25 October 2015, Volume 37 Issue 5

    

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  A comparative study on mass balance between the continental glaciers and the temperate glaciers:Taking the typical glaciers in the Tianshan Mountains and the Alps as examples

  SU Bo, LI Zhongqin, ZHANG Mingjun, GUO Rong, SUN Meiping, CHE Yanjun, YING Xue

  JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2015, 37(5): 1131-1140. https://doi.org/10.7522/j.isnn.1000-0240.2015.0127

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  Under the background of global warming, most of glaciers retreat all over the world. According to the water-thermal environment that glaciers developed in, as well as glacier physical properties, continental glaciers and temperate glaciers can be classified out. The two type glaciers exist significant differences in degree, process and mechanism in respond to climate change. So it is of great significance to conduct the comparative study on mass balance characteristics and mechanisms in respond to climate change between the two type glaciers. In this paper, the Glacier No.1 at the headwaters of the Ürümqi River and Tuyuksu Glacier, respectively in east and west Tianshan Mountains, and Hintereisferner Glacier, Caresèr Glacier and Sarennes Glacier in the eastern, central and western Alps, respectively, are taken as sample glaciers. The characteristics and mechanisms of the mass balance change are compared for the two glacier types. Based on a comparative analysis on the differences in amplitude of fluctuation and phasic change of the mass balance during the 60 years. The results show that the temperate glaciers have greater amplitude of fluctuation than that of the continental glaciers due to their differences in water-thermal environment and in sensitivity to climate change. Phasic change of mass balance was similar in the Alps, but was much different not only between the glaciers in the Tianshan Mountains and the Alps, but also between the two glaciers in the Tianshan Mountains. This indicates that the difference not only exist between different property glaciers but also among the same type glaciers. In addition, on the basis of predecessors' research on glacial retreat mechanisms, the similarities and differences in mechanisms of glacier mass balance between the continental glaciers and the temperate glaciers also studied. The air temperature rising during ablation season and the glacier surface albedo reduction are considered responsible for the accelerated ablation not only for the continental glaciers but also for the temperate glaciers. Moreover, the ice temperature rising and the glacier fragmentation are another important mechanism for speeding up ablation of the continental glaciers and the temperate glaciers.
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  Variation of glaciers in the Sawuer Mountain within Chinese territory during 1959-2013

  HUAI Baojuan, LI Zhongqin, WANG Feiteng, WANG Puyu

  JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2015, 37(5): 1141-1149. https://doi.org/10.7522/j.isnn.1000-0240.2015.0128

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  As the number of glaciers in the Sawuer Mountain(Muz Taw Mountain range) was small, glaciers located at the north and south slopes were divided into the Altai Mountains and the Tianshan Mountains by "Glacier Inventory of China", respectively. Therefore, it is difficult to study the glacier change information, should be given special consideration. In this study, topographic maps, Landsat images, digital elevation model and ground penetrating radar(GPR) data were used to study the glacier variation. Through visual interpretation and interpolation method, glacierized area and glacier length changes were extracted, and the Muz Taw Glacier thickness distribution was also obtained. The results show that:(1) during 1959-2013, glaciers had retreated evidently, glacierized area had shrunk from 17.69 km²  to 10.13 km², with a retreating rate of 42.74%, and an annual retreating rate of 0.14 km²·a^-1approximately;(2) the retreating rate was 37.57% on north slopes and 72.69% on the south slopes, depending on slope aspect and glacierized area;(3) based on the GPR data, it is found that the Muz Taw Glacier volume had decreased by 44.6% as compared with the estimated glacier volume from the topographic map in 1959.

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  Surface flow features of the Dark Glacier in East Antarctica from in-situ observation

  HUANG Jifeng, E Dongchen, ZHANG Shengkai

  JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2015, 37(5): 1150-1159. https://doi.org/10.7522/j.isnn.1000-0240.2015.0129

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  18 filed campaigns of space intersection were taken to monitor the flow of the Dark Glacier in East Antarctica during 2007-2012. The monitor indicated that the average velocity was 0.41 meters per day and the azimuth of the average direction of the flow was 7.01 degree. Generally, the flow velocity in summer was nearly that in winter. However, the flow near the front of the glacier seemed to be more positive in winter. The flow became faster and faster towards the central line from the glacier boundary. The highest speed appeared in the central line and the lowest speed appeared in the boundary area. Along the glacier flow direction, the same flow pattern could be seen, i.e., flow velocity increased towards the terminus from the upstream. The highest speed appeared in the frontier, where more cracks took place. Compared to the former researches, the Dark Glacier seems no significant change in flow velocity.
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  DEM generation and precision analysis of Antarctic ice sheet based on InSAR and ICESat data

  WAN Lei, ZHOU Chunxia, E Dongchen, DENG Fanghui

  JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2015, 37(5): 1160-1167. https://doi.org/10.7522/j.isnn.1000-0240.2015.0130

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  InSAR and ICESat data were combined to generate DEMs of four test sites along PANDA section. In order to eliminate the residual linear trend error, ICESat data was introduced to refine the baselines of the interferometric pairs as control points. Additional ICESat footprints were used to evaluate the accuracies of the DEMs. Accuracy differences of the four DEMs were analyzed and the possible reasons causing DEM errors were discussed. Topographical features and ice streams were the main factors influencing the accuracy of DEMs derived from InSAR on Antarctic Ice Sheet. The effect induced by ice streams was analyzed theoretically. Then analysis and validation were performed considering the impact of ice velocity. Furthermore, Kriging interpolation method was applied to correct the InSAR DEMs and GPS points were used to validate the result. The result showed that corrections performed very well in high latitude areas where ice velocity was small and of consistent distribution, and the accuracy of DEMs can be up to 3-m in these areas. New method like multi-baseline InSAR should be employed to improve the DEMs in areas with large and complex ice velocity.
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  Spatial distribution of winter snow cover depth and density in Ürümqi City during 2011-2013

  LI Xiaolan, JIANG Fengqing, WANG Shaoping, WANG Lei, Muyesser Turdi, ZHANG Zhaoyong, ZHANG Dengqing

  JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2015, 37(5): 1168-1177. https://doi.org/10.7522/j.isnn.1000-0240.2015.0131

