25 December 2016, Volume 38 Issue 6
    

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  • YE Wanhua, WANG Feiteng, LI Zhongqin, ZHANG Hui, XU Chunhai, HUAI Baojuan
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2016, 38(6): 1459-1469. https://doi.org/10.7522/j.issn.1000-0240.2016.0171
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    In this paper, the temporal and spatial distributions of the equilibrium line altitudes (ELAs) of glaciers in High Asia are studied based on the data of glaciers monitoring. The study shows that: 1) spatially, the ELAs of the monitoring glaciers in High Asia follow the latitudinal zonation, longitudinal zonation and regional zonation. 2) temporally, the ELAs of the monitoring glaciers in High Asia have increased to variously extent. During 1960-2013, the ELAs of Ürümqi Glacier No.1 and Ts.Tuyuksuyskiy Glacier in the Tianshan Mountains had risen about 116 m and 80 m, respectively. Compared with the Ürümqi Glacier No.1, Ts.Tuyuksuyskiy Glacier was more sensitive to climate change. During 1983-2007, the variations of the ELAs of the No.125 (Vodopadnity), the Maily Aktru and the Leviy Aktru Glaciers were similar, as a whole, they were risen. Among them, the ELA of the Maily Aktru Glacier had risen about 142 m, ranking at the first. During 1962-2008, the ELAs of the monitoring glaciers in High Asia had risen as a whole, among them, the ELA of the Qiyi Glacier had risen about 264 m, being the fastest and the most one, while that of the Ürümqi Glacier No.1 had risen about 47 m, being the slowest and least one.

  • LI Ruolin, BAO Hongyan, LI Kechen, WANG Chenghai
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2016, 38(6): 1470-1481. https://doi.org/10.7522/j.issn.1000-0240.2016.0172
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    The relationship between soil moisture and precipitation and air temperature was analyzed using the monthly precipitation data of GPCC, temperature data of GHCN_CAMS, monthly mean soil moisture data of GLDAS-NOAH and 3-hourly precipitation and soil moisture of GLDAS-NOAH and observational data for the period from 1948 to 2010. The results show that the temporal scale of global soil moisture memory varies from 20 days to 110 days. In the arid areas, the shallow soil moisture memory (0~10 cm) is shorter than the middle and deep soil moisture memory (10~200 cm); the soil moisture memories in humid and high mountain areas are longer than that in arid areas. The soil moisture memory in the Northern Hemisphere is the longest in spring and that in the Southern Hemisphere is the longest in summer. Precipitation and temperature have different effects on soil moisture in different regions within the same period. The summer and autumn precipitations in the Northern Hemisphere are the main sources of soil moisture, and in mid-low latitudes and Southern Hemisphere, except for the African arid regions, soil moisture increases with precipitation and decrease with temperature. The shallow soil moisture is significantly affected by precipitation and temperature in the same period. The effects of precipitation and temperature in the previous period on soil moisture have spatial difference. The summer and autumn precipitations in the mid-high latitudes of the Northern Hemisphere are the main sources of soil moisture in the spring of next year, and the middle layer soil (10~100 cm) is the main water reservoir layer. The shallow soil is greatly affected by the external environment, of which the ability of saving climatic information is limited. In mid-low latitudes and the Southern Hemisphere, the middle and deep soils mainly save the information of temperature and precipitation in the previous season, with insignificant information of those more than one season. The increase of spring soil moisture in low latitudes may be beneficial to the subsequent precipitation, and the increase of spring soil moisture in the high latitudes may reduce the subsequent precipitation. The effect of the middle soil moisture on the subsequent precipitation is significant in seasonal scale, and the influence of the shallow soil moisture on the subsequent precipitation is more important in daily-to-monthly scale. The increase of spring soil moisture, especially in the middle part, of the arid areas may be beneficial to the decrease of summer temperature.

  • GU Lianglei, YAO Jimin, HU Zeyong, ZHAO Lin
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2016, 38(6): 1482-1490. https://doi.org/10.7522/j.issn.1000-0240.2016.0173
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    Based on the meteorological observation in Naqu BJ site located in a seasonal frozen ground region and Tanggula site in a permafrost region in 2008, the characteristics of microclimate at Naqu BJ site and Tanggula site are analyzed. The results show that the maximum frozen depth in Naqu BJ site is about 1.5 m and the maximum thawed depth of the active layer in Tanggula site is beyond 3.0 m. The seasonal variations of the air temperature, specific humidity, precipitation and snow cover are obvious. Specific humidity and precipitation are concentrated in the period from May through October. Most of the snow cover are appeared in the period from January to March and from October to December. The monthly average ground temperature, air temperature and specific humidity, instantaneous maximum values of specific humidity and wind velocity, monthly range of air temperature in the Naqu BJ site are all greater than those in the Tanggula site. The annual average values of wind velocity, air temperature and specific humidity in the two sites are 4.73 m·s-1, -1.34 ℃, 3.96 g·kg-1 and 4.02 m·s-1, -5.80 ℃, 3.25 g·kg-1 , respectively. The annual precipitation and number of snow cover days of the two sites are 590.50 mm, 114 days and 405.27 mm, 135 days, respectively; the precipitation from May to October of the two sites are 96.20% and 86.55% of the annual precipitation, respectively. The air temperatures of the two sites sudden drop in early February and early November owing to heavy snowfall; the largest daily maximum snow depths of the two sites are in November; the daily maximum snow depth in the Tanggula site is greater than that in the Naqu BJ site. On a typical sunny day, in Naqu BJ site the diurnal variation of wind velocity is distinct in winter and in Tanggula site that is distinct in spring and winter; the daily variation of specific humidity is distinct in summer and autumn rather than in spring and winter in the two sites.

