Two models (HadCM3 and EACHE5), which have good ability for temperature simulation in China, are used to calculate the distribution of frozen ground in China, based on testing of the model performance of the Couple Model Intercomparison Project (CMIP3). The trend of frozen ground change in spatial distribution under Scenario A2 in 2006-2050 was calculated by the Kudryavtsev method with ArcGIS and using the datasets of digital soil and vegetation. In the next 50 years, the frozen ground in China will shrink. In 2050, permafrost on the Tibetan Plateau between the Bayan Har Mountains and Tanggula Range and in the Transhimalaya will degenerate. As compared with that in 2006, the frozen ground area in China will decrease about 10.7%.
The Qinghai-Xizang plateau and its bordering mountains is a special geographical unit in the low and middle latitudes in the Northern Hemisphere, it has widest plateau and many peaks higher than 8 000 m a.s.l. This special geographical unit is a large center of modern glaciation, behind the polar regions (the Antarctica and the Greenland), making China to be a largest glacier country in the low and middle latitudes on our planet. The main feature of the modern equilibrium line altitude (ELA) is latitudinal zonality, increasing about 150 m per degree from 49 N to 28 N. Moreover, the ELA appears asymmetric rings on the plateau. Based on the published literatures, the glaciers during the Last Glacial Maximum were estimated to be 50×104 km2, 8.4 times larger than that of modern glaciers. According to the relationship between summer (June to August) average temperature and annual precipitation at ELA, the ELAs in western China (to the west of 105° E) during the LGM have been reconstructed, and the distribution and features of ELAs were similar to that of present. In the interior and the northwest of the plateau, the decrease of ELAs was less than 500 m, commonly, 200 to 300 m, whereas, the decrease of ELAs was about 800 m on the southeastern margin of the plateau, with a maximal decrease of about 1 000 to 1 200 m. The decrease of ELAs is about 500 m in the Tianshan and Altai ranges. However, there are no glaciers in eastern China (to the east of 105° E) at present. The glacial landforms that formed during the last glacial cycle have been preserved in several mountains, such as Helan Mountains, Taibai Mountains, Changbai Mountains and high mountains in Taiwan Island. The decrease of ELAs was 800 to 900 m, with an absolute value larger than that in western China. According to the reconstructed map of ELAs during last glaciation, and considering the palaeoclimate and palaeoenvironment, it is very clear that there were no glaciers developed on the mountains with peaks less than 2000 m in eastern China during Quaternary.
In this paper, based on observation and expedition, the relationship between ablation and surface debris cover in the tongue area of a large typical valley glacier on the south slopes of Mt. Tuomuer in the Tianshan Mountains has been studied. The surface debris cover is of important impacts on surface ablation, hydrological process of glacier and glacier change. It is revealed that surface debris has obvious inhibiting effect to surface ablation when the depth of surface debris cover is more than 3 cm. The surface ablation of glacier will weaken markedly with increasing the depth of debris cover. Measurement on the surface of the Koxkar Glacier shows that depth of surface debris cover reduces gradually with altitude. Due to the influence of surface debris on surface ablation, the maximum ablation on the Koxkar Glacier appears in the altitude range of 3 800-3 900 m, where the depth of surface debris cover is less 10 cm. Ablation intensity decreases with altitude and reduces with depth of debris cover due to the effect of surface debris. Another pronounced feature of surface debris-cover glacier is that supraglacial lakes develop universally over the ablation area. Supraglacial lake makes melting erosion onto ice and quick draining of lake water, which becomes the main process of runoff yield and conflux. It is found that in the Koxkar Glacier water yield of melting erosion from 2-3 supraglacial lake is equal to the losing ice volume in the glacier terminus per year. These processes, i.e., running in cycle, formation, melting expansion and draining, are produced by thermokarst effect, such as supraglacial lakes, are not only one of important ablation pattern, but also one factor that influences mightily the changes of glacier and glacier hydrological process. Thinning of glacier is primary to the change of the large glaciers in the south slopes of the Mt. Tuomuer, which is unlike to the most glaciers in China, of which changes of glacier terminus and glacierized area are dominating.
