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141.
基于数字高程模型数据和地质数据,首先对青藏高原西北缘西昆仑山脉的山脊线和山麓线进行地形剖面及其地面组成物质形成的地质年代分析,据此获取了从西北到东南的5座典型山峰:昆盖山、慕士塔格山、塔什库祖克山、慕士山和托库孜达坂山的相关数据;然后以公格尔山为例,探讨了山峰区域典型地形剖面线的获取方法;最后对5座山峰进行了典型地形剖面获取及其对应山体组成物质形成的地质年代分析,计算了每座山峰在不同地质年代的组成物质下的地形抬升速率.研究结果表明:西昆仑山脉从西北到东南的5座典型山峰,地形抬升速率在两端较大,中间部位则相对较小,在塔什库祖克山最小,呈近似“V”形;从西北部的昆盖山到东南部的托库孜达坂山,山体组成物质形成的地质年代数量为3-4-5-4-3,呈现先增多后减少的变化趋势,呈“A”形;因此,地形抬升速率与地质年代数量之间呈现负相关的关系. 相似文献
142.
Lateral force, response spectrum and step‐by‐step pushover analyses are performed and compared with the post‐earthquake survey of two Dieh‐Dou buildings seriously affected in the 1999 Chi‐Chi earthquake in Taiwan. The results show that the proposed FE model with finite translational and rotational stiffness can successfully be employed to assess the vulnerability of the frames. The fundamental period of Dieh‐Dou structures is about 1.0 s higher than that calculated by the simplified approach of the codes for regular frames; a modal analysis is, therefore, essential for this typology of structure. The elastic analysis, either lateral force or response spectrum, is shown to be reliable to assess Dieh‐Dou frames when quick results are desired. However, a non‐linear step‐by‐step pushover analysis has the advantage of greater accuracy, as it allows mapping the failure trend and indicating the critical elements. The lateral drifts are compared with the actual observed damage pattern and when the damage level is related to the peak ground acceleration on a vulnerability curve plot, it is shown that the joint failure combined with the lateral drift gives an indication of the global structural behaviour of this historic construction typology. Owing to the unique construction features of the Dieh‐Dou, the joint failure represents also a critical criterion in terms of maximum retention for conservation. Based on a damage level approach, an assessment methodology is suggested that would allow optimizing a strengthening strategy, for protection of these precious structures from future earthquakes while avoiding unnecessary interventions. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
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本文以古建筑档案管理工作需求为基础,兼顾古建筑展示需要,介绍了基于Flex开发的南通市文保单位及历史建筑管理信息系统。重点介绍了系统的设计原理和具体实现方法。结果表明该系统可较好地管理古建筑测量数据,展示古建筑测绘成果。 相似文献
146.
针对历史文化名城苏州市保留的一大批各类历史性建筑,采用WebGIS构建苏州城市控保建筑信息管理系统。系统通过构建的公共信息服务平台发布和政务信息管理平台,对其功能进行设计和实现。该系统为政府和社会正确判断控保建筑的价值和制定相关的政策与立法提供了服务和决策支持。 相似文献
147.
Genevieve M. LeMoine Christyann M. Darwent 《Geografisk tidskrift / udgivet af Bestyrelsen for Det Kongelige danske geografiske selskab》2013,113(2):279-296
Geografisk Tidsskrift—Danish Journal of Geography 110(2):279–296, 2010 Archaeological field research was undertaken in northwestern Greenland between 2004 and 2009 by the Inglefield Land Archaeology Project (ILAP). Over 2400 cultural features were recorded during foot survey, with additional sites located during helicopter reconnaissance. Focusing on the late prehistoric to historic transition, excavation of two Thule-Inughuit winter houses and adjacent middens was carried out at Iita, Foulke Fjord, western Inglefield Land, in 2006. Although constructed during the mid-1800s to early 1900s, the structures were dug into early through late Thule and Paleoeskimo deposits. At Cape Grinnell, in central Inglefield Land, three Thule sod-block houses, a Thule fall-winter qarmat, a Thule cache, a Late Dorset axial-feature, and an early Paleoeskimo axial-feature were excavated. Radiocarbon analysis revealed a tight cluster of dates, ca. AD 1200–1420, from the Late Dorset and Thule features. Preliminary analysis suggests near continual occupation of Iita for at least 1000 years. Cape Grinnell appears to have been inhabited, at least periodically since initial migration of Paleoeskimo into the region ca. 4000 years ago, with intensified Late Dorset-early Thule occupation followed by apparent abandonment coincident with the onset of climatic cooling. 相似文献
148.
《The Professional geographer》2013,65(4):455-456
Theories which explain mental imagery are discussed and are related to cognitive maps. An experiment was conducted to illustrate that people can code information about maps as visual images and use map images for a map-reading task. Subjects were shown maps which were rotated at various angles from north-at-the-top. The time needed to decide if a map was a correct or mirror representation was recorded. The results support the notion that people did this task by forming and rotating map images. 相似文献
149.
Documenting the processes that control the variations in stream geochemistry at different streamflows is important for being able to use chemical tracers to understand catchment functioning. The concentrations of most solutes, including reactive cations (e.g., Na, Ca, K, and Mg) and anions that are primarily derived from precipitation (Cl and Br), in five headwater streams from southeast Australia vary little with streamflow and are close to being chemostatic. By contrast, NO3 and SO4 concentrations are higher at high streamflows. There is also a systematic increase of 3H activities from as low as 1.1 to as high as 2.6 TU with increasing streamflow. The changes in geochemistry cannot be explained solely by increased mineral dissolution at high streamflows or enhanced baseflow driven by hydraulic loading. They are best explained by an increased baseflow input augmented by water mobilized from shallower stores as the catchments wet up. The mean transit times of the water sustaining streamflow varies from 35 to 70 years at low streamflows to <7 years at high streamflows. The use of a range of geochemical tracers, including radioactive isotopes, allows the different possible causes of chemostatic behaviour to be assessed and improves our understanding of catchment functioning. 相似文献
150.
This contribution presents a method for assessing the risk of water degradation in harbour domains. The method describes a normalized Index of Risk, ranging from 0 to 1, which determines the risk of water degradation due to a pollution event. A branch-decision scheme of decision-making theories was implemented in order to obtain this index. This method evaluates the cost of each decision as a function of the vulnerability, proximity and toxicity of the potential contaminant. A novel feature of this method is that the risk is defined by considering the physical behaviour of the harbour (i.e. water circulation patterns). Regions where water residence time is high are considered more vulnerable to pollutant releases. This method could be implemented from an operational perspective, in which case an oceanographic operational system could be used to obtain current forecasts which in turn would be used to forecast risk maps. 相似文献