隔，目的在于讨论一次强地震发生之后，下一次强地震何时发生．在所有情况下地震间隔数目都随时间间隔值的增大呈明显的趋势性减小．给出了８种情况下的间隔数目统计和相应的模拟函数，以及间隔值的经验概率和相应的函数模拟概率．由此可估计时间间隔为某个值的概率，也可估计时间间隔处于某个区间的概率．反之，对于给定的概率，可估计时间间隔的值或它所处的区间．  相似文献   

转移概率预报方法在霜冻预报中的应用     

申建华  李月莲  陈清兰  陈勇  张智辉 《山西气象》2006,(4):15-17

本文在简介转移概率预报方法及最大概率预报原理的基础上,分析了吕梁市1957年～2000年霜冻初、终日期各随机时间序列状态之间的转换规律,结合各序列的初始分布,建立预报模型,并对1995年～2004年的初、终霜日期进行了预报效果检验。结果表明,该方法预报效果好,使用性强,具有良好的应用前景。  相似文献   

探讨灾害规律的理论基础--极端气候事件概率   总被引：20，自引：0，他引：20  

丁裕国 《气象与减灾研究》2006,29(1):44-50

分析了国内外极端气候事件研究的现状,从经典极值分布理论、极值分布模式的参数估计、广义极值分布等方面,阐述了近年来国际上常用的理论及研究方法。为了更好地佐证进行极端气候事件发生概率研究的重要性,列举了作者在该领域的一些成功研究成果,并认为极端气候事件概率问题是探讨气象灾害规律的理论基础。  相似文献   

Earthquake catalogues and modelling strategies. A new testing procedure for the comparison between competing models     

G. Grandori  E. Guagenti  L. Petrini 《Journal of Seismology》2006,10(3):259-269

In this paper we consider the procedures that, on the basis of an earthquake catalogue, yield the magnitude distribution function F _M (F _M generators). In particular, our attention is focused on the F _M generators that are currently used in the frame of the probabilistic seismic hazard analysis at a site. From an engineering point of view, the behaviour of F _M in the range of strong earthquakes is of crucial importance. On the other hand, in general, the statistical validation of F _M in that range is not feasible because of an insufficient number of strong earthquakes in available catalogues.Our investigation is limited to the problem of the comparison between competing F _M generators. We show that a simple empirical F _M generator (called the CFP generator) can be more reliable than generators based on mathematical models. The numerical experiments that support this statement regards two test-sites and two mathematical models of magnitude distribution, namely the truncated-exponential and the characteristic-type models.The main conclusion is the suggestion of a test (called the CFP-test) that can be summarized as follows. Let X be a site for which, with current criteria, a specific F _M ^X generator based on a mathematical model has been selected. At this point, following the comparison approach described in the paper, the F _M ^X generator is compared with the empirical CFP generator. It can happen (actually it happens in many of our numerical experiments) that this test indicates the CFP generator as more reliable than the selected F _M ^X generator.  相似文献   

喀腊塑克水库诱发地震浅析     

彭亮  汪海涛  王兆云 《内陆地震》2007,21(2):149-154

采用判别标志、对比判断方法,尤其是概率分析方法对喀腊塑克水库诱发地震进行了分析。概率分析方法是利用诱震水库和未发震水库的统计资料,考虑了库深、库容、构造应力环境、断层活动性及诱震区介质条件5个因素,再利用概率统计中的贝叶斯公式建立了预测水库能否诱震的概率模型,最终计算出结果。另外,从库区断层活动性及断裂所通过的位置、库水深度及岩石坚硬程度等方面,分析出可能产生诱发该水库地震的位置。结合工作中的体会,提出评价水库诱发地震的步骤和方法。最终分析结果表明,喀腊塑克水库诱发地震的可能性不大。  相似文献   

Hybridization of the probability perturbation method with gradient information     

Kent Johansen  Jef Caers  Satomi Suzuki 《Computational Geosciences》2007,11(4):319-331

Geostatistically based history-matching methods make it possible to devise history-matching strategies that will honor geologic knowledge about the reservoir. However, the performance of these methods is known to be impeded by slow convergence rates resulting from the stochastic nature of the algorithm. It is the purpose of this paper to introduce a method that integrates qualitative gradient information into the probability perturbation method to improve convergence. The potential of the proposed method is demonstrated on a synthetic history-matching example. The results indicate that inclusion of qualitative gradient information improves the performance of the probability perturbation method.  相似文献