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  In this paper, the spatial and temporal distribution characteristics of snow cover depth and density from late December 2011 to late February 2012, and the same periods from 2012 to 2013 in urban and suburb of Ürümqi city were analyzed by using ordinary Kriging interpolation methods, based on data of snow cover depth and density during the winters of 2011-2013. The results show that snow cover depth and density between urban and suburb had significant temporal and spatial differences in the city. Snow cover around the Midong Petrochemical Industrial Park often was thicker in winter, especially during December and February. However, there were some places with more snow on different underlying surfaces inside the downtown areas. Snow cover accumulated gradually on the ground from late December to late February, especially in late December. Meanwhile, spatial variation range of snow cover depth was greater than that of density. Snow cover density in the urban centre was lower than that in the east and northeast of the city in mid-January and late February, while higher in the urban centre in late December than that in suburb. Compared to the same period in 2012, the snow cover amount increased in mid-January of 2013, but the mean density of snow cover increased insignificantly, and the spatial distributions of snow cover depth and density in city altered obviously. This study will be of greatly importance for making up the meteorological data, less and uneven distributed, in the study region, and help scientists and policy makers to understand the regional variations of snow and implement plans for road maintains in winter and against snowmelt flood in spring. The measured data also can help check the accuracy of snow parameters inversed from satellite data.
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  Spatial and temporal characteristics of snow depth in the Tianshan Mountains derived from SSM/I and MODIS data

  REN Yanqun, LIU Hailong, BAO Anming, LIU Jinping

  JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2015, 37(5): 1178-1187. https://doi.org/10.7522/j.isnn.1000-0240.2015.0132

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  This study focus on the temporal and spatial variations of snow cover and change rate in different elevation zones of the Tianshan Mountains by using the MOD10A2 snow synthetic data, from 2003 to 2012. Furthermore, the brightness temperature data of SSM/I and the station-based observation data are used to build up a snow depth retrieval model to compute the snow depth for the study area. Eventually, the spatial and temporal variations of snow depth for the whole Tainshan Mountains and accuracy validation were carried out based on the relief of the Tianshan Mountains The study result shows that there are clear spatial and temporal distributed patterns:(1) spatially, the overall distribution pattern of the snow cover area in the Tianshan Mountains is decreasing from west to east and from north to south, with the maximum snow depth of 80 cm nearby the Mt. Bogda and Heyuan Peak in the north of the Tianshan Mountain and the maximum snow cover area was 37.69×10⁴ km² in 2012;(2) temporally, the snow cover area is fluctuating with a little decreasing tendency;(3) the accuracy evaluation of snow depth shows that the snow depth between 10 cm and 30 cm have relatively higher accuracy with an average error of 2.47 cm, and, on the contrary, the areas with snow depth less than 10 cm and greater than 30 cm have relatively larger deviation.
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  Analysis of glacier change in Manas River basin in the last 50 years based on multi-source data

  FAN Xiaobing, YAN Lili, XU Jinghua, HAO Xiaohua, LI Hongyi, WANG Jian, LIU Dafeng

  JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2015, 37(5): 1188-1198. https://doi.org/10.7522/j.isnn.1000-0240.2015.0133

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  The glacier change in Manas River basin has a greatly effect on the economic and social development in the basin and its surrounding areas. Combined GF-1 and Landsat8 remote sensing images with four glacier inventory data of Manas River basin:the First Glacier Inventory Data(1964), the Second Inventory Data(2009) and the glacier visual interpreting results from TM(1998, 2003), a comprehensive analysis was done on the glacier change in the basin from 1964 to 2013 by using glacier recognition method based on multi-source data and band ratio method to obtain the glacier data in the basin in 2013. The results reveal that the Manas River glaciers have slightly increased since 2009, with glacierized area increased 10.25 km² from 2009 to 2013, which restrained the rapid ablation of glaciers for a long time to some extent; from 1964 to 2013, the glacierized area of the Manas River basin had decreased 161.54 km², from 673.61 km² to 512.07 km², with a decreasing rate of 23.98%. Over the 50 years, the glacierized area in the basin had net decreased below the altitude of 4500 meter and had net increased above the altitude of 4500 meter. The maximum shrinking rate of glacier might go up to 0.5 km²·a^-1 at an altitude of(4000±100) meter. The reduction of glacierized area mainly exhibited in rapid ablation of small glaciers and in retreat of ice tongues mostly, with over 85% of the glacier tongues retreating more than 200 meters. Glacier change in the basin was mainly concentrated on south and north aspects; there was an obvious characteristic that glacierized area turned to increase after the first reduction in the south aspect. From 1964 to 2013, air temperature and precipitation in the basin had obviously increased, with linear increasing rates of 0.26℃·(10a)^-1 and 16.07 mm·(10a)^-1. The research results show that rising temperature and increasing precipitation are main reasons for glacier fluctuation in Manas River basin.
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  Variations of summer extreme precipitation events in Altay Prefecture, Xinjiang Region, from 1961 to 2010

  ZHANG Linmei, MIAO Yunling, LI Jianli, WANG Chenhai

  JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2015, 37(5): 1199-1208. https://doi.org/10.7522/j.isnn.1000-0240.2015.0134

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  In this paper, based on the daily precipitation data of summer(June to August) of seven national basic meteorological stations from 1961 to 2010, NCEP/NCAR data as well, and 74 circulation characteristic data, the thresholds are calculated by the definition of percentile method and the change of summer extreme precipitation is analyzed using a variety of statistical methods including linear trend, variation analysis, Mann-Kendall(M-K), sliding t test, Morlet wavelet transform and correlation analysis methods etc. It is found that:(1) The threshold values of the summer extreme precipitation events in Altay Prefecture were 9~13.1 mm d^-1. The threshold values depended on terrain, and altitude also affected the values. Altitude was also close to the threshold value. They were basically in the exponential relationship, that is to say, the threshold value increased with altitude.(2) In the 50 a, although the annual variation was not obvious, the decadal oscillation of the summer extreme precipitation could be observed. The decadal variations of frequency and intensity were in a good agreement. They were both low in the early 1980s, then increased from the late 1980s until the middle of the 1990s. They got a maximum at the mid-1990s, and then decreased after 2000.(3) In the 50-a, the summer extreme precipitation events had varied smoothly and steady. Hence, a few stations had no mutation records in the past few decades, except for Altay and Fuyun Stations which were the two stations having mutation from the late 1980s to the early 1990s.(4) The atmospheric circulation characteristics such as the North Atlantic North America subtropical high ridge, the North Africa subtropical high ridge and the A-dex of Tibet Plateau are main factors to control the summer extreme precipitation events.
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  Characteristics of the seasonal frozen ground in Badain Jaran Desert

  NING Kai, WANG Naiang, HU Wenfeng, ZHANG Xunhe, SUN Jie, WANG Xu

  JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2015, 37(5): 1209-1216. https://doi.org/10.7522/j.isnn.1000-0240.2015.0135

