地应变震兆异常信息提取方法研究   总被引：2，自引：1，他引：1  

王曰风  张秀萍  李海孝  王长江  段立新  张常慧 《地震地磁观测与研究》2004,25(1):35-40

分析了怀来台体积应变观测资料的特点,研究了体积应变观测资料的气压干扰、仪器漂移的剔除方法和预处理后的资料分析方法,在分析中发现,振幅因子和非潮汐应变速率在1996年以来,在首都圈地区中西部发生的中强地震前,均有大小不同、持续时间不等的异常,这些参数可作为怀来地震台今后地震分析和地震中短期预测的指标。  相似文献   

Turbulent intensity and its similarity function over an Inner Mongolian grassland during spring     

YUE Ping      NIU ShengJie  HU YinQiao & ZHANG Qiang Key Laboratory of Arid Climate Change  Reducing Disaster of Gansu Province  Key Laboratory of Arid Climate Change  Reducing Disaster of CMA 《中国科学:地球科学(英文版)》2010,(5)

Macroscopic reason for the development of turbulences in fluid is the conjunction action of velocity and temperature shears. We use the 2008 spring flux observations in the surface layer over Inner Mongolian grassland, obtain the similarity functions of turbulent intensity under different stratification stability conditions, and calculate the clear day turbulent intensity in the spring, which is then analyzed and compared with the observed values of turbulent intensity. The results show that in the Inner Mo...  相似文献   

基于R树索引的三维场景细节层次自适应控制方法   总被引：1，自引：1，他引：0  

龚俊  朱庆  章汉武  李晓明  周东波 《测绘学报》2011,40(4):531-534

针对大规模三维城市建模需要,介绍一种基于三维R树索引的多细节层次（简称LOD）管理方法,从叶节点层向根节点自动生成LOD场景,并设计实现LOD检索的算法。通过试验分析,证明本文的LOD定义参数能够定量控制三维场景中的渲染目标数目,进而实现三维场景的自适应可视化方法,尤其适合于建筑物和树木类型的地物目标。  相似文献   

南京地区地球物理场与地震构造稳定性   总被引：2，自引：1，他引：1       下载免费PDF全文

熊振  李清河  王良书  周彩霞 《地震学报》2011,33(5):624-636

岩石圈的不均衡状态是地球物理场存在差异的原因,对区域地球物理场进行分析,可以了解岩石圈的不均衡及其构造活动的背景.本文在对南京地区地震地质环境分析的基础上,通过重力异常、地热场、深部速度结构、天然地震层析成像等地球物理资料进行系统分析,研究它们与本区地震构造稳定性的关系;分析研究地震活动,从现今地壳运动速度场与地壳形变...  相似文献   

中国大陆地震条带统计特征分析   总被引：6，自引：0，他引：6       下载免费PDF全文

李莹甄  王海涛  邬成栋  王想  冯建刚  曲延军  王行舟 《地震学报》2011,33(5):568-581

对中国大陆具备相对完整资料的327次M≥5.0地震,分5个工作区进行了统一要求的地震条带图像扫描,发现96次中强震前存在条带图像,约占研究地震总数的29％.其中震前有条带地震与研究地震的比例分别为:华北地区30％,华东南区29％,川滇地区41％,青藏高原西北缘24％,新疆地区16 ％.中强震前出现条带比例最低的是新疆,...  相似文献   

Spatio-temporal point pattern analysis on Wenchuan strong earthquake     

Peijian Shi Jie Liu    Zhen Yang Agricultural College  Jiangxi Agricultural University  Nanchang  China China Earthquake Networks Center  Beijing  China 《地震学报(英文版)》2009,(3):231-237

For exploring the aftershock occurrence process of the 2008 Wenchuan strong earthquake, the spatio-temporal point pattern analysis method is employed to study the sequences of aftershocks with magnitude M≥4.0, M≥4.5, and M≥5.0. It is found that these data exhibit the spatio-temporal clustering on a certain distance scale and on a certain time scale. In particular, the space-time interaction obviously strengthens when the distance is less than 60 km and the time is less than 260 h for the first two aftershoc...  相似文献   

