基于GeoCA和GIS的滑坡滑动面演化规律研究

传统的滑坡稳定性分析大多是建立在以数学模型为基础的一种确定性分析。实际上,滑坡是一个影响因数众多,边界条件复杂的不确定复杂系统。地理元胞自动机是一种时间和空间都离散的动力系统,为之设定相应的状态、元胞空间、邻居、规则和时间,可以很好地模拟滑坡滑动面从稳定到滑移这一微观变化过程,形成GeoCA LANDSLIDE模型。以吴家湾滑坡为例,对其滑动面的演化规律进行了模拟。     

地理模拟优化系统GeoSoS及前沿研究

提出地理模拟优化系统(GeoSOS)的概念、研究内容和实现方法,以提供一种十分有效的地理过程分析和空间探索的工具。地理模拟优化系统的理论基础涉及复杂系统理论、地理信息科学、计算机科学、地理学等。所提出的地理模拟优化系统由3个子模块构成:元胞自动机模拟子系统、多智能体模拟子系统和基于生物智能的优化子系统。建立地理模拟优化系统可以为复杂资源环境及变化提供一种有效的模拟和优化工具,弥补目前GIS对过程分析功能的严重不足。     

基于 CA模型的北京及邻区土地荒漠化动态演化评价

元胞自动机(Cellular Automata,简称CA)是一个时空动态模型,具有鲜明的时空耦合特征,特别适于地理空间系统的动态模拟研究。元胞自动机在地理学中的应用最早可追溯到20世纪60年代。Hagerstrand(1965)在他的空间扩散模型的研究中首先采用了类似于元胞自动机的思想。进入80年代,伴随着元胞自动机本身理论的深入,元胞自动机     

元胞自动机模型在地学中的研究进展

元胞自动机模型具有离散动力学特征，可以模拟和分析一般的复杂系统，对具有空间特征的地理复杂系统更具优势。该模型有“自下而上”、离散、确定性和随机性结合、灵活性和开放性等优点，但亦具有边界的无限、空间同质、元胞形状规则、邻近关系固定以及对实践封闭等缺点。在介绍了该模型优缺点的基础上，分析了元胞自动机的理论研究趋势与主要的应用领域。     

基于CA的小流域分布式降雨径流模拟

构建基于元胞自动机(CA)模型的分布式水文模型,模拟小流域内降雨径流过程。从元胞状态、转换规则与时间步长3个方面扩展普通CA模型,包括5个子状态、5个元胞系数及两条转换规则,并实现模型与GIS的集成。以黄土高原岔巴沟流域的降雨径流观测数据对模型进行了验证分析。试验结果表明,确定性系数、峰现时差与洪峰误差3个评价指数都达到一定精度,实现了流域内径流过程的可视化。结合CA模型与GIS技术可以较为有效地模拟流域次降雨径流过程,模型在该试验区是基本适用的。     

斜长石环带非线性自组织生长过程的元胞自动模拟与分析

主要针对斜长石环带的成因动力学机制模型进行可视模拟的探讨.前人研究认为:斜长石韵律环带的形成仅仅与岩浆后期侵入的周期线性相关,因此,本模拟计算引入非线性元胞自动机分析方法并借助Matlab平台编写计算机软件来模拟斜长石环带生长机制.根据Fick扩散定律等,通过元胞自动分析机,模拟在不同开放程度的岩浆系统背景下的形成过程,结果表明韵律环带不仅仅与有岩浆后期侵入的环境相关,还与晶体附近的岩浆的An浓度的重新趋近饱和有关.     

RS与GIS支持下的汶川县城周边地质灾害危险性评价

地质灾害危险性评价是防灾减灾工作的重要依据。本文以汶川县城周边64 km2为例,应用遥感信息提取技术与GIS空间分析方法,根据IKONOS遥感图像和地形图及野外调查资料,提取了崩塌和滑坡易发性评价因子,采用信息量法确定了因子分值,计算了崩塌和滑坡易发性,并分别提出崩塌和滑坡的危险性计算方法,形成了汶川地区崩塌和滑坡危险性分区图。研究结果表明:新的崩塌和滑坡危险性评价方法能够反映区内地质灾害危险程度,该方法可行,结果合理,这为中、大比例尺区域范围内地质灾害危险性研究提供了有益的思路。     

