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51.
从几个典型的中国古地图的数学基础出发,结合相关的数学方法,探讨了中国古人在地理空间维度认知方面走过的历程。认为,当中国古代地图发展到以"计里画方"进行地图绘制时,已经实现了3维地理空间的科学认知。这也是"计里画方"的制图方法可以持续1 000多年的理论依据。 相似文献
52.
概述辽、金、元三代有关测绘的管理和机构,职官设置,各类测绘状况及成果,着重介绍了元代的测绘技术,发明创造及著述。 相似文献
53.
A classification system for the assessment of slope stability of terrains along highway routes in Jordan 总被引:2,自引:0,他引:2
The establishment of comprehensive development plans, in general, and the proper selection of highway routes, in particular,
require an assessment of landslides or instability hazards in the project sites. The frequent landslides that occurred along
the routes of major highways in Jordan, and particularly along the Amman-Na'ur-Dead Sea highway and Irbid-Jerash-Amman highway,
have substantially increased the cost of construction and caused a considerable delay in the completion of work. The study
of many landslides that occurred in the last 25 years along the highway routes and in the sites of some major civil engineering
projects in Jordan has led to the recognition of major factors that affect the stability of slopes, and thus the safety and
economics of these projects. The geological formation, structural features, topographic characteristics, geometry, and climatic
conditions were adopted as the basis for the classification of terrains in terms of their stability. Each factor has been
assigned a rating to indicate its relative contribution to the overall stability according to engineering judgment and past
experience. The areas have been classified into 5 groups according to their total stability rate. The simplicity, comprehensiveness,
and accuracy are the main characteristics of the proposed classification. Its significance stems from its helpfulness as a
guide to the geotechnical and highway engineers in assessing the overall stability of the alternative routes of proposed highway
projects.
Received: 3 December 1996 · Accepted: 29 April 1997 相似文献
54.
Z. Kaymaz 《Annales Geophysicae》1998,16(4):376-387
This study presents cross-sectional vector maps of the magnetic field derived from IMP 8 magnetometer in the magnetosheath at 30 Re behind the Earth. In addition the vector patterns of the magnetosheath field for northward, southward, and east-west interplanetary magnetic field (IMF) directions are qualitatively compared with those obtained from the Spreiter-Stahara gas dynamic (GD) and Fedder-Lyon magnetohydrodynamic models (MHD). The main purpose is to display the cross-sectional differences in relation to the dayside merging with different IMF directions, allowing the reader to make direct visual comparisons of the vector patterns. It is seen that for east-west IMF directions, the data-based and MHD-based patterns differ noticeably in a similar way from the GD model, presumably reflecting the influence of dayside magnetic merging of the Earths magnetic field with the y-component of the interplanetary magnetic field. All three northward IMF cross sections show comparable field draping patterns as expected for a closed magnetosphere. For southward IMF case, on the other hand, differences between the three cross-sectional patterns are greater as seen in the field vector sizes and directions, especially closer to the magnetopause where more disturbed magneto-spheric conditions are known to be exist. The data comparisons with the MHD and GD models show that the differences result from the magnetic field-flow coupling and that the effects of dayside reconnection are present in IMP 8 magnetic field measurements. 相似文献
55.
《The Professional geographer》1990,42(3):386-390
AMOS—Analysis of MOment Structures . James Arbuckle CLIMATEDATA–Summary of the Day . (Version 1.10). HYDRODATA–U.S.G.S. Daily Values (Version 2.0). The MAP SETS (includes EUROPEAN MAPSET, US MAPSET and WORLD MAPSET). James Taylor 相似文献
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??2012??1???????????????????г??????????????????????????????????????????????????????????????????????????????????????????????????????????????????????к?????????????????????????????????--?????????????????????????????? 相似文献
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The potential impacts of progressing climate change are alarming. Some adverse consequences are now unavoidable and adaptation measures are increasingly needful. This poses enormous challenges for emerging megacities in the Global South, which barely manage in current weather conditions. This paper introduces Fuzzy Cognitive Mapping as a new tool for structured, semi-quantitative assessments of climate change impacts and adaptation measures.Fuzzy Cognitive Mapping is used to evaluate differences in sensitivities to heatwaves and rainstorms across socio-economic groups and for the ranking of useful adaptation options, based on 188 individual interviews to the impacts of extreme weather events in Hyderabad, India. The results of this multi-stakeholder assessment indicate that rainstorms affect low-income residents more than heatwaves, while the opposite is true for medium-income respondents. The latter are also less seriously affected by extreme weather in general. Profession, though, not income determines the kind of impact that people feel most affected by. Individual characteristics like age and gender do not significantly explain differences in the data, but religion does. This is because, in Hyderabad, Muslims live in the older, less serviced and more affected parts of the city. However, semi-quantitative scenario analyses suggest that, under future climate change, many parts of the city will become increasingly exposed to the effects of extreme weather. Planned investments in urban infrastructure will be seriously challenged by climate change and preventive adaptation measures are urgently needed to at least maintain the current level of quality of life. Investments in the health infrastructure appear to be most effective in reducing the impact of heatwaves and investments in the traffic infrastructure most effective in reducing the impact of rainstorms. However, looking at heat and rain events together—which is realistic as they are both projected to increase and often occur in the same year—reveals that investments in water infrastructure and management have greatest potential to reduce impacts across all localities and on all social groups, particularly the lower-income classes. This is because first-order impacts caused by inadequate water infrastructure often give rise to second- or third-order impacts. Addressing the root cause is the most effective way to break cause-and-effect chains and prevent proliferation of negative consequences. Similar studies are suggested in other cities in order to support adaptation mainstreaming in complex urban environments. Fuzzy Cognitive Mapping proved a useful, semi-quantitative tool for climate change impact and adaptation assessments. 相似文献