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51.
Kelan River is a branch of the Ertix River, originating in the Altay Mountains in Xinjiang, northwestern China. The upper streams of the Kelan River are located on the southern slope of the Altay Mountains; they arise from small glacial lakes at an elevation of more than 2,500 m. The total water-collection area of the studied basin, from 988 to 3,480 m, is about 1,655 km2. Almost 95 percent of the basin area is covered with snow in winter. The westerly air masses deplete nearly all the moisture that comes in the form of snow during the winter months in the upper and middle reaches of the basin. That annual flow from the basin is about 382 mm, about 45 percent of which is contributed by snowmelt. The mean annual precipitation in the basin is about 620 mm, which is primarily concentrated in the upper and middle basin. The Kelan River system could be vulnerable to climate change because of substantial contribution from snowmelt runoff. The hydrological system could be altered significantly because of a warming of the climate. The impact of climate change on the hydrological cycle and events would pose an additional threat to the Altay region. The Kelan River, a typical snow-dominated watershed, has more area at higher elevations and accumulates snow during the winter. The peak flow occurs as a result of snow-melting during the late spring or early summer. Stream flow varies strongly throughout the year because of seasonal cycles of precipitation, snowpack, temperature, and groundwater. Changes in the temperature and precipitation affect the timing and volume of stream-flow. The stream-flow consists of contributions from meltwater of snow and ice and from runoff of rainfall. Therefore, it has low flow in winter, high flow during the spring and early summer as the snowpack melts, and less flows during the late summer. Because of the warming of the current climate change, hydrology processes of the Kelan River have undergone marked changes, as evidenced by the shift of the maximum flood peak discharge from May to June 相似文献
52.
Yao Daquan Shuo Zhi Shen Xiaoqi Chen Anguo Zheng Yingping Zheng Haigang Li Lingli 《中国地震研究》2010,24(3):363-370
During an excavation survey to the Daijiayuan vestige of the Western Zhou Dynasty-Late Spring and Autumn Period at Huoshan in Western Anhui,a ground crack related to tectonic movement and filled with silty fine sand was found. This phenomenon was initially confirmed to be due to seismic liquefaction. Many microscopic seismic relics,such as load structure,flow structure,cutoff plane and flotation of organic matter were found in the directional microscopic analysis of deformation. These discoveries and cognitions prove that there were two earthquake events taking place in the Western Zhou Dynasty-Late Spring and Autumn Period in this area. Above-mentioned works enrich and develop the research methods to identify prehistoric earthquake event in eastern China area to a certain extent. 相似文献
53.
In order to maintain the thermal stability of very wide highway embankments in permafrost regions, the thermal isolation
material EPS is often utilized. To examine the effects of this insulation on the China National Highway (G214),
two-dimensional finite element analysis of temperature fields was conducted for varying widths of highway embankments
with and without EPS insulation. The numerical results show that in permafrost regions the effect of thermal aggregation on
asphalt pavement is more obvious when highway embankments are wider, and, specifically for the G214 highway, the insulation
should be more than 25 cm thick for 24-m-wide embankments. However, considering other factors such as the structural
rationality of the embankments and high engineering costs, it might not be feasible to install EPS insulation in
24-m-wide embankments of the G214 highway when the height of the embankments is less than 3.65 m. 相似文献
54.
Recognition of natural deformation during the excavation of ancient remains and tombs is important for tracing or enriching historic and prehistoric deformation records. Recently, the earthquake agencies,in cooperation with the cultural relics and archaeological institutions, conducted a special excavation investigation to the Gaixia remains archaeological scene in Guzhen,Anhui Province. Faults and fissures were discovered there, which,as demonstrated by the preliminary study,are the traces of two stratum d... 相似文献
55.
Wei Shen 《地学前缘(英文版)》2011,2(1):87-91
The self-similar is a common phenomena arising in the field of geology.It has been shown that geochemical element data,mineral deposits,and spacial distribution conform to a fractal structure.A fractal distribution requires that the number of objects larger than a specified size have a power-law dependence on size.This paper shows that a number of distributions,including power-function,Pareto, lognormal,and Zipf,display fractal properties under certain conditions and that this may be used as the mathemat... 相似文献
56.
