中强以上地震发生后半年内地震趋势的模糊聚类分析

利用１次中强以上地震（Ｍ０≥４．７）发生后前６天地震序列的资料，对未来半年内是否可能发生相当（Ｍ＝Ｍ０±０．３）或更大的地震进行模糊聚类分析．根据３６个初选问题的Ｗａｌｌｅｎ评分，精选出１３项能突出表现地震序列的特征参数作为指标．应用模糊聚类的ＦＣＭ算法对地震序列进行分类，Ⅰ类为Ｍ０级中强震后６个月内还有震级为Ｍ≥Ｍ０－０．３级的地震发生；Ⅱ类为Ｍ０级中强震后６个月内无相当或更大的地震。以中国大陆地区１９６６年以来的４８次Ｍ０≥４．７级中强震序列资料建立震后判别模型，然后对近期发生的８次强震序列进行了外推检验。     

东南沿海地震区地震活动特性与未来趋势分析

根据地震资料，对东南沿海地震区地震活动特下及未来趋势进行了初步分析与研究，结果表明：（１）从地震活动轮回分析，东南沿海地震区从１９５９年开始的第五个轮回中的地震活动时段，估计将延续到２０３１年前后结束，而后转入本轮回的平静时段；（２）２０００年以前，研究区有可能发生１次Ｍｓ≥６．０地震，到２００５到则最多发生２次；（３）东南沿海地震区下一次发生Ｍｓ≥６．０地震的地区可能在河源－邵武地震带上，尤其可     

1999年2月份全球M≥5.0地震动态

根据中国地震局地球物理研究所中国数字地震台网数据管理中心（ＣＤＳＮＤＭＣ）从美国地震学合作研究会数据管理中心（ＩＲＩＳＤＭＣ）得到的资料,１９９９年２月份全球范围内共发生Ｍ≥５．０地震８６次（见表１）。其中,Ｍ≥６．０地震６次,Ｍ≥７．０地震１次,最...     

1999年5～6月份全球M≥5.0地震动态

根据中国地震局地球物理研究所中国数字地震台网数据管理中心（ＣＤＳＮＤＭＣ）从美国地震学合作研究会数据管理中心（ＩＲＩＳＤＭＣ）得到的资料,１９９９年５月份全球范围内共发生Ｍ≥５．０地震７６次（见表１）。其中Ｍ≥６．０地震１０次,Ｍ≥７．０地震１次,最大的一次地震发生在巴布亚新几内亚的新不列颠地区,震级为７．０。本月发生的７６次Ｍ≥５．０地震中有５３次发生在东半球,２３次发生在西半球。１９９９年６月份全球范围内共发生Ｍ≥５．０地震７０次（见表１）。其中Ｍ≥６．０地震３次,最大的一次地震发生在墨西哥…     

地震序列类型早期判断的可能性

详细讨论利用地震现场提供的１天、３天和７天观测资料，预测地震序列类型和最大强余震震级的可能性和现实性。４７个Ｍ≥６．０地震的地震序列实例检验表明，利用７天内的观测资料，准确率可达到８５．１％。因此，使用ｂ值横截距法有可能在早期预测最大强余震的震级并判断地震序列的类型。     

1999年1月份全球M≥5.0地震动态

根据中国地震局地球物理研究所中国数字地震台网数据管理中心（ＣＤＳＮＤＭＣ）从美国地震学合作研究会数据管理中心（ＩＲＩＳＤＭＣ）得到的资料,１９９９年１月份全球范围内共发生Ｍ≥５．０地震８１次（见表１）。其中,Ｍ≥６．０地震７次,Ｍ≥７．０地震０次,最...     

模糊数学预测未来一年内临汾盆地最大震级范围

本文选取判别每年可能发生地震的最大震级范围的４个地震活动指标，对临汾盆地３１５年至１９９５年２月Ｍｓ≥４．７５的地震（余震除外）序列，应用模糊数学进行了处理，给出了判别３个震级范围，即５．５≤Ｍｓ〈６．０，６．０〈Ｍｓ≤６．５，Ｍｓ〉７．０的模糊关系方程。对此方程通过对３个典型类地震样本，以及未参加建模的２个地震样本进行了检验与预测。结果均与实际符合较好。本文还对１９９５年２月之后１年内临汾盆地可     

