Remote Sensing and GIS Application to Superlarge Mineral Deposits Prediction in Western Slope of Great Xing''an Mountains, China     

Chen Shengbo 《世界地质(英文版)》2000,3(1)

Supported by Geographic Information Systems (GIS), the multi - source geoscience information in the Western Slope of Great Xing' an Mountains are visual analyzed, including remote sensing data, magnetic data, gravity data and gamma - ray spectrometry data. Thus the structural framework is built up. And the remote sensing image pattern of mineral deposits is established by comparing the remote sensing geological features of five large or superlarge mineral deposits located in the same metallogenic belt in China, Russia and Mongolia. Guided by the image pattern, seven prospective locations of large or superlarge mineral resource are delineated.  相似文献   

A CLASS-MODELLING TECHNIQUE BASED ON POTENTIAL FUNCTIONS     

MICHELEFORINA  CARLAARMANINO  RICCARDOLEARDI  GIULIANADRAVA 《地理学报(英文版)》1991,(5)

A probabilistic and distribution-free class-modelling technique is developed from potential functiondiscriminant analysis.In the multidimensional space of variables the class boundary is built either by thesample percentile of the probability density estimated by means of potential functions,or by the estimateof the ‘equivalent’ determinant of the variance-covariance matrix.The equivalent determinant is that ofa hypothetical multivariate normal distribution whose mean probability density was obtained by potentialfunctions.The bases of this modelling rule are evaluated by means of Monte Carlo experiments.Theresults on four datasets are used to measure the performances of this method,which equal and sometimesexceed the performances of parametric class-modelling methods based on linear and quadraticdiscriminant analysis which were used for comparison.  相似文献   

A new perspective in identifying the precursory patterns of eruptions   总被引：2，自引：2，他引：0  

Laura?SandriEmail author  Warner?Marzocchi  Lucia?Zaccarelli 《Bulletin of Volcanology》2004,66(3):263-275

The complexity of the processes responsible for volcanic eruptions makes a theoretical approach to forecasting the evolution of volcanic unrest rather difficult. A feasible strategy for this purpose appears to be the identification of possible repetitive schemes (patterns) in the pre-eruptive unrest of volcanoes. Nevertheless, the limited availability and the heterogeneity of pre-eruptive data, and the objective difficulty in quantitatively recognizing complex pre-eruptive patterns, make this task very difficult. In this work we address this issue by using a pattern recognition approach applied to the seismicity recorded during 217 volcanic episodes of unrest around the world. In particular, we use two non-parametric algorithms that have proven to give satisfactory results in dealing with a small amount of data, even if not normally distributed and/or characterized by discrete or categorical values. The results show evidence of a longer period of instability in the unrest preceding an eruption, compared to isolated unrest. This might indicate, even if not necessarily, a difference in the energy of processes responsible for the two types of unrest. However, if the unrest is followed by an eruption, it seems that the seismic energy released during the unrest (parameterized by the duration of the swarm and the maximum magnitude recorded) is not indicative of the magnitude of the impending eruption. We also found that, in general, unrest followed by the largest explosive eruptions have a longer repose time than those related to moderate eruptions. This evidence supports the fact that the occurrence of a large eruption needs a sufficient amount of time after the last event in order to re-charge the feeding system and to achieve a closed-conduit regime so that a sufficiently large amount of gas can be accumulated.Editorial responsibility: T. Druitt  相似文献   

包头西6.4级震前地震活动研究     

薛丁  孙加林 《高原地震》1997,(1)

1995年内蒙古临河地区出现中等地震增强活动，之后，阴山地震带西部、中部、东部全部演化出小震异常有序分布图象，主震前震中区无前震活动，阴山带震情窗口反应不充分，强震孕育、发展过程显示出特殊性。  相似文献   

陕西潼关县桐峪金矿区水文地质特征     

刘柏林 《陕西地质》1996,(2)

简要叙述了小秦岭金矿田桐峪矿区水文地质特征、地下水的主要赋存形式、富集规律，以及补给、迳流、排泄条件等。  相似文献   

坝上地区沙漠化过程对景观格局影响的研究   总被引：17，自引：7，他引：17  

常学礼 《中国沙漠》1996,16(3):221-226

用分维数、修改分维数和景观间隙度指数等分析方法，对坝上地区正兰旗南部７０年代和８０年代的沙漠化土地空间格局进行了分析。研究结果表明：在７０年代，潜在沙漠化土地和强烈发展中沙漠化土地格局的聚集度分别为１．４９和１．１２４，随着沙漠化的发展到８０年代，上述两类型的格局趋向分散；而正在发展中沙漠化土地和严重沙漠化土地的聚集度增高，分别为１．４３７和１．０４８。在沙漠化的发展过程中，整个景观的格局和格局多样性趋向复杂，Ｄ和Ｄｍ分别从１．２７９和１．５９１增加到１．２８５和１．５９９；与此相反，不同沙漠化土地斑块的格局和格局多样性却趋向简单，Ｄ和Ｄｍ分别由１．２５９和１．５８４减少到１．１９４和１．４１４。此外，在沙漠化的发展过程中（从７０年代到８０年代），景观格局和格局多样性的变化，小于斑块格局及其格局多样性的变化  相似文献   

加强"十五"重点项目管理 ,努力促进地震科技进步     

林趾祥 《国际地震动态》2002,(9):7-11

总结了山东省防震减灾“九五”期间主要成功的经验和教训,提出了加强“十五”防震减灾重点项目管理的几点意见。  相似文献   

日本农业现代化特征概述     

陈忠暖  王力新 《世界地理研究》1998,(2)

日本战后农业的现代化经历了一个同欧美发达国家农业现代化不同的过程。日本的现代农业以其亚洲型模式、资本与技术的集约性、小农规模经营和广泛的兼业化发展为特色。日本由传统农业平和地转变与过渡为现代农业的路子,为亚洲各国的农业现代化提供了参照和借鉴。  相似文献   

国际五城市空气微生物概况     

陈皓文  宋庆云 《海洋科学进展》1993,(1)

对瓦尔帕莱索、彭塔阿雷纳斯、坎帕纳、新加坡和青岛的港口等空气微生物作了监测。这五个城市空气中的海洋性微生物及陆源性微生物数量(CFU/m~3)按大小次序排列均为:坎帕纳>青岛>瓦尔帕莱索>彭塔阿雷纳斯>新加坡。对空气微生物数量与气温、风速和相对湿度的关系作了初步比较分析后,认为适宜的气温及较大幅度的相对湿度有利于空气中微生物的增加:大风速、低相对湿度或高气温不利于空气中海洋性微生物的增加,本结果反映有关城市间空气污染的差异,坎帕纳的空气状况较差,对所得菌株作了初步分类,其中以不动杆菌较多,次为欧文氏菌等。  相似文献   

导管架平台桩基贯入深度的两级模糊模式优选模型   总被引：1，自引：0，他引：1  

宋玉普  王立成 《海洋工程》2001,19(4):9-14

桩基础是海洋导管架平台结构中的重要组成部分，其贯入深度对海洋平台的造价和运营期间的安全性能起着重要的影响。本文在考虑桩－土之间相互作用非线性特性的基础上，采用非线性等效弹筑模拟海底土层对桩基的作用，对桩基进行有限元分析。由于影响海洋导管架平台桩基础贯入深度的因素很多，而且有些因素带有很大的模糊性，本文采用两级模糊模式优选模型对影响因素进行综合评判，最后得出了适合给定荷载和海底地条件下最为合理的桩基贯入深度方案，具有一定的工程应用价值。  相似文献