有关昆仑山西8.1级地震及其余震活动趋势的讨论

在处理了部分有关资料的基础上,从发震断层旋性、历史地震类比、地震活动图像变化和地震序列特征等多方面对昆仑山口西8．1级地震的余震活动趋势进行了讨论。结果表明：本次8．1级地震的最大余震震级可能为6级左右。     

中国大陆及其邻区8级地震活动图像特征的初步研究及趋势评估(二)

1 8级左右地震趋势评估依据及其初步结果 1．1 以汶川8．0级地震为例、介绍进行趋势预测的几个依据 1．1．1 汶川地震的地点预测依据     

2002年8月8日四川新龙5.3级地震分析

介绍了2002年8月8日四川甘孜州新龙5．3级地震的地震概况、基本参数，分析研究了余震序列、震前部分前兆手段异常情况，介绍了短临预测情况，讨论了未能成功短临预测这次地震的原因。     

2001年11月14日昆仑山口西8.1级地震前地震活动性异常及其思考s

2001年11月14日在昆仑山口西发生了8.1级地震，震中位置为90.9E、36.2N．分析表明，8.1级地震前一些主要地震活动性异常都出现了，例如空区、条带、增强、平静和震群等，且与7级大震比较，这些前兆图象的演变具有类似的过程，所不同的是8.1级地震的前兆地震活动图象涉及的区域范围更大、地震震级更高，这为特大地震的前兆识别和预报提供了依据．最后回顾了对这次大震的粗略预测，并讨论了有关大震预测的某些问题．      

2003年巴楚-伽师6.8级地震中短期异常与预测

对2003年2月24日P楚—伽师6．8级地震中短期异常和中短期预测进行了较系统的分析与总结。结果认为,6．8级地震前新疆6级地震平静4年多,5级地震平静2年,中期阶段地震平静显著;短期阶段5级地震显著增强,震源区出现前震活动,同时全疆定点前兆观测资料出现较为明显的短期异常并观测到少量的临震异常。不同孕震时段的异常特征是6．8级地震中短期预测的依据,因而也是当前经验预报的基础。     

纪念古浪8级大震九十周年——暨对特大地震的研究讨论

置甘肃古浪8级地震发生90周年之际,本文用几种方法回顾性地讨论了特大地震的预测问题。分别用块体交界带指标、高山峰指标探讨了1920年海原8.5级地震发生的位置,并以这两个指标讨论了1927年古浪8级大震发生的位置。从国内某些大震25年周期的相关性和太阳活动峰年讨论了1927年古浪8级大震的发生年份。这些回顾性的指标研究对今后地震动、地震风险区划和预测大地震有一定的参考价值。     

2005年前中国大陆地震震级概率预测

采用以地震震级-频度关系和贝努利随机独立试验模型为基础建立的地震震级概率预测方法，对2005年前中国大陆各地震带的地震危险性进行了预测．结果表明，2005年前，中国大陆东部各地震带发生5级地震的概率一般在0.7以上，大部分在0.8以上；各地震带发生6级地震的概率一般在0.5～0.7之间；7级地震发生的概率也以山西地震带最高，可达0.0858．2005 年前中国大陆西部各地震带普遍具有发生6级地震的可能性(一般达0.9以上)；发生7级地震的可能性在青藏高原周缘各地震带和南天山地震带相对较高(0.7以上)．本文最后对预测结果的可信度、预测概率大小与未来地震的年发生率之间的关系进行了讨论．      

青新交界8.1级地震与远场地电阻率前兆异常的分析

2001年11月14日在青新交界发生8．1级地震的空间分布及地震序列进行了简述，利用远场地电阻率前兆异常信息的映震能力，对8．1级地震前后地电阻率变化特征作了初步探讨与研究，利用远场地电阻率前兆异常观测结果，为地震的前期预测预报提供了一定时的可靠判据。     

昆仑山口西8.1级地震前地震活动异常图像初步研究

通过对昆仑山口西8．1级地震前较大范围的5级以上地震活动性研究，发现地震前空间上存在着5级地震围空和条带现象，时间进程上出现了5级地震活动增强以及GL值高值波动变化现象。还分析讨论了中国大陆几次8级地震后中国西部强震活动特点，认为新疆地区今后几年6级以上地震活动可能处于相对活跃状态。     