新疆地区地震发生的统计分析

根据新疆地区本世纪的地震记载，分别取５．５、６．０、６．５、６３／４、７．０、７．２为震级下限，视各组资料为更新过程的样本、分析地震发生的统计特征。经统计检验，不同震级下限的地震发生皆可认为是泊松过程；本世纪初中强地震在记载中可能有遗漏，为避免由此引出的干扰，使用Ｍｓ≥６．５的资料不应早于１９１４年，使用Ｍｓ≥５．５与Ｍｓ≥６．０的资料均应从１９３１年开始；在地震发生大体上为泊松过程的情况下，地震     

汾渭带和华北平原带强震活动的群集特征

根据描述地震活动时间间隔统计特征的系数Ｃｖ，汾渭带和华北平原带强震活动（ＭＳ≥７．０和Ｍｓ≥６．０）过程显示出明显的非泊松的群集统计特征（Ｃｖ＞１）；对于自公元５００年以来的Ｍｓ≥７．０大地震活动过程，其累计频度（ΣＮ）表现出满足ｌｎ（ｌｎΣＮ）＝Ａ＋Ｂｔ关系的逐步加速释放能量的群集时间结构；对于自公元１０００年以来的Ｍｓ≥６．０强地震活动过程，则表现出几十年－几百年尺度的密集和平静交替发生的幕式群集时间结构。     

1999年3月份全球M≥5.0地震动态

根据中国地震局地球物理研究所中国数字地震台网数据管理中心（ＣＤＳＮＤＭＣ）从美国地震学合作研究会数据管理中心（ＩＲＩＳＤＭＣ）得到的资料,１９９９年３月份全球范围内共发生Ｍ≥５．０地震８９次（见表１）。其中Ｍ≥６．０地震９次,Ｍ≥７．０地震１次,最大...     

A Monte Carlo study of rainfall forecasting with a stochastic model

A procedure for short-term rainfall forecasting in real-time is developed and a study of the role of sampling on forecast ability is conducted. Ground level rainfall fields are forecasted using a stochastic space-time rainfall model in state-space form. Updating of the rainfall field in real-time is accomplished using a distributed parameter Kalman filter to optimally combine measurement information and forecast model estimates. The influence of sampling density on forecast accuracy is evaluated using a series of a simulated rainfall events generated with the same stochastic rainfall model. Sampling was conducted at five different network spatial densities. The results quantify the influence of sampling network density on real-time rainfall field forecasting. Statistical analyses of the rainfall field residuals illustrate improvement in one hour lead time forecasts at higher measurement densities.     

Earthquake Engineering and Engineering Vibration Aims And Scope

正This journal is established by the Institute of Engineering Mechanics(IEM),China Earthquake Administration,to promote scientific exchange between Chinese and foreign scientists and engineers so as to improve the theory and practice of earthquake hazards mitigation,preparedness,and recovery.To accomplish this purpose,the journal aims to attract a balanced number of papers between Chinese and     

Foreword

Destructive earthquakes have caused great damage in China and the United States and collapsing buildings havecaused many deaths and injuries. The field of earthquake engineering studies earthquake hazards, the occurrence ofearthquakes of various magnitudes, the nature of the ground shaking during an earthquake, the vibration of structuresduring earthquakes, the strengthening of existing structures and the design of new structures to be earthquake resistant,and finally, how to cope with earthquake damage and restore a city to normal functioning. Such efforts are in progressin both countries, but unfortunately, the language barrier interferes with the free flow of information between China andthe Untied States. It would be mutually beneficial if some means could be developed to promote the exchangeof information across the Pacific Ocean. This new journal has been established for this purpose and its success willbe an important step in promoting earthquake engineering in China and the United States.     

WORLD ASSOCIATION FOR SEDIMENTATION AND EROSION RESEARCH(WASER)

正President:Giampaolo Di Silvio,Italy Vice Presidents:Ulrich C.E.Zanke,Germany Zhao-yin Wang,China The World Association for Sedimentation and Erosion Research(WASER),inaugurated on Oct.19,2004,is an independent non-governmental,non-profit organization.The mission of WASER is to promote international co-operation on the study     

Enhancing remote sensing research on global change to improve our understanding on Earth system processes

正Global Change includes climate change and other environmental changes caused by the joint interaction among various layers of Earth. From the positive side, global change provides new opportunities to human and other living forms on Earth. In the meantime, it creates tremendous challenges and negative impact. At present, the negative impacts have reached all primary processes of the global ecosystem and every aspect of human society, especially causing degradation of the ecosystem. For instance, intensive deforestation causes decline of biodiversity; global warming causes sea level rise and increases