Xinjiang is the largest area of glaciers and snow cover resources in China. Glaciers and snow melt water plays an important role in water resources. The hydrological processes of the rivers have been changed by the responses of glaciers and snow cover to climate change during last 50 years. The runoff of mountain areas occupies over 80% of the total surface runoff, and the proportion of glaciers and snow melt water is up to 45% or more. The rivers in the Altai Mountains in the northern of Xinjiang and in the north slope of the Tianshan Mountains were mainly dominated by snowmelt runoff. The rivers are located in the southern slope of Tianshan, Kunlun Mountains, Karakorum Mountains and the Ili River Basin was supplied mainly by glaciers melt water. The flood season of the river supplied by snowmelt is in the spring to early summer, and which of the supplied by glacial melt water is in summer. With the transform of the climate changes to warm and humid in Xinjiang, the hydrological processes of alpine basin had presented some significant responses to the climate warming and the snow cover increased: the maximum runoff month advanced in the rivers supplied by snow cover, and the runoff decreased obviously in summer; the runoff in June to September increased significantly in the river supplied by glacier melt, and the runoff in flood season increased, and the annual runoff increased. The changes of the hydrological process in different types of river have had a significant impact on water supply and flood safety management in the lower reaches of rivers. So it is necessary to adjust the strategies of the water resources management in order to adapt the effects of climate change on hydrological processes, and mitigate the effects of climate change on water safety.
The most important factors affecting the active layer depth and distribution of permafrost on the plateau are snow cover and thickness of the organic soil layer, except for air temperature and solar radiation.In this study, data from two typical field sites (Binggou Station and Tanggula Station) on the plateau were used.The two stations were established by the CAREERI, CAS to monitor the impact of snow cover and organic soil layer on the energy balance and thermal state within the active layer.In order to find the process-based explanations for the recent monitoring results, the one-dimensional heat and water flow model CoupModel was used to calculate the vertical heat and water fluxes in a soil-snow-atmosphere system for climatic conditions at the two field sites.The model was successfully adjusted and applied to simulate the active layer dynamics under a surface covered by snow and tundra soil conditions.Subsequently, the model was used to investigate the effects of snow cover and organic soil layer on the active layer.The investigation on the influence of snow cover on the active layer at Binggou Station revealed that snow cover depth is the key to the effect of snow cover on the active layer.The shallow snow cover (less than 20 cm) is advantageous to frozen soil development.The thick snow cover in winter obviously insulates the subsoil against energy losses to the atmosphere.The frozen active layer depth is reduced and not conducive to the conservation of permafrost.Sensitivity study shows that the thawing depth of the active layer decreases with organic increasing.The organic layer makes the underlying soil less responsive to solar radiation and air temperature fluctuations, owing to its low thermal conductivity and high heat capacity, and thus provides a protection against permafrost thawing.Both influences are of importance for the behavior of permafrost under global warming.
By means of RS and GIS techniques, in association with the first glacier inventory data and digital elevation model, statistical studies concerning with the orientation and the altitudinal distributions of glacierized areas in Yarlung Zangbo River basin, and individual glacierized area, average ice thickness and ice volume as well as mass balance and equilibrium line fluctuations for 21 selected large marine glaciers in 1976, 1988, 2005 were conducted. The results enrich the information of the first glacier inventory considerably for the studied basin. The glacierized area changes of the 21 marine glaciers, together with their response to climate change, were also statistically analyzed. The study results suggested that the large marine glaciers, developing over three different climate environments, had shown fluctuation in response to the variation in temperature and precipitation during 1976-1988 and 1988-2005, respectively. Generally speaking, however, no significant advance or retreat could be seen from the 21 large marine glaciers. This was possibly due to the rising precipitation having offset the negative effect of rising temperature on glacier mass balance. Alternatively, there could be a supplementing effect in the accumulation area over high altitude for large glacier. Further study on this issue will be undertaken for much concrete conclusions.
