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基于简化 Newmark位移模型的区域地震滑坡危险性快速评估以汶川MS 8.0级地震为例 总被引：1，自引：0，他引：1
以汶川MS8.0级地震重灾区的11县市为例,初步提出了基于简化Newmark位移模型的地震滑坡危险性应急快速评估方法。利用汶川地震即时地震动参数、工程地质岩性经验分组及地形坡度数据,借助ArcGIS空间数据建模工具编制了地震滑坡危险性快速评估流程模块。计算了区域浅表层饱和岩土体斜坡的静态安全系数Fs、临界加速度ac,并借此分析了地震滑坡易发性。利用经验式获得了汶川地震Arias强度和区域滑坡位移DN分布,实现了汶川地震重灾区地震滑坡危险性的快速评估,为应急救灾决策提供了参考。通过对比评估结果和震后滑坡调查成果,可知数十处灾难性滑坡绝大部分位于-高危险区的龙门山主中央断裂带两侧约20km地带中,显示了评估方法的可靠性; 同时,分析指出了空间数据精度及更新不足导致局部评估结果欠佳的局限性,并提出了改进建议。 相似文献
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基于Mamdani FIS模型的滑坡易发性评价研究 总被引：1，自引：0，他引：1
滑坡的形成是众多非线性关系的影响因子相互作用的结果,传统滑坡预测方法需要大量实地勘查数据。利用Mamdani FIS(模糊推理系统)模型对三峡库区巴东-秭归段进行滑坡易发性预测,并对结果进行评价。通过地理信息系统(geographic information system,GIS)、遥感(remote sensing,RS)技术和区域地质背景资料获取地形类、生态环境类和地质背景类共3类7种滑坡影响因子,建立了192条相关的推理规则,在Matlab平台下基于Mamdani FIS模型得到研究区滑坡易发性预测指数,并生成滑坡易发性区划图。预测结果的受试者工作特征曲线下的面积值为82.8%,显示滑坡评估效果良好。结果证明,与其他模型相比,基于空间信息技术的Mamdani FIS模型,利用其非线性分析能力和基于专家意见的推理规则,评估滑坡易发性时不需要先验知识支撑,简化了模型使用时对数据的要求。另外,该模型只需通过专家意见改变推理规则就可以应用于不同的地质地理环境区域,显示其较强的适应性。 相似文献
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数字高程模型（DEM）蕴含丰富的地形地貌信息,基于DEM的数字地形分析方法为岩溶地貌研究提供了科学、有效的技术手段。文章针对前人应用DEM研究中国岩溶地貌所涉及的关键技术方法,从岩溶地貌识别的尺度效应、岩溶地貌的识别与分类、岩溶地貌的形态及格局分析、岩溶区生态环境变化等方面进行了梳理和分析,提出未来应构建科学的岩溶地貌数字分类体系,对岩溶地貌进行多尺度、深层次的地形分析和定量表达,并从地形现状研究拓展到地形演变的过程与机理研究,发掘出DEM在岩溶地貌研究中更多的应用。 相似文献
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基于无人机航摄的高陡/直立边坡快速地形测量及三维数值建模方法 总被引：1，自引：0，他引：1
对复杂地形的高陡/直立边坡的地形测量及三维数值模型的建立一直是地质工作者面临的难题。近年来,无人机由于其形体小巧、机动性强以及可以获取高分辨率影像的特性在地质调查中受到了广泛的应用。本文基于低空无人机倾斜摄影技术,借助Agisoft Photoscan三维实景建模软件和基于逆向工程的Geomagic Studio强大的点云数据处理功能,结合南方CASS的地形制图功能对复杂地形的高陡/直立边坡实现快速地形成图。并利用Geomagic Studio的CAD曲面建模功能,重构复杂地形的高陡/直立边坡闭合CAD曲面模型,再通过Hypermesh强大的几何处理及网格划分能力,对CAD曲面模型进行模型切割并网格化,实现复杂地形的高陡/直立边坡的精细三维数值模型的建立,最后转化为FLAC3D可识别的文件格式进行计算分析。本文选择了浙江省神仙居景区飞天瀑景点作为实例研究,结果表明,无人机的使用使复杂地形的高陡/直立边坡实现了快速高效且精确的地形成图和三维建模。该方法具有简单实用、快速便捷且实用性强的优点。 相似文献
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近些年来地下水中多组分反应-运移模型在地球科学及环境领域开始得到应用,但其求解较为复杂,为了提高计算效率,可以采用去耦合化方法处理,从而使模型求解得到简化。针对自然界中广泛存在的非均质地质体,提出该类条件下的去耦合化方法,即根据水-岩间、水溶组分间反应的不同,将整个研究区划分为若干子区域,获得对应的去耦合化矩阵。对化学场中各子区域间相邻边界进行设定,达到简化模型求解的目的。最后,以一维非均质介质中基于热力学平衡的反应-运移问题作为算例,基于以上方法进行求解,并与该算例经PHAST软件所示的结果较为一致。结果表明,基于去耦合化方法获得的各离子浓度随时间演变和沿空间分布特征与PHAST所示的结果较为一致,显示该方法在非均质区域模拟溶质运移等方面具有较好的适用性。 相似文献
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面向流域水资源管理,提出了一个基于GIS/RS的流域分布式水文模型,模型主要包括单元水文模型与河网汇流模型两大部分。单元水文模型涉及到冠层截留、融雪、蒸散发、坡面流、非饱和土壤水运动和地下水出流等水文物理过程。产流计算考虑到地形坡度的影响采用基于地形指数的计算方法。汇流演算基于河网结构采用分段马斯京根方法。模型的大部分参数与输入信息可以利用GIS和RS技术获取,能够对气候变化和人类活动对下垫面的改变,做出快速的模拟与响应。 相似文献
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在断层错动下跨断层埋地管道反应模拟方法中,壳模型有限元方法较简化索模型解析方法能更好地反映管道壳体反应特性,而目前国内外规范仍多采用便于应用的简化索模型解析方法。基于壳模型有限元方法,与索模型解析方法的对比计算分析,探讨了两类方法的管道轴向拉伸应变计算值差异及引起差异的主要因素,并在管道跨断层交角较小（小于70°）的情况下,提出了基于管道埋藏土层波速值和断层错动量两个参数的改进Newmark方法。进一步地计算分析表明,对于不同的管道跨断层交角和管材特性情况,改进的Newmark方法对壳模型方法计算结果的拟合度达到了0.87。 相似文献
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Simon Catling 《GeoJournal》2004,60(2):149-158
There have been few studies of trainee teachers' conceptions of the term ‘geography’. Building on these, this study identifies
a number of conceptions of geography held by primary school trainee teachers in England. Their ideas are compared with their
understanding of the reasons for teaching geography to young children. Similar outcomes emerge. While a small number of primary
trainee teachers see geography education as concerned with the study of places, a slightly larger group view teaching geography
as developing children's sense of responsibility for the earth and its people. However, by far the largest groups of students
perceive geography's role to be to develop younger children's awareness and knowledge of the environment. Additionally, a
sizeable group of trainees see geography as providing knowledge about the features and countries of the world. The implications
of these findings are considered for the brief geography study units which primary teacher trainees take as part of their
