Optimization of management procedures with control on uncertainty risk     

Witting  L. 《ICES Journal of Marine Science》1999,56(6):876-883

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Synthetic isoseismals of three earthquakes in California and Nevada   总被引：1，自引：0，他引：1  

L. Sirovich 《Soil Dynamics and Earthquake Engineering》1997,16(6):353-362

Recent tests on a series of earthquakes in California and Nevada suggest that in some regions the approximate shapes of the territories with equal earthquake-induced damage (expressed in terms of macroseismic intensity) could be synthetically traced out with a simple formula. This formula takes into account some gross features of the source: depth and length, unilateral or bilateral rupture, radiation patterns, rupture velocity, and directivity. Having been formulated on an empirical basis, the formula is however compatible with the so-called asymptotic approach, in which the far-field component of the Green's function is used. This paper presents the synthetic isoseismals of the earthquakes at Cedar Mountain, Nevada, 1932; Fairview Peak-Dixie Valley, Nevada, 1954; and Coalinga, California, 1983. An overall consistency, from acceptable to remarkable, between the observed intensity patterns and the synthetically back-predicted intensity has been obtained for them. Where the detailed modelling techniques available today are inapplicable, due to insufficient information on the features of the seismic sources, or to save time and money, the new formula may be utilizable for improving seismic hazard calculations.The formula was also used inversely for back-predicting geometric-kinematic parameters of the Coalinga 1983 earthquake from macroseismic maps. This gave characteristics for its source which are in good agreement with the majority of data inferred from modelling and from analyzing modern instrumental recordings. This striking result opens new perspectives in retrieving information on the source of ancient earthquakes for which only macroseismic information is available.  相似文献   

The New Seismic Zonation Map for the Territory of Armenia     

S. Balassanian  S. Nazaretian  A. Avanessian  A. Arakelian  V. Igumnov  M. Badalian  A. Martirossian  V. Ambartsumian  A. Tovmassian 《Natural Hazards》1997,15(2-3):231-249

In the present work a new, deterministic, seismic zonation map for the territory of Armenia is presented. It has been compiled on the basis of the newest seismological, geological and geophisical data. Creation of the map included: determination of a seismic hazard area for the territory of Armenia; compilation of a map of active faults; identification of active blocks; identification of seismic source zones; calculation of a seismic effect from the seismic source zones (SSZs). Seismic effect on the Earth's surface from the singled out SSZs is calculated in the form of an intensity of seismic influences expressed in units of MSK-64 scale, and horizontal soil accelerations expressed in fractions of gravity force acceleration (g). The map compiled will allow comparison between the deterministic model with a probabilistic seismic zonation model for the territory of Armenia (in preparation), in order to analyze the western and eastern standards of seismic hazard assessment on the basis of the same complete data base.  相似文献   

陕西韩城北部矿区煤层气形成条件评价     

王生全 《西北地质科学》1997,18(1):40-45

以大量的测试为基础，从煤层生气性、储气性、渗透性及围岩封盖性等方面对陕西韩城北部矿区煤层气的形成条件进行了研究与评价；划分了各煤层生、储、渗、盖类型，为本区今后煤层气勘探开发提供了科学依据。  相似文献   

1993年10月26日甘,青交界托来牧场Ms6.0地震前兆异常特征的研究     

毛可  孙景芳 《地震》1995,(3):260-268

１９９３年１０月２６日托来６．０级地震发生在甘肃河西前兆台网控制范围之外，本文在研究河西中西部地区前兆台网综合监测能力及总结震例的基础上指出，前兆台项少，持续时间短，空间分散是托来地震前兆异常时空分布的显著特征，并对形成的原因进行了探讨。  相似文献   

内蒙古河套地方性砷中毒区地质环境特征与成因探讨   总被引：1，自引：0，他引：1  

李树范  李浩基 《内蒙古地质》1995,(Z1)

论文通过对内蒙古砷中毒病区地质环境调查和防砷改水试验工作。从病区地质环境特征入手，系统分析了构造环境；第四纪地质环境水文地质环境，水化学环境，岩矿地球化学环境和古地理及生物化学环境等诸方面特征，对高砷的地质环境成因进行了探讨．得出十条高砷病区与地质环境之间的成因关系，认为高砷病区的形成与地质环境特征有着密切的成因联系．地方性砷中毒是在特定的地质环境条件下形成的。这对地方性砷中毒的形成、分布及防治具有一定的指导意义，亦为后期防砷改水提供了科学依据。  相似文献   

