25 October 2006, Volume 28 Issue 5
    

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  • DING Yong-jian, LIU Shi-yin, YE Bai-sheng, ZHAO Lin
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2006, 28(5): 623-632. https://doi.org/10.7522/j.issn.1000-0240.2006.0091
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    The study objects in this work are lakes in the Tibetan Plateau,Inner Mongolia and Xinjiang regions.Dynamic relations between lake and climate change are revealed through analyzing the variations of typical lakes and climate change in each lake regions.The relationship between variations in area of lake and climate change in phase is analyzed in a regional scale.It is found that the lakes locating in the cold and the arid regions of China have highly sensitivity to the climate change.The lakes in the Inner Mongolia lake region are affected mainly by precipitation in view of climate.As a whole,precipitation has more noticeable impact on the lakes in the Xinjiang lake region.But Air temperature also has definite impact due to glaciers in the region.Precipitation and air temperature have the different effects on different lakes on the Tibetan Plateau.The relationship between lake and climate change is even more complicated in a regional scale.The lakes,as a whole,tend to shrink under the conditions of precipitation increasing and air temperature rising on the Tibetan Plateau.
  • WANG Yi-bo, WANG Gen-xu, CHENG Yu-fei, LI Yuan-shou
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2006, 28(5): 633-641. https://doi.org/10.7522/j.issn.1000-0240.2006.0092
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    The high-cold ecosystem on the Tibetan Plateau is very sensitive to the changes of global climate.The hinterland of the Tibetan Plateau,i.e.,the source regions of the Yellow River and the Yangtze River,is selected as the target region.Using the data frequently collected from remote sensing technologies and the investigation data of ecosystem belts,it is systematically analyzed that the response features of the typical high-cold frozen earth on the Tibetan Plateau(e.g.cold arid earth of calcium sedimentary,simply cultivated cold arid earth,frozen embryonic earth of grassland and simply cultivated earth)to the change of high-cold ecosystem by using the ecological comprehensive index(including physical index: the soil structure,components and hydraulic features;chemical features of soil and the content of nutrient).The result shows that the main high-cold ecosystem(high-cold meadow,high-cold steppe and high-cold marsh grassland)is seriously degrading with climate change.The topsoil of high-cold earth is evidently coarsely granulated,38.7% of the tiny-grain topsoil of grassland frozen embryonic earth and simply cultivated earth is lost,and the degree of small opening and the volume weight of the soil increases.The saturated hydraulic conductivity of the high-cold grassy marshland soil increases drastically with the decrease of comprehensive ecological index.The moisture gathering phenomenon on the topsoil of high-cold grassland does not exist any more when the vegetation coverage rate is below 50%,and the saturated hydraulic conductivity on the topsoil of high-cold grassland varies in a narrow range.The content of whole nitrogen and organic matter contained in the soil of high-cold meadow and high-cold steppe decreases like the form of parabola and exponential curve.With the future climate change and with the interference of human activities,the change of the ecosystem on the Tibetan Plateau will lead to continuous degradation of the high-cold frozen earth environment and produce a significant influence on the carbon cycle.
  • LU Zi-jian, WU Qing-bai, SHENG Yu, ZHANG Lu-xin
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2006, 28(5): 642-647. https://doi.org/10.7522/j.issn.1000-0240.2006.0093
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    By monitoring the heat and water process of the active layers for some sites(included sand-gravel site,removed vegetation site and meadow site beneath the original surface and the effect of engineering activity near Beiluhe,Tibetan Plateau,the effect of engineering activity on the characteristics of heat and water transfer and of freezing and thawing are compartively analyzed.It is concluded that the freezing and thawing process and the thickness of active layers change with the changes of ground characteristics,affecting the permafrost further.The change of heat and water process of the active layers at the engineering sites is intenser than that at the original surface site,and the permafrost stability of the engineering sites is lower than that at the original surface site.
