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1.
丝绸之路青海道吐蕃时期墓葬出土木材记载的森林干扰史   总被引:1,自引:0,他引:1  
森林动态与气候变化及人类活动有着紧密的联系,了解森林干扰的发生历史对准确预测全球变暖背景下的森林动态具有重要意义,也可为理解历史时期的气候变化和人地关系演变提供线索.文章利用丝绸之路青海道沿线吐蕃时期3个墓葬中出土的78棵祁连圆柏(Juniperus przewalskii Komarov)原木作为研究对象,利用树木年...  相似文献   

2.
TM图像在成都市演变研究中的应用   总被引:3,自引:0,他引:3  
通过TM图像研究城市空间形态,获知城市演变规律,服务于城市规划、建设和管理,已成为城市遥感应用的一个新领域。成都是中国西部的城市明星,其发展过程凝聚了物质和精神财富的精华,通过TM图像研究其演变,对建设和谐的成都具有重要的指导意义。利用成都市1988年和2003年的陆地卫星遥感TM图像,采用目视解译方法,结合同一时期成都市相关文字图表资料,从小比例尺图像上获取城市演变的宏观信息,从大比例尺图像上获取城市演变微观信息。研究表明,成都市从1988年到2003年具有空间结构形态演变与城市非物质演变的辨证统一和城市发展以人为本演变规律。  相似文献   

3.
库尔勒市城市空间扩展特征及其驱动因素研究   总被引:3,自引:2,他引:1  
以库尔勒市1990年、1995年、2000年、2005年、2010年以及2015年6个时期的Landsat TM/ETM+影像作为基础数据,借助ENVI 4.5、Arc GIS 10.1等专业软件对影像进行监督分类和空间分析。在此基础上,分析库尔勒市近25 a来土地利用时空变化规律、城市空间扩展趋势及演变过程、城市重心转移方向及距离和城市空间扩展形态变化特征等。研究表明:近25 a间库尔勒市建设用地面积大幅度增加,所占比例不断上升,年均增加速率为15.18%。耕地和未利用地对城市建设用地扩展贡献较大。城市向东南方向扩展,城市重心向东南方向转移了总共2 118.46 m。城市空间扩展紧凑度呈下降趋势,分形维数呈上升趋势,表明城市空间扩展趋于结构疏散化、形状复杂化。针对于以上特征及扩展趋势,分析了库尔勒市城市空间扩展的驱动因素并提出一些对策建议,为城市可持续发展提供科学依据。  相似文献   

4.
城市空间扩展是城市中心的经济、社会、政治和文化等人文因素和土地利用、地貌形态等自然因素在地域上的向外推进与扩散。在遥感影像和统计年鉴等资料的支持下,以烟台市为例,探讨了城市空间扩展的过程与动力机制。烟台市在建国后相当一段时期内城市空间扩展缓慢,1985年城市化开始加速,进入21世纪后城市空间快速扩展;其城市空间扩展机制受自然条件、经济发展水平、交通状况、国家政策与城市规划等诸多因素影响。  相似文献   

5.
丝绸之路国内段主要包括丝路东段(西安至敦煌)和丝路中段(新疆地区),是丝路文明演化的主体地段,也是古丝绸之路开通之前跨大陆交流的关键地段。丝路东段和中段降水的时空格局存在显著差异,人类活动历史也有明显区别。然而,6000 a B.P.("B.P."为"距今(1950 A.D.)年")左右丝路东段农业强化之后,至古丝绸之路开通(约2000 a B.P.)该地区人地关系演化的时空过程和动力尚不清晰。文章通过总结丝绸之路国内段沿线地区已发表的碳十四测年与植物考古资料,结合丝路东段和中段古气候记录的对比分析,探讨了该地区6000~2000 a B.P.人类活动的时空格局和影响因素。结果显示,丝路东段6000~4000 a B.P.的粟黍农业发展促进了农业人群的广泛扩张,人类活动强度还受到降水变化的影响;4000~2000 a B.P.该地区人类活动强度的主要影响因素是跨大陆交流带来的生业模式多样化、生产工具的革新和地缘政治形势变化,而不是气候变化。丝路中段6000~4000 a B.P.人类活动强度很低,4000~2000 a B.P.人类活动强度显著提升,与降水变化呈现较为一致的特征,青铜时代的降温则可能导致人类定居空间的南向移动。本研究显示丝绸之路国内段不同时间与空间人地关系演变过程和主导因素存在显著差异,有助于理解丝绸之路开通之前其核心区的人与环境相互作用变化过程和机制。  相似文献   

6.
中国城市空间分布的双侧对称性   总被引:2,自引:1,他引:1  
借助尺度归并和笛卡儿变换思想考察中国城市的宏观分布规律,发现中国城市在一定的空间和规模尺度上具有双重对称性:以秦岭—淮河为界,南方城市与北方城市呈现双侧对称特征;以呼和浩特—太原—郑州—武汉—广州沿线为轴,东部城市与西部城市形成双侧对称局势。中国城市的宏观对称性与地球公转和自转的方式有关,海陆差异、地表形态和水系构成是影响城市对称格局的重要因素。城市的对称分布属于广义的形态发育问题,对称形成的内在机制可能在于人类空间行为的自组织演化。  相似文献   

