25 February 2005, Volume 27 Issue 1
    

  • Select all
    |
  • CHENG Guo-dong
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2005, 27(1): 1-7. https://doi.org/10.7522/j.issn.1000-0240.2005.0001
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    More than half of the total length of the Qinghai-Tibet Railroad (QTR) traverses warm (0 to -1℃) permafrost areas, and about 40% of its total length is in ice-rich permafrost areas. The construction of the QTR also must consider the impacts of climatic warming along the QTR during the next 50~100 years. The latest projection indicates a warming of 2.2 to 2.6 ℃ on the Qinghai-Tibet Plateau (QTP) by the year 2050. Therefore, the key to the successful construction of the QTR is to protect permafrost from being thawed. Although railroad construction in permafrost areas has had a history of more than 100 years, the troubled sections of the railroads in permafrost areas have been greater than 30% of their total length. Based on the experiences and lessons learned from the road construction in permafrost areas, both in China and abroad, the author proposes that the principle of "active cooling" of railroad roadbed by lowering permafrost temperatures should be used in designing QTR, rather than that of "passive protection" of permafrost through increasing thermal resistance of roadway, such as increasing fill thickness and or using insulative materials. This is especially important for the road sections in warm, ice-rich permafrost. In addition, this paper proposes several methods for "cooling the roadbed" by controlling radiation, convection and conduction through modifying roadway structure and using different fill materials.
  • Ted S. Vinson, Yoon-Shin Bae
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2005, 27(1): 8-16. https://doi.org/10.7522/j.issn.1000-0240.2005.0002
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    A probabilistic approach may be adopted to predict freeze and thaw depths to account for the variability of (1) material properties, and (2) contemporary and future surface energy input parameters (e.g. air temperatures, cloud cover, snow cover) predicted with global climate models. To illustrate the probabilistic approach, an example of the prediction of thaw depths in Fairbanks, Alaska, is considered. More specifically, the Stefan equation is used together with the Monte Carlo simulation technique to make a probabilistic prediction of thaw penetration. The simulation results indicate that the variability in material properties, surface energy input parameters, and temperature data can lead to significant uncertainty in predicting thaw penetration. The Taylor series method was performed to determine the mean and standard deviation of thaw penetration and the results were compared to the Monte Carlo simulation results. The close comparison of the results suggests that the simpler Taylor series method may be applied to many cold regions problems to account for the variability of input parameters.
  • Ted S. Vinson
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2005, 27(1): 17-32. https://doi.org/10.7522/j.issn.1000-0240.2005.0003
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Only one access road leads into Denali Park. The serviceability and safety of this gravel road is obviously of paramount importance to the National Park Service (NPS). Since the late 1950s and mid-1960s major icings and a landslide, respectively, have occurred along the Denali Park access road. During the summer of 1990 the landslide activity intensified. The central section of the Park through which the access road traverses is designated as a wilderness area. Consequently, off road field exploration required to quantify the hazards and remediation activities that may be proposed to mitigate icings and stabilize the landslide, are severely restricted and closely scrutinized by the NPS. The results of an evaluation of (1) the current state-of-the-practice to control icings, and (2) thaw stabilization techniques that could be applied to the northwest corner of the landslide are presented herein. The recommendations which followed, respecting the wilderness area designation for the Park, are also presented.