  • LI Yuting, LIU Jinbao, WANG Zengwu, Basang, XIAO Yao
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2016, 38(6): 1491-1500. https://doi.org/10.7522/j.issn.1000-0240.2016.0174
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    Snow is an important part of the Earth's surface with high reflectivity and low thermal conductivity which can affect earth's energy and radiation balance. By using the methods of remote sensing and GIS, a wide range of snow cover information is obtained. The spatial distribution characteristics and variation of snow cover are revealed, which can be provided to relevant departments of disaster prevention and mitigation. Based on the MOD10A2 data and records from 48 meteorological observatories of temperature, precipitation, humidity, air pressure and sunshine time from 2003 to 2012 in Sichuan Province, the spatial and temporal variation characteristics of snow cover and their relation with the climate factors in the province in recent 10 years were analyzed. The analysis results show that the spatial distribution of snow cover in the province is high snow cover rate in the western plateau, less snow cover in the Chengdu plain and even no snow cover in eastern basin. From 2003 through 2012, snow cover area had showed a small fluctuation with a peak in 2008. As a whole, snow cover area has a little shrinking tendency; it is found that snow cover rate has significant relation with temperature and precipitation and insignificant relation with air pressure and sunshine time. It is demonstrated that snow cover change in the province is mainly controlled by temperature rather than by precipitation; the higher the temperature and the more the precipitation, the less the snow cover area.

  • LIU Huolin, HU Zeyong, CHENG Si, CHEN Lin
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2016, 38(6): 1501-1509. https://doi.org/10.7522/j.issn.1000-0240.2016.0175
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    The land surface processes over the central Tibetan Plateau were simulated by the Common Land Model and the Noah Land Surface Model, based on the observed meteorological data at Nagqu Station of Plateau Climate and Environment in the Tibetan Plateau of CAS from October 1, 2012 to October 1, 2013. The results showed that both models can capture the characteristics of radiation flux. Simulation of upward long-wave radiation is most successful, followed by that of net radiation, and the worst one is that of upward shortwave radiation. Both models performed well on soil temperature, especially on the temperature of shallow soil and in summer. Soil freezing and melting all start from the surface and spread downwards. Temporally, the simulated freeze-thaw process by the CoLM Model is closer to the observed one. For simulating the soil moisture, both models are able to predict the changing tendency with a relatively large bias.

  • ZHAO Wenyu, LIU Hailong, WANG Hui, HU Weijie
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2016, 38(6): 1510-1517. https://doi.org/10.7522/j.issn.1000-0240.2016.0176
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    Snow cover is one of the sensitive factors to climate change in arid area. There is a close relationship between snow cover days and snow cover area. In order to analyze the spatial distribution of snow cover days, eight-day synthetic data of MODIS from Terra (MOD10A2) and Aqua (MYD10A2) were used. Firstly, the snow cover days (500 m×500 m) in Tianshan Mountains were obtained through removing the effect of cloud based on combined snow cover products of MODIS. Then, based on annual snow cover days and DEM data, the spatial and temporal variabilities of snow cover days with elevation and aspect from 2002 through 2014 were analyzed. The results show that the distribution of snow cover days had been extremely uneven. The maximum annual mean snow cover days were 193 days. The snow cover days in 83.92% area of the Tianshan Mountains had changed little during the 13 years. About 48% snow cover days was no more than 30 days. The snow cover days had increased with elevation, with a large spatial difference. More snow cover days (>30 d) were gathered in the north, northeast, east, west and northwest aspects. This study will be useful for estimating water resources in arid areas.

  • YANG Cheng, YAO Jimin, ZHAO Lin, QIAO Yongping, SHI Jianzong
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2016, 38(6): 1518-1528. https://doi.org/10.7522/j.issn.1000-0240.2016.0177
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    Based on the data of four AWSs (automatic weather station) located in permafrost region of northern Tibetan Plateau including AYKMS, ZNHMS, TGLMS and XDTMS and MOD02 data of study area (88°-95° E, 32°-38° N) in 2013, the characteristics of diurnal variation and seasonal variation of surface albedo at these AWSs and spatial distribution of surface albedo of the study area in summer and winter are analyzed. It is found that the values decreased in the following order: winter, spring, autumn and summer. The number of the peaks of surface albedo in winter, spring and autumn was more than that in summer. When solar altitude angle was greater than 40, surface albedo basically remain unchanged. The values of surface albedo in ground freezing and thawing process ranked as frozen completely stage > diurnal freeze-thaw cycle stage > thawed completely stage, and during the diurnal freeze-thaw cycles, surface albedo decreased significantly in the middle period of every day. The values of surface albedo was majority between 0.1 to 0.3 in both summer and winter. In winter, the area where surface albedo was greater than 0.3 was significantly greater than that in summer. Surface albedo reduced from AYKMS to TGLMS in the study area in summer.