  • YANG Jian-ping, DING Yong-jian, LIU Jun-feng
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2006, 28(5): 648-655. https://doi.org/10.7522/j.issn.1000-0240.2006.0094
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    The spatial distribution and inter-decadal variations of snow cover are analyzed with the use of snow data of 16 meteorological stations in the source regions of the Yangtze and Yellow Rivers and their periphery.The results show that there are a maximal center and a minimal center of the snow depth in the study regions.The maximal center of snow depth is between the headwaters of the Yellow River and the southeastern source regions of the Yangtze River around the main peak of Bayan Har Mountains.The minimal center of snow depth is between northeastern source regions of the Yangtze River and northwestern source regions of the Yellow River.Annual snow depth is mainly determined by snow depth from October to May of the following year(v period).The ratio of cumulative snow depth in the v period to annual cumulative snow depth is more than 71.0%.There is less contribution of snow depth from June to August to annual snow depth.But number of snow cover days from June to August is not negligible.It accounts for 1/3 of the annual number of snow cover days.The annual variation of snow is not fully consistent in different areas of the source regions of the Yangtze and Yellow Rivers.The snow falls mainly in January in the south of the line from Qumarl b to Darlag.Snow has two high value periods in the north of the line.One is the period from October to November.The other is March to May.Snow cover starts early,duration of snow is long,snow finishes lately and snow melting process are slow in the headwaters of the Yellow River and the source regions of the Yangtze River.However,snow cover starts lately,snow cover develops slowly and snow melting process is quick in the eastern source regions of the Yellow River.The snow cover in the study regions increases definitely over the past 40 years. Snow cover in the v period increases by 62.11% in the source regions of the Yangtze River and by 60.18% in the source regions of the Yellow River.However, there is marked difference in snow variation in the two source regions.The snow was less from the 1960s to the initial stage of the 1970s,rich from the middle stage of the 1970s to the 1990s in the whole source regions.The snow obviously increased from the middle stage of 1970s to the end of 1980s,and decreased in the 1990s.Snow cover in the v period increases by 60.95% in the whole source regions.Snow variation in the source regions of the Yangtze River dominates that in the whole source regions.
  • LIU Jing-shi, WEI Wen-shou, HUANG Yu-ying, SHANG Si-cheng
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2006, 28(5): 656-662. https://doi.org/10.7522/j.issn.1000-0240.2006.0095
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    Watersheds in the permafrost regions have been under the influence of climate change for centuries,especially in the last two decades when permafrost degradation was accelerated and intensified.This degradation was designed to speed up water transfer,to increase soil erosion,to improve agricultural productivity and ecological environment.It is important to evaluate the effects of these impacts to hydrology in order to develop a sustainable water resources management in cold regions.This study evaluated the changes in both winter air temperature and stream-flow regime for a selected drainage basin in high altitude following a large scale of permafrost degradation in the Tianshan Mountains,China.The non-parametric Mann-Kendall tests were used to identify the trends in both winter air temperature and stream-flow under confident levels at 99% and 95%,respectively.The results showed a significant upward trend.Pettitt’s test indicated that shift points of winter stream-flow and temperature occurred in 1985 and 1995,respectively.Comparison of winter flow duration for two 24-years periods starting and ending in 1980 showed significantly an upward trend in winter stream-flow.Increase in winter stream-flow varied from 14% to 26%,and in January it was 26%.It is found that there are reliable positive non-linear correlations in the increase of winter stream-flow between October and November.The increase of winter stream-flow in October and November resulted in the increase of winter stream-flow.Both rise of temperature and increase of discharge at the beginning of frost can greatly increase drainage of subsurface water in January,when the maximum variability occur The total increase in winter flow is increasing with time,with a significant change from the 1990s.However,there is an uncertainty about the winter stream-flow change due to short of observations of permafrost and snow cover in the Tianshan Mountains,China.