加入不变矩的高分辨率遥感图像分类     

徐海卿  李培军  沈毅 《国土资源遥感》2008,(2):9-14

不变矩是表达图像几何形状信息的参数,具有几何变换的稳定性,在图像识别领域已经得到广泛应用。本文将3种常用的不变矩,即胡氏矩、Zern ike矩和小波矩,运用到高分辨率遥感图像分类中,并与只利用光谱信息的图像分类结果进行对比。结果表明,在高分辨率图像分类中加入不变矩图像可以显著提高分类精度,尤其是对那些具有相似光谱特征但同时具有不同形状和结构特征的地物分类更加有效。  相似文献   

A model of capillary cohesion for numerical simulations of 3D polydisperse granular media   总被引：1，自引：0，他引：1  

V. Richefeu  M. S. El Youssoufi  R. Peyroux  F. Radjaï 《国际地质力学数值与分析法杂志》2008,32(11):1365-1383

We present a 3D discrete‐element approach for numerical investigation of wet granular media. This approach relies on the basic laws of contact and Coulomb friction enriched by a capillary force law between particles. We show that the latter can be expressed as a simple explicit function of the gap and volume of the liquid bridge connecting a pair of spherical particles. The length scales involved in this expression are analyzed by comparing with direct integration of the Laplace–Young equation. We illustrate and validate this approach by application to direct shear and simple compression loadings. The shear and compression strengths obtained from simulations reproduce well the experimental measurements under similar material and boundary conditions. Our findings clearly show that the number density of liquid bonds in the bulk is a decisive parameter for the overall cohesion of wet granular materials. A homogeneous distribution of the liquid within the bridge debonding distance, even at low volume contents, leads to the highest cohesion. The latter is independent of the liquid content as far as the liquid remains in the pendular state and the number density of liquid bonds remains constant. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

2005年青藏高原唐古拉地区地表能量收支状况分析   总被引：4，自引：4，他引：0  

姚济敏  赵林  丁永建  谷良雷  乔永平 《冰川冻土》2008,30(1):119-124

利用青藏高原唐古拉地区2005年涡动系统和10 m气象塔数据资料,计算分析了该地区地表能量收支状况.结果表明: 感热与潜热均有明显的季节变化特征,感热春季较大,夏季有下降趋势;潜热夏秋季节较大,冬春季节较小;净辐射在冬春季节主要转化为感热,夏秋季节转化为潜热,这些主要受季风、活动层冻、融过程及净辐射变化的影响.Bowen比夏秋季节平均为0.7,冬春季节平均为3.4,变化范围为-1.0～17.9.另外,研究显示降雨对感热、潜热通量影响较大.  相似文献   

基于析因数值实验方法的蒸发皿蒸发归因研究   总被引：2，自引：0，他引：2  

王婷婷  孙福宝  章杰  刘文彬  王红 《地理学报》2018,73(11):2064-2074

蒸发皿蒸发是唯一可长时间大范围观测的潜在蒸发,其准确估算和长时间序列趋势变化归因分析,对变化环境下干旱研究、水文过程理解分析与预估具有重要意义。本文筛选出416个具有连续观测的气象台站资料,率定了PenPan模型中适合模拟中国20 cm口径（D20）蒸发皿蒸发的风速函数,发展了基于去趋势法的析因数值实验归因法,对比了此方法与常用的偏导归因法在1960-2014年、1960-1993年（“蒸发悖论”时段）及1993-2014年（“蒸发悖论”消失）蒸发皿蒸发趋势变化的归因结果。结果表明,使用新率定的风速函数f_q(u₂)=3.977×10^-8(1+0.505u₂)能更准确模拟中国D20蒸发皿蒸发;相较于偏导归因法结果,析因数值实验法也能对蒸发皿蒸发趋势变化进行定量归因分析,且归因结果略优于偏导归因法结果;此外,可利用析因数值实验法的基准态信息来对偏导归因法结果进行校正,从而更准确地对蒸发皿蒸发趋势变化进行归因分析,加深对蒸发皿蒸发趋势变化的理解,为水文水循环研究准确分析提供保障。  相似文献