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1.
Traditional theories of geographical cycle and pediplain cannot describe correctly the development of planation surfaces in karst regions. Authors, therefore, put forward conception of karst planation and karst planation surface, suggesting that karst planation is another type of planation process characterized by chemical erosion and transformation. To identify the distinction between evolution features of normal landforms and those of karst landforms developed in the South China, authors suggest karst planation surfaces under similar environmental conditions may reach a lower altitude and gradient ratio, in contrast with normal landform areas. This may be applied to researching on Tibetan Plateau uplift. 相似文献
2.
青藏高原可能是东亚上空沙尘气溶胶的重要源地。利用WRF/chem模式模拟了1961-2015年逐日青藏高原的起沙量,其结果表明:1)起沙源区主要分布在高原西部、藏北高原南部、雅鲁藏布江及其支流河谷和柴达木盆地;2)月起沙量具有双峰型结构,峰值分别出现在4-5月及11-12月;春季及秋冬季排放的沙尘气溶胶大致有以藏北高原为中心向东南方向分布的规律;3)高原年平均起沙量为10.13±1.89Tg,从1961-2015年呈现震荡向上的趋势;4)青藏高原对东亚(不包含青藏高原)月起沙量的平均贡献率为16%,其中冬季均能达到25%以上,1月最大可以达到48%。这一研究表明青藏高原是重要的沙尘源地。 相似文献
3.
青藏高原盐湖极端的自然地理条件孕育了一类独特的嗜盐微生物。阐述了青藏高原盐湖嗜盐微生物的主要类群及其对盐胁迫的适应机制,分析了青藏高原盐湖嗜盐微生物的特点、研究进展,以及盐湖嗜盐微生物资源的应用前景。青藏高原盐湖极端环境嗜盐微生物的研究具有重要的理论意义和应用价值,为探索生命的本质与起源,开发新型的食物、药品以及新材料、新技术,提供了宝贵的独特生物资源。 相似文献
4.
德尔尼蛇绿岩:青藏高原最北端的特提斯岩石圈残片 总被引:3,自引:0,他引:3
对位于青海省玛沁县境内的德尔尼蛇绿岩进行了报道,并使用地球化学方法进行了确认和判别。研究表明,其岩石组合相对简单,由玄武岩、辉长岩和蛇纹岩3个单元组成。玄武岩微量元素判别表明,该蛇绿岩形成于典型洋脊环境,属于西地中海型岩石圈残片,是青藏高原目前发现的最北端的特提斯蛇绿岩,向东可能与南秦岭勉略带相连 相似文献
5.
通过对青藏高原拟步甲科昆虫足的比较研究发现,为适应严酷的高原环境,足的适应性特征主要是:地面活动的种类足明显伸长;地下活动种类足明显短缩,胫节外缘具齿,端外角明显延伸;生活于陡峭地区的种类胫节内端距发达,跗节腹面端部出现浓密的毛刷. 相似文献
6.
青藏高原风化壳红土的沉积地球化学和矿物学特征及环境意义 总被引:4,自引:0,他引:4
对青藏高原主夷平面上分布的风化壳红土进行了沉积地球化学和矿物学方面的研究。结果表明,高原风化壳红土中细粒物质(粒径小于1mm)的粒径分布范围较广且比较均匀;红土中粘粒部分的主要化学成分为SiO2,Al2O3和Fe2O3;粘土矿物多属于伊利石-高岭石型组合,少数属高岭石-伊利石型组合。高原风化壳红土处在红土化的初期阶段,间接反映了青藏高原古岩溶发育时期的湿热气候。 相似文献
7.
文章通过对考古材料的分析研究,论证了西藏高原史前游牧业的起源、游牧经济与文化的基本面貌以及早期游牧民族在高原的迁徙与移动空间等问题,力图勾勒出距今约5000年的新石器时代以至西藏"早期金属器时代"史前游牧人群的生态环境、生活样态、艺术创造等不同的侧面与断面,揭示高原游牧业由原始农业转化而来的历史进程。 相似文献
8.