Investigation of Quaternary glaciation in the mountains in northwestern Yunnan Province, ranging from 4 000 to 4 500 m a.s.l., indicates that the glaciation mainly depended on the planation surface from 4 000 to 4 300 m a.s.l. Glaciers were small ice caps and valley glaciers during the early and middle stages, and limited cirque glaciers during the late stage of the Last Glaciation. Glacial advance mainly took place during the Last Glaciation. Analyzing the equilibrium line altitudes in the Last Glaciation, summits of the mountains and the planation surface altitudes indicates that the planation surfaces, on which glaciers in the Last Glaciation depended, were 50-400 m higher than ELA. The altitude between 4 000 and 4 500 m provided the beneficial height for the glaciers development. Analyzing the evolution of glacial extent shows that the glacial extent during the middle of MIS 3 was larger than that in the Last Glaciation Maximum (LGM). It is believed that the glacial advance during the MIS 3 was due to both plentiful precipitation and low temperature. Data of paleo-temperature and paleo-precipitation and Quaternary glaciation investigation reveal that the Last Glaciation was resulted from climate change and tectonic movement.
By using a 1-h temporal resolution and 30-m spatial resolution grid-based distributive surface mass-energy model, the energy distribution and mass balance on the Laohugou No.12 Glacier were simulated. The period of simulation was from June 1st to September 30 th, 2012. The simulated results were validated by solar and net radiation data from meteorological stations and measured mass-balance data, respectively. The simulated results show that terrain factors have a considerably effect on solar radiation. Diffuse radiation accounts for 38% of global radiation. The mass balance averaged over the simulated period is 893 mm w.e. During the simulative period and over the glacier, the net radiation is the principal energy source (84%), followed by the sensible het flux (16%); whereas the main energy expenditure is the heat flux for snow/ice ablation (62%), followed by the latent heat flux (38%).
In this article, based on the meteorological data from 64 meteorological stations from 1960 to 2010, the changing trend of frozen ground over the past 50 years in Xinjiang are analyzed and the relations between temperatures (average ground temperature and air temperature), precipitation in spring and winter, average snow depth and frozen ground depths (averaged one and the maximum one) are discussed. The following conclusions can be drawn: (1) Viewed 10 years as a span, both the average frozen ground depth and the maximum frozen ground depth over the past 50 years have decreased steadily. The average frozen ground depth has decreased 7 cm, 10 cm and 4 cm, respectively, and the maximum frozen ground depth has decreased 11 cm, 16 cm and 9 cm, respectively, in Xinjiang, North Xinjiang and South Xinjiang; (2) Average air temperature and ground temperature in Xinjiang have increased undulately and have good correlation with frozen ground depth, with correlation coefficient of -0.67 and -0.77, respectively, with average frozen ground depth, and -0.51 and -0.65, respectively, with the maximum frozen ground depth. The rise of ground temperature and air temperature means decrease in frozen ground depth; (3) Annual precipitation in winter and spring has better correlation with frozen ground depth, with correlation coefficients with average frozen ground depth and the maximum frozen ground depth of -0.40 and -0.37, respectively. Besides, the average snow depth in Xinjiang has a few relativity with frozen ground depth, due to the insulating effect of snow on the ground.
Based on the data of daily mean air temperature and topsoil ground temperature (0-cm, 10-cm and 20-cm) in spring (March to May) from 74 weather stations in Heilongjiang Province from 1981 to 2012,the temporal-spatial characteristics of the topsoil ground temperature in spring are analyzed. According to the spatial distribution of EOF2, the south area and the north area are defined in the province. The main conclusions are as follows: The topsoil ground temperature of spring in the province has obvious annual fluctuation. More specifically, the temperature plunged to the lowest point in 1987 and to the peak in 2008.
Despite the fluctuation, the topsoil ground temperature from 1981 to 2012 had increased. However, there were nine years with the topsoil ground temperature lower than the normal since 1991. There is a significant positive correlation between the ground temperatures at 10-cm depth and at 0-cm or 20-cm depth. The topsoil begins to thaw in March and the ground temperature at 10-cm depth stands at 6 ℃ mainly in April by adopting a 5-day running mean method. Taking the air temperature and the 20-cm ground temperature as two factors, the 10-cm ground temperatures are predicted by using the dual linear regressive model from 1981 to 2012 for every weather observations in Heilongjiang Province. The absolute error averaged over the province is 1.05 ℃ and the error in April is the minimum among three months of spring. The average absolute error is 1.05 ℃ and the maximum error is 1.9 ℃ for a prediction of 10-cm ground temperature of spring, 2013.