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  Through continuous ground temperature monitoring in Badain Jaran Desert hinterland and professional investigation, it is found that Badain Jaran Desert belongs to seasonal frozen soil area with freezing duration of four mouths a year. Local topography and lakes are the key factors controlling the distribution of seasonal frozen soil area. The maximum frozen depth of seasonal frozen soil in the windward slopes and leeward slopes is obviously greater than that in the fields among the hills. The maximum depth of seasonal frozen soil around a lake is obviously shallower. By comparing the ground temperature and air temperature around the Badain Jaran Desert with those in Badain Jaran Desert hinterland and considering the discovery of sand wedge group around the desert, it is clearly that the desert in northern China belonged to discontinuous permafrost region in the Last Glaciation.
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  Discovery of large frost mound clusters in the source regions of the Yellow River on the Tibetan Plateau

  WU Jichun, SHENG Yu, CAO Yuanbing, LI Jing, FENG Ziliang, WANG Xinbin

  JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2015, 37(5): 1217-1228. https://doi.org/10.7522/j.isnn.1000-0240.2015.0136

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  Frost mounds in a large cluster are identified in Duogerong basin in the source regions of the Yellow River on the Tibetan Plateau by field investigation in the winter of 2012, which was previously regarded as dunes or kames. The majority of these frost mounds are elliptical shapes in plane, together with ridge and crescent shapes. They are normally 3~6 m in height(less than 10 m) and extend from dozens of meters to hundreds of meters(not more than 300 m). Frost mounds spread densely in basins; on average, there are 5~8 mounds per km²(locally up to 10 mounds per km²), embedded with small ponds and lakes. Most frost mounds keep intact shapes, but partially or completely collapsed ones can be seen because of the ground ice cores thawing. Frost mounds in different collapsing stages are found in the depressions of the basin. The boreholes at the top of mounds reveal that there are ice layers between the depths from 5 m to 20 m, partly with pure ice layers of 2 m or more in thickness. From appearance and type of the ground ices, the frost mounds are identified as lithalsas rather than pingos. Preliminary investigation indicates that these lithalsas are formed during Neoglaciation after Magathermal in Holocene. Discovery and identification of the frost mounds in Duogerong basin may contribute to the construction and safe operation of existing engineering projects and infrastructures and to the researches of regional paleo-environment, hydrologic conditions and periglacial landforms.
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  Comparative analyses of geopotential height and wind field from multiple reanalysis data over the Tibetan Plateau

  HU Mengling, YOU Qinglong, LIN Houbo

  JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2015, 37(5): 1229-1244. https://doi.org/10.7522/j.isnn.1000-0240.2015.0137

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  In this study, the applicability of geopotential height and wind velocity reanalysis data is evaluated, including 20CR, CFSR, NCEP1, NCEP2, ERA-Interim, ERA-20CM and JRA-55 reanalysis datasets, over the Tibetan Plateau by compared with radiosonde data. The analysis is focused on climatology, climate change and annual variation by means of various statistical analysis methods(root mean square error, correlation analysis, etc.). It is found that there are many clear differences among the reliabilities of reanalysis datasets, seasonal, regional and vertical. Geopotential heights of NCEP1 and ERA-Interim are comparatively closest to observation data in climatology. In contrast, the error of ERA-Interim and ERA-20CM data is large. In spring and summer, the reliability of reanalysis data of NCEP1 and NCEP2 wind velocity are higher than that of other reanalysis data, while during autumn and winter ERA-20CM wind velocity data is better. Based on the comparison in climate change trend, one can see that JRA-55, ERA-Interim and NCEP1 reanalysis data are able to objectively represent the geopotential height changing trend, with some temporal and spatial disparities. For annual variation, reanalysis datasets and radiosonde data almost get consistent description, except for ERA-20CM. Seasonally, reanalysis datasets show higher reliability in winter, followed by spring, with a poor reliability in summer.
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  Causes and processes of desertification in Madoi County in the source regions of the Yellow River

  YAO Zhengyi, LI Xiaoying, DONG Zhibao

  JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2015, 37(5): 1245-1256. https://doi.org/10.7522/j.isnn.1000-0240.2015.0138

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  Under the influence of global climate change, Madoi County in the source regions of the Yellow River is facing serious ecological and environmental problems, such as desertification, wetland shrink, grassland degradation and so on. By means of field investigation, interpretation of remote-sensing images, analysis of stratigraphy and grain-size analysis, causes and processes of desertification in Madoi County are analyzed in this paper. The results show that widely distributed fossil aeolian sediments and alluvial deposits of the Yellow River and its tributaries are the material sources of the desertification in the source regions of the Yellow River. The grain size characteristics of modern mobile dunes and fossil dunes are very similar, showing obvious relationship of inheritance and transformation of them. The distribution of the modern mobile sand dunes has not exceeded the scope of the fossil aeolian deposits. Due to environment changes, fossil aeolian sediments are subsequently fixed, and dense turf forms on the surface to protect underlying loose sand. Mechanical destroy of the turf is a crucial step for modern desertification. In Madoi County, mechanical damage of turf layer is associated with permafrost degradation. Permafrost degradation is different in different landforms. On fixed/fossil dunes, subsidence pits would form on the dunes due to permafrost degradation. Tensile cracks and extending falls would form around the edge of the pits leading to expose of underlying loose sand. On the slopes, slump scarps would be created by permafrost degradation, leading to expose the underlying soil. In the flat ground such as alluvial plain, waterlogged depression would form on the surface for differential frost heave and thaw settlement. With lowering of ground water level due to permafrost degradation, the bottom layer of the soil would be exposed. The destruction of turf leads to exposure of the underlying aeolian sediments. The aeolian sediments are eroded by wind, creating lateral recession, resulting in the upper soil collapse and leading to more aeolian sediment exposed. Alternation of wind erosion and gravity erosion would expand the blowouts, slump scarps, wind erosion patches, leading to merger of them, and eventually formed mobile dunes, eroded badlands and gobi deserts.
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  The atmospheric boundary layer structure characteristics over the Hetao-Arid Region in summer:observation and analysis

  CUI Yang, CHANG Zhuolin, SANG Jianren, ZUO Hejiang

  JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2015, 37(5): 1257-1267. https://doi.org/10.7522/j.isnn.1000-0240.2015.0139