NCAR Community Land Model (CLM) is a currently sophisticated land surface model. For the purpose of validating CLM in studying land-atmosphere process in the Tibetan Plateau, the simulated data of WRF (Weather Research and Forecasting Model) by using dynamical downscaling method were applied to the forcing data sets of CLM model. Comparing the observed data from weather stations in the plateau with the air temperature and downward short wave radiation of the forcing data set found that the correlation coefficients between the simulated and observed monthly mean air temperatures and downward shortwave radiations are larger than 0.92 (p >0.05), and those for atmospheric pressure and specific humidity are larger than 0.80 (p >0.05). The simulated data of WRF model can be used to drive the CLM model, though it is unstable to simulate precipitation and wind velocity. Thus the simulation performance of CLM in the Tibetan Plateau using ground temperature from weather stations and eddy flux data sets is validated. It is revealed that the simulation of surface temperature is reasonable, but there is larger deviation between simulated and observed surface temperatures. The correlation coefficients for latent heat flux and sensible heat flux are 0.87 and 0.68(p >0.05), respectively. Based on the feasible forcing data set and reliable simulation results, the temporal and spatial distributions of energy balance on the Tibetan Plateau are analyzed.
To initially describe the relationship between surface vegetation characteristics and soil properties in permafrost active layer in Xidatan on the Tibetan Plateau, two sampling plots were selected, where the vegetation characteristics, soil properties and permafrost active layer were investigated simultaneously. It is found that the plots are dominated by shallow root vegetations, with 63% and 62.2% of belowground biomass concentrated in the top 0~10 cm soil layer. The existence of permafrost and hydrothermal regime in the permafrost active layer play a decisive role in the evolution of vegetation ecosystem under the same climate condition. The total nitrogen, available nitrogen and available kalium are found closely related to organic matter content, and decreased significantly with permafrost degradation and with depth increasing. Additionally, it is demonstrated that degree of permafrost degradation has great influence on the available nutrients and nutrients in soil surface.
The upper reaches of the Heihe River was selected as a study area. Based on topographic maps in 1960 and Landsat TM images in 1990, 2000 and 2010, glaciers distribution for four periods have been automatically derived by object-oriented image interpretation method combined with expert knowledge. Spatial-temporal distribution and changes of glaciers are analyzed with GIS an RS method. It is found that during 1960 2010, glaciers had shrunk significantly by 138.90 km2 in total, and the ratio of retreated glacierized area to the glacierized area in 1960 is 35.6%, with a retreating rate of 2.78 km2 per year. Glaciers are mainly located in the western and middle portions of the study area, ranging from 4 200 to 5 300 m in altitude. The lower limit of glacier distribution is 4 000 m. The glacier retreat is found in the low elevation with an upper limit of 4 600 m a.s.l. Air temperature rising is considered to be the key factor of glacier retreat in this region. Glaciers will markedly shrink owing to continuous climate warming.
Mass balance is the best measure of glacier health. Owing to laborious field work, mass balance measurements are restricted to a few glaciers, preventing the assessments of regional specific mass balance and glacier volume changes. Satellite elevation data provides feasible opportunities to monitor the glacier elevation changes, and then one can estimate the glacier volume changes easily. Here, the SRTM and ICESat data are used to derive the glacier volume changes in the Qilian Mountains. The results show that glaciers in the Qilian Mountains are losing mass in the early 21st century with a glacier thinning rate of (0.345±0.258)m·a-1((0.293±0.219)m w.e). It is estimated that the average mass loss over the entire study region is (534.2±399.5)×106 m3 w.e.a-1. Due to relative independence and large spatial seperation of various glacierized regions, small scale of glaciers and sparse distribution of ICESat ground tracks, the uncertainty might be high.
By applying remote sensing (RS) and geographic information system (GIS) technology, combined with Bomi meteorological data of 1960-2010, glaciers distribution characteristics and spatial and temporal variations of typical large glaciers during 1980-2010 in region of Bomi County, Tibetan Plateau are analyzed. The results show that there are a total number of 2,040 glaciers with a total area of 4 382.5 km2 in region of Bomi County, glacier total area of 4 086 km2 located at an altitude of 4 000~6 000 m, accounting for 93.2% of the total area of the glacier. There are 1 504 glaciers with an area of 3 180.04 km2 distributed on the southern slope, accounting for 73.73% of total glacier number and 72.56% of total glacier area respectively, while accounting for less than one-third ones on the north slope. Extraction four periods of 1980, 1990, 2000 and 2010 glacier area of the 24 large glaciers with greater than 20 km2 were analyzed. The all 24 greater glaciers in Bomi County have a decreasing trend from 1980 to 2010, a glacier area of 1 592.78 km2 in 1980 retreat to one of 1 567.04 km2 in 2010, a total retreated area of 25.74 km2; which glacier change of 1980 to 1990 contributed the largest retreated area of 16.62 km2, accounting for a total area of glacier retreat amount of 64.6%. Records data of Bomi Meteorological Station show that there has been a continuous temperature rise, especially after 1980, which might seriously cause the glacier shrinkage, and changes in precipitation have less impacting on the glacier variation.