  • LIU Wei-gang, REN Jia-wen, QIN Xiang, LIU Jing-shi
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2006, 28(5): 663-667. https://doi.org/10.7522/j.issn.1000-0240.2006.0096
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    From April to October in 2005,hydrological observation of the Rongbuk catchment was carried out in Mt.Qomolangma(Mt.Evereast)region.The results are as follows: daily discharge in ablation period has a good correlation with temperature.The runoff from June to August is about 80% of the total runoff in the observation period.Comparing with the hydrological data in 1959,the runoff in the same months in 2005 was much more and the runoff in June,July and August increased by 69%,35% and 14%,respectively;the runoff depth was 622 mm and the runoff modulus was 38.52 L·s-1·km-2.The precipitation derived from the Rongbuk glacier ice core and the meteorological station in Tingri near Mt.Qomolangma has shown a decreasing trend since the 1950s while temperature has risen slowly.Temperature rising is a major factor causing the runoff increasing.
  • LIU Ya-ping, HOU Shu-gui, REN Jia-wen, WANG Ye-tang, GEN Zhi-xin
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2006, 28(5): 668-671. https://doi.org/10.7522/j.issn.1000-0240.2006.0097
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    Temperatures were measured at the ice-core borehole(4 518 m a.s.l.)in the Miaoergou flat-topped Glacier,East Tianshan Mountains,in August 2005.The length of Ice-core to the bedrock is 60 m.The primary temperature features of the Miaoergou flat-topped Glacier is revealed through the measurement.The temperature profile shows that there was a kind of warm-type ice temperature in the August and the ice temperature is always below 0℃.Ice temperature decreased linearly from -2.92℃ at 1m to-7.61℃ at 6 m deep in the surface layer,with a temperature gradient of -0.94℃·m-1.The effects of heat conduction and meltwater refreezing contribute to the above high temperature gradient.The lowest temperature of the deep layer was -8.27℃ appeared at the depth of 50 m,which is very low among those measured in the mountain glaciers in China.The contributions of meltwater and cold advection in the glacier influence greatly the location of the lowest temperature.A minimum temperature gradient(0.011℃·m-1)appeared from 50 m to bedrock in the profile and at the bedrock the temperature was -8.16℃,far below the melting point.From the temperature gradient near the bedrock,the geothermal flux can be inferred,which transfers heat to the bottom of glacier.It is believed that the effect of glacier movement is very small.
  • XIE Chang-wei, DING Yong-jian, LIU Shi-yin, LI Bing, ZHU Guo-cai
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2006, 28(5): 672-677. https://doi.org/10.7522/j.issn.1000-0240.2006.0098
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    Using radio echo sounder,ice thickness of the Keqikaer Glacier tongue was measured in 1981 and 2004,respectively.In this paper the changes of thickness and advance/retreat of Keqikaer Glacier is studied from comparing topographical maps, aerial photos and satellite images obtained at different time.Results indicated that the Keqikaer Glacier has retreated since the 1990s and become thinner since the 1980s.Thickness of the ice tongue has decreased with a speed of 0.5~1.5 m·a-1 since 1981.The shrinkage of the glacier terminus is less than 2% of the total length during the last 30 years.The retreat of terminus position and the thinning of ice thickness give significant information that glaciers on the south slopes of Tomur Peak are decreasing intensively in the recent time.
  • ZHANG Gou-sheng, SHI Xing-he, LI Dong-liang, WANG Qing-chun, DAI Sheng
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2006, 28(5): 678-685. https://doi.org/10.7522/j.issn.1000-0240.2006.0099
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    Using the data of temperature,precipitation,snow cover and so on from the Tuotuohe Meteorological Station at the headwaters of Yangtze River from 1959 to 2003,the annual and seasonal series of meteorological factors are worked out.The interannual and decadal climate changing features are analyzed preliminarily by using the climate diagnosis method.It is found that in the recent 40 years,summer air temperature increased obviously in the region.The annual maximum,minimum and seasonal mean air temperatures in the 1990s were 0.6~1.2℃ higher than that in the 1980s(or the 1960s).In the 1980s the air temperature was the lowest. Precipitation has an increasing trend in winter and a decreasing trend in summer.precipitation in spring and autumn increased but snow depth decreased.Strong wind days were more in the 1980s and the 1990s than that in the 1960s and the 1970s.In general,summer temperature increase,precipitation decrease,and strong wind days increase in the 1980s.This climate changes were strengthened in the 1990s,and expanded to spring and autumn,as a result,grassland deteriorating,permafrost thawing and glacier retreating quickly,wetland shrinking,and finally,eco-environment worsening.