Based on the 16d-composite MODIS (moderate resolution imaging spectroradiometer)-NDVI(normalized difference vegetation index) time-series data in 2004, vegetation in North Tibet Plateau was classified and seasonal variations on the pixels selected from different vegetation type were analyzed. The Savitzky-Golay filtering algorithm was applied to perform a filtration processing for MODIS-NDVI time-series data. The processed time-series curves can reflect a real variation trend of vegetation growth. The NDVI time-series curves of coniferous forest, high-cold meadow, high-cold meadow steppe and high-cold steppe all appear a mono-peak model during vegetation growth with the maximum peak occurring in August. A decision-tree classification model was established according to either NDVI time-series data or land surface temperature data. And then, both classifying and processing for vegetations were carried out through the model based on NDVI time-series curves. An accuracy test illustrates that classification results are of high accuracy and credibility and the model is conducive for studying a climate variation and estimating a vegetation production at regional even global scale. 相似文献
9.
New evidence for the Qinghai-Xizang (Tibet) Plateau as a pilot region of climatic fluctuation in China 总被引:11,自引:1,他引:11
Over 40 a observed temperature data in 172 stations in China and historical proxy data were analyzed. Evidence suggested that
during 1980–1994, the warmest year appeared first in southeastern part of the Qinghai-Xizang (Tibet) Plateau (henceforth SETP)
and then gradually spread northwards and eastwards to eastern China. The climatic change on century time scale in recent 600
a shows 3 relatively warm and clod stages in China. Each warm and cold stage appeared first in Tibet Plateau (henceforth TP)
and then in the Qilian Mountains, then in the eastern parts of China. The warm and cold stages in TP were 10–60 a earlier
than in the eastern China. The facts show that TP is a pilot region of climatic fluctuation in China on the time scale shorter
than 103a. 相似文献
10.
RZB型钻孔应变仪在青藏高原东缘地应力监测中的应用 总被引:2,自引:0,他引:2
介绍新一代RZB-3型钻孔应变仪, 及其用于地壳应力应变连续观测的特点。对四川江油地应力监测站RZB-3A型分量式钻孔应变仪观测数据进行了初步分析, 结果表明: 安装于江油地应力监测站的RZB-3A型分量式钻孔应变仪有着较高的分辨率。系统参考元件的数据表明, 观测系统分辨率优于10-9应变量级, 不仅记录到清晰的固体潮汐, 还记录到宽频带应变地震波。特别地, 由于四分量钻孔应变观测的优越性, 已经获得的数据表明, 该观测系统对台站邻区地壳水平应变场的面应变测量精度较高。因此, 将新型分量式钻孔应变仪应用于青藏高原东缘地应力连续观测, 对于揭示该区域应力场活动与地震的关系有重要意义。 相似文献
11.
南文渊 《大连民族学院学报》2013,15(2):127-131
神山是藏族民众对青藏高原高山环境的一种精神创造和象征性符号。藏族宗教从地域权限和文化影响范围将神山分为世界宗教神山、区域族群神山、部落社会神山与民众个人魂山四种层次,将每个区域内的一座或一组高山奉为神山而崇拜,并做为禁忌之地而加以保护,它在历史上强化了族群的团结整合,同时通过崇拜活动使神山呈现自然景观与人文景观的高度和谐,具有了审美价值,保护了高原山系生态环境;在整个青藏高原,高高矗立的神山是人类社会的一种精神寄托,是人与自然和谐的象征。 相似文献
12.
