25 November 1999, Volume 21 Issue 4
    

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  • CHENG Guo-dong
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 1999, 21(4): 289-309. https://doi.org/10.7522/j.issn.1000-0240.1999.0060
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    During the past four decades, breathtaking progress has been achieved in China from almost zero to increasingly advanced stages in glaciology and geocryology. The interactions between the cryosphere and climate are of great concern at present. Studies on the water resources in arid and cold regions, hazards control and cold regions engineering under a warming climate are critically important to the sustainable and concordant development of the regional economies and ecosystems. As a mechanism for the above topics, geographic information sciences have significantly facilitated the data processing and insights into the fledgling cryosphere sciences and therefore, should be expedited.
  • HUANG Mao-huan
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 1999, 21(4): 310-316. https://doi.org/10.7522/j.issn.1000-0240.1999.0061
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    Many temperature measurements have been made on 29 glaciers in China since 1959. The regional thermal features of glaciers are now revealed. It is distinguished that there are three categories of temperature distribution in China, i.e., cold, temperate and polythermal. Temperate glaciers are located in the southeastern Tibetan Plateau. The heat conduction in the surface layer and the heat transfer within a glacier can be quantitatively described. Two-dimensional temperature distributions are gained for the Glacier No.1 at the headwaters of the Urumqi River in the Tianshan Mountains and for the Chongce Ice Cap in the West Kunlun Mountains. Geothermal flux is derived from measurements down to or closed to the bottom. The Tibetan Plateau is an area with high geothermal flux. The author suggests to measure more ice temperature by using the boreholes for extracting ice core, however, there is no need to repeatedly measure the temperature within the near-surface layer.
  • MA Wei, CHENG Guo-dong, ZHU Yuan-lin, XU Xiao-zu
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 1999, 21(4): 317-325. https://doi.org/10.7522/j.issn.1000-0240.1999.0062
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    The State Key Laboratory of Frozen Soil Engineering is an unique comprehensive laboratory which carries out the studies of frozen soil engineering in China. Its establishment and development will have very important significance for developing Geocryology in China. On the occasion of greeting the 40th anniversary of the Institute of Glaciology and Geocryology, the laboratory has made its way for 9 years. Looking back and looking ahead, it is clear that only aiming at the frontier of Geocryology and solving the fundamental, crucial and integrated problems of engineering, resources and environment in the economic and social development in the cold regions of China can we establish the most advanced state key laboratory and make the studies of frozen soil engineering of China be in the lead in the world.
  • LI Zhong-qin, YE Bai-sheng, ZHANG Ming-jun
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 1999, 21(4): 326-335. https://doi.org/10.7522/j.issn.1000-0240.1999.0063
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    This paper presents a review of the scientific work of the Tianshan Glaciological Station over the past 10 years. The progress of scientific research, student training and construction of the station is summarized. In addition a prospect is also given.
  • HUANG Jia-hui, CUI Guang-xin, YANG Wei-hao
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 1999, 21(4): 336-338. https://doi.org/10.7522/j.issn.1000-0240.1999.0064
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    Based on the practice of artificial freezing engineering in deep alluvium and simulation tests, it is found that there exists an obvious difference between frozen soil mechanics for shallow alluvium and for deep alluvium. The concept of frozen soil mechanics for deep alluvium, its research topics and methods are presented in this paper.