  • JIN Hui-jun, CHENG Guo-dong, MA Wei, HE Ping
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2005, 27(1): 33-40. https://doi.org/10.7522/j.issn.1000-0240.2005.0004
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The 6th International Symposium on Permafrost Engineering was successfully held in China in September 2004. About 150 scientists and engineers from 7 countries attended the symposium in Lanzhou on 5~7 September, and about 35 people from 6 countries participated in the field trip along the Qinghai-Tibet Highway/Railway on 8~13 September and the seminar in Lhasa on 14 September 2004. During the Symposium, the latest progress on permafrost engineering and the surveys, design and construction of the Qinghai-Tibet Railway were exchanged and inspected. Fifty-eight technical papers in English from the Symposium were published in the first volume of the Proceedings of the Symposium, as a supplement of the Journal of Glaciology and Geocryology, before the symposium. About 6 papers from the symposium are published in the second volume in the volume 27(1) of the Journal of the Glaciology and Geocryology, after the symposium.;The Qinghai-Tibet Railway (QTR) under construction will traverse 632 km of permafrost, and the engineers are facing unprecedented engineering and environmental challenges. With the QTR under construction and to be completed in 2007, permafrost engineering has become the research focus of permafrost scientists and engineers in China. Many encouraging and promising achievements in permafrost engineering have been obtained during the past three years. However, there are still numerous engineering and environmental problems needing to be solved or resolved. ;In the discussions, some experts pointed out that methods, such as removal of snow cover on the embankments and toe areas, light-color embankments and side slope surfaces, awnings for shading the solar radiation, hairpin or tilted thermosyphons, could be applied to actively cool the roadbed of the QTR. Some new ideas on utilization of the natural cold reserves were proposed to protect the QTR permafrost roadbed from thawing. Many questions and answers on the survey, design, construction, operations, maintenance and environmental protection were exchanged in situ and in the Lhasa seminar with participation by some major railway designers, regulators and administrators.
  • HUANG Di-fu, ZHAO Shi-yun, ZHANG Lu-xin
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2005, 27(1): 41-45. https://doi.org/10.7522/j.issn.1000-0240.2005.0005
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Permafrost problems are the core of the three principal technical difficulties in the Qinghai-Tibet railway construction. The 40 years of permafrost research in China have built a solid technical base for the Qinghai-Tibet railway construction. But the large-scale railroad construction in permafrost regions brings forward much more and deeper requirements in relation to permafrost. In this article, the Qinghai-Tibet railway construction is taken as a background to deeply analyze the technical problems related with permafrost in the construction, in combination with the practice of scientific research, design, construction and construction supervising. Some innovation theories on the issues in the Qinghai-Tibet railway construction are put forward. These theories are applied widely in the construction in permafrost regions and proved to be highly effective. Thus, the Qinghai-Tibet railway construction in permafrost regions has improved greatly.
  • LA You-yu, ZHANG Lu-xin
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2005, 27(1): 46-49. https://doi.org/10.7522/j.issn.1000-0240.2005.0006
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Since the beginning of the Qinghai-Tibet Railway construction, the research of the permafrost engineering, synthesizing the previous achievements in permafrost studies, has obtained good fulfillment results. Viewing with system engineering theory, the research aims at the influence of large-scale construction practice on permafrost and permafrost environment and the interaction of permafrost and permafrost engineering, and takes the engineering deformation as the comprehensive goal, and the thermal mechanisms of permafrost engineering problems as the essence. The engineering thermodynamic structure is taken as the main measures to solve problems. At the same time, the study of permafrost engineering and the construction in permafrost regions are promoted to a new level, and a solid technical foundation is established for constructing a top-grade plateau railroad in world.
  • WU Qing-bai, DONG Xian-fu, LIU Yong-zhi
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2005, 27(1): 50-54. https://doi.org/10.7522/j.issn.1000-0240.2005.0007
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Monitoring of permafrost change due to climate change and engineering activity along the Qinghai-Tibet Highway shows that there is a large difference in the response of permafrost to climate change and engineering activity, which obvious varies with mean annual ground temperature. The change in cold permafrost is more significant than that in warm permafrost due to climate change. However, the change in cold permafrost is less significant than that in warm permafrost due to engineering activity. The effect of climate change is larger than that of engineering activity for cold permafrost, but it is just contrary for warm permafrost. The reason is that the effect of engineering activity on permafrost has an enlarging action as compared with the effect of climate change in several years after a construction completion. As a result, the response of permafrost under an engineering state to climate change becomes insensitive. Inferred from the annual ratio of permafrost temperature rising due to climate change, it is required 50 years for cold permafrost surface temperature and 20 years for warm permafrost surface temperature rising to the engineering state; it is required 20 years for cold permafrost temperature and 5 to 8 years for warm permafrost temperature at the depth of 6 m rising to the engineering state. Therefore, warm permafrost will experience the effects of both climate change and engineering activity in several years after a construction completion, but clod permafrost requires much more time to experience the two effects. It is significant important to consider the effect of climate change on permafrost for an engineering in permafrost regions.