7.
丝绸之路经济带节点城市人文驱动因素对环境的影响   总被引:1,自引:0,他引:1  
“一带一路”上升为国家战略,推进丝绸之路经济带建设使中国西北地区由过去发展的腹地转变为开放的前沿。通过引入STIRPAT模型,研究分析了丝绸之路经济带节点城市人文驱动因素对环境的影响,设定了三种情景分析节点城市未来低碳发展情况。结果表明:人文驱动因素对碳排放的影响程度较大,模型拟合优度达到95.2%,能源消耗强度(T)、富裕程度(A)和人口数量(P)的弹性系数分别为0.511、0.285和0.222,基准情景下二氧化碳排放总量呈现稳步上升态势,政策情景和低碳情景下碳排放存在“拐点”,预计碳排放峰值将在2025-2033年间出现,低碳情景峰值比政策情景提前8 a到达,峰值总量减少40.79×104 t。最后针对分析结果就丝绸之路经济带节点城市人文驱动因素对环境的影响提出了相关建议,即控制人口数量、优化产业结构、强化污染治理。  相似文献   

8.
论文分析了高架轨道交通对城市景观的双重影响:高架桥作为一种新的城市构筑物,为人们提供了欣赏城市的新的观赏点和观赏方式;但处理不当的高架构筑物具有破坏自然景观、影响人们的视觉、造成尺度失调、影响城市色彩和谐、破坏城市原有肌理等负面影响。进而论文提出了高架轨道交通的设计原则及改善轨道交通城市形象的应对措施:第一,巧妙选线,充分利用轨道交通沿线风景资源,形成轨道交通视觉廊道;第二,提升高架桥的空间景观形象:桥下空间综合利用,完善城市功能;桥侧空间精心设计,增强桥体人性化因素;重视高架桥体及附属物的形象设计,达到技术与艺术的完美统一;第三,建设具有地域风格的换乘站。  相似文献   

9.
城市地下空间开发的战略需求   总被引:1,自引:0,他引:1  
开发利用城市地下空间资源是城市可持续发展的必然选择,也是我国城市发展进入新时代的重要标志。本文从我国城镇化发展态势及面临的问题出发,剖析我国地下空间的战略需求及其驱动因素。同时进一步从不同发展阶段城市人均地下空间需求的角度出发,通过层次分析法确定影响地下空间开发需求的因子,并通过对未来我国城市对地下空间的需求等级划分以及不同等级城市人口容量的研究,推算不同等级城市的人口总量和人均需求量,并对我国中远期城市地下空间需求进行了预测分析。  相似文献   

10.
景观学视野下的城市色彩研究——以广州为例   总被引:2,自引:0,他引:2  
分析了中国城市色彩历史影响因素和现状,提出将城市色彩作为城市景观大系统中的子系统研究的观点,并以广州城市色彩控制规划为例,分析了城市色彩的影响因素,阐述了城市色彩的控制目标和基本控制策略。  相似文献   

11.
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.  相似文献   

12.
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.  相似文献   

13.
Robert L. Linnen   《Lithos》2005,80(1-4):267-280
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.  相似文献   

14.
Some olistolites reworked in a Tertiary flysch of Mount Parnon (Peloponnesus, Greece) exhibit a Late Permian assemblage, dominated by Paradunbarula (Shindella) shindensis, Hemigordiopsis cf. luquensis and Colaniella aff. minima. This association corresponds to the Late Wuchiapingian (=Late Dzhulfian), a substage whose algae and foraminifera are generally little known. Contemporaneous limestones crop out in the middle part of the Episkopi Formation in Hydra, but they are rather commonly reworked in Mesozoic and Cainozoic sequences. The palaeobiogeographical affinities shared by the foraminiferal markers of Greece, southeastern Pamir, and southern China, are very strong (up to the specific level), and are congruent with the Pangea B reconstructions. To cite this article: E. Skourtsos et al., C. R. Geoscience 334 (2002) 925–931.  相似文献   

15.
PALEONTOLOGY     
正20141596 Liu Yunhuan(School of Earth Sciences and Resources,Chang’an University,Xi’an 710054,China);Shao Tiequan Early Cambrian Quadrapyrgites Fossils of Xixiang Boita in Southern Shaanxi Province(Journal of Earth Sciences and Environment,ISSN1672-6561,CN61-1423/P,35(3),2013,p.39-43,3 illus.,20 refs.)  相似文献   

16.
正20141719 Chen Zhijun(State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences,Wuhan 430074,China);Chen Jianguo Automated Batch Mapping Solution for Serial Maps:A Case Study of Exploration Geochemistry Maps(Journal of Geology,ISSN1674-3636,CN32-1796/P,37(3),2013,p.456-464,2 illus.,2 tables,10 refs.)  相似文献   

17.
正20140962 Chen Fenning(Xi’an Institute of Geology and Mineral Resources,Xi’an710054,China);Chen Ruiming Late Miocene-Early Pleistocene Ostracoda Fauna of Gyirong Basin,Southern Tibet(Acta Geologica Sinica,ISSN0001-5717,CN11-1951/P,87(6),2013,p.872-886,6illus.,56refs.)  相似文献   

18.
PETROLOGY     
正1.IGNEOUS PETROLOGY20142008Cai Jinhui(Wuhan Center,China Geological Survey,Wuhan 430205,China);Liu Wei Zircon U-Pb Geochronology and Mineralization Significance of Granodiorites from Fuzichong Pb-Zn Deposit,Guangxi,South China(Geology and Mineral Resources of South China,ISSN1007-3701,CN42-1417/P,29(4),2013,p.271-281,7illus.,  相似文献   

19.
正20141205Cheng Weiming(State Key Laboratory of Resources and Environmental Information System,Institute of Geographic Sciences and Natural Resources Research,CAS,Beijing 100101,China);Xia Yao Regional Hazard Assessment of Disaster Environment for Debris Flows:Taking Jundu Mountain,Beijing as an  相似文献   

20.
正20141266Fan Chaoyan(Guangdong Provincial Key Laboratory of Mineral Resources and Geological Processes,Guangzhou 510275,China);Wang Zhenghai On Error Analysis and Correction Method of Measured Strata Section with Wire Projection Method(Journal of  相似文献   

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