  • JIN Hui-jun, WU Jie, CHENG Guo-dong, NAKANO Tomoko, SUN Guang-you
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 1999, 21(4): 339-350. https://doi.org/10.7522/j.issn.1000-0240.1999.0065
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    The areal extent of cold freshwater wetlands on the Tibetan Plateau is estimated to be 0.133×106 km2, suggesting a significant methane potential. Methane fluxes from wet alpine meadows, peatlands, Hippuris vulgaris mires and secondary marshes were 43.18,12.96,-0.28 and 45.90 mg·m-2·d-1, respectively, based on the transection studies at the Huashixia Permafrost Station from July to August 1996. Average CH4 flux in the thaw season was extrapolated to be 5.68 g·m-2 according to the areal percentage of wetland areas in the Huashixia region. CH4 fluxes at four fixed sites, representative of similar ecosystems, ranged from-19.384 to 347.15 mg·m-2·d-1, and the average CH4 fluxes varied from 6.54 to 71.97 mg·m-2·d-1 at each site from April to September 1997. CH4 emissions at each site during the entire thaw season was estimated from 1.21 to 10.65 g·m-2, displaying strong spatial variations. Seasonal variations of CH4 fluxes were also observed at the four sites. It is found that CH4 bursted in the early thaw season, and increased afterwards with rising soil temperatures. Episodic fluxes were observed in summer, which influenced the average CH4 flux considerably. Annual CH4 emissions from cold wetlands on the plateau were estimated at about 0.7~0.9 Tg based on the distribution of wetlands, representative CH4 fluxes, and number of thaw days. The centers of CH4 releasing are located in the sources of the Yangtze and Yellow Rivers, and Zoige Peatlands.
  • WANG Shao-ling, ZHAO Xin-min
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 1999, 21(4): 351-356. https://doi.org/10.7522/j.issn.1000-0240.1999.0066
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    Ground temperatures monitored at four observation sites in permafrost regions on the Tibetan Plateau was analyzed. It was found that the ground temperature at the depth of 12~20 m increased 0.2~0.4 K and the permafrost thickness decreased 4~5 m from the base in Xidatan Site from 1975 to 1989; and the ground temperature at the depth of 6~15 m increased 0.2~0.4 K in Kunlun Pass Site from 1982 to 1997. Contrast observations show that a sand cover, 15~20 cm in depth, can result in a ground temperature decrease of 0.1~ 0.2 K in MS66 Site; and a removal of vegetation can result in a ground temperature decrease of some 0.2 K in Hoh Xil Site. The monitor demonstrates that many factors that control permafrost developing have duality, e.g., sand and vegetation are able to increase or decrease the ground temperature. These factors, in conjunction with permafrost behaviour, play different roles under different conditions. Therefore, it is necessary to study, understand and evaluate permafrost and its engineering geological properties taking the viewpoint of dynamic variation.
  • TIAN Li-de, YAO Tan-dong, STIEVENARD Michel, JOUZEL Jeal
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 1999, 21(4): 357-361. https://doi.org/10.7522/j.issn.1000-0240.1999.0067
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    The spatial variation of δD in precipitation in West China is discussed in this paper, and the relationship between δD in precipitation and temperature is analyzed as well based on the measured δD in precipitation samples collected in 6 sites in West China during mainly the summer of 1996. δD in precipitation in West China shows an intensive spatial variation:lower in the south of the Tibetan Plateau and higher in the north of West China. Analysis shows that the low value of δD is caused by obvious impact of southwest monsoon, and a very high value is due to the regional water cycle in the arid regions. δD in precipitation in the interior of the continent shows a strong “temperature effect”, while not in the south of the Tibetan Plateau.
  • LIU Feng-jing, Mark WILLIAMS, SUN Jun-ying, ZHU Shou-sen, Eran HOOD, CHENG Guo-dong
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 1999, 21(4): 362-370. https://doi.org/10.7522/j.issn.1000-0240.1999.0068
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    Daily samples of stream water were continuously collected for solute analysis at three sections in the headwater basin of the Ürümqi River from April 30 to June 8, 1997. Solute data for chemographs showed that ionic pulse occurred in stream water at G1 and DC Sections, having a weak impact on solute concentrations of BS Section. Hydrological separation using reactive dissolved silica as a tracer demonstrated that soil-restored water or subsurface water occupied approximately 39.6%, 69.9% and 77.1% of the total discharges at G1, DC and BS Sections, respectively. However, low runoff and subsurface water proportion at the glacial basin didn’t mean lower exports of some solute in stream water. High denudation rates derived from glacial comminution for pyrite, gypsum and biotite made the concentrations of K+ and SO42- in stream water at G1 Section several times those at DC and BS Sections. Dissolution of pyrite might produce extra H+, while dissolution of carbonate and gypsum might largely consume H+, resulting in stream water not to be finally sensitive to acidification.