The Heigou River originates on the southern slope of the Mount Bogda, the largest glaciated center in the eastern Tianshan Range. Ancient glaciers advanced and retreated dramatically during the glacial-interglacial cycles in Quaternary, the spectacular glacial depositional landforms were produced and well-preserved in the Heigou River valley, recording a complex history of Quaternary glacial cycles and landform evolution. These glacial landforms are a direct imprint of fluctuation of the ancient glaciers. Dating the glacial landform could determine the temporal and spatial variations of the ancient glaciers in this valley and also provide essential information for reconstructing the paleoenvironment in this region. Optically stimulated luminescence (OSL) dating technique was used to determine the ages of the fluvioglacial deposits (the sand lenses that sandwiched between tills in moraines) and glacial tills in this valley with single aliquot regenerative-dose (SAR) protocol. Based on the dating results, and considered the principle of geomorphology and stratigraphy, the data of palaeoclimate as well as the glacial histories in the other valleys of the Tianshan Range, the following conclusion could be drawn: five glacial advances occurred in the Heigou River valley, they are glacial advances of Little Ice Age (glacial advances in the cold periods since the 16th century) and Neoglaciation (glacial advances during the last 3-4 ka) in Holocene, and other three glacial advances in the late and early period of last glaciation and penultimate glaciation, are equivalent in age to MIS 2, MIS 4 and MIS 6. In addition, the dating results of glacial tills and fluvioglacial deposits show that the SAR protocol was appropriate for equivalent dose (De) determination of fluvioglacial deposits and that OSL did not work to date glacial tills in this study, because the signals in quartz grains in glacial tills was not completely bleached. The glacial landforms indicate that the ancient glaciers at their maximum extensions during the LIA, Neoglaciation and the last glaciation were 7.6 km, 11 km and 14 km long, respectively.
In this paper, the characteristics of microparticles in atmospheric precipitation and the temporal variation of insoluble dust particles in rain water are analyzed primarily on the samples collected around the Mt. Yulong. The analyses indicate that there exist distinct seasonal features of the microparticles and chemical ions in precipitation, and the concentration of microparticles increase significantly in precipitation in the post-monsoon season, reflecting distinct seasonal variations of precipitation chemistry. The representative chemical ions and dust particles (SO42-, Mg2+, Ca2+, K+, NH4+, NO3- and dust) in Lijiang and Ganhaizi atmospheric precipitation are well correlated, indicating that they have common sources. Variations of chemical ions and dust particles in precipitation are greatly consistent with each other. The variations of pH value and electricity conductivity (EC) are greatly depended on and influenced by the dust events which frequently occur in spring or winter. It is also revealed that marine aerosols has no contribution to the dust deposition in precipitation around the Mt. Yulong, except for Cl- and part of Na+. Moreover, chemical composition and dust analyses indicate that the atmospheric environment in Lijiang is somewhat influenced by the anthropogenic activities.
Oasis farmland in arid regions mainly depend on water diversion for irrigation by canals, where a large deal of water is evaporated from the canal surface, especially under the condition that the channel distributes widely in the oasis, so estimating the evaporation from canal surface is very significant for water resources management. In this paper, canals in Zhangye Oasis are taken as the main research object, and the evaporation from canal surface is estimated using an empirical equation, which was based on energy balance and proposed by Mihara. It is found that (1) when it is sunny, evaporation rate in the daytime is significantly larger than that in the nighttime, but it does not different a lot between daytime and nighttime when it is cloudy. Air temperature and relative humidity are the key factors to evaporation rate; (2) when it is sunny, cumulative evaporation in the daytime is about twice as much as that in the nighttime, but almost the same in daylight and at night when it is cloudy. Evaporation rate is the dominant factor.
Traditional statistics and geostatistics methods are used to study the soil moisture variation characteristics in vertical direction, spatial heterogeneity in horizontal direction and spatial distribution in the overgrazed and the nocuous grass invading alpine meadow in the Qilian Mountains. The results show that in vertical direction, soil moisture decreases with depth, and so does the variation rate. Coefficient of variation of the soil moisture distribution in superficial layer and deep layers are larger than that in middle layers. In horizontal direction, the soil moisture in 0~40 cm depth range possesses a feature of moderate variability. The 10~20 cm depth range is mainly affected by root system, with the maximum variability in the random section. For the rest layers, soil moisture due to variability of random section decreases with depth, while that due to the autocorrelation section increases. In macroscopic view, content of soil moisture is closely related to micro-topography, with positive correlation with the distance to rivers and negative correlation with the height above sea level.