  • FENG Yingying, LI Zhuolun
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2016, 38(6): 1529-1537. https://doi.org/10.7522/j.issn.1000-0240.2016.0178
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    The negative accumulated temperature is an index of cold degree in winter. Theoretically, its change associates with permafrost development. In this paper, empirical orthogonal function, wavelet transform, as well as cluster analysis, are used to analyze the negative accumulated temperature in Northeast China, aiming to explore the spatial and temporal variations of negative accumulated temperature, to acquire its relation with permafrost degeneration and annual mean temperature change. The results showed that from 1957 to 2007, the negative accumulated temperature in Northeast China, which was calculated from 81 meteorological observation stations, had increased. The increase rate during the 51 years had decreased progressively from northeast to southwest of the study area. From 1957 through 2007, the study area can be divided into three periods according to the negative accumulated temperature, i.e., cold, warm and cold periods. In the Da Hinggan Mountains and the northern Xiao Hinggan Mountains, The warm periods were shorter, with large annual and interannual amplitudes of vibration. Except in north of Heilongjiang Province and east of Inner Mongolia Autonomous Region, the lowest, highest and mutation years of negative accumulated temperature were the same, which indicated the regional synchronization of accumulated temperature change. The increase of negative accumulated temperature was in accordance with permafrost degradation and the increase in annual mean temperature.

  • CAI Peng, LI Fang, WANG Zhengquan, ZHAO Xian
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2016, 38(6): 1538-1543. https://doi.org/10.7522/j.issn.1000-0240.2016.0179
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    Ground temperature directly affects the growth of crops. Under the background of climate warming, the research on the change of temperature in the shallow ground has an important significance for guiding agricultural production. Based on the air temperature and 0~20-cm ground temperature datasets in Jining National Weather Station during 1961-2015, using climate inclination rate, accumulative anomaly, signal to noise, Monte Carlo test and other statistical methods, their annual and seasonal changes and abrupt changes are analyzed. The results show that both the annual and seasonal averages of air temperature and ground temperature display significant warming trend, with a rate of 0.18~0.58℃·(10a)-1. The amplitude of ground temperature warming is less than that of air temperature. The maximum increase in ground temperature appears in spring, and that in air temperature appears in winter. Between annual average ground temperature and air temperature there is significant positive correlation, with a correlation coefficient of 0.87 or more. The maximum correlation coefficient (in spring) is between 20-cm ground temperature and air temperature (0.93); the minimum (in winter) one is between 5-cm ground temperature and air temperature (0.87); Changes in extreme values of air temperature and surface temperature are highly significantly correlated, with the maximum correlation coefficient between their average minimum values. The annual average temperature and 15-cm, 20-cm average ground temperatures changed abruptly in 1986, 0-cm average ground temperature changed abruptly in 1993, with a cold period before shift and a warm period after shift. Since the late 1980s, the variations of air temperature and 20-cm ground temperature have been closest. There were good consistencies in the anomalous year of air temperature and 0-cm ground temperature among the four seasons; the air and ground temperatures in spring, summer and autumn were anomalously high in 2014, 2013 and 1998. The impact of the air temperature anomaly on anomalous ground temperature is smallest in winter.

  • HE Ze, HE Yuanqing, ZHANG Zhigang, HE Lihua, QI Cuishan, LIU Jing
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2016, 38(6): 1544-1552. https://doi.org/10.7522/j.issn.1000-0240.2016.0180
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    The Mt. Yulong is situated in the southeast of the Tibetan Plateau, where the well preserved glacial remnants (including the lowest latitude moraines in the northern hemisphere) provide a natural laboratory to study the Quaternary glacial and the past global climate evolution process. Getting more details about these glacial remnants is important for deeply understanding the regional change of paleo-climate and paleo-environment, as well as the development and utilization of the glacial tills. However, because of shortage of dating records and controversy of climate background, there are no consensus about how many times of glacier advance during the Quaternary. In this paper, OSL dating techniques was used on the glacial sediments at Mt. Yulong. OSL dating data and evidences from geomorphology and stratigraphy reveal that glaciers had advanced during local last glacial maximum (~25 ka) at east side and mid-MIS 3b (~50 ka) at west side of the Mt. Yulong. The Penultimate Glaciation had appeared at ~240 ka in late Middle Pleistocene, corresponding to MIS 8. At that time, there were multiple composite valley glaciers at Mt. Yulong.

