首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 359 毫秒
1.
珠江三角洲公路系统震害预测   总被引:1,自引:0,他引:1  
赵成刚  张锐 《华南地震》1995,15(3):34-39
在收集整理珠江三角洲地区几条主要干线道路上的桥梁和场地害预测资料的基础上,利用我们建立的基于人工神经元网络的桥梁震害预测方法,对这几条干线道路上的桥梁进行了震害预测。并在此基础上,对这几条干线道路系统的车通性进行了分析。  相似文献   

2.
本文采用改进的连续亨明方法对兰州市城关区有张掖地区进行场地类型的图象识别。结构表明,将图象识别方法用于场地类型的划分是可行的。它不仅改进了以往经验的、宏观的工作方法,而且在方法上实现了数值和计算机化,在增进识别能力的同时,提出了识别的准确度和速度。利用图象识别方法可以综合分析地质构造、场地上,地形地貌等多种因素或特征,并对特征进行选择,定量地对场对类型进行识别分类。  相似文献   

3.
广西地区的水系展布与活动断裂及新构造应力场的关系   总被引:3,自引:0,他引:3  
尹克坚 《华南地震》1995,15(1):62-67,94
对广西以及邻区的部分河流进行了统计分析,认为广西水系较好地反映了广西断裂的展布和活动性,一些原称隐伏断裂应当看成活动断裂,文章还对水系统计法进行了讨论,指出该方法在理论上存在某些缺陷,在实际操作上也存在较多问题。  相似文献   

4.
设计和安装了地应力壶,在1977-1978年进行了观测,用日变曲线异常进行临震预测。在地震三要素预测中,发震时间预测较准确;在地点上震中方位角预测较准,震中距难以预测;震级预测误差较大。  相似文献   

5.
沉积盆地岩浆侵入的热模拟   总被引:15,自引:1,他引:15  
沉积盆地中岩浆的侵入会导致盆地地温史的变化,影响烃类成熟度,本文对沉积盆地中岩浆侵入过程进行了热模拟,分析了岩浆侵入对沉积盆地温度结构和成油窗的影响,在计算中,既考虑了岩浆凝固过程释放的潜热,又考虑了岩石比热,热导率随温度的变化对热模拟结果的影响,通过计算认识到:沉积盆地中侵入岩浆在垂直方向上的热扩散比水平方向热扩散更快,几公里大小的侵入体其热影响可以在时间上持续数百万年,在空间上扩散至十数公里,  相似文献   

6.
中国大陆强震组的预测研究   总被引:1,自引:0,他引:1  
地震活动图象无论在时间上还是在空间上都具有层层嵌套的自相似结构。我国大陆地区强震预报的基本程式是,在空间上由大到小,在时间上由长到短,逐步逼近地进行。与地震系统的层次结构大体相应。但是当对各个重点危险区作判定时却是彼此孤立进行的。对于已发生的强震的意义缺乏足够分析。本文根据强震成组的基本特点及前兆异常中存在地震组异常的基本事实,提出了地震组预测的原则和基本方法。  相似文献   

7.
本文从地球物理场出发,通过严密的数学物理推导,提出了磁力测深公式,并导出了著名的重力测深公式的更一般表达式。为了得到更为精确的解,本文又提出了应用最优化理论的空间域迭代算法,并根据地球物理模型对于高斯优化法进行了改进,在算法上有所创新,使其在计算机上实现时算法简单,计算速度快。文中还列举了一些模型的实验结果,对磁力测深公式及迭代算法的有效性及可靠性进行了论证。用本文方法对实际资料的处理结果是令人满意的,证明该方法有一定的实用性。  相似文献   

8.
黑龙江红河谷及邻近地区地震活动特征   总被引:2,自引:0,他引:2  
孟宪森  陈洪洲  关玉辉 《地震》2002,22(1):77-83
应用地震活动性研究的基本方法对黑龙江河谷及邻近地区的地震活动特征进行了研究。结果表明,其地震活动在时间上具有一定的准周期特征,在空间上和主要构造带关系密切,近期中强地震活动可能比较活跃。  相似文献   

9.
天山地区地震学中短期预报方法研究及效能评价   总被引:3,自引:2,他引:1  
利用多种地震活动性方法,对南北天山地区较大地震前的地震学中短期前特征进行了系统分析,并从地震活动的空间分布及时序特征两方面,提出了6个研究子区的前异常判定指标,在对种种上地震学方法的效能进行R值评分的同时,还对它们之间的盯关性进行了讨论。  相似文献   

10.
介绍了以ArcViewGIS平台为开发平台,利用网络划分技术对鞍山市建筑物进行了单元划分,对每个单元进行了建筑物群体震害预测;在ArcViewGIS平台上构建信息管理系统的技术思路与实现步骤:最后给出了反映鞍山市建筑物在不同地震烈度下的破坏结果,以及造成的直接经济损失与人员伤亡情况。  相似文献   

11.
12.
13.
《国际泥沙研究》2014,(4):F0003-F0003
  相似文献   

14.
《国际泥沙研究》2014,(2):F0003-F0003
  相似文献   

15.
《国际泥沙研究》2014,(3):F0003-F0003
  相似文献   

16.
17.
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.  相似文献   

18.
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.  相似文献   

19.
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.  相似文献   

20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号