  • DENG Zhao-ping, GUO Ni, WANG Jie-min, MA Jin-hui
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2006, 28(5): 686-693. https://doi.org/10.7522/j.issn.1000-0240.2006.0100
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    The vegetation cover annual and inter-annual variations were analyzed in the typical vegetation regions,including forest,grassland,oasis,rain-fed cropland and desert in Northwest China,using the GIMMS(Global Inventory Modeling and Mapping Studies)NDVI data set,which was collected at a spatial resolution of 8 km and 15 days interval,for the period from January 1982 to December 2003.At the same time,the vegetation cover dynamics in whole region was studied.The results show that the NDVI average annual curves had a single peak in these regions,such as forest,grassland,irrigating oases and rain-fed cropland where be planted spring wheat mainly.The curves have double peaks in those regions,where usually is planted winter wheat.For same type vegetation,the time when the NDVI peaks occurs delay one month according to different altitude and latitude.The NDVI variation trends of forest were decreased;the tread of grassland were increased;rain-fed cropland maintained flat and the irrigating oases had remarkable rising trends.The frequency and extent of NDVI variation was highest in rain-fed cropland region,where is the most sensitive areas influenced by precipitation;forest taken second place and the irrigating oases were lowest.The characteristic of NDVI in the whole area was increasing during the past 22 years.The increased areas accounted for 20.5% of Northwest China,where distribute mainly in oases Xinjiang and Hexi corridor,irrigating regions along the Yellow River and grassland regions in Qinghai Province.The increase of NDVI is the most notable in oasis.The decreased regions accounted for 4.8%,where primarily distributed in the eastern part of Northwest China.
  • DENG Ming-jiang
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2006, 28(5): 694-702. https://doi.org/10.7522/j.issn.1000-0240.2006.0101
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    As air temperature rising and precipitation increasing in Tarim River Basin since the middle of 1990s,Aksu River,Yarkent River,Kaidui River and Hotan River,which the four tributary river systems contribute flows to the Tarim River,turn simultaneously into high water(wet-year or abundance of water)period,and providing an unusual and historical opportunity for ecosystem restoration of mainstream of Tarim River.The recently unusual climate changes in Tarim basin and Xinjiang region attract extensive attention worldwide in science and public circles.The arguments for a climatic shift to warm-humid under global warming and intensive water cycle,or change in hydrological cycle period,are becoming a discussion hotspot about the cause of the phenomena.Based on the data of temperature,precipitation and runoff of hydrological and meteorological stations in mountain areas of source rivers during last 50 years,author analysis the change of discharge of Tarim River,and evaluated emergent water transfer for ecosystem restore in the lower reaches of the Tarim River.
  • WU Su-fen, LUI Zhi-hui, HAN Ping, ZHU Zhi-chao
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2006, 28(5): 703-706. https://doi.org/10.7522/j.issn.1000-0240.2006.0102
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    Based on the analysis of meteorological and hydrological data of the Ürümqi River basin,climate change in the past 40 years was analyzed,together with a correlation analysis of climate parameter,glacier meltwater and precipitation runoff.In the alpine glacier regions,the increase of temperature has major effect on the variation of glacier-melt runoff.With a 0.5℃ temperature increasing,the meltwater runoff increases 3.3514×106 m3.If the temperature increases 0.5℃ in the near future,meltwater runoff will reach about 35×106m3.At the same time,precipitation has an effect on runoff of medium-high mountain regions.When precipitation increases 20 mm,rain runoff will increase 8.9 106 m3.Variation of runoff due to precipitation change shows an ascending tendency,with an annual increment of 0.4095×106 m3,equivalent to an increment of glacier meltwater.But,as compared to the increased percentage of runoff from glacier meltwater,the increase amplitude is smaller.Facing the impact of climate change on water resources,measures,such as reducing pollution and increasing vegetation coverage,are suggested.