  • WANG Rongmei, Ayxamgvl, YU Lan, Abdukirem, LI Fengjing
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2016, 38(6): 1553-1559. https://doi.org/10.7522/j.issn.1000-0240.2016.0181
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    In this paper, based on the sandstorm data from 11 weather observation stations in Kashgar Prefecture from 1961 through 2010, using statistical method, method of Menn-Kendell trend test and Surfer Software, the spatial and temporal distribution, change trend and abrupt change of sandstorm in Kashgar Prefecture were analyzed. The result shows that there is a high incidence area (14.5 days per year) in Yecheng County in the south of the prefecture. The annual sandstorm days seem in decreasing. The decreasing rate is 2.3 d·(10a)-1 in Kashgar urban area, 2.7 d·(10a)-1 in Yopurga County, 5.0 d·(10a)-1 in Yingjisha County, 3.9 d·(10a)-1 in Marabishi County, 4.2 d·(10a)-1 in Makit County, 4.7 d·(10a)-1 in Yecheng County, 3.5 d·(10a)-1 in Yarkant County, 1.7 d·(10a)-1 in Poskam County, 1.8 d·(10a)-1 in Payzawat County and 0.3 d·(10a)-1 in Taxkargan County. The sandstorm days have large difference from year to year. The sandstorm had taken place more frequently in the 1960s and the 1970s, but had decreased in the 1990s. Sandstorm days mainly appear in spring and summer and appear less in fall and winter. Most sandstorm appear within the time from April to July, accounting for 79.2% of the total days. In November, December and January the sandstorm less occur, when only 2.54% of the annual sandstorm days present. In the 1980s, sandstorm in the prefecture had abruptly decreased. In order to reduce the harm of sandstorm, it is necessary to strengthen environmental protection, to control population growth, to reduce environmental pressure and to increase surface vegetation cover, to strengthen management of water and soil resources, to establish and improve the dynamic monitoring and early warning systems, to better study the preventing and reducing natural disasters.

  • ZHOU Xiaoli, Jiala, XIAO Tiangui
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2016, 38(6): 1560-1567. https://doi.org/10.7522/j.issn.1000-0240.2016.0182
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    This paper established a grade evaluation method for snow disasters based on Euclidean distance function. This method is used to evaluate the grades of 370 snow disasters which are selected from 39 stations in Tibet during 1979 to 2013. Research results show most of the snow disasters are the first grade and the second grade snow disasters, the third and the fourth grade snow disasters are relatively rare. Most snow disasters occurred in spring, the number of snow disasters in winter is less than that in spring and snow disasters occurred only 9 times in summer. The third grade snow disaster frequency gradually decreased during 1979 to 2013. Before the 1990s the third grade snow disasters occurred in winter in most cases, but since then they generally appeared in spring. The fourth grade snow disasters most occurred in the 1990s and could persist a long time, and most of them occurred in winter during 1990s. Since the 21st century the fourth grade snow disasters decreased and the frequency occurring in winter is approximately equal to that occurring in autumn.

  • CHEN Junhao, LI Dongwei
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2016, 38(6): 1568-1574. https://doi.org/10.7522/j.issn.1000-0240.2016.0183
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    Artificially multi-circle freezing method has been widely used in shaft excavation and masonry in deep stratum. However, the frozen temperature field needs further study. In this paper, one freezing shaft was taken as the prototype, together with freezing temperature field model tests under conditions of freezing pipes without deflection in key formations and temperature field numerical calculation considering the freezing pipe deflection, and also taking advantage of the temperature field of information visualization software to analyze the in-situ measurement results. The results of the three methods were compared. It is found that the frozen pipe deflection impacts on the effective thickness of the frozen wall a little, but has a great influence on the average temperature of frozen wall and the freezing circles intersection time. It is easily to generate closed unfrozen pressure water sump inside the frozen wall, causing frost heave force gathered, resulting in disadvantage of the overall stability of the frozen wall and the borehole excavation. This study will be useful for the multi-circle freezing method design and construction.

  • WU Chao, ZHANG Shujuan, ZHOU Zhiwei, SUN Zhizhong
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2016, 38(6): 1575-1582. https://doi.org/10.7522/j.issn.1000-0240.2016.0184
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    At present triaxial compressive tests in laboratory are usually conducted by axial loading method with a constant confining pressure. However, the soil in the practical engineering is often in a stress status that the confining pressure coincides with axial loading. According to the practical consideration, triaxial shear tests for frozen silty sand were carried out under different confining pressure paths. Bases on the deformation of the tested sample, the modified formula of the sample section is proposed, and then the data was processed. The results show that the confining pressure path has little influence on the initial and final segments of stress-strain curve when the water content is small, and at the middle section of stress-strain curve, the curve of varying confining pressure is lower than that of constant confining pressure, and the smaller the initial confining pressure is, the lower the curve position is. When the water content equals or exceeds the saturation value, the combination of confining pressure path and ice content controls the trend of stress-strain curve; the final section of stress-strain curve is higher under the varying confining pressure than that under the constant confining pressure, and the features of middle segment are related to ice content and initial confining pressure. The confining pressure path has insignificant effect on the relation between strength and confining pressure. When the water content is small, the strength values of the two confining pressure paths are close each other; when the water content is high, the strength of constant confining pressure is less than that under varying confining pressure.