On the gradient observational data of the atmospheric surface layer from September 1997 to December 1998 collected by two
sets of Automatic Weather Station (AWS) installed in Gaize and Shiquanhe on the western Tibetan Plateau, mean surface roughness
lengths at the two stations above are determined to be 2.7 and 2.9 cm, respectively. The bulk transfer coefficients each day
are computed by the profile-flux method, means of the bulk transfer coefficient for momentum (i.e. drag coefficient) in 1998
are 4.83×10−3 and 4.75×103 at the two stations. The surface fluxes of momentum, sensible heat and latent heat each day are further estimated by the
bulk formulas, annual mean of these fluxes is 3.4×10−2 and 1.8×102N/m2, 73.1 and 67.2 W/m2, 15.4 and 2.9 W/m2, respectively. The diurnal and seasonal variations are obtained by a composite method and the relationships among the heat
transfers between land and atmosphere, plateau monsoon and plateau rain season are also discussed. 相似文献
13.
青藏高原地面抬升证据讨论 总被引:26,自引:1,他引:26
当前学术界在青藏高原地面何时达到现代高度问题上存在着许多不同观点,概括起来主要有3种:14Ma前已达到高于现代的最大高度,8Ma前已达到或超过现代高度,距今3.4Ma来分阶中强烈上升并逐步达到现代高度,之所以出现如此大的意见分歧,除高原面积广阔,研究程度不深和覆盖面不够的原因外,不同研究者所使用研究方法和证据的差异也是重要因素,在分析了各种证据对高原地面上升的记录机理后,我们认为夷平面、河流附地, 相似文献
14.
The reconstruction of fossil planation surface in China 总被引:3,自引:0,他引:3
On the basis of results of relative subjects, the fossil planation surface has been discussed by the authors from the point of geomorphologic view. The discussion contents included the characteristic information, research methods, paleotopography (gradient and altitude) and other problems about fossil planation surface. The recognition and reconstruction of fossil planation surface mainly rely on the following characteristic information: ( i ) the character of erosion unconformity surface; (ii) the paleo-weathering crust and residual deposits; (iii) the paleo-karst and filled deposit in the paleo-karst under the unconformity surface,and (iv) the character and environment of sediment above the unconformity surface. According to the above-mentioned characteristic information, the authors recognized and reconstructed two stages of fossil planation surface on Paleo-land of North China and Yangtze Paleo-land. These two fossil planation surfaces formed from Middle Ordovician to Lower Carboniferous and from Lower Permian to Upper Permian respectively. The paleo-gradient of fossil planation surface changed within 0.31‰-1.32‰, mostly less than 1.0‰. According to the developing depth of paleo-karst, the authors considered that in Suqiao buried-hill region of Paleo-land of North China, the paleo-altitude is 300 m or so above paleo-sea-level. The authors hope that the research is in favor of discussion about rising scale and process of the Tibetan Plateau. Besides, the research of fossil planation surface can provide a theoretical base for relative research,such as the reconstruction of paleoenvironment, the evolution and drift of paleo-continent, the formation and distribution of weathering ore deposits, the reservior and prospection of oil and gas, etc. 相似文献
15.
《科学通报(英文版)》1999,44(20):1851-1851
Guliya ice core records, high lake-level records in the Qinghai-Xizang Plateau and at its north side as well as vegetation succession records indicated that during the period of 30-40 kaBP, namely the later age of the megainterstadial of last glacial period, or the marine oxygen isotope stage 3, the climate of the Qinghai-Xizang Plateau was exceptionally warm and humid, the temperature was 2-4℃ higher than today and the precipitation was 40% to over 100% higher than the current average, all these suggested the existence of an exceedingly strong summer monsoon event. It has been inferred that the occurrence of such an event was attributed, on the one hand, to the stronger summer low pressure over the Plateau, which strengthened the attraction to the summer monsoon; on the other hand, to the vigorous evaporation of the tropic ocean surface, which promoted the moisture-rich southwest monsoon to flow over the Qinghai-Xizang Plateau. The background responsible for the formation of the very strong summer monsoon was that the period of 30-40 kaBP was just in the strong insolation stage of the 20ka precessional cycle, when the Qinghai-Xizang Plateau received extraordinary strong solar radiation and thus enlarged the thermodynamical contrast between the Plateau and the mid-south part of the Indian Ocean. 相似文献
16.