  • LIU De-xiang, BAI Hu-zhi, NING Hui-fang, GUO Jun-qin, DONG An-xiang
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2006, 28(5): 707-712. https://doi.org/10.7522/j.issn.1000-0240.2006.0103
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    Based on the data of 60 meteorological stations including precipitation,average temperature,average minimum and maximum temperatures in March October,and materials of drought-affected area and grain decrease in Gansu Province from 1971 to 2000,the response of arid meteorological disaster to climate change is analyzed by using statistical methods.The results indicate that the drought-affected area and the grain decrease caused by drought have significant negative correlation with precipitation,and positive correlation with average temperature,average minimum and maximum temperature.Because of climate warming,a continuous rise in temperature,and a decrease in precipitation,the extreme drought climate events took place frequently,and the climate became warmer and dryer more rapidly in Hedong in Gansu Province.All of these are important factors that enlarged the drought-affected area and resulted in a considerable decrease in grain production.This material may be used directly in monitoring,forecast and evaluation of the arid meteorological disaster,and also have certain reference significance for executing the project of "The Response to the Climatic Change".
  • PENG Jian-feng, GOU Xiao-hua, CHEN Fa-hu, LIU Pu-xing, ZHANG Yong-xiang, ZHANG Yong, TIAN Qin-hua
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2006, 28(5): 713-721. https://doi.org/10.7522/j.issn.1000-0240.2006.0104
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    Tree-ring cores were taken from four sites at different elevations of the same slope on the Anyêaqê Mountains,where the environment is sensitive and the relative height is large.Four tree-ring width chronologies Sabina przewalskii Kom were determined using standard dendrochronological methods.The more signal-to-noise ratio(SNR)and agreement with population chronology(ESP),the stronger common environment information of tree in different sampling sites held.These values decreasing with increasing elevation reflects that micro-environment had great influence on tree-growth at high elevation.However,mean sensitivity(M.S.)and standard deviation(S.D.)show a decrease from the low limit to middle-high elevation,with an increase above the middle-high elevation.The first principal component accounting for 61.495%of the variance in all chronologies shows that the mainly dominant factor is consistent in the whole slope. Also correlation and response analyses between PC1 and climatic factors reveal that climatic factor is the most importance to tree-growth in the whole slope,especially temperature.The mean sequence of dependable tree-ring width standard chronology among sampling sites decreased with increasing altitude,and trees appeared during warm weather.These indicate that appearance and up-growth of tree gradually move up along the slope with the coming of warmth phase.High correlation between tree ring-width dependable chronologies at different elevations of these sampling sites shows that the high-frequency changes among tree ring chronologies are consistent,but there is some diversity in the low-frequency changes of tree ring chronology.The lag-correlation analysis and correlation analysis after low-pass filter of dependable standard chronologies between upper-limit and low-limit suggest that the tree growing at the upper-limit lags behind that at the low-limit in response to environment factors.The amplitude of vibration of tree-ring width indices changing with elevation shows that tree growing in the maximal height of precipitation has the minimal sensitivity in response to environment factors.
  • ZHANG Jie, ZHANG Qiang, TIAN Wen-shou, HE Jin-mei
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2006, 28(5): 722-727. https://doi.org/10.7522/j.issn.1000-0240.2006.0105
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    By using MODIS data from Terra and Aqua satellite,6 hours precipitation data of 18 cases from 2002 to 2005,applying 6S Model and Mie Model,some parameters,including optical thickness of cloud,efficient radius of cloud particle and content of liquid water,are retrieved.Their special distributions are also analyzed by combining with GIS software.Then,the relation of all those parameters and 6 hours precipitation are analyzed.The results show that there is a striking dissimilarity in special distribution of the optics thickness and efficient radius of cloud particle,which is influenced by terrain,with a maximum on the south slopes lower than 4 300 m of the mountains,a region with rich resources of cloud water.There are positive correlation between precipitation and the three parameters.Precipitation probability is large when optical thickness changes from 8 to 20,efficient radius of cloud particle changes from 6 to 12 μm and content of liquid water is more than 0.04 g·m-3.Content of liquid water higher than 0.15 g·m-3 at 4 300 m a.s.l.shows that there is a large potential to exploit cloud water in the Qilian Mountains.