Madoi in the source regions of the Yellow River in the Tibetan Plateau was taken as an experimental area. After nearly two years' observations of radiation and energy flux, radiation budget, energy distribution in different seasons, including latent heat, sensible heat and soil heat flux on alpine meadow underlying surface, the data are analyzed. Also the changes of intensity of surface heating field in winter, and the influence of snow on the surface heating field are analyzed by Bowen ratio energy balance method. It is demonstrated that the total radiation and net radiation are intense. The average daily total radiation is 18.06 MJ·m, with a maximum of 979.5 W·m, and latent heat flux is 1 388.58 MJ·m, showing that the main way to transfer heat is latent heat flux all the year round. Seasonally, sensible heat and latent heat are equivalent in winter, sensible heat is principal in spring, and latent heat is principal in summer and autumn. Annual soil heat flux is 38.06 MJ·m, accounting for about 1.8% of the total heat balance, showing a seasonal imbalance. In the winter, |G|>H+LE, which means soil heat flux is the most distinct component in the heat balance.
Holocene millennial-scale climatic change was reconstructed based on the analyses of grain size and geochemical elements from the peat deposits in Gonghe basin, northeastern Tibetan Plateau. The reconstruction indicates that the regional warm and humid degree gradually increased in 10.0~8.6 cal ka BP, while it was obviously cold and dry from 8.6 cal ka BP to 7.1 cal ka BP. Subsequently, the warm and humid degree reached an optimal state in general between 7.1 cal ka BP and 3.8 cal ka BP, although there were frequently climatic fluctuations. From 3.8 cal ka BP to 0.5 cal ka BP, the climate tended to be cold and dry, and became warm and wet again afterwards. These characteristics are consistent with the climatic variation in the eastern China. In addition, 10 millennial time scale cold events were discovered during the Holocene, which are well comparative with palaeoclimatic records from ice cores, lake, peat and aeolian deposits in the plateau, and climatic fluctuations in the high and low latitudes of the Northern Hemisphere. Therefore, it is believed that the regional climate changes are dual characterized by a "monsoonal model" and a "millennial time scale oscillations".
Using radar-rain gauge to estimate areal rainfall is one of the major ways to improve the application of radar, which has great advantages in both the wide coverage of radar scanning and high single-point precision of rain-gauge. Based on the correlation with radar echo and rainfall in northeastern marginal areas of the Tibetan Plateau, a regional heavy rain case on May 10, 2012, is compared and spatial calibrated by using average calibration, optimal interpolation and variational-Kalman filter. It is found that the Z-I relationship with terrain is very different. Compared with precipitation observation, one can see that the local Z-I relationship by method of optimization is better than the others in diverse bands or districts, which effectively changes the situation of estimating lowly. In the mean time, the variational-Kalman filter method has the advantage of radar areal scan, which nicely reflected the spatial distribution of rainfall, able to calibrate well. In addition, it will be more effective in spatial precipitation estimation if take correct mathematical measures through the equations with multi-elevation angles and multi variable.
Glacier variations results from global climate change. Global warming leading to glacier shrinking and snow cover decreasing has become a hot issue in the world. The Tibetan Plateau is the world's third pole and its glacier and snow covers change is also the important content in cryopsheric sciences research field. In this paper, we choose 13 multi-spectral images of HJ-1A/1B satellite, acquired from May to September, 2011 including Zhadang glacier. The snow cover areas in glaciated region were extracted from each of the 13 images by using the maximum likelihood classifier. The correlation analysis was performed between the extracted snow cover areas in glaciated region and the daily average temperature. The results show that the snow cover areas in glaciated region decreased first and then increased during the period from May to September, 2011 (37% in May, 18% in July and 21% in September respectively). In addition, the results also indicate the snow cover areas in glaciated region has an obviously negative relationship with the daily average temperature in the study site.