  • DU Yuxia, MA Wei, ZHAO Shuping, ZHANG Ze, MING Jiao
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2016, 38(6): 1583-1591. https://doi.org/10.7522/j.issn.1000-0240.2016.0185
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    When the laser displacement sensor is used in frozen soil experiment, the linearity will decrease because of the worse environment condition. Therefore, all sensors must be calibrated in the simulated environment conditions before a test. In order to verify the applicability of the laser displacement sensor in frozen soil experiment, according to the structures, features, technical index of the FT-50 RLA220 laser displacement sensor made by German SensoPart, a calibration device was designed, which is composed of temperature control box, calibration holder, FT-50 RLA220 laser displacement sensor, gage block and data acquisition device. The outputs of two displacement sensors under different temperatures and displacement points had been recorded. Based on the calibration results, the fitting parameters of sensors under different temperatures were corrected. The experimental results also show that calibration goodness-of-fit of the two laser displacement sensors are 0.999 and 1, respectively, with the maximum linearity of 0.88%FS and 0.32%FS, respectively.

  • LUO Yaofei, ZHANG Zhengqi, ZHANG Ke
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2016, 38(6): 1592-1597. https://doi.org/10.7522/j.issn.1000-0240.2016.0186
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    In order to investigate the water stability and performance deterioration of warm mix asphalt (WMA) mixture in cold plateaus, the WMA mixture with Aspha-min, Sasobit and Evotherm were selected to do freezing-thawing split test and scattering loss test. The differences of water stability for hot mix asphalt (HMA) and WMA mixture were compared. Finally, the impact of freezing-thawing cycles was quantitatively evaluated. The results show that the water stability of HMA is better than that of WMA mixture under the long-term impact of climate factors; the performance of WMA mixture decreases with freezing-thawing cycles, the water stability of WMA mixture remains stable after 15~18 freezing-thawing cycles, so 15 freezing-thawing cycles is taken as test criterion of performance evaluation for asphalt mixture in cold plateaus. The water stability of WMA mixture with Aspha-min is worst among all selected mixtures.

  • WU Zhiqiang, ZHANG Mingyi, YOU Zhilang, WANG Jiwei
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2016, 38(6): 1598-1606. https://doi.org/10.7522/j.issn.1000-0240.2016.0187
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    After the construction of the Qinghai-Tibet Railway, with the influence of global warming and human activities, the desertification is accelerated on the Tibet Plateau, Because of the invasion of sand, some ballast layers are filled and covered along the railway, and thus the albedo of the ballast layers are changed. Therefore, the effect of sand cover on the albedo of the railway ballast layer are studied in this paper. The results showed that with the increase of the sand cover ratio, the albedo of the railway ballast layer model first decreases, then increases. When the railway ballast layer was completely covered by sand, its albedo reached the maximum. By comparing the used method and the ASTM-E1918A method, it is found that when the variation of solar intensity is less than 20 W·m-2 in sunny days with no clouds and no haze, the results from the used method are very close to those from the ASTM-E1918A method, with a differences of about 0~0.002. Based on comprehensive analysis it is believed that used method is more convenient and reliable in measuring the albedo of unstable materials. However, the effect of sand cove on the heat balance of ballast layers still needs further to be study.

  • ZHANG Ruyi, JIANG Haibo, WANG Zhengcheng
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2016, 38(6): 1607-1614. https://doi.org/10.7522/j.issn.1000-0240.2016.0188
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    In the operating process of water delivery channel in cold regions, due to continuous low temperature, the ground temperature declines gradually, resulting in change of the base soil moisture distribution and causing frost heaving, and then damaging the channel's structures. The chain effect is a significant characteristic of frost heaving damage. In order to analyze the channel's frost heaving damage mechanism and the factors of frost damage in cold regions, the destruction theory is applied. In this study, based on system theory, the frost heaving damage chain structure is analyzed, and a chain effect relation model of frost heaving damage is established. Taking the channel lining structure in cold regions damaged by frost heaving as an example, the effects on the frost heaving damage of channel lining structure of channel base soil particles, soil composition, air temperature and ground temperature changes and soil moisture migration after one freeze-thaw cycle are analyzed. The chain mechanism of frost heaving damage on channel lining structure is analyzed, which is under the external environment condition such as temperature, moisture, the distribution of ground temperature affected by soil properties and soil moisture. The soil moisture transfer is affected by the soil temperature and the soil properties; the soil frost heave is a response mechanism to the soil temperature and moisture distribution. Based on these relations, a broken disaster mitigation chain is proposed.

  • YANG Baiyi, ZHANG Lingxian, GAO Yang, XIANG Yang, MOU Naixia, Suolang Danba
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2016, 38(6): 1615-1623. https://doi.org/10.7522/j.issn.1000-0240.2016.0189
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    Glacier length is a major parameter to describe glacier change and climate change. In this study, the methods of extracting glacier mainstream line and glacier center line are integrated to extracting glacier length. This integrated method is based on Gaofen-1 satellite remote sensing data and digital elevation model (DEM), and is tested upon the Purog Kangri ice field on the Tibetan Plateau. First, the glacier boundary is extracted by the band threshold method and visual interpretation. Then the glacier length is extracted by the glacier mainstream line method, the glacier center line method and the integrated method, respectively. The results show that the mainstream line method has the higher accuracy when the glacier area is larger than 1 km2, while the center line method has the higher accuracy when the glacier area is smaller than 1 km2. The integrated method has the highest accuracy, 97.9%, with high efficiency.

