25 May 1999, Volume 21 Issue 2
    

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  • JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 1999, 21(2): 97-98. https://doi.org/10.7522/j.issn.1000-0240.1999.0024
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  • XU Zhongmin
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 1999, 21(2): 99-106. https://doi.org/10.7522/j.issn.1000-0240.1999.0025
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    This paper describes the scenariobased framework for multi criteria decision analysis in water carrying capacity. Scene analysis play two roles in the process of multi criteria decision analysis: choosing scenarios to decision-maker and identifying potential compromises to various interest groups in formulating individual preference orders. The overall procedure and some experiences in applying it with the text of regional water resource planning in the middle of Heihe River are discussed.The water carrying capacity model in Heihe valley consist of six sub-model such as macro-economic model, population model, land resources subject model, water resources development and utilization model, water environment model and water projects investment model. In accordance with specific conditions of Heihe valley, the table of L9(34) was adapted to establish the multiple criteria decision-making model in Zhangye district, three scene was designed according to variation of water-supplyed in Jiuquan district.
  • Communication Department of Qinghai Province; State Key Laboratory of Frozen Soil Engineering, LIGG, CAS; Highway Survey and Design Institute of Shanxi Province; Sixteenth Engineering Department of Railway Ministry
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 1999, 21(2): 107-114. https://doi.org/10.7522/j.issn.1000-0240.1999.0026
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    Dabanshan tunnel is coated in a bitter cold region and its mean annual air temperature is-3.1℃. Formation of permafrost in the rock surrounding the tunnel is unavoidable, no matter whether there is thermal insulation material in the lining. Frost damage due to surface freezing in the lining would result in the surface stress exceeding the strength of the concrete.If there is a thermal insulation door, the permafrost in the rock surrounding the tunnel wouldnot be formed. The boundary between bitter cold and intermediate cold regions is taken as the line of mean annual air temperature equal to -1.0℃. The thermal insulation door is the best measure against frost heaving in frozen soil regions.
  • LING Feng, WU Ziwang
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 1999, 21(2): 115-119. https://doi.org/10.7522/j.issn.1000-0240.1999.0027
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    This paper discusses the influence of seepage of surface water in the sides of embankment on the temperature field of roadbed in permafrost regions. First, a mathematical model is established based on the heat transfer theory and seepage theory.Then, based on the observed data, the variation process of temperature field in the experimental roadbed,which is in Huashixia along the Qinghai-Kangding Highway in the Tibetan Plateau, after five years fromthe present is simulated in terms of Galerkin finite element method. The prediction results show that in case of no seepage effect, the maximum thawing deepths of ground in left sides of embankment, embankment itself and right side of embankment in the fifth year are 1.4 m, 3.2 m, 1.4 m and in case of seepage effect they are 1.4 m, 3.6 m, 1.6 m, respectively. The seepage of surface water in the sides of embankment will deepen the maximum thawing depth, and the nearer the boundary of roadbed in horizonal direction to the headwaiers, the deeper the maximum thawing depth in the vertical direction is.
  • XU Baiqing, YAO Tandong
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 1999, 21(2): 120-124. https://doi.org/10.7522/j.issn.1000-0240.1999.0028
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    The air-bubble formation process has been studied experimentally on the Dasuopu ice core from the northern slope of Mount Xixabangma. It is found that air-channel volumes decrease gradully as the depth increase, but the firn remains permeable in the depth above the horizon of firn transiting to ice.At the transition depth the air-channels are closed off to be isolated bubbles. Apparently, there exist age difference between air trapped in bubbles and surrounding ice. only after the air-channels are closed off completely, the age of the air increases with the surrounding ice in the same rate. Air-bubble formed in different depth at different sites depending on accumulation rate and mean annual temperature, but at the same mean density of 0.79 ~ 0.83 Mg·m-3. The air-channel in Dasuopu firn core closed rapidly in the depth of 40~47 m. There is 50% air-bubble formed in the depth of 45 m. It is caculated that the age difference between air and surrounding ice is 59 a, and the bulk age range of air trapped in ice bubbles is 11 a.