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  The atmospheric boundary layer structure characteristics over the Hetao-Arid Region in summer were investigated by using observational data by the mobile boundary layer wind profile radar(Airda K/LLX802J) in July, 2013 and the radiosonde data in Yinchuan. The daily variation of meteorological elements in the boundary layer, such as wind, temperature, atmosphere refractive index structure constant, relative humidity and vertical velocity were analyzed. It was revealed that the atmospheric refractive index structure constant detected by the Airda K/LLX802J wind profiler radar can better reflect and distinguish the turbulence occurrence, development, and the wind change and wind shear in the boundary layer over the Hetao-Arid Region in Northwest China. The summer average boundary layer height(BLH) of the region was 2127.2 m in daytime and 1760.7 m in nighttime in July. The BLH of daytime was 366.5 m higher than that of nighttime. The strong atmospheric convection activities over the Hetao-Arid Region were mainly concentrated in the boundary layer below 800 m, and the convective activity was weak between 800 m and 2000 m in summer. Non-adiabatic heating of Hetao-Arid Region's land surface to air temperature and water vapor content was mainly took place in the boundary layer below 800 m in summer. In contrast, the changes of air temperature and water vapor content in the boundary layer between 800 and 2000 m over the region mainly affected by the day-night alternating and the large-scale weather systems. In summer, wind speed in Hetao-Arid Region increased with height in the boundary layer below 300 m. Wind speed shear was easy to take place at 07:00-11:00 and 18:00-21:00 in the boundary layer below 500 m. In the boundary layer below 300 m, SSW wind prevailed in daytime, and southerly wind prevailed in nighttime, but the southeast wind always prevailed in the boundary layer from 300 to 2000 m. Meanwhile, the wind direction shear was prone to take place in the boundary layer below 300 m at 21:00-23:00 in summer. Due to the diurnal variations of solar radiation, land surface heating, surface evaporation and influence of the surface roughness, the vertical velocity over the Hetao-Arid Region increased with height in the boundary layer below 300 m at daytime and below 200 m at nighttime, but nearly did not change from 300 m to 2000 m boundary layer at daytime and nighttime in the summer.
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  Analysis of the influences of freezing-thawing action on rock slope stability of water conservancy engineering in high cold areas

  ZHOU Zhidong, LIU Wu

  JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2015, 37(5): 1268-1274. https://doi.org/10.7522/j.isnn.1000-0240.2015.0140

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  The Tibet Autonomous Region is located in the main part of the Tibetan Plateau, where the climate is cold with large temperature difference, strong solar radiation and so on. In the region, freezing-thawing action is especially prominent above 4000 m altitude and causes a certain influence on the slopes. In this paper, on the basis of experiment, the finite difference method is adopted; a key water conservancy project intake slope of spillway tunnel is taken as an example to analyze the influences of freezing and thawing on the stability of the slope under different conditions by calculation. Through calculation and analysis, it is found that there is a tiny decrease in stability coefficient of slope safety caused by freezing-thawing action. Although it is a little change, but because there are many critical stable slopes in the region, freezing-thawing action increases the possibility of slope deformation and damage and causes loss and damage to the project slopes. Therefore, in the construction process the necessary measures should be taken. It is very necessary to use anti freezing-thawing materials. Side slopes should be timely anchored and closed in order to prevent a large number of intrusive rain water or groundwater and effectively reducing the effects of freezing-thawing action.
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  The Harbin section of the Songhua River in melting period:Hydrodynamic simulation and spatial and temporal hydrodynamic features

  WANG Hong, LIU Shuo, WAN Luhe, SUN Xihan

  JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2015, 37(5): 1275-1282. https://doi.org/10.7522/j.isnn.1000-0240.2015.0141

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  Owing to ice melting in spring, the rivers in North China enter the spring flood season, when the water level, water depth and flow field of the rivers change greatly, affecting water environment management, protection and utilization of water resources. In order to make a scientific analysis of water dynamic change in the Harbin section of the Songhua River during the ice melting period, DEM images were vectorised by using ArcGIS 10.0. The orthogonal curvilinear coordinate grids of the study area were setup by the RGFGRID program of Delft3d software. In this paper, a two-dimensional mathematical model of the Harbin Section of the Songhua River was established by using EFDC model. The hydrodynamic conditions in different time and space of the section between October and January in 2014 were simulated, and the data measured in Harbin Hydrological Station was used to verify the simulation results. The maximum difference between the simulated and measured water levels was 0.33 m, with a relative error less than 10%. The simulation results showed that mean water level was 116.38 m in the spring flood season, 116.54 m in the wet period, 115.64 m in the dry season, and 116.23 m in medium season. The water depths in Zhushuntun Section and Ashe Estuary Section in the wet period were significantly higher than that in the spring flood season; the water depths in Hulan Estuary and Dadingzi Mountain Sections in the flood period were almost same as in the spring flood season. In Dadingzi Mountain Section the water depth was shallow always, where ice jam took place easily. In the spring flood season the flow velocity of Zhushuntun, Ashe Estuary, Hulan Estuary and Dadingzi Mountain Sections was 0.55, 0.61, 0.43 and 0.57 m·s^-1, respectively; in the wet period the flow velocity of them was 0.59, 0.66, 0.47 and 0.63 m·s^-1, respectively; The flow velocity of them in the spring flood season was closed to(or slightly less than) that in the wet period, when the flow was gentle without vortex. This model can simulate the river's hydraulic elements changing with time and space, so as to simulate and predict the hydraulic condition in different typical hydrological years. This study would provide basis to decision-makers in water navigable management, winter and spring water resources allocation, water quality simulation, water quality target management, water environment capacity calculation and reduction of total pollutant emission.
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  A review of studies on roadbed frozen damage and countermeasures in seasonal frozen ground regions in China

  WU Libo, QI Wei, NIU Fujun, NIU Yonghong

  JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2015, 37(5): 1283-1293. https://doi.org/10.7522/j.isnn.1000-0240.2015.0142

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  Roadbed is significantly affected by the climate, environment and freezing-thawing cycles, thus frozen damage is still a serious problem in the roadbed construction in seasonal frozen ground regions, though many advances in the frozen damage researches have been achieved. With the road projects developing in China, more and more roads will be built in the seasonally frozen ground regions. So as to guide engineering practice better, it is necessary to make a new document review on the research findings in this field. Based on the previous studies, the distribution areas and the major failure forms of roadbed frozen damage are summarized; the main influencing factors that cause engineering problems to the roadbed are discussed; the existing counter measures are analyzed and summarized in this paper. Meantime, some ongoing engineering problems and suggestions are put forward, which provide new ideas for improving the studies on roadbed frozen damage and counter measures in seasonal frozen ground regions.
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  Development trend and statistics of the field of geotechnical mechanics and engineering in cold regions funded by NSFC during 2006-2015

  SHEN Yanjun, YANG Gengshe, TANG Liyun, WANG Xuan

  JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2015, 37(5): 1294-1303. https://doi.org/10.7522/j.isnn.1000-0240.2015.0143