  • JIANG Xi
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2006, 28(5): 728-738. https://doi.org/10.7522/j.issn.1000-0240.2006.0106
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    The snow and ice albedo plays a key role in the energy balance between the earth and atmosphere.Its variation depends up two aspects,i.e.the reflecting properties of snow/ice and the sky conditions.So,many factors affect the snow and ice albedo,such as physical properties of snow and ice,including grain size,density,water content,impurity and so on.Again,cloud affects the albedo,because it changes the incoming solar radiation and its spectral distribution.In view of the changes in reflecting properties of snow/ice and the sky conditions,the albedo of snow and ice exhibits its diurnal,seasonal and spatial variations.The progress of numerical model and satellite remote sensing in snow/ice albedo are also reviewed in this article,especially focused on the Bidirectional Reflectance Distribution Function(BRDF)and the imperfection of albedo inversion in remote sensing.
  • WANG Jian, QI Yuan, CHEN Zheng-hua, MA Ming-guo, LI Jing, HUANG Chun-lin
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2006, 28(5): 739-747. https://doi.org/10.7522/j.issn.1000-0240.2006.0107
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    Ecosystem services are the material base and the headspring of whole resources and environment for human survivorship.In this paper,a dynamic assessing model about ecosystem services and function value is put forwards,based on the knowledge of multidisciplinary.The key points focus on discussing the principal factors,which adjust the function of remote sensing technique in the model,and setting up the frame of dynamic assessing model on ecosystem services and function value.A dynamic monitoring model,which takes the ratio of biomass and index of currency change as adjusting factors,is established.After pre-processing,the input parameters include 10-day maximum composite NDVI,precipitation,temperature,total solar radiation,soil parameters based on Co-Kriging Interpolation. The processing model CASA(Carnegie-Ames-Stanford Approach)has been used to simulate APAR,FPAR,humidity of soil,latent evapotranspiration,and then calculate annual NPP in Gansu province,and then the results are validated by using observation data and other relative outcomes.Afterward,using the dynamic model, the grassland ecosystem services and function value of 1999 and 2002 in Gansu province are assessed,with the input parameters of NPP and the factor of dynamic adjusting currency,respectively.The results show the grassland ecosystem services and function value in Gansu province was 28.36 billion RMB Yuan in 1985,140.37 billion RMB Yuan in 1999 and 130.86 billion RMB Yuan in 2002,with an increasing trend after 1985.However,the ecosystem services and function value have regional characteristics and change with time.At present,ecosystem services and function value assessment research have many uncertain factors,therefore;further accelerating quantitative research and searching solid and validating technique will be an important subject in ecology and other interrelated fields.
  • JIAO Wen-xian, XU Zhong-min, SHANG Hai-yang, CHENG Huai-wen
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2006, 28(5): 748-754. https://doi.org/10.7522/j.issn.1000-0240.2006.0108
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    Analysis of environment impact of human activities has become a hot topic in the current time.On the basis of introducing the ImPACT identity,combined with a case study of virtual water consumption in Gansu province during 1990-2003,the utility of the ImPACT identity in environment impact assessment is explored.It is found that,compared with the period of 1990-1995,in 1996-2000 and 2001-2003 income of Gansu province increases dramatically,and use intensity and efficiency improve greatly,which adjust the virtual water consumption.Income elasticity analysis shows that when income increases 1%,the amount of agricultural production consumption per capital will increase 0.13%,while use intensity will decrease 0.87% and environment impact will increase 0.14%.Comparison analysis shows that,in 2000,the virtual water intensity of rural area(0.706 m3·Yuan-1)is dramatically higher than that of urban(0.051 m3·Yuan-1).Adjusting the consumption structure in a proper way will do good to reduce environment impact.Setting up an environment objective and examining the responsibility of driving forces shows that higher objective requires higher improvement for both producer and consumer.As the environment objective of achieving 50% of the amount of virtual water consumption in 2003,with the use intensity decrease by 1.5 times and efficiency improve one time based on the "actual situation" of the period 1990-2003,it is possible to achieve the objective in a reasonable period(28 years)meanwhile with a more rapid economic development.In conclusion,ImPACT identity can be used to analyze the effect of driving forces on environment impact quantificationally and it is significant for seeking sustainable policies.