  • HUO Wenmian, YAO Tandong, LI Yuefang
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 1999, 21(2): 125-128. https://doi.org/10.7522/j.issn.1000-0240.1999.0029
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    The trace lead concentration and its isotopic composition in the upper 40 m of Dasuopu ice core has been directly measured by ICP-MS at Pg? g-1 level. The lead concentrations profile in the ice core show an increase in most recent decades and an abrupt increasing tendency in the recent years.Isotopic evidence shows that the abundance of U degenerated leads (206Pb+207Pb) increase and the abundance of Th degenerated lead(208Pb) decrease with lead concentration. We believe that the increase of lead concentration results from superposition of various increasing lead sources characterized by rich U degenerated lead, and natural lead sources can not interpret this phenomenon. Anthropogenic lead accounts for a large part of Pb budget in the ice core, especially, in the recent two decades the anthropogenic lead becomes overwhelming. Burning leaded gasoline is the major source of pollutant lead in atmosphere.The record of lead concentration in the Dasuopu ice core indicates that the situation of atmosphere over the surrounding counties goes from bad to worst. The Pb deposited in the Dasuopu Glacier is probably supplied by the Indian summer monsoon, which climbed over the pass at the head of the glacier, so the use of leaded gasoline in south Asian counties may be a major source of lead in atmosphere over this region.
  • ZHOU Houyun, YU Suhua, ZHU Zhaoyu, LI Shjie, LI Bingyuan, WEN Qizhong, HE Yixian
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 1999, 21(2): 136-140. https://doi.org/10.7522/j.issn.1000-0240.1999.0030
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    Based on a R / S analysis of FeO,Fe2O3 and ratio of FeO/ Fe2O3 from Tianshuihai Lake core, which is scaled with time, it is found that there are obvious Hurst effect with Hurst indexes of 0.85, 0.76 and 0.65 respectively. All the three Hurst indexes are greater than 0.5, showing a persistence in the climate and environment evolution around the Tianshuihai lake area during the past 200 ka or more.At present it is not clear why these Hurst indexes are different from each other. Maybe this shows a difference in the intensity of persistence in climatic and environment variation. The persistence in the climatic and environmental evolution around the Tianshuihai lake area since 200 ha BP or more also existed in some other areas and probably resulted from the uplift of the Tibetan Plateau through the Cenozoic era.
  • ZHENG Benxing, ZHAO Xitao, LI Tiesong, WANG Cunyu
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 1999, 21(2): 145-150. https://doi.org/10.7522/j.issn.1000-0240.1999.0031
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    Located between the Nujiang River and the Lancang River, Mainri Mountain is famous and mysterious, whose main Peak, Mount Kawagarbo, is 6 740 m a.s.l., the highest peak in Yunnan Province. Melang Glacier, 11.7 km in length,on the eastern slope of the Mount Kawagarbo, is now the second longest glacier in the Hengduan Mountains. The glacier extends to about 2 660 m a.s.l., with an area of 13 km2. It is the lowest monsoon maritime glacier in the Hengduan Mountains. Its firn basin is 5 km long from north to south and 3 km wide from east to west. The equilibrium line on it varies from 4 800 to 5 200 m a.s.l. In the middle of the firn basin, there is a beautiful lake, some 50 m in diameter. Crossing the mouth of the firn basin, ice flows downwards,through two large ice-fall, near 1000 m in height,and a few wide and plane stages, finally extends into the region of dense primeval forest Meltwater suplies the Lancang River.In 1902 a British mountaineering team failed in climbing the mount. Afterwards other 4 teams from America, Japan and China also suffered the same failure. The last one was the Sino-Japan Joint Mountaineering Team, whose members were killed at Camp 3 (5 300 m a.s.l.) by a large avalanche, on 3rd January,1991. Their bodies were found under the first ice-fall (about 4 000 m a.s.l.) on 18 July, 1998. The moving distance is about 4 km, equivalent to an annual velocity of 533 m. The flow velocity is the maximum among all glaciers in the Hengduan Mountains.The Melang Glacier has been advancing since 1959. It advanced 730~930 m from 1959 to 1971, 70 m from 1971 to 1982 and 280 m from 1982 to 1998.The reason is a favour of temperature and precipitation.