基于GIS的巴东新县城滑坡灾害风险系统

本文提出了基于GIS的滑坡灾害风险预测系统流程。并将滑坡灾害风险评价模型与GIS技术先进的图形处理和空间分析功能相结合,建立了巴东县新县城区滑坡灾害风险预测系统。系统由信息管理子系统、危险性预测子系统、易损性预测子系统、风险预测子系统四大子系统构成。系统在对相关信息进行采集、存贮、检索和管理的基础上,结合物元模型、BP模型等专业预测模型,实现了滑坡灾害危险性、易损性评价,最终取得了滑坡灾害风险分布图,为三峡库区内各县的滑坡灾害信息管理和风险预测提供了新途径。预测成果可为研究区的国土规划和移民工程的顺利实施提供依据和保障。     

基于GIS技术实现地学信息数字化

GIS是一项借助于计算机实现的高新技术,是实现管理和研究空间数据的技术系统.围绕着这项技术的研究、开发和应用形成了一门交叉性、边缘性的学科.GIS是一个包含了计算机软件、硬件、地理数据和专业人员的系统,GIS是数字地球的关键技术和核心组成部分.它是采集、储存、管理、分析、描述、显示、应用空间和地理分布有关数据的信息系统,是数据分析、融合与整合技术,已广泛运用于地学领域,并获得巨大成功.     

公路沿线花岗岩风化区滑坡危险度评价--以日本49号国道合户地区为例

对公路沿线边坡进行稳定性评价及滑坡灾害分析，对于由滑坡、泥石流等引起的公路灾害的防治具有重要指导意义。为了评价处于花岗岩风化区的日本福岛县合户地区49号国道沿线边坡的滑坡危险程度，在调查和分析了该地区的表层破坏模式、并通过简易探测方法摸清了风化土层的厚度分布后，将研究区域划分为边坡单元(Slopeunit)，使用椭球体下半部模拟滑动面的形状，通过随机试算法确定各边坡单元危险滑动面的位置及空间形状；采用一种基于GIS的边坡稳定性三维分析模型计算各边坡单元最小安全系数以及滑坡发生概率，定量评价滑坡灾害危险程度。所有的计算过程及结果显示均在一个基于GIS平台的系统中完成，为如何利用GIS技术更好地为滑坡灾害防治工作服务拓宽了思路。     

The terrestrial fauna of the Late Triassic Pant-y-ffynnon Quarry fissures,South Wales,UK and a new species of Clevosaurus (Lepidosauria: Rhynchocephalia)

Pant-y-ffynnon Quarry in South Wales yielded a rich cache of fossils in the early 1950s, including articulated specimens of new species (the small sauropodomorph dinosaur Pantydraco caducus and the crocodylomorph Terrestrisuchus gracilis), but no substantial study of the wider fauna of the Pant-y-ffynnon fissure systems has been published. Here, our overview of existing specimens, a few described but mostly undescribed, as well as freshly processed material, provides a comprehensive picture of the Pant-y-ffynnon palaeo-island of the Late Triassic. This was an island with a relatively impoverished fauna dominated by small clevosaurs (rhynchocephalians), including a new species, Clevosaurus cambrica, described here from a partially articulated specimen and isolated bones. The new species has a dental morphology that is intermediate between the Late Triassic Clevosaurus hudsoni, from Cromhall Quarry to the east, and the younger C. convallis from Pant Quarry to the west, suggesting adaptive radiation of clevosaurs in the palaeo-archipelago. The larger reptiles on the palaeo-island do not exceed 1.5?m in length, including a small carnivorous crocodylomorph, Terrestrisuchus, and a possible example of insular dwarfism in the basal dinosaur Pantydraco.     

Définition d'une limite multicritère ; stratigraphie du passage Campanien–Maastrichtien du site géologique de Tercis (Landes,SW France)Definition of a multi-criteria boundary; stratigraphy of the Campanian–Maastrichtian interval of the geological site at Tercis (Landes,SW France)

Lithostratigraphy, physicochemical stratigraphy, biostratigraphy, and geochronology of the 77–70 Ma old series bracketing the Campanian–Maastrichtian boundary have been investigated by 70 experts. For the first time, direct relationships between macro- and microfossils have been established, as well as direct and indirect relationships between chemo-physical and biostratigraphical tools. A combination of criteria for selecting the boundary level, duration estimates, uncertainties on durations and on the location of biohorizons have been considered; new chronostratigraphic units are proposed. The geological site at Tercis is accepted by the Commission on Stratigraphy as the international reference for the stratigraphy of the studied interval. To cite this article: G.S. Odin, C. R. Geoscience 334 (2002) 409–414.     