  • LAI Yuan-ming, ZHANG Ming-yi, YU Wen-bing, LI Shuang-yang
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2006, 28(5): 755-759. https://doi.org/10.7522/j.issn.1000-0240.2006.0109
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    A series of Laboratory studies were carried out on the cooling effects of closed crushed rock layers,whose thickness was 1.3m and average particle sizes were 8.3,14.8,22.1 and 27.1 cm,respectively.The experimental results indicate that,when the temperature fluctuates periodically,the crushed-rock layers with different particle sizes all have a certain cooling effect;however,the cooling effect of the crushed rock mass of the mean particle size of 22.1 cm is the best among them.From synthetical analyses,it is found that the optimized particle size range with better cooling effect of the closed crushed-rock layer is 20~30 cm under the experimental condition in this paper.The research shows that under the global warming and engineering construction conditions,even if the mean temperature at the surface of an embankment is above 0℃,the underlying permafrost can be protected effectively as long as the “thermal diode” effect of the crushed-rock layer is utilized efficiently.
  • WEN Zhi, SHENG Yu, MA Wei, LIU Yong-zhi
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2006, 28(5): 760-765. https://doi.org/10.7522/j.issn.1000-0240.2006.0110
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    In order to protect permafrost from further thaw due to human activities,thermal insulation treatment might be the first choice for embankment design in permafrost regions.In 1992,a testing embankment with insulation was built at the Kunlun Mountains in the Qinghai-Tibetan Highway.An insulated section and an uninsulated section for comparison were built and instrumented in 1995,to monitor the effect of insulation.Ground temperature observations in the recent 8 years show that the insulation in embankment works normally and it may decrease the annual range of ground temperature greatly.It is found that there is hardly any change of the thermal conductivity of EPS for the 12 years after the embankment construction,which means that environmental factors,such as vehicle loading,moisture content,and freezing-thawing action etc.have less effect on the insulation.In addition,the mean temperature rising rate of the permafrost underlying the embankment with insulation is smaller than that of permafrost underlying embankment without insulation in the seven years.Heat budget calculation shows that the heat exchange value may decline enormously due to the using of insulation in embankment.Moreover,insulation may decrease three-quarter heat entering into the embankment as compared with familiar embankment.Based on a finite element analysis,where is suited to use insulation method along the Qinghai-Tibetan Highway and how to use it are suggested.
  • WANG Ren-he, WANG Wei, CHENG Yong-feng
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2006, 28(5): 766-771. https://doi.org/10.7522/j.issn.1000-0240.2006.0111
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    Aimed at the pile foundation in frozen soil of a high voltage transmission line project in Xinjiang Region,a laboratory tensile model test is carried out under artificial frozen condition.The characteristics of load-bearing capacity of a single pile and its mechanical behaviors under a vertical tensile load in frozen soil with various temperatures were revealed from the test.The pile’s axis force,adfreezing force between pile and soil and its distribution in frozen soil, as well as the relationship between vertical displacement of pile and load,were analyzed.Function formulas were given out to describe the effect of temperature on adfreezing force and bearing capacity.The results were compared with that of a pile in compressive condition.Through the research,adfreezing force of a pile and the relationship between tensile bearing capacity and temperature in tensile condition were gained.It is useful for pile foundation designing and constructing in western frozen areas.