云南地区3次6级间歇性双震第二主震的前震特征分析

分析大姚6．2，6．1级间歇性双震地震序列的地震波、地震活动变化，以类比方法分析了同震型的1976年盐源-宁蒗6．7，6．4级地震序列，1971年普洱6．7，6．2级地震序列，寻求第二主震的前震活动特征，结果表明：大姚6．2级与盐源-宁蒗6．7级序列中均出现一组P，S波振幅比为直线的前震；双震序列在第一主震后20～60d内，出现3，4级地震频度增高与b值、h值偏离余震衰减准同步异常的现象，第二主震临震前数天出现3，4级地震平静，与第二主震时间间隔仅2～9h，相距震中8km内发生3级显著地震。为预测预报间歇性双震序列的第二主震提供了一定判据。     

SCIENCE CHINA Earth Sciences SUBJECT INDEX TO VOLUME 57(2014)

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Distribution of throughfall and stemflow in multi‐strata agroforestry,perennial monoculture,fallow and primary forest in central Amazonia,Brazil

The partitioning of rain water into throughfall, stemflow and interception loss when passing through plant canopies depends on properties of the respective plant species, such as leaf area and branch angles. In heterogeneous vegetation, such as tropical forest or polycultural systems, the presence of different plant species may consequently result in a mosaic of situations with respect to quantity and quality of water inputs into the soil. As these processes influence not only the water availability for the plants, but also water infiltration and nutrient leaching, the understanding of plant effects on the repartitioning of rain water may help in the optimization of land use systems and management practices. We measured throughfall and stemflow in a perennial polyculture (multi‐strata agroforestry), monocultures of peach palm (Bactris gasipaes) for fruit and for palmito, a monoculture of cupuaçu (Theobroma grandiflorum), spontaneous fallow and primary forest during one year in central Amazonia, Brazil. The effect on rain water partitioning was measured separately for four useful tree species in the polyculture and for two tree species in the primary forest. Throughfall at two stem distances, and stemflow, differed significantly between tree species, resulting in pronounced spatial patterns of water input into the soil in the polyculture system. For two tree species, peach palm for fruit (Bactris gasipaes) and Brazil nut trees (Bertholletia excelsa), the water input into the soil near the stem was significantly higher than the open‐area rainfall. This could lead to increased nutrient leaching when fertilizer is applied close to the stem of these trees. In the primary forest, such spatial patterns could also be detected, with significantly higher water input near a palm (Oenocarpus bacaba) than near a dicotyledonous tree species (Eschweilera sp.). Interception losses were 6·4% in the polyculture, 13·9 and 12·3% in the peach palm monocultures for fruit and for palmito, respectively, 0·5% in the cupuaçu monoculture and 3·1% in the fallow. With more than 20% of the open‐area rainfall, the highest stemflow contributions to the water input into the soil were measured in the palm monocultures and in the fallow. Copyright © 1999 John Wiley & Sons, Ltd.     

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.     

Anthropogenic Eutrophication and Red Tide Outbreak in Lacustrine Systems of the Kashmir Himalaya

Red tide, a recurrent phenomenon has become conspicuous in several Kashmir lake ecosystems since 1991. The responsible organism (Euglena pedunculata), a rare flagellate rediscovered in the Kashmir Himalaya (Khan 1993) caused first and unprecedented red tide outbreak, constituting a maximum of 96% of resident numerical phytoplankton density in Dal Lake. At present, conflicting hypotheses exist on the generation of causal assemblage(s) imparting redness to waters: Jeeji Bai (1991) linked its origin to acid precipitation – a fallout of burning oil‐fields during the Gulf War – whilst Khan (1993) holds local factor(s) responsible. Field/experimental studies support the latter contention that the influx of untreated sewage, in unison with warm temperatures, high levels of PhAR, iron and interruption to hydrological flow‐pattern together with absence/or reduction in grazing activity created conducive environmental milieu for red tide outbreak. Dal Lake “red tide” drifted the bloom‐inoculum to other waters, including Lake Wular, where additional ecological niches were carved out, threatening the aesthetic value and biological diversity of Kashmir lakes. Ecological monitoring indicates frequent seasonal red tide occurrence in Dal Lake (including summer‐autumn event of 1998) which testifies its unabated eutrophication status. Further studies are needed on ecological adaptability and biogeographic distribution of this rare and unique red tide‐causing flagellate.