  • REN Jiawen
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 1999, 21(2): 151-154. https://doi.org/10.7522/j.issn.1000-0240.1999.0032
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    The glaciers in Danghe Nanshan are developed under very dry and cold climate. The present snow-line, 4930 m a.s.l., is higher than that estimated roughly before. The measurement of main anions and canons has been made for some samples collected from surface snow on a glacier, meltwater beside the glacier, river water and rain water in front of the glacier. The result shows that the ionic composition of the surface water is controlled by the local surface chemical composition and basically belongs to HCO3, SO4-Ca type. Comparison of the ionic concentrations in snow and rain samples with those inneighbouring regions suggests that ions in atmosphere in these area are mainly from terrestrial origin and human activities have insignificant contribution.
  • YUAN Xizhong
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 1999, 21(2): 155-158. https://doi.org/10.7522/j.issn.1000-0240.1999.0033
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    Based on the investigation and the observation of thaw settlement of subgrade under different ground temperature regimes in the northern part of Da Hinggan Mountains, this paper presents the law of thaw settlement of subgrade in continuous permafrost zones in Da Hinggan Mountains. The key factor controlling the amount and the process of thaw settlement of subgrade is permafrost conditions. The change of permafrost environment controls the stability of the subgrade. The influences of vegetation,supra-permafrost water and height of embankment on the permafrost environment and the stability of subgrade are analyzed. Some measures for anti-thaw settlement of subgrade in the zones of permafrost with higher ice content are suggested, such as using non-masonry foundation pipe culvert, geotextile material and improving drainage condition.
  • WANG Shaoling, ZHAO Xinmin
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 1999, 21(2): 159-163. https://doi.org/10.7522/j.issn.1000-0240.1999.0034
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    Ground temperature monitored at four observation sites in permafrost regions on the Tibetan Plateau are analyzed. It is found that the ground temperature at the depth of 12~20 m increased 0.2~0.4K 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 MS No. 66 Site; and a remove of vegetation can result in a ground temperature decrease of some 0.2 K in Hob 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 company 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 a viewpoint of dynamic variation.
  • JI Fang, ZHAO Hu
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 1999, 21(2): 164-168. https://doi.org/10.7522/j.issn.1000-0240.1999.0035
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    In this paper 6 soil profiles in different elevation zones in the Altay Mountains are chosen and the mechanical composition of soil, the eroded degree of mineral in the ground layer, the clay mineral through X-ray diffraction pattern, and the silica sesquioxide ratio of the clay particles are analyzed.The results show that, as a whole, weathering of soil was weak and there was no obvious difference in the type of clay mineral and molecular ratio SiO2/ R2O3 of clay particles in different elevation zones. Clay mineral was dominated by hydromica and the silica sesquioxide ratio of the clay particles is 2.78 ~3.37. Only were the differentials of the weathering degree observed at several respects. The content of the clay particles in the surface layer in alpine area was higher than that in lower mountain area, whereas the peak height of X-ray differaction pattern of the main clay mineral was reverse. Because of cold and wet condition in the alpine areas, the eroded degree of the original minerals in the ground layer was stronger than that in the lower mountain areas.
  • HE Chunyang, DING Yongjian, LI Xin
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 1999, 21(2): 169-174. https://doi.org/10.7522/j.issn.1000-0240.1999.0036
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    A new method, visualized method GIS-based, for computing glacier variation is put forward. The Glacier No.1 at the headwaiers of theUrumqi River, Tianshan Mountains, is taken as an example. By tradition. pole method was widely used,whose substance is estimating mass balance for a whole glacier from a few typical and discrete records.Therefore calculated result depends on sampling number, accuracy and representative. The visualized method continuously simulates the change of glacier surface through grid data of DEM and computes glacier variation in a certain duration. The method needs digitized glacier map in different duration or remote sensing data or direct measurement using Global Position System (GPS). As compared with traditional polemethod and calculation method (isoline method), the visualized method has quick, visual and economic advantages and may be realized through remote sensing (RS) and GPS technique. In this paper the principle,process and computing program of the visualized method are discussed. A satisfied result is obtained as applying this method to the Glacier No.1 at the headwaiers of the Urumqi River. The computation result is compared with measured mass balance. In the compared duration from 1980 to 1986, the height of glacier surface and ice volume computed by the visualized method decreased about 1653 mm and 2.87×106m3 and those by traditional method decreased 1961 mm and 3.61×106m3. If measured specific mass balance is corrected based on glacier area change, then the height of glacier surface and ice volume computed by traditional method should decrease 1849 mm and -3.30×106m3. It is also found that there is a close relation between the visualized method and pole method. The causes of error have been analyzed. Most of error come from measurement and calculation of mass balance. Partial error is caused by digitized DEM and visualized computation. In general, this study is concerned with the application of 3S technique to glaciology. The purpose is now focused on methodology. The method provides a route for study of glacier variation using 3S technique.
  • JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 1999, 21(2): 174-174. https://doi.org/10.7522/j.issn.1000-0240.1999.0037
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  • LI Ping, XU Xiaozu, PU Yibin, WANG Jiacheng, TAO Zhaoxiang, WANG Yujie
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 1999, 21(2): 175-180. https://doi.org/10.7522/j.issn.1000-0240.1999.0038
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    Unidirectional freezing tests with saturated soil in an open system were conducted under different initial and boundary conditions in the laboratory. The digital technique of picture is considered able to obtain the real record of thickness of frozen fringe and ice segregation during soil freezing. Duplicated films were mad and the digital technique of picture was used after tests. According to amount of frost heaving and picture disPOsal, time of initiation, position,and thickness of frozen fringe and individual ice lens as well as hydraulic conductivity of frozen fringe can be obtained.The results of picturial analyses show that the digital technique of picture has heigh analytical precision and can avoid low efficiency and visual fatigue as compared with separated layers by manual work. So this technique is a practical and a new research method.Under the given test conditions, the velocity of ice segregation decreases in POwer form with elapsed time. The temperature of ice segregation decreases with frost depth quickly advancing in the initial stage of tests, and then increases and stabilizes as result of reduced temperature gradient with increasing the length of frozen section. The hydraulic conductivity of frozen fringe decreases in exponential form with elapsed time.
  • TANG Maocang, LIU Yanxiang
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 1999, 21(2): 181-183,185. https://doi.org/10.7522/j.issn.1000-0240.1999.0039
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    Three questions in need of further studies have been proposed by Shi Yafeng in 1994 based on the progress of glaciology studies in China. 1) the reason for the inconsistency of glacial maximum in different regions; 2) possibility of another glaciation evolution pattern, i.e., the glacial Period is simultaneous with the rainy phase, which is quite different from the monsoon region pattern; 3) in glaciation evolution did climatic or tectonic factors play a major role? The above mentioned points are the basic questions in glaciology facing towards the 21st Century and expected to be solved on the basis of the interdisciplinary combinations among glaciology,climatology and geodynamics. Some viewpoints were put forward in present paper as a preliminary attempts.
  • JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 1999, 21(2): 185-186. https://doi.org/10.7522/j.issn.1000-0240.1999.0040
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  • JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 1999, 21(2): 186-186. https://doi.org/10.7522/j.issn.1000-0240.1999.0041
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  • ZHANG Jinzhao, WU Jingmin, LI Zhulong
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 1999, 21(2): 187-191. https://doi.org/10.7522/j.issn.1000-0240.1999.0042
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    Qinghai-Tibet Highway is the key way to join the Tibetan Autonomous Region and Qinghai Province, and is the best useful entrance and exit of the Tibetan Autonomous Region whih provides more than 85 percent of goods from the other inner provinces to the region. This paper reviews every steps of the 40 years studying in several topics, and sums up the content and the fruits. The methods of exploring technique is developing from drilling to a combination of drilling and radar. The subgrade is developing to use the methods of elevating the height of fill, setting heat insulation and setting waterproof and heat preservation side-road. The pavement is developing to use modified asphalt concrete and steel fiber concrete now, from grit and aggregate pavement in the 1950’s to asp. macadam pavement, bituminous surface treatment pavement in the 1970’s. The bridge and culvert is developing from wooden structure mainly in the 1950’s and 1960’s to reinforced concrete and prestressed reinforced concrete. At the same time the permafrost and the temperature field along the way is studied. Further research on the Qinghai-Tibet Highway is suggested in order to be a sustainable development way and to mitigate the diseases on subgrade,pavement and bridge.