initial teacher training programme in English higher education. The conclusion is that it is important to widen primary trainee
teachers' perspectives during even the briefest of units, not least to enable them to teach the national curriculum requirements
for geography in primary schools.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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K. Bouwer Prof. Dr. 《GeoJournal》1985,11(4):307-312
The author outlines the relationships between geography and the study of environmental problems. After WW II when these problems were growing in number and complexity, many geographers turned to the quantitative study of spatial relations and processes, neglecting the ecological aspects of human life on earth. However, recently human and physical geography are turning again to an ecological point of view. In the study of environmental problems, a synthesis of the spatial and the ecological traditions in geography is possible. The spatial aspects of environmental problems and environmental management in a systems-theory framework are the central points in the contribution of geography to an interdisciplinary environmental science. 相似文献
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The behavioural approach in human geography accentuates the view of quality of the environment through man and his value orientations. The quality of environment from the point of view of human experience raises behavioural-geographical questions that are the core of the presented topic. Aspects of environmental imaginations and sensations as well as human value system are presented as variables affecting the structure of the perceived environment and human spatial behaviour. In this context, the authors present results of two behavioural studies that correspond to new models of man and environment from the viewpoint of a behavioural approach. The suggested humanistic approach in behavioural geography emphasizes above all the emotional aspect of the relationship between man and environment, which through environmental values, spatial sensations, and meanings, leads to human spatial behaviour. 相似文献
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Gary A. Dymski 《Geoforum》1996,27(4):439-452
This essay evaluates the evolution of Paul Krugman's ideas about economic geography between 1989 and 1996, focusing on the scope and intention of his work. While Krugman's geographical writings have acknowledged diverse research traditions, he has increasingly focused his efforts on formal spatial models that embody the methods of mainstream economic modeling. This emphasis reflects Krugman's view that formal modeling holds the most promise for understanding spatial aspects of urbanization. Krugman's interventions into economic geography have in turn allowed him to develop and articulate his own view of the future of social science: that is, the explanation of self-organizing behaviour should be the focal point of research, and formal modelling is the key means of advancing this agenda. 相似文献
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Modeling water-table fluctuations in a sloping aquifer with random hydraulic conductivity 总被引：1，自引：0，他引：1
To prevent environmental problems like water logging and increase in soil salinity which are responsible for the degradation of the top productive soils, an optimum ditch drainage design is required. For this purpose a knowledge of the spatio-temporal variation of the water table is essential. In this study the spatio-temporal variation of the water table in a sloping ditch drainage system has been modeled from a stochastic point of view, incorporating randomness in hydraulic conductivity to get the expression for the mean and the standard deviation of the water-table height. The hydraulic conductivity has been considered to be a realization of a log-normal distribution. Application of these expressions in the prediction of mean water-table variation with the associated error bounds has been demonstrated with the help of a ditch drainage problem of a sloping aquifer. The sensitivity analysis has also been carried out to see the effect of variability in the hydraulic conductivity on the water-table fluctuations. The error bounds quantified on the water-table height will thus help in the decision-making process for proper drainage design. 相似文献