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  With the proposal of "One Belt and One Road", a national strategy, many problems about geotechnical mechanics and engineering will present during the construction of the Silk Road Economic Belt, and will be a new research hotspot in geotechnical engineering field. The National Natural Science Foundation of China(NSFC), the highest-level research fund organization, has received the widespread attention, and the projects funded by NSFC represent the forelands of the corresponding fields. Focused on the field of geotechnical mechanics and engineering in cold regions, based on the statistics about the funding scale, organizations, subject categories of the projects funded by NSFC in recent ten years(2006-2015), the overall development trend of geotechnical mechanics and engineering in cold regions funded by NSFC is analyzed. The research topics are arranged in classifications, and the present development is systematically analyzed. According to the statistics and analysis in this field, the corresponding research and development trend that should be focused on in the future are analyzed. This paper would be useful for the people, who like to apply a foundation of NSFC in the field of geotechnical mechanics and engineering in cold regions.
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  Effect of climate factors on the runoff over Lhasa River basin during 1981-2013

  ZHANG Hezhen, Zhuoma, XIANG Fei, Zhuoga, Gesang

  JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2015, 37(5): 1304-1311. https://doi.org/10.7522/j.isnn.1000-0240.2015.0144

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  In this paper, the variations of air temperature, precipitation and evaporation, together with their effect on runoff, over the Lhasa River basin in Tibet were investigated by using the monthly precipitation, air temperature and evaporation data observed at two meteorological stations and the runoff data measured at a hydrological station in Lhasa during 1981-2013. It is found that the precipitation has increased in the past 33 years over the Lhasa River basin, especially the precipitation during the cold season, reaching an increasing rate of 3.51 mm·(10a)^-1. The annual and seasonal mean temperatures exhibit significant increasing tendency while the evaporation shows significant decreasing tendency. The annual temperature changing rate is 0.58℃·(10a)^-1, the warm season temperature changing rate is 0.42℃·(10a)^-1 and the cold season temperature changing rate is 0.74℃·(10a)^-1; the annual evaporation changing rate is 127.2 mm·(10a)^-1, the warm season evaporation changing rate is 82.2 mm·(10a)^-1 and the cold season evaporation changing rate is 45.5 mm·(10a)^-1. The 1980s is pretty cold and dry period with less precipitation, low temperature and large evaporation, followed by more precipitation, higher temperature and smaller evaporation in the 1990s, then precipitation and temperature reached the highest values and smallest evaporation at the beginning of the twenty-first century. Thus, Lhasa River basin has entered a relatively warm and humid period, when annual variation of runoff was quite small, and the annual and seasonal runoff varied consistent with the tendency of precipitation and temperature, namely runoff in the 1980s was the smallest and then increased with time, and appeared the maximum at the beginning of the twenty-first century. The annual runoff and the runoff during the warm season in the Lhasa River basin exhibited low water level since less precipitation in 1983; however, runoff was extremely stable for the whole basin during other periods without remarkable variation. Precipitation in Lhasa River basin directly controls the magnitude of runoff and warm season precipitation plays an important role in the formation of runoff. The pronounced temperature rise and the variation of underlying surface due to human activity might cut down the contribution coming from the increasing precipitation and decreasing evaporation on the runoff formation areas.
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  Analyzing the hydrological characteristics and differentiation over the typical small basins in the upper reaches of the Weihe River

  HUANG Chenlu, YANG Qinke, HUANG Weidong, SONG Geqing, LIU Yahui

  JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2015, 37(5): 1312-1322. https://doi.org/10.7522/j.isnn.1000-0240.2015.0145

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  According to the measured hydrological and meteorological data over the two typical small basins in the Weihe River basin, the basin hydrological characteristics and differentiation with different climate and underlying surface were analyzed. It is found that in Qingyuan River and Niugu River basins the annual average air temperature is rising, the precipitation, runoff, silt discharge and precipitation runoff coefficient are totally decreasing; annual variations of precipitation, runoff and sediment are not the same. In 1998-2013, the precipitation of Qingyuan River basin decreased 8.6% as compared with that in the Niugu River. From 1993 to 2013, the runoff of Niugu River had decreased 21.4%; from 2000 to 2013, the silt discharge of Qingyuan River had decreased 24.0%. Between the two basins, the differences in area, river length, elevation and vegetation cover rate are-29.4%~-4.5%; the differences of air temperature and precipitation are-27.4%~16.7%; the difference in runoff is-90.2%~-84.7%; the difference in silt discharge is 292%~347%. Study of the impacts of hydrological factor on climate, underlying surface and human activities shows that from 1996 to 2013, Qingyuan River basin runoff had decreased 11.6%; from 1993 to 2006, Niugu River basin had decreased 25.9%; and then from 2007 to 2013, had decreased 10.5%. By the way, the diversion sediment reduction of human activities has a certain direction significance for basin comprehensive management and ecological environment construction. Meanwhile, full using different small watershed hydrological-meteorological data to analyze the changes of hydro-meteorological elements can provide an important basis for using distributed hydrological model to serve medium and small river flood forecasting and warning.
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  Evaporation paradox in the Heihe River basin

  WANG Zhongfu, YANG Lixiao, BAI Xiao, HE Chansheng

  JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2015, 37(5): 1323-1332. https://doi.org/10.7522/j.isnn.1000-0240.2015.0146

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  In this paper, based on the data from 12 meteorological stations in the Heihe River basin from 1960 to 2010, firstly potential evapotranspiration was calculated by using FAO Penman-Monteith model and then the changing tendencies in potential evapotranspiration and air temperature were analyzed by using rotated empirical orthogonal function(REOF) clustering method and Mann-Kendall test. The existence of "evaporation paradox" was also discussed. The results indicate that according to the rotated empirical orthogonal function(REOF) clustering method, the Heihe River basin can be divided into four subareas. "Evaporation paradox" only existed in the Hexi Corridor region(areas Ⅱ and Ⅲ) from 1960 to 1993; due to a marked increase in potential evapotranspiration, "evaporation paradox" had disappeared from 1994 to 2010. From 1960 to 2010, no "evaporation paradox" phenomenon had existed in other subareas. 1993 was a turning point for the potential evapotranspiration tendency, after which potential evapotranspiration in the Heihe River basin showed a statistically significant upward tendency. Wind speed was an important factor that affects the appearance and disappearance of "evaporation paradox" in the Hexi Corridor region in the Heihe River basin.
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  Analysis on utilization efficiency of agricultural water resources in Ganzhou District, Zhangye Prefecture

  WU Cuifang, LIU Xuebin, DENG Xiaohong, XIONG Jinhui, GAO Wenqi

  JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2015, 37(5): 1333-1342. https://doi.org/10.7522/j.isnn.1000-0240.2015.0147

