地磁前兆异常的动态从属函数

地震前兆涉及到多种地球物理观测方法,且计量单位各不相同,因此,各类前兆异常之间无法进行直接的定量对比,这给地震预报研究带来了困难.应用异常从属函数值（无量纲量）可统一规划不同性质、不同计量单位的地震前兆异常.本文通过研究地磁资料从属函数,发现1995年9月20日山东苍山Ms5.2级地震前有明显的前兆异常.增强了对地震前兆异常的识别能力,文中提出该方法在地磁场研究中应注意的问题.     

华北地区地震异常前兆信息场演化特征及其与地震关系的研究

在对地震异常前兆信息量先前研究的基础上,进一步给出了描述各种地震异常前兆信息量的普适性综合数学表达式.从大量震例资料入手,再次研究了地震异常延续有效性的问题,进而建立了地震异常持续有效时间与延续有效时间的数学关系式.收集整理了1980～1997年华北地区水化、形变、地磁、应力、水位、地电等371个观测项目、上百万个前兆观测数据,对每一观测项目逐一计算了它们的地震异常前兆信息量.研究了华北地区近20年的地震异常前兆信息场的演化特征及其与地震的关系,建立了华北地区Ms≥5地震的中短期综合预报指标体系,经R值评分检验,表明该地震综合预报指标体系在中短期地震预测中具有一定效果.     

滇西实验场区温泉碳同位素地震地球化学特征

引言最近若干年来,中、苏、美、日等一些多地震国家广泛开展了水文地球化学地震前兆的观测和研究。目前已经明确,水文地球化学综合观测在地震预报工作中具有十分重要的地位。要实现地下水预报地震,一方面要建立广泛的科学的监测台网,另一方面必须深入开展各类地球化学前兆异常的机理的研究。研究前兆机理最重要的是要搞清形成前兆异     

滇川甘及邻区短临观测前兆标志体系研究现状

地震预报研究近二十年来有明显的进展，但强地震短期预报和临震预报仍是当今世界的一大科学难题。逐步解决这一难题的途径仍然是如何正确地观测、识别和解释地震前兆的问题。提取有一定物理基础有一定重现率的短临前兆标志，乃至建立各类地震异常短临前兆标志体系，是目前国际地震预报致力探索的重大科研课题。较完善的短临前兆标志体系目前在国际上并没有先例；即使是适用性较强的地区性体系也未见到。基于目前观测成果，短临地震异常微观前兆标志体系是由众多单项前兆组成，它包括形变、应变、地下水、地磁、地电等多种观测方法。研究地震…     

滇川甘及邻区短临观测前兆标志体系的研究

对中国滇川甘及邻区各类前兆观测的资料进行连续时间序列处理，较系统分析了各台单项短临异常判据，初步建立了区域性各学科短临地震前兆标志体系，同时研究了孕震短临过渡过程的非线性特征，给出了经验性强震短临三要素预报的规则和做法。     

江宁台地电阻率异常震例的中短期预报回归方程的建立

本文研究了１９８３年以来江宁台３００ｋｍ范围内Ｍｓ＞４．５地震的５０ｋｍ范围内地方小震的地电阻率异常震例的中、短期前兆异常特征，分析统计了异常参量与地震三要素之间的关系，并初步建立起中短期预报回归方程，大体给出江宁台所能监控的不同强度地震的最大范围和一般距离；研究表明江宁地电前兆异常有其自身的特征。充分研究单台单手段的前兆异常对地震综合预报水平的提高是有益的。     

唐山7.8级地震前张道口井流体异常的综合信息量

多年来利用地下流体异常预报地震主要依靠的是单项观测资料，随着地震预测研究的深入和监测技术的发展，开展单井多项观测和提取综合前兆异常已是面临着的新任务。本文据张道口井的多年多项流体观测资料，提出了单井流体异常综合信息量的计算方法。     

西北地区地震综合预报判据与指标研究

本文简述了西北地区各类前兆台网的分布及效能,系统论述了地震综合预报判据与指标的研究现状。主要研究结果是:认为无论是地震活动性异常还是前兆异常均显示出近源异常占优势;通过分析多样和复杂的前兆现象提取了其若干共同特征;结合综合预报判据和指标阐述了跟踪震情不断修正预报意见的思路。     

地电阻率短临前兆异常的判定方法研究

本文用一阶差分和相干加权计算等方法对地电阻率观测资料进行处理，其结果较好地突出了短临前兆异常。进而研究了地电阻率短临前兆变化特征及其短临预报指标；采用归一化方法将电阻率各异常参量转换为地震前兆信息量，为多种前兆方法进行综合跟踪预报提供了必要的基础资料。     

近二十年四川中短期地震预报工作的进展和问题

近二十年来四川地区地震和前兆观测台网得到了较大的发展，获得了丰富的各类连续观测资料，积累了一批宝贵的震例；在中短期地震预报方法和指标的研究，包括观测前兆，地震活动图象，地震波分析，综合预报和现场工作方面取得了多项成果；在９次中强地震前作出了一定程度的中短期预报；同时也存在不足和诸项困难有待解决。     

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

正~~     

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.