  • CHEN Yun, LIU Guang, LIAO Jingjuan
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2016, 38(6): 1624-1629. https://doi.org/10.7522/j.issn.1000-0240.2016.0190
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    With the development of satellite and sensor, remote sensing technology has been widely used in the glacier change monitoring. In order to make the glacier change detection in the study area more efficiently and intuitively, a method of improved IHS Fusion is proposed in this paper, based on multi-temporal and homologous satellite images. Different with the traditional IHS method, the improved HIS fusion method replaces the H and S components with I component. Applying the improved IHS method, the changed region between two images at different time will be highlighted in the fused image, and then the changed areas can be extracted by using the classification method of decision tree. Two Landsat images were selected to do experimental research. The result shows that it is better than band ratio method in both the qualitative analysis and quantitative analysis.

  • ZHANG Wei, HAN Haidong
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2016, 38(6): 1630-1643. https://doi.org/10.7522/j.issn.1000-0240.2016.0191
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    Ice volume data is the initial parameters for predicting glacier variation and sea-level change. Therefore, research on ice volume estimation has important theoretical and practical significance. Methods of estimating mountain glacier volume can be divided into the following categories: field survey, empirical formula method and physical analysis method. The principles, development status and existing problems of these methods were analyzed in this paper in order to provide reference for the future estimation and simulation of mountain glacier volume. Field survey has high accuracy, which is suitable for long-term monitoring small glaciers. Empirical formula method is simple and rapid, suitable for large regional or global ice volume estimation. Physical analysis method is relatively complex, but it is not necessary to have initial parameters. Air-borne glacier penetrating radar, UAV, ANN theory and other theoretical model provide new opportunities for estimating mountain glacier volume.

  • ZHANG Xiyin, ZHANG Mingyi, LU Jianguo, PEI Wansheng, YAN Zhongrui
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2016, 38(6): 1644-1657. https://doi.org/10.7522/j.issn.1000-0240.2016.0192
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    Water migration is the key contributor for frost heave during soil freezing, and the driving force of water migration depends on soil temperature, unfrozen water content, matric suction and the relationship between them. The relationship is known as the soil-water characteristics in frozen soils. Generally speaking, the soil-water characteristics and the hysteresis effects have similar change laws between drying-wetting and freezing-thawing processes. It seems that the soil-water characteristics in frozen soils can also be explained based on the existing theories on soil-water characteristics in unfrozen soils. However, there are several special factors cannot be ignored, such as negative temperature, phase change and so on during freezing and thawing process. Therefore, it is believed that although the soil-water characteristics and the hysteresis effects are similar, their mechanisms may be quite different. Therefore, a great deal of work need to be done to develop the soil-water characteristics during soil freezing and thawing. Detailed analysis and summary are provided about the present situation and the existing problems of the water characteristics during soil freezing and thawing, as well as references for the aftertime study are put forward: a) establishing a typical model to the soil below freezing point to predict soil-water characteristics effectively with limited data; b) investigating the similarity and difference of the soil-water characteristics effect between unfrozen and frozen soil, and demonstrating the mechanism of the hysteresis effect during freezing and thawing; c) promoting the research of measurement techniques of the soil-water characteristics in frozen soil.

  • LIU Saiyan, HUANG Qiang, WANG Yimin, LI Yunyun, LI Xiangyang
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2016, 38(6): 1658-1665. https://doi.org/10.7522/j.issn.1000-0240.2016.0193
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    Taking Datong River basin as a study area, using SWAT model, the hydrological effects in the basin was quantitatively analyzed based on the land-use/cover change scenarios in 1985 and in 2005. The results showed that: (1) during 1985-2005, the most evident change of land-use was grassland shifting to farmland and construction sites. As a result, the grassland proportion greatly reduced, from 46.7% to 20.9%, and the cultivated land area from 1 065.8 km in 1985 increased to 3 243 km in 2005; (2) compared with the land-use situation in 1985, the simulated multi-year average runoff of 2005 increased 1.92×108 m, with the increasing gradually from northwest to southeast due to the different in main land-use among the upstream, midstream and downstream; (3) annual runoff increase was mainly in the flood season, with a rate of 0.40×108 m·mon-1, while in non-flood-season runoff decreased with a rate of 0.024×108 m·mon-1. Therefore, it is of great importance to make reasonable land-use plan and to improve the ability to conserve water resources for sustainable development in the basin.

  • YANG Kang, LIU Qiao
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2016, 38(6): 1666-1678. https://doi.org/10.7522/j.issn.1000-0240.2016.0194
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    Supraglacial drainage system is one of the most important parts of glacial drainage systems, which impacts glacier surface ablation processes through transfer and drainage of surface meltwater. The existence of supraglacial drainage system also significantly impacts glacier flow and dynamics. Most of the conventional glacier hydrologic models suggest that surface meltwater can efficiently drain from glaciers and thus ignore the ability of supraglacial drainage system to retain meltwater. However, the impact of this retention, which leads to large uncertainties in glacier runoff prediction, could not be ignored. Therefore, it is crucial to improve the understanding in supraglacial drainage systems. The formation of supraglacial drainage system is controlled by glacier size, physical characteristics and ablation zone distribution. There is a seasonal development process of supraglacial drainage system from subsurface flow to slush flow and then to open channel flow. This dynamic supraglacial drainage system can route glacial surface meltwater into moulins, ice crevasses or supraglacial lakes through supraglacial networks with variable efficiencies and delays over space and time. In this paper, an attempt is tried to review the current supraglacial drainage system studies, and to discuss the evolution, distribution and constitution of supraglacial drainage system in sequence and their roles in meltwater transfer and drainage. In particular, hydrodynamics of supraglacial networks are discussed in detail to illustrate the pattern, efficiency and meltwater partition of supraglacial drainage system.