  • DENG You-sheng, HE Ping, ZHOU Cheng-lin, LI Yi-chi, FANG Jian-hong, HUANG Shi-jing, ZHANG Qinghua
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2006, 28(5): 772-775. https://doi.org/10.7522/j.issn.1000-0240.2006.0112
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    The permeability of saline soils is studied in laboratory.Experiments show that for the same dry density,permeability decreases with the saline content;for the same soil,with increase in saline content,permeability of soils with sodium sulphate decreases more significantly than that with sodium chloride.When soils have the same dry density and the same salt,permeability of fine grained saline soils decreases more remarkably than that of the coarse grained saline soils. If the salt content is constant,for the same soil,the permeability decreases with increase in dry density in a linear relationship within a certain range of dry density;when the dry density is beyond this range,permeability and the dry density are related with a power function.
  • CHEN Xiao-qing, CUI Peng, YANG Zhong, QI Yong-qing
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2006, 28(5): 776-781. https://doi.org/10.7522/j.issn.1000-0240.2006.0113
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    Two large-scale debris flows burst out in Chongdui Gully of Nyalam County on May 23 and June 29,2002,causing tremendous disasters to the hydropower station,the China-Nepal highway,communication establishment,and farming and stockbreeding,and resulting economic loss of above 7.5 million Yuan.Investigation to the upstream of the gully and analysis of the climate data demonstrate that these two debris flows were caused by glacial meltwater and moraine-dammed lake outburst.The contribution of the glacial meltwater accounted for about 74%,and that of moraine-dammed lake outburst accounted for only 26% of the maximum discharge.In order to control debris flows,many countermeasures have been present,including civil and plant measures,as well as efficient management.
  • WANG Jun, YI Ming-kun, FU Hui, YIN Yun-ji, GAO Yue-xia
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2006, 28(5): 782-786. https://doi.org/10.7522/j.issn.1000-0240.2006.0114
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    Severe flooding or ice-related damage can result from a rise in stage associated with ice jams in cold regions.It is important to predict the stage or the evolution of an ice jam in a river for disaster mitigation.Prediction of ice-related phenomena is correlative with ice jam location,rise in upstream water level and the information of breakup ice jam.There are empirical models,threshold models,statistical models,regression models,logistic regression,discriminant function analysis and artificial intelligence.Recently,the research focus on the possibilities of occurrence of ice jams in a straight channel.Based on experiment data,the variety of stage in a curved channel in upstream is analyzed in this paper.In addition,water levels in the upstream and at many cross sections in a bend channel are studied with artificial neural network.The results show that the artificial neural network method is more precise than the regression models.
  • LI Rui, GUO Jian-wen, YAN Bao-jie, LIU Guang-xiu
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2006, 28(5): 787-794. https://doi.org/10.7522/j.issn.1000-0240.2006.0115
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    Construction of freeway will promote the development of local economy,however it will impact on the vegetation,animal,geology,hydrology and water resource,Land-use pattern,air quality,human activity,and so on.Freeway project has the properties of long distance,multiple points as well as broad surface,and it’s probable of affecting intensively on environment from various aspects throughout the period from constructing to making use of it.The environmental carrier of freeway in mountainous area is mainly natural environment, that is,geological environment.Among mountainous areas,the landform and geological condition is complicated,geological environment is vulnerable,geological disaster is frequent,considering of which,constructing expressway is inevitably to cut and fill carverns as well as building tunnel,those measures destroy geological environment seriously,result in or intensify various geological disasters,increase the unnecessary constructing investment,even bring about hidden trouble of safety during period of constructing and operating.To meet the need of constructing a high standard expressway among mountainous area while considering much factors such as traffic,environment protecting and ecology,we must attach importance to geological environment.As auxiliary tools,the 3S(GIS,RS,GPS)and virtual geographic environment technologies are very helpful to support resolving the actual problems.What we are doing in this research relies on an actual traffic project,a section from Niubei to Tianshui of the expressway from Baoji to Tianshui,which aims to design and make road virtual geographic environment coming true with the help of 3S technologies.
  • JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2006, 28(5): 795-796. https://doi.org/10.7522/j.issn.1000-0240.2006.0116
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