Agricultural production in Kashgar Prefecture has been damaged frequently and severely by hailstone since 2000. Eighteen hailstone weather processes were analyzed based on the data monitored with new generation weather radar (CINRAD/C) in the western Kashgar during 2009-2012, with the hailstone warning indexes applied in central China and East China. Three hailstone warning indexes were summarized for western Kashgar Prefecture. It is found that the combination reflectivity (CR) is greater than or equal to 50 dBz, the echo top height (ETH) is greater than or equal to 9 km and the cloud vertical integrated liquid water content (VIL) is greater than or equal to 20 kg m-2 . The accuracy rate of hailstone warning reached 84.6% for the historical data from 2011 to 2012 on account of above indexes in western Kashgar. According to monitoring products from 14 hailstone weather processes with detailed records, the hailstone warning effectiveness is 27 min on average. Taking the continuous strong hailstone processes on May 13, 2012, May 23, 2012 and June 18, 2013, respectively, as examples, analyzing their monitoring data before and after the hailstones found that the hailstone shooting start time synchronized with the time of monitored maximum (high) radar value in the three processes, and CR and ETH reached the threshold values of warning indexes. However, VIL reached the warning index 11 ~ 19 min later, and the time necessary for radar product achieving warning index was 7~17 min earlier. So, it is possible to increase the hailstone warning effectiveness more than 30 min in the western Kashgar, which proves the feasibility of hailstone weather real-time warning by using CINRAD/C monitoring product, and provides strong technical support for local hailstone disaster prevention.
For studying thermal stability of tower footing along the Qinghai-Tibet DC Interconnection Project, a coupled heat transfer model among air, thermosyphon and soil is established. Based on the model, heat transfer processes around the cone-cylinder pipe and cooling effects of the thermosyphon are simulated by finite element method. Results from the numerical simulation indicate that in cold seasons as thermosyphon works, ground temperatures around the thermosyphon have great gradients and distribute as a spindle, which reveals a remarkable cooling effect of thermosyphon. Meanwhile, cold energy from thermosyphon flows quickly to base of cone-cylinder pipe as high thermal conductivity of the concrete pipe. As a consequence, extensive cold permafrost develops beneath the pipe, which is good for cone-cylinder pipe. In warm season, thermosyphon does not work and shallow ground temperatures are determined by air temperature. Also since high thermal conductivity of the pipe, the maximum seasonal thawing depth near pipe is obviously greater than that beneath original ground with a difference about 35 cm. Ground temperature around the pipe is uniform between profiles with and without thermosyphon. Quickly cooling processes of ground temperature near the pipe occur mainly within the first 5 years after application of the thermosyphon. And then, depth of permafrost table and permafrost temperatures increase slowly as air temperature increase. Overall, under the scenario of climate warming, soil beneath cone-cylinder pipe still keeps frozen, which meet the need of the project.
Evaluation of the embankment thermal stability is a complicated decision-making issue. Through the application of extension theory, mean annual ground temperature, volume ice content, nature permafrost table, embankment height and road trend are selected as the evolution indexes of embankment thermal stability in permafrost. An entropy-weight and matter-element e xtension model is established by introducing the entropy weight method into theory of extenics, which avoids non-determinacy and optional randomness resulted from subjective opinions. Embankment over permafrost along the Qinghai-Tibet Railway is evaluated using the entropy-weight and matter-element e xtension model. Comparing of evaluated results with the field observation shows that the evaluation is very satisfying. The present method is reasonable in comprehensive assessment of the embankment thermal stability.
As China's ongoing electric transmission lines constructed in permafrost regions, the issues related to permafrost are concerned increasingly. The general disasters of thawing and freezing in the transmission lines constructed in permafrost regions and the solutions are analyzed in this paper. It is found that since the moment when the tower foundation of transmission line was buried, the permafrost around the foundation has been disturbed more strongly and the heat transfer has been more prominent as compared with those in highway and railway foundations. Therefore, controlling of diseases resulted from frost heaving and thaw settlement should be conducted in every stages of the construction of transmission lines. Transmission line belongs to dotted line project, so the frost heaving and thaw settlement would be avoided or eliminated by wise selection of line and tower type. Frost heaving should be paid more attention in choosing tower type. The choice of the construction period and time and the controlling of the construction process will be effective in controlling thermal disturbances if there is an open excavation foundation. A simultaneous permafrost monitoring following the construction going on will play an important role in analyzing project stability, switching engineering construction sequence, and operating and maintaining the project. It turns out that the performance of the permafrost issues are varying in different stages, it could only be tackled scientifically by a comprehensive research.