  • LIU Shi-yin, SHANGGUAN Dong-hui, DING Yong-jian, HAN Hai-dong, ZHANG Yong, WANG Jian, XIE Chang-wei, DING Liang-fu, LI Gang
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2005, 27(1): 55-63. https://doi.org/10.7522/j.issn.1000-0240.2005.0008
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Recent studies indicate that most alpine glaciers around the world have retreated during the past decades under global warming. In this study, a region with temperate glaciers, mainly influenced by the Indian Monsoon, is selected to examine the present status of glaciers under a warming background. Aerial photos, topographical maps, China-Brazil Earth Resource Satellite (CBERS, with resolution of 19 m and acquired on Jan. 30 2001) and Landsat Thematic Mapper (TM, acquired on Oct. 26 1999) images are used. Aerial photos are mainly applied for identifying the end and lateral moraines formed at the end of the Little Ice Age, which was thought to occur in the mid-1920s. CBERS and Landsat TM images geometrically corrected and co-registered to 1:100 000 topographical maps are applied to extract the information of glacier distribution at the time the imageries acquired. It was concluded that the measured 102 glaciers in the region have all in retreat from the 1920s to 1980, with a total areal and ice volumetric decreases of 47.9 km2 and 6.95 km3. It is estimated that all glaciers in the region have lost 13^8% of their total area and 9.8% of the total ice volume during the same period. Since 1980, glaciers in the region have also experienced an ice mass loss process in general, according to the data of 88 glaciers with a total area of 797.78 km2 from topographical maps in 1980 and the CBERS image in 2001. About 60% of these glaciers have been losing their mass and other glaciers have advanced. Analysis indicates that glacier retreat has significantly impacted glacial meltwater runoff, resulting in 50% decrease of runoff from 1915 to 1980. The trend of glacier retreat and climatic warming during the last century, especial during the past two decades, shows a possibility that mass loss of glaciers in the region will be accelerating in the future.
  • CHE Tao, LI Xin
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2005, 27(1): 64-67. https://doi.org/10.7522/j.issn.1000-0240.2005.0009
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The snow storage retrieved from passive microwave remote sensing brightness temperature data has the following features: 1) there is no a positive increasing or decreasing trend of snow storage in 1993-2002, but an annual variation exists; 2) there are several main snow packs including Northeast, North of Xinjiang, the East Tibetan Plateau and the periphery of the plateau, and North China plain; 3) there are some main stable snow-cover regions, such as Northeast China and North China, North of Xinjiang, and the Tibetan Plateau; 4) the snow storage in the Tibetan Plateau is less than that in Northeast China, while the number of days of snow cover in the former is more than that in the latter. The snow cover in the Tibetan Plateau, however, is more important in climate significance rather than in water resources. The mean maximum of annual snow water resources in China is about 102.79 km3 in 1993-2002, with the maximum one, about 131.34 km3, in the year 1999/2000.
  • GAO Wei-dong, WEI Wen-shou, ZHANG Li-xu
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2005, 27(1): 68-73. https://doi.org/10.7522/j.issn.1000-0240.2005.0010
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Snow cover is an important component in a climatic system, and is very sensitive to the change in climatic environment, especially in arid areas. Seasonal snow cover is the most active factor that affects the environment in arid and cold regions. In this paper, the change trends of seasonal snow cover, precipitation and temperature in cold season in the intermediate zone of the West Tianshan Mountains are tested by using average dispersion method, least square method and auto-regression-moving average method based on the data of annual maximum snow cover depth, monthly mean temperature and precipitation observed in the Tianshan Station for Snow and Avalanche Research, Chinese Academy of Sciences in 1967-2000. The results show that snow cover depth in the intermediate zone of the West Tianshan Mountains increases in the last 33 years. The temperature and precipitation variations in the cold season in the intermediate zone of the West Tianshan Mountains are also in an increasing trend. During the last 33 years, the seasonal snow cover and precipitation in cold season have annually increased by 1.43% and 0.12%, respectively, and the temperature in cold season has increased by 0.8 ℃. Verifying the time series of precipitation and air temperature shows a positive value, that is to say, the precipitation and air temperature are increasing. However, the temperature change is more than the precipitation change. By using Mann-Kendall technique,it is found that temperature change is, but precipitation is not abrupt during this period. The correlative and regressive analyses show that there is a significant positive correlation between the seasonal snow cover and the precipitation in cold season, but a weak negative correlation between the seasonal snow cover and the temperature in cold season.