Geochemical characteristics of soil gas in the Yanhuai basin,northern China     

Ying Li Jianguo Du  Fukuan Wang Xiaocheng Zhou Xiaodong Pan  Ruqing Wei Institute of Earthquake Science  China Earthquake Administration  Beijing  China Inner Mongolia Corporation Ltd.of Geologic Engineering  Hohhot  China Earthquake Administration of Jilin Province  Changchun  China Liaocheng Seismology Hydro-chemistry Test Station  Liaocheng  China 《地震学报(英文版)》2009,(1):93-100

The geochemical backgrounds and origins of soil gases in the Yanhuai basin are discussed based on the regional seismogeological data and concentrations of Rn,Hg,CO2,H2,He and CH4 in soil gas measured at 422 investigating sites in field during September to October 2007.The geochemical background values of Rn,Hg,CO2,H2,He and CH4 are(8105.8±5937.4) Bq/m3,(9.7±5.8) ng/m3,(395.9±35.3)×10-6,(4.0±2.3)×10-6,(15.9±10.4)×10-6 and(12.7±8.1)×10-6,respectively.The geochemical backgrounds of the soil gases are higher in...  相似文献   

Ground motion attenuation relations of small and moderate earthquakes in Sichuan region   总被引：1，自引：0，他引：1  

Lanchi Kang    Xing Jin  Fuzhou University  Fuzhou  China Earthquake Administration of Fujian Province  China 《地震学报(英文版)》2009,(3):277-282

On the basis of 10 935 broadband velocity records of 135 earthquakes (ML3.0-6.4 and epicentral distance of 26-623 km) occurred from May 12 to June 10 in 2008, which are collected from 27 bedrock stations included in Sichuan Earthquake Monitoring Network, the corresponding acceleration records are obtained by a real-time simulation method. Then by regression analysis on the data, the relation between the peak ground acceleration and velocity attenuation of small and moderate bedrock earthquakes occurred in S...  相似文献   

Effects of precipitation and landuse on runoff during the past 50 years in a typical watershed in the Loess Plateau, China   总被引：2，自引：0，他引：2  

Huaxing BI  Bin LIU  Jie WU  Lei YUN  Zhihan CHEN  Zhewei CUI Prof. in hydrology  College of soil  water conservation  Box  Beijing Forestry University  Qinghua East Road  Haidian District  Beijing  China  Researcher in hydrology  Xifeng station of soil  water conservation  Xifeng  Gansu Province  China Graduate Assis. 《国际泥沙研究》2009,24(3):352-364

In the past century, great progress has been made worldwide in our understanding of forest-water relationship. The successful forestation programs implemented in China-which have improved the ecological environmental conditions-have gained the attention of many researchers and highlighted the relationship between forestation and water yields. The arid and semi-arid Loess Plateau has received attention from water engineers and eco-hydrological researchers in China because of a shortage in water resources. We selected one of the oldest stations conducting soil and water conservation experiments, the Xifeng soil and water conservation station, and chose the Nanxiaohe catchment and its paired catchments （Yangjiagou catchment and Dongzhuanggou catchment） as our research areas. Trends in precipitation, air temperature, streamflow over the past 50 years, and the effect of changing land use on streamflow were analyzed. The Mann-Kendall test showed that precipitation had a negative trend （downward trend）, whereas air temperature showed a positive trend （upward trend） from the past to present in the Nanxiaohe catchment. However, the trends seen in precipitation, air temperature did not contain any ＂jumping points.＂ The paired catchment approach is used to detect the effects of land cover change on hydrology in the Yangjiagou and the contrast catchment, i.e., Dongzhuanggou catchment in our study. The results showed a large change in land use in the Yangjiagou catchment from 1954 to 2008. An increase in forested land （from 0% to 40.08% from 1954 to 2008） and a reduction of bare land （from 51.26% to 5.50% from 1954 to 2008） accounted for a large part of the change in land use. However, the land use changed little in the contrast catchment. The comparison of streamfiow in the paired catchments showed that forestation reduced streamflow by 49.63% （or 6.5 mm） each year.  相似文献   

河南商城汤泉池温泉电阻率成像     

王继华  李清林  谢汝一  徐顺强 《CT理论与应用研究》2009,18(3)

电阻率成像法在地热勘查中,可以客观较真实地反映断层、热储地质体的基本特征.本文阐述了地电成像的原理、方法以及汤泉池温泉地热地质条件,对4条电阻率成像剖面进行了解释及综合分析,为定井提供了依据.  相似文献