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  Improving the water utilization efficiency is a key way to resolve water shortage in arid and semi-arid areas. In this paper, data envelopment analysis method is used to study the utiization efficiency of agricultural water resources in Ganzhou District, Zhangye Prefecture, Gansu Province, China, from farmers' view.DEAP 2.1 software is used to measure utilization efficiency of agricultural water resources and to estimate the potential of agricultural water-saving in this district based on thesurvey data of input and output in 2012 in the district. Finally, policy suggestions are put forward for how to improve the utilization efficiency of agricultural water resources based on this analysis. The results are shown as follows:firstly, the level of utilization efficiency of agricultural water is higher than that of the agricultural production efficiency in Ganzhou district. Secondly, the effect of adjusting the planting scale is more obvious than reducing water input to improve the utilization efficiency of agricultural water. Thirdly, the towns, whose utilization efficiency of agricultural water are higher, have more input redundancy of water, with serious water wasting; the towns, whose utilization efficiency of agricultural water is lower, have fewer water input redundancy with less water wasting. Fourthly, it is estimated that there is 76.825 million cubic meters of agricultural water-saving potential in Ganzhou District.
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  Spatio-temporal distribution of terrestrial evapotranspiration in Huaihe River basin based on MOD16ET data

  YANG Xiuqin, WANG Lei, WANG Kai

  JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2015, 37(5): 1343-1352. https://doi.org/10.7522/j.isnn.1000-0240.2015.0148

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  Terrestrial evapotranspiration(ET) is the key connection of a wide array of Earth system processes, which links water cycles and energy balances over land. The Huaihe River basin is located in the transition climate zone from North China to South China. In order to further understand the response of water cycles to climate change, global or regional, spatial and temporal analysis of ET in the Huaihe River basin is essential. Remote sensing technology has obvious advantages in monitoring evapotranspiration of heterogeneous surface. Based on verification of the accuracy of MOD16 ET, in this paper, the spatial and temporal characteristics of the Huaihe River basin were analyzed entirely. It is found that(1) the magnitude and spatial distribution of MOD16 ET over the Huaihe River basin are basically reasonable;(2) the multi-year averaged annual ET corresponds with the sum of four seasonal ET of the basin and has characterized by higher value in south and lower value in north;(3) in the last 15 years, the average annual ET of whole basin has ranged from 531.7 to 634.0 mm, with an indistinctive downward tendency; seasonal variation of ET has been approximately unimodal, which changes obviously with reason:143.7 mm in spring, 257.2 mm in summer, 120.7 mm in autumn and 66.6 mm in winter;(4) spatially, in the northwest, annual ET changing rate in grid scale is mainly dominated by summer, autumn and winter ET changing rate, but in the east annual ET changing rate is dominated by spring ET changing rate primarily. The research results have important significance for how to solve the shortage of water resources, how to utilize the limited water resources, and how to monitor and forewarn flood and drought disaster.
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  Research on the spatial variation characteristics of soil moisture and temperature in Dayekou basin of the Qilian Mountains

  NIU Yun, LIU Xiande, MIAO Yuxin, CHE Zongxi

  JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2015, 37(5): 1353-1360. https://doi.org/10.7522/j.isnn.1000-0240.2015.0149

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  Soil water and temperature impact greatly the function of water conservation. In order to study space change of water conservation function in a basin, the Dayekou basin in the Qilian Mountains has been chosen to study the spatial variation characteristics of soil temperature, and one million data has been obtained by 90 detectors of soil moisture and temperature, which has been analyzed by using the methods of variation coefficient. Results showed that:(1) There is a variation trend that soil moisture increases with altitude by a rate of about 2.35%·(100m)^-1, and soil temperature decreases with altitude by a rate of about 0.74℃·(100m)^-1.(2) The soil moisture on half-shady slopes is 1.2 times higher than that on half-sunny slopes, and 1.7 times higher than that on sunny slopes, and the soil moisture on half-sunny slopes is 1.4 times higher than that on sunny slopes. The soil temperature on half-shady slopes is 1.6 times lower than that on half-sunny slopes, and 2.2 times lower than that on sunny slopes, and the soil temperature on half-sunny slopes was 1.3 times lower than that on sunny slopes.(3) The correlation between soil moisture and depth is a quadratic parabola relation, with a linear temperature decreasing rate of about 0.536℃ per 10 cm.(4) The soil moisture under sub-alpine scrub forest is 1.5 times higher than that under arbor forest, 1.7 times higher than that under grass, and the soil moisture under arbor forest is 1.2 times higher than that under grass; The soil temperature under sub alpine is 1.6 times lower than that under arbor forest, and 2.3 times lower than under grassland. The soil temperature under arbor forest is 1.4 times lower than that under grassland.(5) The variation of soil temperature is the most severe on high altitude and half shady slopes, and the variation of soil temperature under grassland is the lowest on low altitude slopes and sunny or half-sunny slopes. This research conclusion is useful for searching river basin water balance and water conservation function, adjusting and managing stand structure and utilizing water resources.

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  Influence of climate change on various animal husbandry critical periods in northeastern Tibet Autonomous Region during 1961-2013

  DU Jun, MA Pengfei, DU Xiaohui, YUAN Lei

  JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2015, 37(5): 1361-1371. https://doi.org/10.7522/j.isnn.1000-0240.2015.0150

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  Based on daily mean air temperature data from ten meteorological stations in northeastern Tibet Autonomous Region from 1961 to 2013, the spatial and temporal distribution characteristics of the animal husbandry critical periods(the pasture growing season, green grass period, livestock fatten period and livestock losing weight period) were analyzed by using the methods of inverse distance weighted, inear regression and Mann-Kendall test et al, and the animal husbandry critical period in the next 50 years and 100 years are estimated. The results show that:(1) in the 53 years, the duration of pasture growing season had lengthened with a rate of 1.70 d·(10a)^-1due to the ending date delayed and the duration of green grass period had increased with a rate of 1.53 d·(10a)^-1; the first date of livestock fatten period had no obvious changed, but the ending date of the period postponed, thus the period had extended with a rate of 1.84 d·(10a)^-1; the livestock losing weight period had shortened with a rate of 4.33 d·(10a)^-1, resulting in beginning date significantly postponed and the ending date obviously early. In addition, the change of the pasture growing season was positively related with longitude, and negatively related with altitude.(2) M-K mutation test shows that the duration of pasture growing season had an earlier mutation in 1998, the green grass period had an obvious abruptly lengthened in 2005, while the abrupt of livestock fatten period and livestock losing weight period occurred in 2003.(3) In terms of decadal variations, from the 1980s to the 2000s, the durations of pasture growing season, green grass period and livestock fatten period had increased, but the livestock losing weight period had decreased.(4) Under the climate warming scenario with a rate of 0.044℃·a^-1, the durations of pasture growing season, green grass period and livestock fatten period would lengthen with a rate of 20.2, 18.4, 21.6 days, respectively, in the next 50 years and with a rate of 40.3, 36.9, 43.2 days, respectively, in the next 100 years; while the livestock losing weight period would shorten with a rate of 23.2 days in the next 50 years and with a rate of 46.5 days in the next 100 years. Obviously, this change tendency will be very beneficial to animal husbandry production in northeastern Tibet Autonomous Region.
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  Effects of grazing intensity on species diversity and biomass in alpine-cold forb meadow on the Tibetan Plateau