  • JIAO Ke-qin, Shuji IWATA, YAO Tan-dong, JING Zhe-fan, LI Zhong-qin
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2005, 27(1): 74-79. https://doi.org/10.7522/j.issn.1000-0240.2005.0011
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The advance sequence of the Zepu Glacier in the Bodoi Zangbo watershed in the Nyainqê ntanglha Range during the last 3.2 ka are revealed by field investigation and 14C dating data. Three advances of the glacier in the Neoglaciation can be obviously distinguished. They are Dana Glacial Advance [14C(3242±101) a BP], Danading Glacial Advance [corresponding to Ruoguo Glacial Advance, [14C(1920±110)~1540±85 a BP] and Baitong Glacial Advance [14C(1056±115)a BP]. In the Dana glacial advance, the Zepu Glacier was 6~9 km longer, its area was 17.10 km2 larger, and its snowline was 157.0 m lower than those at present, and air temperature was 1.0~1.9 ℃ lower than that at present. Two advances of the glacier in the Little Ice Age can be distinguished. They occurred in the 15th or 16th century [14C (580±130)a BP] and the 19th century [(14C 197 80~190 80 a BP)]. In the glacial advance in the Little Ice Age, the Zepu Glacier was 2.0 km longer, its area was 11.16 km2 larger, and its snowline was about 100.0 m lower than those at present, and air temperature was 0.65~1.23 ℃ lower than that at present. Superglacial till develops particularly on the surface of the glacier. The glacier is still very thick, and the shrinkage of the glacier tongue is not so obvious. However, the glacier is violently thinning, and several modern flank moraines form in both sides. The 14C dating data of charcoal oddments and humus buried in earth reveal that there were some human activities including deforestation, land reclamation and grazing in the Bodoi Zangbo watershed during the period from 2000 to 700 a BP.
  • WU Guan-jian, YAO Tan-dong
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2005, 27(1): 80-87. https://doi.org/10.7522/j.issn.1000-0240.2005.0012
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Central Asia is an important dust source in the Northern Hemisphere. Dust from this area is transported by different atmospheric circulations, deposited along different routes, and recorded in the Guliya and the GISP2 ice cores, the Baoji loess section, the lacustrine sediment from Lake Biwa, the North Pacific deep-sea sediment. The REE, mineralogy, and isotope composition also prove that the dust in the North Pacific and Greenland ice sheet comes from the Central Asia, especially the Taklamakan Desert. Concentration, particle size, and accumulation rate are chosen for proxies of those atmospheric dust records. In this paper, the dust records of the sediments since the Last Interglacial are compared and discussed. It is found that some records are consistent and some records are different, though the comparison is limited by timescale and resolution. All the records show a low dust concentration during the MIS 5 and MIS 3, and a high dust concentration during the last glacial. Though a change in source areas may influence all the records, the transport, sedimentation, and regional or local situations would affect the dust records, such as a low concentration in the Guliya ice core during the Last Glacial Maximum and a high dust concentration in North Pacific eolian sediments in the Middle Holocene. So, it seems necessary that all these records need to be integrally considered in order to get a more comprehensive knowledge on the evolution of Central Asia dust and atmospheric circulation. Due to its high elevation and desertification process, the Tibetan Plateau might also be a very important dust source area in the Northern Hemisphere.
