地震短期预测的概率方法浅议

和天气预报相比,地震预测,特别是地震的短临预测更为困难。概率方法真实地反映了地震发生的随机性,真实地反映了人类对于地震认识的局限性,加快短期预测的概率方法研究与应用是十分必要的。概率预测是经验预测、统计预测和物理预测的综合,各类地震预测方法特别是物理预测方法的发展还很不充分,目前仍处于探索阶段。从目前我国地震预测的现状来看,应大力发展统计预测方法。地震目录可为我们提供对背景地震发生率的估计,而前兆的出现使我们可以得到地震发生率大大高于背景发生率的时段,其增益越强,时段越短,越接近于理想预测。前兆和地震之间的关系的统计检验对于概率预测起着十分重要的作用。该文提出,应按实用化的要求逐步规范各种地震预测方法。这对地震预测研究的健康发展是至关重要的。     

以菏泽地震为例探讨地震学综合预测方法

在前人提出的地震预测方法基础上提出一种地震学综合预测方法。 首先利用动态图像方法(地震条带与地震空区)大致确定潜在地震危险区; 然后利用中、 强地震产生的库仑应力确定孕震区; 最后利用地震矩快速释放模型和相关长度增长模型判断孕震区是否进入短临状态。 在地震三要素预测中, 发挥地震学典型预测方法的优势, 并且对相关性较小的预测方法的预测结论相互对比、 印证, 以便得出更可靠的预测结果。 文中还利用这种综合预测方法对1983年菏泽5.9级做了简略研究, 结果表明这种综合预测方法的预测结果和菏泽地震基本上是一致的。     

设定地震的分类及其确定方法

讨论了震害预测中的设定地震,将其分为检验型设定地震、预测型设定地震和重现型设定地震,并论述了３种设定地震的确定原则和方法．作者还进一步论述了３种设定地震在不同震害预测方法中的应用     

地震预测方法Ⅱ:评述

本文分析了各种地震预测方法对地震的预测情况.首先通过岩石力学实验和有限元模拟计算结果分析了含裂纹岩石材料的变形破坏过程;其次,将实验室岩石破坏过程的观测结果和有限元模拟计算结果外推到地壳岩石的变形破坏过程,从地震发生的物理力学机理出发,对多种地震预测方法进行了评述,研究这些地震预测方法的有效性和尚待解决的问题,同时对利用物理化学方法预测地震的前景进行了讨论.     

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     

基于Molchan图表法的新疆流体资料预报效能检验

正我国作为世界地震预测预报实践性探索的开先河者,在40多年的地震预测预报探索与研究中,逐步形成了以长中短临时间阶段性和跨多学科综合性为基础的经验预测、统计预测以及物理预测,并初步建立了科学的地震预测预报思路及工作方法。近年来,对于可能的地震前兆与地震之间的关系,国内外地震学家们通过构建"物理"模型,开展了多种地震预测模型的研究,试图深入理解地震的成因机制,寻找有效实用的地震预测预报方法,并且已在地震的中长     

地震拓扑预测

本文对地震参数建立了地震拓扑空间并把灰色系统理论中的拓扑预测方法引入地震预测之中,研究地震长趋势的预测问题。     

地震储层预测方法研究进展

本文重点介绍地震储层预测方法中的油气预测，岩性预测，储层厚度预测及孔隙度预测等内容，简述提高地震储层预测精度的途径之一－特征优化方法，并指出了今后地震储层预测方法研究的方向。     

利用相关因子预测中国大陆强震的支持向量机方法

中国大陆地震活动与太阳活动、地球自转和全球地震活动之间存在较强的非线性关系。文中以太阳黑子数、地球自转速率变化数据和全球7级以上地震总应变释放量作为预测因子,使用支持向量机分类方法建模预测中国大陆年度地震强度,预测效果较好,表明支持向量机分类方法是一种较好的预测中国大陆地震活动强度的方法。     

地震预测研究与展望

概要介绍了近年来国际上就地震预测所展开的争论，分析了VAN方法所反映的地震前兆研究动向；就地震前兆观测与数据资料库建设、地震前兆的统计分析、地震的动力学预测、地震预测算法的发展等方面，论述了国际地震预测研究的进展；并概略地介绍了中国的地震预测研究进展．     

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

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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.     

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.     

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.