The effect of water on accessory phase solubility in subaluminous and peralkaline granitic melts

The solubilities of columbite, tantalite, wolframite, rutile, zircon and hafnon were determined as a function of the water contents in peralkaline and subaluminous granite melts. All experiments were conducted at 1035 °C and 2 kbar and the water contents of the melts ranged from nominally dry to approximately 6 wt.% H₂O. Accessory phase solubilities are not affected by the water content of the peralkaline melt. By contrast, solubilities are affected by the water content of the subaluminous melt, where the solubilities of all the accessory phases examined increase with the water content of the melt, up to 2 wt.% H₂O. At higher water contents, solubilities are nearly constant. It can be concluded that water is not an important control of accessory phase solubility, although the water content will affect diffusivities of components in the melt, thus whether or not accessory phases will be present as restite material. The solubility behaviour in the subaluminous and peralkaline melts supports previous spectroscopic studies, which have observed differences in the coordination of high field strength elements in dry vs. wet subaluminous granitic glasses, but not for peralkaline granitic glasses. Lastly, the fact that wolframite solubility increases with increasing water content in the subaluminous melt suggests that tungsten dissolved as a hexavalent species.     

Quaternary stresses revealed by calcite twinning inversion: insights from observations in the Savonnières underground quarry (eastern France)

Calcite samples were extracted both from the rock matrix and the superficial coating of a karstified fault plane of an underground quarry, located in the eastern border of the Paris basin. The karstification is dated as Quaternary. Analysis of mechanical calcite twinning reveals that only the calcite matrix has also undergone a compression trending WNW that can be attributed to the Mio-Pliocene alpine collision. Both coating and matrix have undergone a strike-slip regime with σ₁ roughly trending north–south, that could correspond to the regional present-day state of stress, a strike-slip compression rather trending NNW, modified by local phenomena. To cite this article: M. Rocher et al., C. R. Geoscience 335 (2003).     

HYDROGEOLOGY

正20141756 Chen Ruige(Mathematical College,China University of Geosciences,Beijing100083,China);Zhou Xun Numerical Simulation of Groundwater Level Fluctuation in a Coastal Confined Aquifer with Sloping Initial Groundwater Level Induced by the Tide(Geological Bulletin of China,ISSN1671-2552,CN11-4648/P,32(7),2013,p.1099-1104,6 illus.,16 refs.) Key words:confined water,groundwater level     

METAMORPHIC PETROLOGY

正20141408 Cai Jia(Institute of Geology,Chinese Academy of Geological Sciences,Beijing100037,China);Liu Fulai Petrogenesis and Metamorphic P-T Conditions of Garnet-Spinel-Biotitebearing Paragneiss in Danangou Area,Daqingshan-Wulashan Metamorphic Complex Belt(Acta Petrologica Sinica,ISSN1000-0569,CN11-1922/P,29(7),     

SERIALS

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GEOPHYSICAL EXPLORATION

正20142386An Guoying(China Aero Geophysical Survey and Remote Sensing Center for Land and Resources,Beijing 100083,China)Application of Satellite Remote Sensing in Regional Hydrogeological Investigation:Taking Cenozoic Strata in Wenquan Sheet(1∶250 000)of Karakoram Range as an Example(Geosci-     

QUATERNARY GEOLOGY & GEOMORPHOLOGY

正20141016An Chengbang(Key Laboratory of Western China’s Environmental Systems,Ministry of Education,Lanzhou University,Lanzhou 730000,China);Zhao Yongtao Lake Records during the Last Glacial Maximum from Xinjiang,NW China and Their Climatic Impli-     

PETROLEUM GEOLOGY

正20141538 Cao Qing(School of Earth Sciences and Engineering,Xi’an Petroleum University,Xi’an 710065,China);Zhao Jingzhou Characteristics and Significance of Fluid Inclusions from Majiagou Formation,Yichuan Huangling Area,Ordos Basin(Advances in Earth Science,ISSN1001-8166,CN62-1091/P,28(7),2013,p.819-828,7 illus.,3 tables,43 refs.)