中等地震前信息增益时空变化特征

着重研究了河南省及邻区6次ML4．7级以上地震前信息增益变化图像和信息增益时，空变化特征，依据这些特征将地震分为Ⅰ型（异常－发震型）和Ⅱ型（异常－消失－发震型）两种类型。在此基础上，根据信息增益的时，空扫描图像，对异常地区的地震趋势和将要发生的地震的震级（是否大于5级），震中位置和发震时间进行了探讨。     

基于MaPInfo的中长期地震预测动态系统

“中长期地震预测动态系统”（MapDEP2000 for Windows)是以强震时－空概率增益综合预测模型与单项地震预测模型的预测效能评价方法为理论基础，以强大的数据为支持，集成桌面地图信息系统（MapInfo0的主要功能而研制完成的运行于Windows9x或以上环境下的地震综合预测系统。系统具有中长期单项预测方法的计算，异常提取，效能评价，概率增益统计，外推预测和概率增益综合预测等计算与各种输入／输出，图形显示等强大而实用的功能，为运用数据库和GIS实现多手段，多尺度，动态和交互的信息综合，进行地震预测提供了一套实用的系统和完整的解决方案，本文对该系统的科学依据，设计思想和主要功能进行了介绍。     

关于发展我国地震科技信息工作的思考

地震科技信息的积累和应用是我国地震科学事业发展的基础，我国的地震信息工作在地震预报的探索和研究中以及地震工程应用中，均发挥了重要的作用，为进一步认识地震科技信息的重要性，发展这一事业，本文就地震科学研究与地震科技信息的内在联系，地震科技信息的运行机制及地震科技信息工作的发展提出了一些新的观点。     

本世纪初我国大陆7级大震危险性研究

地震大形势研究结果表明，我国大陆地区（含边境）１９９９年已进入为期１２年的相对平静幕，幕内可能发生３次７级地震，最大震级不超过７．２级。首发７级地震为２０００年６月８日缅甸７级（位于中缅边境）。预计第二个７级地震危险时间在２００５±０．５年。第三个在２００８年前后。分析了我国主要地震区强震概率增益，给出了３个危险地点。未来３年即２００１～２００３年是相对安全时段，我国大陆不会发生７级以上破坏性地震。２０１１～２０２０年可能进入新世纪第一个７级大地震相对活跃幕，预计该幕持续１０年， 可发生１０次７～７.６级大震。     

中—长期地震预测方法概率增益的评估

对各种不同时空尺度地震预测方法的概率增益Ｋ的评估,是应用地震预测综合概率增益模型的基本研究内容之一。各种尺度地震预测方法可分为空间增益,时间增益和时空增益三种类型,初步研究了概率增益Ｋ的评估方法,给出预测状态概率评估概率增益Ｋ的关系,并得出地震预测方法的Ｒ值评分与概率增益Ｋ的关系     

水库地震的综合概率增益预测法研究

在水库地震预测中首次引进了地震概率增益综合预测模型,叙述了该方法的基本原理;探讨了影响水库地震最大震级发生的因素;结合中国水库及其水库地震震例资料,对水库地震综合影响因素E值、库容、库水深度因素或指标预测水库地震最大震级的效能R值和经验概率增益K值进行了统计和评价,表明概率增益综合预测能够对各种预测方法预测水库地震的效果进行定量分析。在此基础上,选择国内外若干水库进行了水库地震最大震级回溯性检验,表明该方法作为一种新的水库地震最大震级预测方法是可行的     

地震活动的分幕研究及其我国主要地震区带未来十年的趋势预测

地震学者认为，在地震活动区一个较长的地震活动期里，地震群体活动的强度有一个发展变化的过程。笔者认为在一个地震活动期里，不仅地震群体活动在强度上有一个变化过程，而且在地震活动期的各个阶段中地震活跃幕和平静幕的持续时间也可能会有较显著的不同。基于这一思想，文中研究了华北地震区、我国西部及其邻区以及全国大部分地震带，在一个较长的地震活动期里，随着地震幕强度的变化，幕的持续时间和平静幕的持续时间通常有两种     

地震危险综合评判的分量分析方法

地震危险性评判，通常需要将多种方法的结果加以综合。为了去除各种方法中可能的重复信息，并对各种方法对危险性评判结论的重要程度进行合理的度量，使综合的结果更加合理，我们引入了分量分析方法。本文首先介绍了分量分析方法的基本原理，其次阐述了该方法在地震危险性综合评判中的应用，最后给出了华北北部中长期地震危险性预测的一个计算实例。     

中长期时空增益综合预测模型及其初步应用

阐述了中长期地震时空增益综合预测模型的基本原理和单项预测方法的信度评价方法,给出了概率增益与预测效能评分R值的关系,并对R值评分法进行了推广．以华北地区为试点,研究了不同地震活动期与活动幕的时间概率增益、活断层的空间概率增益和以垂直形变为代表的时空联合的概率增益,并采用中长期地震时空增益综合预测模型,对华北北部地区的综合概率增益进行了示例性预测．      

西北地区东部地震前兆观测的概率增益

在前人工作的基础上,应用概率增益的思想对西北地区东部地震前兆观测的综合概率增益进行了探索性的应用研究。结果表明,前兆手段的概率增益异常集中出现在震前半年至震前1～3个月,异常项数随时间向发震时刻逼近而增加,未来震中在异常区附近,异常在空间上较为集中;前兆综合概率增益变化较大,中强地震前最高可达6个量级,但与台网的分布密度有关;中强地震前的平均台项概率增益总体上与震级大小有关,另外还与前兆台项的映震效果有关。     

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.