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南天山野云沟石炭系研究新进展 总被引：1，自引：0，他引：1
南天山野云沟石炭系的沉积特征和构造背景研究,有助于合理建立塔里木北缘含油气盆地古地理格局和区域构造格架。石炭系上部碎屑岩中发育典型的鲍玛序列,粒度统计分析显示,其水动力状态为浊流成因,从而确认南天山野云沟石炭系中存在浊积岩。通过对该碎屑岩的岩相分析,认为其可能形成于海底扇环境。26组古流向资料计算表明,其物源来自南侧的古塔里木陆块;12个砂样的碎屑成分统计、10个样品的岩石常量元素资料和3个样品的岩石稀土元素资料分析,说明其形成的构造背景属再旋回造山带和被动大陆边缘。 相似文献
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新经济地理学与传统经济地理学之比较研究 总被引：1，自引：0，他引：1
自20世纪90年代以来，藤田、克鲁格曼、维纳布斯等以迪克西特和斯蒂格利茨垄断竞争模型为基础，用不完全竞争、报酬递增和市场外部性等理念构建新的经济地理模型，掀起了一场“新经济地理学”革命。新经济地理学在理论基础、研究特点和方法等方面与传统经济地理学表现出明显不同，其理论创新受到经济学界和地理学界的普遍关注。但是，也有一些学者对它提出了同样引人注目的抨击。通过对新经济地理学与传统经济地理学进行比较，对一些重大理论假设、研究方法与特点进行简要分析，有助于廓清对新经济地理学与传统经济地理学之异同的正确认识，以期推动新经济地理学的理论研究与应用以及新经济地理学与传统经济地理学领域的学术交流。 相似文献
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Martin J. Haigh 《Geoforum》1985,16(2):191-203
General system science, like geography, is an integrative discipline that spans the divide between the physical and social sciences. Geography, like general system science, seeks to examine the universe of observation as a functioning whole and attempts to study together the things other disciplines study separately. However, within both geography and the system sciences at large, there are many different philosophies and methodologies. A special attribute of the general system approach is an explicit adoption of an organismic rather than a mechanistic world view. This has caused general system practitioners to develop theory in more bioscientific areas of concern such as growth, hierarchical organisation and the theory of evolution. To date, much of the systems science in geography has preferred the static, mechanistic ethos of systems analysis and systems engineering. However, general system science's concern with historic processes and the dynamic self-determined relationships between systems structure, functioning and selfcreation may be more appropriate to geographical research. A search is made for general system methodologies in current geographical research and for particular applications of aspects of the new general systems theory of evolution and theory of systems attractors as defined by Ilya Prigogine and Erich Jantsch to geography.Today, we seem to be at the tip of an iceberg of scientific change... Every discipline is in the midst of a revolution... What is exciting about this theoretical chaos is not that each discipline will emerge with a new paradigm to guide future investigations but that a new grand paradigm may be forming, one that will integrate all structure and processes from the farthest reaches of the Universe to the reasonances of subatomic particles. The Grand Paradigm is somewhere in the future and we may live to see it THEISEN, (1981, p. 758). 相似文献
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Derek R. Diamond 《Geoforum》1979,10(3):275-282
Failure to fully understand or recognise crucial but culturally-determined British dimensions has led to confusion and error even among the British geographers in understanding and contributing to, urban and regional planning. This point assumes more rather than less significance in the context of a discussion between British and Soviet geographers. This paper therefore examines in part one, three fundamental features of the British system of urban and regional planning and then proceeds in part two to focus on the aims and their implementation. It concludes with a reference to the nature of the relationship between planning and geography. 相似文献