  • HAN Hai-dong, DING Yong-jian, LIU Shi-yin
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2005, 27(1): 88-94. https://doi.org/10.7522/j.issn.1000-0240.2005.0013
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    A simple model is developed to estimate the heat balance parameters in the ablation season of the debris-covered Kerqikaer Glacier on the basis of energy balance theory, heat conductivity and heat flux transfer. The model outputs include sensible heat flux, latent heat flux, ground heat flux and net radiation. Analyses on the outputs show that net radiation is the primary heat source, and the heat absorbed in the debris cover is lost mainly in the form of sensible heat and latent heat for moisture and heat exchanges between debris cover and air, and only about 21.0% is stored in the debris cover. One of the features of heat income over the debris-covered middle ablation area is that the ratio of the sensible heat flux decreases while ground heat flux increases significantly in comparison with that on the ice surface and debris cover in the upper ablation area. The heat outcome comprises sensible heat exchange, heat for evaporation and downward ground heat flux with the ratio of 39.1%, 39.9% and 21%, respectively. Heat for evaporation is significant in the heat outcome in comparison with that on the upper ablation area. Of the total heat income, only 7.8% is used for temperature increase of the deeper part of the debris cover and conduction downwards.
  • ZHANG Shi-qiang, DING Yong-jian, LU Jian, LIU Shi-yin
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2005, 27(1): 95-99. https://doi.org/10.7522/j.issn.1000-0240.2005.0014
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Water-heat process in the Tibetan Plateau is significant to global climate change. Variances of soil moisture and soil temperature are the key factors of simulating water heat process. In this paper, a water and energy balance macroscale hydrological model is used to compare the simulated result with observed data on the step of 1 hour during 399 days in Tuotuohe. The simulated soil temperature was discussed. The simulated soil temperatures in 11 depths (0 m, 0.2 m, 0.4 m, 0.6 m, 0.8 m, 1 m, 1.3 m, 1.6 m, 2 m, 2.3 m and 2.71 m) were tested. The NSE (Nash-Sufciffe Evaluation) at depths of 0 m, 0.2 m, 0.4 m, 0.6 m, 0.8 m, 1 m, 1.3 m and 1.6 m are greater than 0.9, at depth of 2 m is 0.882, at depth of 2.31 m is 0.7299, and at depth of 2.7 m is 0.369, which indicates that the model is stable in yearly scale and can simulate for a long period in the Tibetan Plateau. The NSE at 2.3 m and 2.71 m is not well either by using damping algorithm or by using constant algorithm, which indicates that the model needs to modify in the future, especially, the energy equation at the bottom of soil.
  • YE Bai-sheng, LI Chong, YANG Da-qing, DING Yong-jian, SHEN Yong-ping
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2005, 27(1): 100-105. https://doi.org/10.7522/j.issn.1000-0240.2005.0015
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In this paper the changing trends of monthly precipitation over China during the last 50 years are analyzed based on the long-term precipitation data at 678 meteorological stations in China, and the response of river runoff to climate change are also analyzed based on the monthly runoff data at the main hydrological stations of the Yellow River, the Yangtze River and the Songhua River/Amur River by using the linear regression methodology. It is found that the monthly variation of precipitation demonstrates an obvious region-dependence. A generally decreasing trend is mainly in the eastern region of China from August to December, and an increasing trend is in South China from January to March. The contradiction between water supply and demand during fall and winter becomes more and more serious owing to the obvious decrease of river runoff in the dry season caused by the uneven change in precipitation within one year, and especially because of the constant decrease of precipitation from August to December, and the discharge increase due to increase in precipitation in flood period lead to more floods. In addition, the earlier snowmelt process in the spring due to warming climate in the upper Yangtze River and the Yellow River, originated all from the Tibetan Plateau, leads to an increase of runoff in the two rivers in snowmelt period. The long-term trends in discharge at the control stations in the three rivers during 1951-1998 show positive from January to April, but negative from June to December, except for an increasing trend in discharge at Datong station in the lower Yangtze River in July, at Tangnag Station in the upper Yellow River in June and at Harbin Station in the Songhua River in August. This is caused by precipitation change, earlier snowmelt due to global warming, and human activities such as irrigation and regulation of hydropower stations.