CO2 geological storage potential and suitability assessment could be divided into five stages in China, which are regional predicted potential (E-class), basin presumed potential (D-class), target controlled potential (C-class), location base potential (B-class) and perfusion project potential (A-class). 1:5 000 000 maps will be compiled in the first stage, CO2 geological storage maps of sedimentary basins will be compiled in the second and third stages, and CO2 geological storage maps of demonstration project will be compiled in the fourth and fifth stages. Mapping of CO2 geological storage potential and suitability assessment should be done step by step, and the specific method can be improved continuously in the practice process.
Based on monthly precipitation data from six meteorological stations and annual runoff data from six hydrometric stations in the Yarlung Zangbo River basin from 1961 to 2010, the changes of precipitation and its influence on runoff were analyzed in this paper. The main results are as follows: the precipitation shows no significant increase in the period, with the rate of 3.3 mm (10a)-1, and 1.9 mm (10a)-1 in the dry season and 1.4 mm/10a in the wet season. Precipitation was more in the 1960 s, stable in the 1970 s, the least in the 1980 s, with an increase in the 1990 s and no significant increase in the first ten years of this century. The CV (variation coefficient) of runoff was 0.15~0.40, with a small annual variation and periodic variation. The 1960 s was a relative wet period, followed with a decrease in the 1970 s and a minimum in the 1980 s, then a rise again. A statistical analysis shows that there is a significant correlation between precipitation and runoff, and the change of precipitation is the most important impact factor to the runoff in the Yarlung Zangbo River basin.
Drought and flood are the most representative extreme hydrological event, which arouse more and more people's concern under the background of global change. In this paper, using traditional meteorological drought index-standardized precipitation index (SPI) and wavelet analysis, inverse distance weighting interpolation method and regression analysis to analyze the distribution of droughts and flood and key controlling factors in the Tarim River basin in recent 300 years. It is found that the drought and flood events have significantly increased in recent 300 years; flood events are more serious than drought events; frequently occur and cluster together in Kashgar, Aksu and other place; drought and flood have taken place alternately from west to east of the Tarim River in nearly 60 years; there was 15-year periodicity of disasters in the Tarim River basin; in the study area humidification will strengthen in the further 5-10 years; PNA impacting the fall and winter's SPI values are more significant; finally, droughts and floods have more serious impact on the industry of agriculture and animal husbandry, especially the flood disaster.
To investigate the impact of land use change on the water yield in the upper reaches of the Fen River, the drainage basin above the Hecha Hydrological Station was selected as a case study area. Two approaches, including transfer matrix analyzing of land use and hydrological simulating with SWAT model, were applied. A transfer matrix analysis of the land use in this basin from 1995 to 2010 found that land use had characteristics of stage. From 1995 to 2000, the main land use change was transformation from farmland to forest and from farmland to grassland. From 2000 to 2010, the area of construction land had increased, which occupied the farmland. Using the calibrated SWAT model, the water yields of three land use scenarios were simulated under the same climate conditions from 1990 to 2000. The differences between their water yields were small, because the land use changes were not obvious from 1992 to 2000. The average annual water yield of the land use in 1995 was 85.69 mm, in the 2000 s was 85.75 mm and in the 2010 s was 85.82 mm. However, the water yield from year to year was inconformity, because there were less and normal precipitation years and more precipitation years, and the soil moisture declines as the land use change, indicating that the water yield of a basin is not only associated with land use, but also affected by precipitation. As regards to sub-basins, it was also found that precipitation affects the hydrologic response to the land use change in a basin. The above results show that under the replacing farmland with forest and grassland policy and social and economic development, land use in the Fen River basin were the transformations from farmland to forest, from farmland to grassland and from farmland to construction land. The changes could increase a small amount of runoff and decrease soil water, but the response of the watershed hydrological process to land use change is also depend on precipitation.
In this study, the change trends of bacterial abundances and the affecting factors in soils of various belts (ranging from 10 m to 500 m) parallel to the Qinghai-Tibet Highway were investigated. Along the highway, the abundances of bacteria in the soils range from 2.71×107 copies·g-1dw to 7.20×108 copies·g-1dw. Perpendicular to the highway, the abundances of bacteria in the soils increase from 10 m to 500 m and then turn to stationary, with a significant boundary at the distance of 50 m. Correlation analyses between the environmental factors and the abundances of bacteria in the soils indicate that the soil bacterial abundance have significant positive correlation with the total nitrogen, the total organic carbon and the vegetation coverage. The study results indicate that the distance of the Qinghai-Tibet Highway influencing the soil bacterial abundance is approximately 50 m.