  • BO Yue, WANG Yi, LI Jiamin, WANG Chenghai
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2016, 38(6): 1679-1690. https://doi.org/10.7522/j.issn.1000-0240.2016.0195
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    The distribution features and variation tendency of cloud water and the relation to summer and fall rainfall and winter and spring snowfall are analyzed over the Tibetan Plateau (TP) by using cloud amount, cloud optical thickness (COT) and cloud water path (CWP) of ISCCP from 1984 through 2009. The influence of cloud amount change on precipitation under climate change background in TP are discussed also. The results show that the distributions of CWP, COT are similar to total cloud amount over TP. There were significant differences in seasonal change and distribution. Total and high-level cloud amounts in spring and summer were more than those in fall and winter. The high values of total cloud amount were located in the Karakoram and southeastern TP, as well as in the low lands in Hoh Xil. Decreasing tendency of total cloud amount is revealed over most of TP by linear regression analysis. However, there were an increasing tendency in CWP in eastern TP and a slight decreasing tendency in western TP. The change in CWP was primarily dependent on the enhanced moisture from the Bay of Bengal. CWP and COT has increasing over the central and eastern TP in recent decades. Precipitation in summer and fall was increasing over most TP, which has tight relation with cloud amount, CWP and COT. There was a little decreasing tendency of maximal snow depth in winter and spring, with a significant correlation to the variation of total cloud amount. The cloud water resources over the central and eastern TP have increasing tendency under global climate change.

  • XIAO Dingmu, QIN Ningsheng, HUANG Xiaomei
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2016, 38(6): 1691-1700. https://doi.org/10.7522/j.issn.1000-0240.2016.0196
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    Tree-ring width standardized chronology was established through study of Sabina tibetica in Lixin Town in the source regions of the Yangtze River. Correlation analysis showed that moisture is the main factor controlling tree growth in the regions. It is found that the standardized chronology is significantly correlated with precipitation in the regions from March through May, with a correlation coefficient of 0.69. Thus, precipitation from March through May in the Yangtze River source regions during 1602-2013 was reconstructed. The reconstruction captures 44.9% of the instrumental precipitation variance. There are 10 wet periods and 10 dry periods in the reconstructed precipitation series over the past 412 years. The reconstruction indicates that there is a remarkably wetting in the last 10 years. Empirical mode decomposition of the series shows that the series can be decomposed into 7 IMF components. Among them, 2-4 year and 6-10 year fundamental components indicate the relation between precipitation and atmosphere (such as ENSO); 11-28 year fundamental component indicate the possible link between regional precipitation and solar activity. According to analysis of temporal and spatial correlation, it is found that the reconstructed series has good temporal and spatial representation. In addition, the reliability of the reconstruction could be confirmed by some documents and historical records.

  • ZHANG Guiling, JIAO Yuanmei, LIU Chengjing, DING Yinping, ZHANG Kanfeng
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2016, 38(6): 1701-1709. https://doi.org/10.7522/j.issn.1000-0240.2016.0197
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    Precipitation during the rainy season over the Malizhai River basin at the cultural landscape heritage core area of the Honghe Hani rice terraces was taken as the object to analyze its hydrogen and oxygen isotopic compositions and then to put forward an atmospheric precipitation equation to describe its characteristics through comparison with those in neighbor areas, in China as a whole and in the globe. The effects of meteorological parameters including temperature, humidity, precipitation and elevation also analyzed to judge the vapor sources. The results indicate: (1) δ18O in precipitation in rainy season has a large changing range and an obvious isotopic depletion. (2) The local meteoric water line is δD=7.59δ18O+3.31, with less slope and intercept, showing large amount of precipitation and a strong evaporation, with multi-vapor sources not only from the hot tropical marine air mass of India Ocean and Bengal Bay, but also from the second evaporation of surface water at the local scale. (3) There are obvious isotopic effects of precipitation, temperature and altitude in the study area, characterized by comprehensive impact without obvious leading factor.