  MAO Shaojuan, WU Qihua, LI Hongqin, ZHANG Fawei, LI Yingnian

  JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2015, 37(5): 1372-1380. https://doi.org/10.7522/j.isnn.1000-0240.2015.0151

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  Changes of community structure, aboveground biomass, species diversity and the relationship between biomass and species diversity in an alpine-cold forb meadow under different grazing intensities in the northeast Tibetan Plateau, China, were studied. Results show that:1) The vertical structure differentiation was not obvious in heavy grazing(HG) with only 1 layer structure, while, in light grazing(LG), moderate grazing(MG) and non-grazing(CK), the vertical structure changed to two layers because of the better growth of grasses and Kobresia humilis; 2) the important value(IV) of Sedge, Gramineae and Forbs varied differently under different grazing intensities; The community compositions maintained at a high level in CK and MG, while it decreased in HG; 3) despite that short-term overgrazing might inhibit the growth of desirable forage and decrease the communities composition, the communities composition remained stable, because the constructive and dominant species had strong adaptability owing to their grazing resistance, eco-biological and hereditary characteristics; 4) the order of aboveground biomass was Sedge >Gramineae >Forbs in CK, LG and HG, while the order was Gramineae >Sedge >Forbs in MG, and the order of total biomass was MG >LG >CK >HG; the order of root-shoot ratio was HG >CK >MG >LG and the difference between HG and LG was significant.
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  Relationship between alpine meadow root distribution and active layer temperature variation in permafrost areas

  YUE Guangyang, ZHAO Lin, WANG Zhiwei, ZOU Defu, ZHANG Lele, QIAO Yongping, ZHAO Yonghua, NIU Li

  JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2015, 37(5): 1381-1387. https://doi.org/10.7522/j.isnn.1000-0240.2015.0152

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  The belowground root system can be a good indicator of adapting special permafrost environments, such as high-cold climate, repeatedly freezing and thawing process. In view of the lack of alpine root research on the Tibetan Plateau, different alpine meadow communities were selected to observe roots distribution and active layer temperature variations in permafrost areas along Qinghai-Tibetan Railway. The effects of active layer temperature variation on root spatial distributions and patterns were studied to reveal the adaptive mechanism of roots system in the changing permafrost environment. The results show that root growth and distribution are significantly impacted by change in soil temperature during the seasonally freezing and thawing process. In general, the upper soil layers are the most optimal location for roots in permafrost areas, roots have no enough living time to reach deep soil layers without impediments of frozen soil. So vast biomass is accumulated within the top soil and decreases sharply with depth. The overall mean root biomass of alpine grasslands was 3.38 kg m^-2, with the density of 21.41 kg m^-3 in 0~10 depth range, accounting for 63.4% of the total root biomass. Long-term cold environmental condition around root zone tends to increase root dry mass as well as overall productivity of alpine meadow communities. There is a tight relationship between alpine meadow root density and cumulative temperature of >0℃. Further research will help to have better knowledge and understanding of root growth and root function as related to permafrost heat and water status.
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  Foliar δ¹³C values of Sabina przewalskii in different habitats on the Tibetan Plateau: variation and relation with environmental factors and tree height

  ZHANG Youfu, CHEN Tuo, ZHANG Peng, XU Guobao

  JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2015, 37(5): 1388-1395. https://doi.org/10.7522/j.isnn.1000-0240.2015.0153

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  The foliar stable carbon isotopic composition(δ¹³C) of Sabina przewalskii Kom., a dominant tree population on the northeast Tibetan Plateau, and its correlation with foliar carbon and nitrogen contents, tree height, precipitation and soil moisture are examined. The results show that δ¹³C values range from-28.58‰ to-23.95‰, with an average of-25.66‰. The individual variation range of δ¹³C value, respectively, is 2.69‰ and 2.93‰ in two homogenous habitats, which indicates that the variation of foliar δ¹³C is determined by both botanical genetic character and environmental factors. The correlation of δ¹³C with tree height is strongly negative(p<0.01), and the negative correlation do not vary with sample sites. Foliar δ¹³C do not correlate with foliar nitrogen and carbon contents. The correlations of δ13C with soil moisture and precipitation are remarkably negative(p<0.001).
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  Study of the water sources of Salsola abrotanoides under various precipitation conditions

  XING Xing, CHEN Hui, CHEN Tongtong, HAN Lu

  JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2015, 37(5): 1396-1405. https://doi.org/10.7522/j.isnn.1000-0240.2015.0154

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  In arid and semiarid regions, precipitation is the most important water source for plants. The objective of this study is to determine the proportions of different water sources drawn by Salsola abrotanoides, examine the consistence of this proportion for Salsola abrotanoides during the growth season, investigate the water sources of Salsola abrotanoides along a precipitation gradient in Qaidam Basin. Salsola abrotanoides was selected to test the stem water δ¹⁸O and δD using Picarro L-2130i and Finnegan MAT-253. δ¹⁸O and δD was also tested for different available water resources including river water, soil water(profiled as 0~10 cm, 10~30 cm, 30~50 cm, 50~70 cm, 70~90 cm) and effective precipitation at same time, which were sampled every 15 days from June to September in 2010 in Da Qaidam and Dulan areas. The Multi-source mixed linear model was used to analyze the contribution of different water sources to Salsola abrotanoides. The Da Qaidam area local meteoric water line(LMWL) equation is y=7.656x+4.796(R²=0.908); The Dulan area local meteoric water line(LMWL) equation is y=6.005x-7.856(R²=0.7391). Both Da Qaidam and Dulan areas have strong evaporation. The wind speed in Dulan area is larger than that in Da Qaidam area, and the temperature was higher also. Vapor of the precipitation make the rake ratio and Ex d lower. Salsola abrotanoides can adjust their capabilities for up-take from different water sources and other physiological properties with variation in natural precipitation, but the strategies are various. At Da Qaidam site, where annual precipitation is low, Salsola abrotanoides obtains the highest proportion of water from soil water. However, the Salsola abrotanoides at Dulan site, where annual precipitation is higher, depended mainly on effective precipitation. Salsola abrotanoides at Da Qaidam site mostly uses soil water from deep layer. While at Dulan site, Salsola abrotanoides absorbs water from shallow soil more evenly. Both Salsola abrotanoides at Da Qaidam and Dulan areas change the absorbing proportion of different water sources during growth season. These results suggest that Salsola abrotanoides can adjust their capability for up-take from different water sources and other physiological properties with variation along a precipitation gradient. Precipitation pattern change will lead the Salsola abrotanoides' water use strategies adaptive change.
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  Evolutional characteristics of heat resources during farming period and its effect on agricultural production in Zhangye Prefecture