The Binggou is located in the upper reaches of the Heihe River, Southern Qilian Mountains. Vegetation plays an important role in sustaining a stable runoff of the Heihe River in this region. There are many researches about hydrology and vegetation in the region, but less about underground microorganisms. In this study, the functional microorganisms participated in N and P cycles are focused on. A few vegetation quadrats were investigated in situ and soil samples were taken at three altitudes. The soil physicochemical properties were determined and the functional microorganisms including nitrifier, denitrifier, diazotroph, phosphate-solubilizing bacteria (PSB) and phytate-mineralizing bacteria (PMB) were cultured in laboratory. Colony forming units (cfu) of these functional microorganisms were counted. It is found that number of the functional microorganisms decreases with soil depth. Interestingly, number of nitrifier decreases and that of denitrifier and diazotroph increases with altitudes (2 905 m-4 130 m a. s. l.). Canonical correspondence analysis (CCA) shows that number of nitrifier is mainly affected by the underground biomass and the soil pH value, while number of denitrifier, diazotroph, PSB and PMB correlates with soil moisture, vegetation coverage and aboveground biomass. Hierarchical cluster analysis indicates that the superficial soil layers (0-40 cm) at lower altitudes (E1-2 905 m and E2-3 128 m) will cluster together. The deeper soils (60 cm) at lower altitude cluster with the soils at higher altitude (E3-4 130 m). This study demonstrates that number of the functional microorganisms mainly depends on altitude and its covariables in alpine soils.
In this study, the bacterial distribution and diversity in rhizosphere soil of Achnatherum splendens Trin changing with altitude in the upper reaches of Shule River were studied. The study results show that the number of cultivable bacteria varied between 1.7×107 -10.8×107 CFU·g-1, with an average of 6.4 ×107 CFU·g-1; there was a tendency that the number of cultivable bacteria decreased first and then increased; there was a significantly positive correlation between the number of cultivable bacteria and soil total nitrogen, urease and sucrose; the relationship between the number of cultivable bacteria and organic carbon and phosphatase was positive too; pH was a negative factor, which influences the number of cultivable bacteria and the diversity of bacteria. Based on 16S rDNA gene sequences and the phylogenetic tree, the cultivable bacteria in the study area include 15 genera, of which Pseudomonas and Bacillus genus are the dominate bacteria.
The Source Area of the Yellow River (SAYR) is located in the transition zone of permafrost and seasonally frozen ground on the northeastern Qinghai-Tibet Plateau. The changes in alpine ecosystems and interactions of frozen ground and alpine vegetation under a warming climate and degrading permafrost have been of concerns for a long time. Under such a circumstance, what are the characteristic of vegetation in different zones of frozen ground. To investigate the vegetation features in the SAYR, four monitoring sites were established: Chalaping site in the continuous permafrost zone in the southern SAYR; Zalinghu site in the southern bank of the Zhaling (Gyaring) Lake in the patchy permafrost zone in the south-central SAYR; Maduo Xiang (Village) site in discontinuous permafrost zone in the western SAYR, and Elinghu site in the northern bank of the Eling (Ngöring) Lake in zone of seasonally frozen ground in the north-central SAYR. In combination with the surveys on plant ecology and monitoring for the hydrothermal processes around these sites, the variations in different types of frozen ground were analyzed. Preliminary results demonstrated that vegetation coverage and the values of diversity indices were higher in cold (<-1 ℃) permafrost regions: Chalaping>Maduo Xiang (Village)>Elinghu, whereas the southern bank of the Zaling (Gyaring) lake in patchy permafrost zone had the lowest vegetation coverage and its values of diversity indices were between Chalaping and Maduo Xiang, manifesting a serious plant degradation. As for the evenness indices, the Zhalinghu had the highest value followed by Chalaping. The aboveground biomass investigation declined in the order of Chalaping>Maduo Xiang (Village)>Zalinghu>Elinghu, and some species appeared in the northern bank of the Eling (Ngöring) Lake indicating the vegetation degradation. This study on alpine vegetation in the SAYR provides some basic features for understanding the ecological changes under degrading permafrost conditions. However, more systematic investigations and monitoring need to be carried out to better evaluate the ecological and hydrological impacts of climate change and permafrost degradation.