针对航天发射初始段测控设备布站受地形影响的问题,提出了一个基于最大仰视角的测控设备选址方法.以测控设备无遮挡最大仰视角的通视性分析方法为基础,在数字高程模型(digital eleration model,DEM)空间数据中,将航天器飞行星下投影点为中心,按照螺旋方式,以中心为起始点由里向外分析布站区域中DEM各网格点与航天器的通视性,通过比较航天器各时刻的通视性,得到某时段内覆盖航天器飞行弧段的可视区域,选择满足两两距离大于规定值的三个网格点作为测控设备选址地点. 相似文献
17.
青藏高原西部燕山晚期花岗岩地球化学特征及其大地构造意义 总被引:1,自引:0,他引:1
对青藏高原西部燕山晚期花岗岩进行了地质、地球化学综合研究。结果表明 ,燕山晚期早白垩世花岗岩为 I型 ,形成于火山弧环境 ,岩石组合为石英二长闪长岩 -花岗闪长岩 -二长花岗岩 ,岩石系列为高钾钙碱性系列 ,A/ CNK<1,稀土元素含量中等 ,并且属轻稀土富集型 ,铕亏损不明显 ,L IL E有选择地得到富集 ,HFSE相对亏损 ;晚白垩世花岗岩为 S型 ,形成于同碰撞环境 ,岩石组合为二云母二长花岗岩 -二云母花岗岩 ,岩石系列为高钾钙碱性系列 ,但 A/CNK>1.1,稀土元素含量较低 ,铕亏损明显 ,微量元素中以 Rb和 F含量高为显著特征。为研究喀喇昆仑山构造演化提供了限定条件 相似文献
18.
夷平面研究作为一个永远年轻的课题,在经过1890~1910年和1950~1970年两次研究高潮以后,目前再度成为国内外地学界研究的热点,正在酝酿着第三次研究高潮.本文在形态分析、构造分析和相关沉积分析的基础上,确定了嵩山山顶古平坦面是早第三纪晚期形成的夷平面,它可与华北以及全球陆地同期的地形面进行对比. 相似文献
19.
2006-2050年西藏人口发展趋势预测 总被引:13,自引:0,他引:13
人口是社会发展的主体,和谐社会应以和谐人口为基础,实现西藏人口和谐发展必须要认清西藏目前人口的现状,把握西藏人口未来的发展趋势。文章利用中国人口信息中心提供的人口预测软件CPPS对西藏2006-2050年人口发展趋势做出了预测,结果表明:(1)西藏人口将保持持续增长的态势,2006-2050年将增加150万;(2)育龄妇女人数不断增长,2006-2050年将增加23万,平均每2年增加1万;(3)2006-2050年劳动适龄人口将增加65万,劳动力资源质量的高低对西藏未来经济的发展影响越来越大;(4)人口年龄结构从成年型向老年型转变,人口再生产类型由增加型过渡到稳定型进而过渡到减少型;(5)随着人口年龄结构的老化,西藏老年负担系数稳步上升,少儿负担系数缓慢下降,“人口红利”期将持续到2030年左右。 相似文献
20.
随着西方传教士在中国的传教,近代报纸也应运而生。与此同时清王朝在西方的坚船利炮面前不堪一击。政府的腐败必然导致强敌对主权的践踏或领土的侵占。在清王朝的衰败过程中,西藏也成了英、俄等国家觊觎的对象。晚清众多的报刊对与西藏有关的问题进行了多角度的报道,而这些报刊中《神州日报》及时报道关于西藏的重大政治事件、全面介绍政府的筹藏方略及其民间对西藏问题的关注、转译外国报纸对西藏问题的介绍。梳理研究这些报刊资料可以帮助我们了解当时的舆论导向、批驳现实中分裂西藏的错误舆论及其行为。 相似文献