  YIN Xuelian, WANG Juanli

  JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2015, 37(5): 1406-1411. https://doi.org/10.7522/j.isnn.1000-0240.2015.0155

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  Based on the daily air temperature data from six counties of Zhangye Prefecture during l961-2010, the annual and decadal variations and their abrupt characteristics of beginning and the ending dates of farming period, farming days, as well as cumulated temperature higher than 0℃ in Zhangye Prefecture were analyzed by using the methods of five-day sliding average, climatic tendency rate, Mann-Kendall test and mutation test. The results show that, spatially, during the 50 years, the beginning date of farming period delayed with the increase of latitude in the central Hexi Corridor, but the ending date presented reverse tendency. The farming days decreased from southeast to northwest, and the cumulated temperature higher than 0℃ was outstandingly different in the south and the north of Zhangye Prefecture. Temporally, the beginning date of farming period was in advance and the ending date prolonged obviously, as well as the farming days extended, cumulated temperature higher than 0℃ increased from 1961 to 2010 in Zhangye Prefecture. From the1970s to the early 1980s, the beginning date of farming period postponed and the ending date was in advance, the cumulated temperature higher than 0℃ and farming days decreased in the most weather stations in the central Hexi Corridor. In the 1990s, it could be found that the ending date extended obviously, so farming days also extended, the cumulated temperature higher than 0℃ increased evidently. Especially in the 2000s, the cumulated temperature higher than 0℃ increased to the maximum during the last 50 years. The ending date of farming period, farming days and cumulated temperature higher than 0℃ in oases in front of mountains and desert oases had abruptly changed in 1995/1997, 1982/1990 and 1996/1999, respectively. The increase of heat resources in farming period had some influence on the adjustment of cropping structure and cropping production in Zhangye Prefecture.
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  Study of the tourism climate adaptability in Tibet Autonomous Region

  SHI Lei, HUANG Xiaoqing, Nima Ji, Ciren Yangzong, LUO Zhen

  JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2015, 37(5): 1412-1419. https://doi.org/10.7522/j.isnn.1000-0240.2015.0156

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  In order to analyze the tourist climatic adaptation in Tibet Autonomous Region, the following works were done sequentially:(1) calculating wind effect index and temperature-humidity index based on the observational data from 38 meteorological stations during 1980-2014 in the autonomous region and classifying through cluster analysis;(2) dividing the tourism resources in the region according to the cluster result, combined with landscape features and administrative division;(3) evaluating and analyzing the changing trend of wind effect index, temperature-humidity index and air oxygen content index, respectively, of various divisions. Then, tourism resources of the autonomous region can be divided into the following six divisions:Amdo and parts of the southern periphery of the region(DivisionⅠ), northern Ali and most of Nagqu(Division Ⅱ), southern Ali, most parts of Qamdo and southwest of Shigatse(Division Ⅲ), most of the Brahmaputra(Division Ⅳ), the western Nyingchi and the central Qamdo(Division Ⅴ), and the southeastern Nyingchi(Division Ⅵ). It is found that the spatial distribution of wind effect index and temperature-humidity index have a decline tendency from southeast to northwest. The biological temperature in the east is more comfortable, which is suitable for tourism during March to October, while in the west the temperature is lower, with the suitable tourism time is May to September. The variation tendency of monthly oxygen concentration is a parabolic curve, with a peak in August and a nadir in January. Oxygen content in southeast is the highest, 60% or more. In recent years, the climatic condition in the region is evolving towards warmer and more comfortable. The annual wind effect index and temperature-humidity index in the region represent significant linear growth tendency with the ratio of 21.79·(10a)^-1 and 0.32·(10a)^-1, respectively. The suitable time for tourism in the drainage basin of Brahmaputra and part of east has extended by 1~2 months in recent five years as compared with the past 30 years.
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  An evaluation of tourism climate suitability in Altay Prefecture

  CAO Kaijun, YANG Zhaoping, MENG Xianyong, HAN Fang

  JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2015, 37(5): 1420-1427. https://doi.org/10.7522/j.isnn.1000-0240.2015.0157

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  Climate comfort degree(CCD) is one of most important factors which can affect the tourists choosing tourism destination. 54-a climate data(from 1960 to 2013) were selected in this paper as the input data; using GIS spatial analysis method the temperature humidity index(THI), wind chill index(K), index of clothing(ICL) and comprehensive comfort index(C) were calculated in monthly scale for Altay Prefecture within 500 m500 m grid size with consideration of temperature lapse. After comparatively analyzing the differences between climate comfort and comfort period of the four indexes(THI, K, ICL and C), it was found that the comprehensive comfort indexes can reflect the comprehensive effect of human feeling about climate factors from an objective view, and can achieve more accurate assessment results. In addition, it was also found that the tourism climatic comfort levels are greatly influenced by terrain and season in Altay Prefecture. Travel comfort level changes obvious, and outdoor travel comfortable period is short. Winter is not suitable for outdoor activities and spring is still not comfortable in the southern hilly areas and plains of the Altay Mountains. While in summer, the human feeling is better both in the hilly areas and the mountain valleys, accounting for 39.62% of the total, with the rest areas of less comfortable. The south of Habahe, Burqin, Altay and the central and south of Fuhai are feeling more comfortable in autumn. Travel comfortable period in Altay Prefecture lasts 1 to 5 months, with regional distribution of tourism resources fitting for climate characteristics, which is conducive to develop tourism in the prefecture.
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  An essay of the cryosphere investigation in the western United States

  DING Yongjian, QIN Dahe, REN Jiawe

  JOURNAL OF GLACIOLOGY AND GEOCRYOLOGY. 2015, 37(5): 1428-1434. https://doi.org/10.7522/j.isnn.1000-0240.2015.0158

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