分析梳理了防洪减灾风险、风险及其分析、风险管理和治理等概念,指出防洪减灾理念从20世纪早期的"控制洪水"到20世纪后期的"减小洪灾损失"再到21世纪初的"降低洪灾风险"的演变,与防洪减灾形势、社会公共管理水平等密切相关;防洪减灾风险源于洪水时空变化的不确定性、承灾体的不确定性和防灾减灾措施实际效果的不确定性等,需要根据具体问题做具体分析;防洪减灾风险管理指采取多方参与方式,在洪灾发展周期的不同阶段,针对多种不确定性,综合分析各种风险,力求做出相对科学的决策。在防洪减灾风险管理的研究和实践中,应重视有关人文因素及其不确定性、构建风险分析文化的重要性。 相似文献
57.
The November 14, 2001 Ms8.1 Kunlun Mountains earthquake in northern Tibet is the largest earthquake occurring on the Chinese mainland since 1950. We apply a three-dimensional (3-D) finite element numerical procedure to model the coseismic displacement and stress fields of the earthquake based on field investigations. We then further investigate the stress interaction between the Ms8.1 earthquake and the intensive aftershocks. Our primary calculation shows that the coseismic displacement field is centralized around the east Kunlun fault zone. And the attenuation of coseismic displacements on the south side of Kunlun fault zone is larger than that on the north side. The calculated coseismic stress field also indicates that the calculated maximal shear stress field is centralized around the east Kunlun fault zone; the directions of the coseismic major principal stress are opposite to that of the background crustal stress field of the Qinghai-Xizang (Tibet) Plateau. It indicates that the earthquake relaxes the crustal stress state in the Qinghai-Xizang (Tibet) Plateau. Finally, we study the stress interaction between Ms8.1 earthquake and its intensive aftershocks. The calculated Coulomb stress changes of the Ms8.1 great earthquake are in favor of triggering 4 aftershocks. 相似文献
58.
Ionospheric electromagnetic perturbations observed on DEMETER satellite before Chile M7.9 earthquake 总被引:1,自引:0,他引:1
Xuemin Zhang Jiadong Qian Xinyan Ouyang Xuhui Shen Jin’an Cai Shufan Zhao Institute of Earthquake Science China Earthquake Administration Beijing China 《地震学报(英文版)》2009,(3):251-255
Based on the ionospheric electromagnetic data observed on DEMETER satellite of France, the ionospheric electromagnetic signals were analyzed within 10 days before Chile M7.9 earthquake on November 14, 2007. It is found that, low frequency electromagnetic disturbances began to increase in a large scale of latitude, and reached to a maximum one week prior to the earthquake, and at about three days before the quake, the peak values shifted to lower latitude. Taking three days as a group, spatial images of a fe... 相似文献
59.
THE LATE QUATERNARY RIGHT LATERAL STRIKE-SLIPPING OF ZHONGDIAN—DAJU FAULT IN NORTHWEST YUNNAN, CHINA
THE LATE QUATERNARY RIGHT LATERAL STRIKE-SLIPPING OF ZHONGDIAN—DAJU FAULT IN NORTHWEST YUNNAN, CHINAthesubject“TherecentdisplacementandDynamicsoflithosphereintheQinghai XizangPlateau”ofnation
alclimbingproject“Therecentdisp 相似文献
60.
LATE CENOZOIC TECTONICS ALONG THE NORTHWESTERN MARGIN OF THE TARIM BASIN: INTERACTIONS BETWEEN THE TARIM BASIN AND THE SOUTHERN TIAN SHAN, WEST CHINAgrants 4 98340 50and 4 9732 0 90fromtheNSFofChina;;andproject96 913 0 7 0 1fromtheMinistryofSci
enceandTechnology ,China… 相似文献