  • WANG Zengru, WANG Cheng, DONG Xiaohong, GAO Bingmin
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2016, 38(6): 1710-1717. https://doi.org/10.7522/j.issn.1000-0240.2016.0198
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    The relation between diversity and productivity is a controversial issue in ecology. In this study, the species richness, biomass and key environmental factors of typical plant communities are investigated in alpine meadow in the upper reaches of the Shule River on the Tibetan Plateau. The aims of this study are to examine the relation between species richness and biomass in different plant communities and to evaluate the effects of key environmental factors on the relation. It is found that: 1) There are no significant correlation between species diversity and productivity in the plant communities, which are constructed by the plant species of Cyperaceae family or Ranunculaceae family, such as Kobresia pygmaea+Carex qinghaiensis comm., Kobresia capillifolia+Carex atrofusca comm., Thalictrum aquilegifolium+Leontopodium nanum comm. and Carex qinghaiensis+Artemisia nanshanica comm. However, the relation between species richness and biomass shows significantly positive correlation in the plant communities, which are constructed by Gramineae family species, such as Stipa purpurea+Aster tataricus comm. and Stipa purpurea+Saussurea arenaria comm. 2) In the CCA ordination analysis, the accumulative interpretation amount of the environmental factors on the plant community distribution pattern reaches 83.4%, which demonstrates that the environmental heterogeneity result in the plant communities distribution; furthermore, the depth of the active layer of permafrost (denoted as PF) is the most important factor to explain the distribution of plant communities. Notably, when PF is more than -4 m, there is no significant correlation between species richness and biomass, whereas, when PF is less than -4 m, the species richness-biomass relation is significantly positive correlation. These results might be helpful to deeply understand the relation between biodiversity and ecosystem function in alpine meadow.

  • ZHANG Kai, LI Xingjie, YANG Wei, WANG Junhao, ZHANG Qiong, GUO Lei, SHI Hongxia, LUO Bin
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2016, 38(6): 1718-1723. https://doi.org/10.7522/j.issn.1000-0240.2016.0199
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    In order to study the ambient PM2.5 pollution and it's constituent of heavy metal and PAHs, and to explore the influence of ambient PM2.5 on birth quality of mice, PM2.5 data and PM2.5 samples were collected from Chengguan District of Lanzhou City from Oct. 2015 through Mar. 2016. Heavy metals and PAHs of PM2.5 were analyzed. In the meantime, 30 pregnant SD mice in the 10th day of pregnancy were exposed to PM2.5 by tracheal instillation with a given dose of 0, 50, 100, 200 μg·ml-1·d-1. The offspring quantity and body weight, heart/body ratio, lung/body ratio, male/female ratio of F1 mice were figured to evaluate the birth quality. The results showed that the daily concentration of ambient PM2.5 in the heating period in Lanzhou City meets the national standard, with more than 48 days above that standard. The major heavy metal and PAHs were respectively Pb and Fluoranthene. Animal experiment demonstrated that the body weight of F1 mice were reduced with PM2.5 exposure dose. Compared those with zero dosage group, the heart/body ratio and lung/body ratio of PM2.5 exposure groups were significantly reduced, while offspring quantity and sex differentiation had no difference. It is revealed that ambient PM2.5 could have reproductive toxicity to female mice during pregnancy and affected the birth quality and growth of F1 mice.

  • ZHAO Nianwu, GUO Lianyun, LI Xiaodong
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2016, 38(6): 1724-1731. https://doi.org/10.7522/j.issn.1000-0240.2016.0200
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    In this paper, the relations between variation of soil moisture in different growing periods, precipitation and pasture yield in Stipa growing season are analyzed based on the data of soil moisture, precipitation and pasture yield from 1999 through 2012 in Qinghai Province. The following conclusions can be drawn: (1) Precipitation increases remarkably in Stipa growing period in the province year by year. (2) Precipitation in the grass green and yellow periods has a decreasing tendency and in heading period, flowering period and maturity period has an increasing tendency, especially, in flowering period. (3) Soil relative moisture in pasture growing period increases year after year and has significant dependence on precipitation in growing period. Soil moisture increase remarkably at flowering, maturity, heading and yellow periods. There is a significant positive correlation between soil moisture and temperature at flowering period, with a significant negative correlation between soil moisture and temperature at heading period and whole growth period. Between soil moisture and precipitation, there is a significant positive correlation at heading, flowering, maturity and whole growth period. There is a significant correlation between yield of Stipa and soil moisture in yellow period.

  • YAN Liangdong, GUO Jianping, QI Donglin, LI Lin, SU Shulan
    JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2016, 38(6): 1732-1738. https://doi.org/10.7522/j.issn.1000-0240.2016.0201
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    In this paper, meteorological drought due to fewer precipitation impacting pasture yield in Qinghai Province was studied. A relationship between precipitation in pasture growing season and pasture yield was given. The pasture yield loss affected by the meteorological drought was able to calculate, but the error was large, which was unable to satisfy the requirements of estimating pasture yield, pasture grazing capacity and livestock marking rate. Consequently, the "no-drought pasture yield" method based on the Lagrange interpolation method was introduced for the scenario that there was no drought in the province. Then the pasture yield loss could be calculated in the province. According to the "no-drought pasture yield" method, statistics and evaluation model of drought loss could be set up; and then to be applied in pasture yield assessment of Qumarlêb County, Qinghai Province from 2013 through 2015, of which the error was between 3.59% and 6.02 % for the three years. It was proved that using the drought damage assessment method could evaluate the drought loss of pasture yield and assess the actual pasture yield in the study area. This method can be popularized and applied to pasture forecast, pasture grazing capacity prediction and assessment of livestock production in the future.