  • ZHANG Ying-hua, WU Yan-qing, DING Jian-qiang, WEN Xiao-hu
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2005, 27(1): 106-110. https://doi.org/10.7522/j.issn.1000-0240.2005.0016
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In arid regions of western China, water resources come from mountain watersheds and disappear in the desert plains. The exchange of surface water and groundwater takes place two or three times in a basin. It is essential to analyze the interaction between groundwater and surface water, so as to use water resources effectively and predict the change in the water environment. The conventional method of analysis, however, measures only the flow of a stream and cannot determine groundwater seepage accurately. Because of the distinct difference of δ18O between groundwater and surface water, the method of using 18O was examined as an indicator for analyzing the interaction. With the addition of the mass balance equation, the composite proportion of different mixing components can be calculated. A conclusion was drawn from the computed result that, in the oases of the middle Heihe River, flood irrigation on vast farmlands has made a great impact on the transform between groundwater and surface water. The irrational irrigation has caused some problems, such as environmental deterioration and land subsidence.
  • BAI Hu-zhi, LI Dong-liang, DONG An-xiang, FANG Feng
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2005, 27(1): 111-116. https://doi.org/10.7522/j.issn.1000-0240.2005.0017
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Based on the data of 66 observatories in the Tibetan Plateau, the number of strong wind days from 1971 to 2000 in the plateau and that along the railway, spatial distribution of strong wind and the features of wind direction are analyzed. Meanwhile, The maximum wind velocities and maximum wind pressures with probabilities of 2% and 1% are calculated. It is found that the strong wind mainly occurs along the railway in the plateau, with distinct annual and decade variations. The supreme maximum wind velocity and the maximum annual mean wind velocity all occur at the central part of the railway, the Tuotuohe area, with prevailing west wind direction. Whereas, the maximum 10-min mean wind velocity and wind pressure with probabilities of 2% and 1% occur in Amdo County. The critical wind velocities for train operation at various stations along the railway are calculated referred to the observation at Dabancheng Station. To guarantee rail transportation safely, it is suggested that some windbreak establishments would be built at the wind eye areas between the Kunlun Mountain Pass and the Cona Lake, as well as the frequently turning rails.
  • CHANG Juan, WANG Gen-xu, WANG Yi-bo
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2005, 27(1): 117-123. https://doi.org/10.7522/j.issn.1000-0240.2005.0018
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In the arid regions of Northwest China, regional eco-environment and economic construction are controlled and limited by the rationality of land use structure. Taking Zhangye Prefecture in the Heihe River basin as an example, this paper analyzes the changes in main land use types, including cultivated land, woodland, grassland, lands in desertification and their effect forces. The results show that the land use change is controlled basically by physical conditions, and significantly affected by human activity. The increase in cultivated land is directly related to rising in utilization ratio of water resources, and the increase in population is also one of the main causes for cultivated land augment. The cultivated land decrease is mainly related to land desertification caused by irrational human activity. Although woodland change is also limited by physical conditions, the function of human factor is more important than physical effects. The cause of grassland decrease is overgrazing and irrational human activity. Based on the analyses, a suggestion for the principles guiding rational land use structure in the prefecture is put forward in the paper.
  • REN Jia-wen, YAN Ming
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2005, 27(1): 124-127. https://doi.org/10.7522/j.issn.1000-0240.2005.0019
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    During the first scientific expedition of Chinese Arctic Yellow River Station from July to August, 2004, basic features of glaciers near the station and the situation of glaciological research in this region were investigated. Based on these, the perspective of future work in this region is discussed. It is thought that in near future we should lay stress on the combination of monitoring glacier variation and glacial processes such as mass balance, energy budget and meteorological-hydrological processes. Due to strong melting and meltwater percolation, it is not suitable to ice core study in the region near Ny-Alesund.
  • LI Guo-yu, LI Ning, QUAN Xiao-juan, YANG Li-ming
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2005, 27(1): 128-133. https://doi.org/10.7522/j.issn.1000-0240.2005.0020
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The adjustable ventilated embankment, which is adopted in the Qinghai-Tibet Railway, is one of the ideal engineering measures to protect a warm frozen soil. In this paper, Finite Element Method has been used to operate a numerical analysis of 3-D temperature field and to make a comparison between the ordinary ventilated embankment and the adjustable ventilated embankment. It is found that the adjustable ventilated embankment can prevent the thermal entry from air into the ducts and the thawing of the permafrost beneath the embankment during summer, and that the location of 0 ℃ isotherm of the adjustable ventilated embankment is higher than that of the ordinary ventilated embankment in summer. The permafrost table of the adjustable ventilated embankment rises significantly. The permafrost underlying the embankment is protected better. Also the thawing bulb does not appear in summer. In addition, the time that the mean temperature of the permafrost underlying the adjustable ventilated embankment decreases below -1 ℃ is much earlier than that underlying the ordinary ventilated embankment. These indicate that the cooling effect of the adjustable ventilated embankment on permafrost is better than that of the ordinary ventilated embankment.
