迁安-青龙4.2级地震的短临预报

１９９９年５月１２日在迁安市发生Ｍｓ４．２级地震,震前在唐山才 区的东端４组地震平静长达８年之久,地震能量显示出５个月的低值异常,距震中６５ｋｍ的滦县西法宝深井水位于震前１个月出现反年变加速上升异常。据此,唐山市地震局对此次地震作出了成功的短临预报。     

1998年8月伽师6.0级、6.6级地震前阿合奇台和乌什台地倾斜异常

引言１９９８年８月２日伽师６．０级、８月２７日６．６级地震前,位于震中２８０ｋｍ东北方向的阿合奇地震台和乌什地震台的地倾斜资料均出现了不同程度的前兆异常。尤其是阿合奇台的地倾斜,在两次地震前异常特点明显。笔者应用“八五”攻关成果软件,对这两次地震进行了跟踪分析研究,并对１９９８年８月２７日６．６级地震作出了地震“三要素”预报。１　阿合奇台地倾斜异常阿合奇地震台ＳＱ－７０Ｂ型石英水平摆倾斜仪于１９８９年开始投入观测,历年来记录较稳定,对其周围发生的较大地震均有较好的异常对应。１．１　日均值分量异常…     

地震预报探索与张北6.2级地震

１９９８年１月１０日在河北省张北县和尚义县之间发生６．２级地震,震震深度为０ｋｍ。震前一二年发现有明显的地震前兆异常：４级地震条带明显,区域地震增强并出现低ｂ值异常等;     

1992年新疆和田地区地震及地倾斜异常

分析了新疆和田地区１９９２年４月５日发生的Ｍｓ５．９地震和同年９月２日、１２月２５日发生的Ｍｓ４．６级地震的震前地倾斜异常情况。利用迭代法对地震平静年份的资料进行处理，做出正常背景曲线并与异常图象比较，收到了良好效果。另外还各单位介绍了田地区的地质构造背景及历史地震活动，并对常用处理资料方法的预报效能以及异常量大小和震级的关系进行了讨论。     

地下水动态模糊分维特征初探

利用模糊分维计算公式，计算了１９８３年１１月７日山东荷泽Ｍｓ５．９级地震和１９９２年１０月２２日江苏射阳Ｍｓ４．６级地震震中附近的井水位、水氡观测值的模糊分维值。结果表明，地震发生前其模糊分维值有明显的降维现象，异常显示比始观测曲线异常显示明显。     

大同—阳高2次地震前的震级熵异常

利用最大熵原理推导了连续随机变量震级熵的表达式，计算大同－阳高地震前后≥２．０地震的震级熵，计算结果表明，从１９８８年４月开始，震级熵开始出现低值异常，１９８９年３月熵开始回升，在回升途中发生了１９８９年１０月１８日的大同－阳高６．１级地震，１９９０年４月份后震级熵再次出现低值异常，９月份后震级熵再次回升，在回升途中发生１９９１年３月２６日的５．８级地震。     

1999年11月1日大同-阳高Ms5.4级地震预报纪实

１９９９年１１月１日在山西省大同－阳高地区发生了一次Ｍｓ５．４级地震。这次地震前笔者采用测震学方法对华北地震活动性进行分析研究,结果发现华北缺震曲线,华北地震曲线、频度曲线都出现低值异常。邢台震区月频度曲线６月份小震活动增强。北京地区缺震曲线、频度曲线都出身低值异常。１９９９年６月份在晋冀蒙三省交界地区的大同附近小震活动丛集、频度与蠕变加速,并于９月１２日发生了左云ＭＬ４．７级信号震。据此,笔者在     

1995年4月15日营口高坎M＿L5．0地震概述

１９９５年４月１５日营口高坎Ｍ＿Ｌ５．０地震，震中区烈度达Ⅵ度。总结发现，震前在一定的震兆异常背景上，出现一批短临前兆异常，如深井水位、水氡、水温、水汞、地倾斜、地电阻率、宏观等。分析认为，它可能是介质较薄弱的老震区对大区域应力场作用增强的反映，是我省震情发展中一次重要的地震事件。     

伽师—阿图什6.7级地震阿图什地倾斜异常特征

１９９６ 年３ 月１９ 日新疆伽师—阿图什地区发生了６．７ 级强烈地震。震前阿图什地震台倾斜仪记录的中短期和短临前兆异常特征为：中短期趋势性异常的方向向背离震中的方向倾斜,持续了１３个月;震前两个月趋势异常出现短期恢复,之后加速异常;临震前５ 天异常快速恢复,并伴有观测值的临震突跳现象,地震发生在异常的恢复之中     

包头西6.4级地震前后水化异常的分析

用“八五”攻关水化、水位地震短临预报方法分析研究了１９９６年５月３日包头西６．４级前后震中周围３００ｋｍ范围内水化群体异常随时间的变化特征与地震的关系,结果表明利用该方法可以对包头西６．４级地震发震时间进行短临预测,证明了该方法在地震预报中具有重要实用价值。     

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.