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974.
河西内陆河地表水与地下水转化及水资源利用率研究 总被引:16,自引:8,他引:16
河西内陆河水资源产生于祁连山区 ,河流出山以后依次穿越山前洪积扇、走廊南部盆地、北部盆地 ,最后进入尾闾湖 .由于山前洪积扇、南北盆地及河床具有良好的通透性和巨大的蓄水能力使地表水易于转化为地下水 ,出山水量的很大一部分渗入地下避免无效蒸散损耗 ;同时由于特殊的串珠状水文地质盆地构造 ,水资源具有同源性和多次转化特点 ,使水资源的利用率大大提高 .研究表明 ,1999年河西水资源总量为 6 3 79× 10 8m3 ,其中 ,地表水资源量为 5 8 36× 10 8m3 ,地下水资源量为 5 6 39× 10 5m3 ,地表水与地下水重复计算量高达 5 0 96× 10 5m3 .三个流域水资源利用率达到 6 1 4%~ 2 11% 相似文献
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东喜马拉雅构造结大陆碰撞以来构造年代学框架及其与哀牢山-红河构造带的对比 总被引:13,自引:0,他引:13
东喜马拉雅构造结经历了前期楔入和后期垮塌变形.楔入事件发生于~60Ma、~23Ma和~13 Ma,垮塌开始于6~7Ma.哀牢山红河构造带同样经历早期走滑和后期正断,走滑年代分别为58~56Ma、23Ma和13Ma,后期正断开始于5.5 Ma.上述年龄的意义在于~60Ma的变形代表印度与欧亚大陆的初期碰撞;2 Ma为青藏高原及邻区的主变形期;13Ma的变形也代表一次汇聚事件,并形成青藏高原的东西向伸展.6~7Ma以后的垮塌作用代表了青藏高原的快速隆升. 相似文献
977.
IntroductionAnisotropy is a universal phenomenon in the upper mantle. The mechanisms, which cause elastic anisotropy of in-situ rocks, include lattice preferred orientation of the minerals composing the rocks and preferred orientation of magma chambers. Lattice preferred orientation (LPO) of olivine is widely believed to be the dominant cause of the upper mantle anisotropy. The observational results of the upper mantle anisotropy can be explained by tectonic process relating to plate motion.… 相似文献
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979.
东天山碰撞造山与金铜成矿系统分析 总被引:15,自引:2,他引:13
根据碰撞带不同单元按构造一岩石地层划分原则,分出有序和无序两套地层岩石组合,分属两个不同的构造一火山活动带,碰撞造山与韧性剪切带强时空耦合.碰撞带两侧岛弧火山岩和带内碰撞花岗岩特征和成岩成矿时代、地球化学省等表明其较特殊的碰撞造山和陆内造山成盆多阶段演化特点。与碰撞造山有关的金铜矿分七种成因类型。现划10个成矿区带分属两个古陆边缘成矿系统,金矿成矿可分为五个阶段。金铜矿成带分布与碰撞造山演化有关,空间上北部铜矿带,南部金矿带,为今后进一步找矿指明了方向,提出了具体靶区。 相似文献
980.
A PRELIMINARY STUDY ON THE METHOD OF SEISMIC INTENSITY ASSESSMENT BASED ON RESIDENTIAL BUILDING DATA AND HIGH RESOLUTION REMOTE SENSING IMAGES 下载免费PDF全文
After destructive earthquakes, the assessment result of seismic intensity is an important decision-making basis for emergency rescue, recovery and reconstruction. This job requires higher timeliness by government and society. Because remote sensing technology is not affected by the terrible traffic conditions on the ground after the earthquake, large-scale seismic damage information in the earthquake area can be collected in a short time by the remote sensing image. The remote sensing technique plays a more and more important role in rapid acquisition of seismic damage information, emergency rescue decision-making, seismic intensity assessment and other work. On the basis of previous studies, this paper proposes a new method to assess seismic intensity by using remote sensing image, i.e. to interpret the building collapse rate of a residential quarter after an earthquake by high-resolution remote sensing images. If there already are detailed building data and building structure vulnerability matrix data of a residential area, we can calculate the building collapse rate under any intensity values in this residential area by using the theory of earthquake damage prediction. Assuming that the building collapse rate interpreted by remote sensing is equal to the building collapse rate predicted by using the existing data, it will be easy to calculate the actual seismic intensity of the residential area in this earthquake event. Based on this idea, according to the relevant standard specifications issued by China Earthquake Administration, this paper puts forward some functional models, such as the calculation model of building collapse rate based on remote sensing, the data matrix model of residential building structure, the prediction function matrix model of residential building collapse rate and the prediction model of residential building collapse rate. A formula for calculating seismic intensity by using remote sensing interpretation of collapse rate is also proposed. To test and verify the proposed method, this paper takes two neighboring blocks of Jiegu Town after the Yushu M7.1 earthquake in Qinghai Province as an example. The building structure matrix of the study block was constructed by using pre-earthquake 0.6m resolution satellite remote sensing image(QuickBird, acquired on November 6, 2004), post-earthquake 0.2m aerial remote sensing image(acquired by National Bureau of Surveying and Mapping, April 15, 2010) and some field investigation data. The building collapse rate in the two blocks was calculated by using the interpretation results of seismic damage from the Remote Sensing Technology Coordinating Group of China Seismological Bureau. The seismic damage matrix of building structures in Yushu area is constructed by using the abundant scientific data of the scientific investigation team of the project “Comprehensive Scientific Investigation of the Yushu M7.1 Earthquake in Qinghai Province” of China Seismological Bureau. On this basis, the collapse rate prediction function of different structures in Yushu area is constructed. According to the prediction function of collapse rate and the building structure matrix of the two blocks, the building collapse rate under different intensity values is predicted, and the curve of intensity-collapse rate function is drawn. By comparing the building collapse rate interpreted by remote sensing and the intensity-collapse rate function curve of this two blocks, the seismic intensity of both blocks are calculated to be the same value: Ⅸ degree, which is consistent with the results of the field scientific investigation of the earthquake. The validation shows that the method proposed in this paper can effectively avoid the influence caused by the difference of seismic performance of buildings and accurately evaluate seismic intensity when using remote sensing technique. The method has certain application value for earthquake emergency work. 相似文献