  • HOU Shu-gui, QIN Da-he, REN Jia-wen, SHENG Wen-kun, CHEN Tuo
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 1999, 21(4): 371-379. https://doi.org/10.7522/j.issn.1000-0240.1999.0069
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    Analyses of pH and conductivity in precipitation sampled during June 1995 to June 1996, in snow pits sampled during the winter of 1995-1996 and during the summer of 1996, and in shallow ice core retrieved in May 1996 from the headwaters of the Ürümqi River are presented in this paper. Though a certain degree of shift appears for pH and conductivity in the post-deposition and firnification processes, a relationship between pH and conductivity is still preserved in the ice core records, which validates the application of the ice core pH and conductivity records from the areas with strong melting for paleoclimate reconstruction.
  • XU Bai-qing, YAO Tan-dong
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 1999, 21(4): 380-384. https://doi.org/10.7522/j.issn.1000-0240.1999.0070
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    The air-bubble formation has been studied experimentally in the Dasuopu ice core from the northern slope of Mount Xixabangma. It was found that air-channel volume decreases gradually, but the firn remains permeable down to the depth above the transition of firn to ice, i. e., about the depth of the air-channels closing off to be isolated bubbles. Apparently, there exists an age difference between air trapped in bubbles and surrounding ice. Only when the air channels close off completely, the age of the air increases in the same rate as the surrounding ice. Air-bubbles formed in different depths at different sites depending on accumulation rate and mean annual temperature, but approximately at a mean density of 0.79~0.83 Mg·m-3. The air-channels in the Dasuopu firn core closed rapidly in the depth between 40 and 47 m, and 50% of air-bubbles were formed in the depth of 45 m. It is calculated that the age difference between air and its surrounding ice is 59 a, and the bulk age distribution width of air trapped in ice bubbles is 11 a.
  • LIU Chun-ping, YAO Tan-dong, THOMPSON L. G., DAVIS M. E.
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 1999, 21(4): 385-390. https://doi.org/10.7522/j.issn.1000-0240.1999.0071
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    Determination of microparticles, including >2.0 μm, 2.0~2.5 μm and >5.04 μm in diameter, since the Little Ice Age in the Dunde ice core is presented. Three increasing and three decreasing periods are distinguished since 1400 AD. Among them, the greatest one was from the end of the 17th Century to the early 18th Century. Microparticle concentration variation corresponds to climate change. The higher the microparticle concentration is, the colder and drier the climate is; the lower the microparticle concentration is, the warmer and wetter the climate is. A comparison of microparticle concentration and sand-dust storm frequency indicates that there exits a good relationship. Most of the material deposited on the Dunde ice cap is thought to have originated in the surrounding arid and semi-arid areas, probably transported into the Qilian Mountains by sand-dust storms. When microparticle concentration appears in special values, sand-dust storms would happen.
  • LAN Yong-chao, KANG Er-si, MA Quan-jie, YANG Wen-hua, YAO Zhi-zong
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 1999, 21(4): 391-395. https://doi.org/10.7522/j.issn.1000-0240.1999.0072
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    The catchment above Longyangxia Gorge in the upper Yellow River basin is situated in the northeast of the Tibetan Plateau. Meltwater from snow is the main water supply to the rivers in this region during spring (late March to early June). In this paper, the study target is the inflow to the Longyangxia Reservoir, the largest reservoir in the upper Yellow River basin, during late March to early June. Then a mid-term operational runoff prediction model based on snow cover data from AVHRR images of NORR meteorological satellite and ground surface hydro-meteorological data, called double sifting and stepwise regression model, is presented to forecast the inflow during this period. Examining at the reservoir shows that the forecast accuracy is satisfying.