  • LIU Zhi-qiang, LAI Yuan-ming
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2005, 27(1): 134-139. https://doi.org/10.7522/j.issn.1000-0240.2005.0021
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Finite element formulae are derived by Galerkin’s method from the differential equation of three-dimension temperature fields, taking account of phase change. The temperature distributions of ventilated embankments are calculated under the case that the annual mean air temperature in the Tibetan Plateau will increase 2.6 ℃ in the future 50 years and the yearly-average temperature at the native surface will be -1 ℃. The calculation results for ventilated embankments with and without insulated doors are analyzed and compared. The ventilated embankment with insulated doors can efficiently decrease the temperature in embankment, 0.5~1 ℃ lower than that of ventilated embankment without insulated doors. The zones below 0 ℃ in ventilated embankment with insulated doors are larger than those without doors. It is revealed that an embankment with insulated doors absorbs less heat than that without insulated doors. As a result, it may provide more thermal stability of the embankment, and guarantee the railway safer operation. Finally, an advice to the design department is suggested based on the analyses.
  • JIN Hui-jun, Max C. Brewer
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2005, 27(1): 140-146. https://doi.org/10.7522/j.issn.1000-0240.2005.0022
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The Alaska Arctic is located at north of the Brooks Range and from the Bering Sea to the Canadian border, with an arctic marine climate. Cold and continuous permafrost with thicknesses from 200 to 300 m, sometimes to 700 m, are widespread. The most prominent surface manifestations of the underlying permafrost include numerous small lakes and ponds, ice-wedge polygons and tundra wetlands on the arctic coastal plain. The engineering construction in the Alaska Arctic was mainly driven by naval and commercial exploration, development and transportation of crude oil and natural gas from the Prudhoe Bay, Cape Simpson, Umiat and Barrow areas, and some military operations, such as the Distant Early Warning Line radar stations since 1940s. There are many experiences, lessons learned and body of knowledge obtained during all these engineering construction periods. The most successful engineering feats include the exploration and later development of the Prudhoe Bay oil/gas field, Alyeska Hot Oil Pipeline, and environmental protection regulations during most of these engineering activities, which resulted only minor impacts considering so many mega-projects were undertaken with very limited knowledge of permafrost terrain in advance. In order to successfully and economically engineer for construction and operations in the arctic, it is necessary to think "cold", and to plan and act accordingly. The construction engineer must be innovative and not be bound by mid-latitude mind-settings gained from education, training or conventional wisdom. The engineer and the environmental scientist must work as a team during the initial field survey, during the design phase, and during the actual field construction. The engineer needs to know the environmental parameters, constraints and potential opportunities. The environmental scientist needs to know the engineer’s construction design and problems, and understand the engineering constraints, equipment capabilities, and the economics of potential alternative courses of action. These understandings cannot be acquired working alone, then trying to coordinate results after each has invested time and effort and developed plans and positions which they are reluctant to modify.
  • XIAO Zheng, ZONG Ling, WANG Yuan
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2005, 27(1): 147-149. https://doi.org/10.7522/j.issn.1000-0240.2005.0023
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Monitoring appearing rate of radon in land is discussed in this paper,and a easy monitoring method is put forward, which is compared with the local static method that appeared in some documents. It is revealed that, for monitoring the appearing rate of 222Rn in land, the monitor with CR-39 solid nuclear radius is simple, convenient, easy to operate, and accurate. It is applicable to monitoring the appearing rate of 222Rn in large ex-service uranium mine. In addition, the monitoring method has satisfactorily applied to monitoring a heap of waste stone in an ex-service uranium mine.
  • JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2005, 27(1): 150-152. https://doi.org/10.7522/j.issn.1000-0240.2005.0024
    Abstract ( ) Download PDF ( )   Knowledge map   Save