Snow is one of the most important elements in cryosphere. Most of snow cover is located in the remote regions where access is difficult and the climate and transportation conditions are poor. Thus remote sensing technology becomes a very useful and efficient method to obtain the snow information. Compared with optical remote sensing and passive microwave remote sensing, synthetic aperture radar (SAR) not only has the capabilities of penetrating clouds and providing day and night remote sensing data, but also has the capability of penetrating snow cover to retrieve subsurface information. In this review, the snow cover researches by SAR data in recent years, including several existing algorithms of SAR and InSAR to identify snow cover and estimate of snow water equivalent, snow depth, snow density and snow wetness, are described.
The Chinese HJ satellites with smaller constellation, which were launched on September 6, 2008, have been improved on spatial resolution. and they are focus on environmental and disaster monitoring and meteorological forecast. In this paper, snow cover of Qilian mountains is exacted at different regions and altitude by means of HJ-1B, meanwhile the optimal threshold of NDSI using HJ satellite is determined through the snow area derived from Landsat ETM + images at same period. At last, the threshold precision are estimated with Kappa test.
Based on daily snow depth data from fifty meteorological stations, daily data of remote sensing snow depth and of livestock mortality, daily remote sensing snow depth were verified by using the measured data. It is found that the remote sensing snow depth can represent the snow status well. The intensity of disaster was analyzed using snow index, demonstrating that the risk is high in the Three River Head Regions, partly in the Qilian Mountains, and low in the west of the Qaidam Basin, the eastern agriculture areas and partly around the Qinghai Lake. By analyzing the correlation between snow index and livestock mortality, the threshold values of meteorological index are determined under different snow disaster grades, and the snow risk division is made for the province according to the values. The division shows that: the light snow disaster is mainly in the Qaidam Basin, most parts of the eastern agriculture areas and partly around the Qinghai Lake, with the frequency of above 50% mostly; the frequencies of moderate snow disaster and serious snow disaster are low, below 20%, in the province; the extremely serious snow disaster is in most parts of the Three River Head Regions, especially in Nangqen, Yushu and Chindu, with the frequency of more than 50%. Countermeasure is put forward based on the characteristics of snow disaster.
Analyzing the data of pasture, precipitation and disaster monitored and investigated in 20 grassland ecological monitoring sites in Qinghai Province, from 2003 to 2011, found that grassland herbage yield and precipitation have closely relation, e.g., between the forage yield at the end of August and the precipitation from May to August there is a good correlation, able to pass the 0.001 correlation test. Optimal simulation equations between forage yield of different grassland types and precipitation in different months are established. Drought levels are divided using average number of precipitation percentage. The relationship between drought level and forage and livestock losses is established. Then quantitative evaluation of direct economic loss of the grassland and livestock due to drought and snow disaster comes true. Comparing drought and snow disaster losses proportion of animal husbandry and relating drought with snow disaster through economic loss visually show the size and proportion caused by loss under different levels of disaster. With snow disaster level increasing, the loss proportion of snow disaster increases, and the snow disaster loss will be 2.5 times of drou-ght. The evaluation model is in line with grass pasture growth law and livestock production characteristics.The evaluation is accord with the actual loss of animal husbandry. Therefore, the evaluation can be used in the grassland animal husbandry assessment, no matter precipitation is more or less.
Global warming results in temperature rise and precipitation variability become large. Thus, extreme weather events and meteorological disasters appear continuously. Based on the data from 47 meteorological stations and 20 agriculture representative stations, the actual and theory yields of pasture are analyzed in this paper by means of moving average and linear regression method, together with analyses of the vulnerability of hazard-affected bodies and the disaster prevention ability. Division of drought disaster in Qinghai Province is discussed. It is found that 1) the highest-risk areas are mainly in the west of Qingnan Region, around the Qinghai Lake, Qaidam basin and Qilian Mountains; 2) the middle-risk areas are mainly in the southwest of Qingnan Region; 3) the lowest risk areas are mainly in the southeast of Qingnan Region. This division basically coincides with the history records of drought disaster, which is useful for prevention and mitigation of drought disaster in the province. Observations should be strengthened in the highest-risk and middle-risk areas so as to reduce drought disaster. The government should adopt good measures to disaster prevention and reduction. These are good for sustainable development of animal husbandry.
Climate drought is one of the most frequent meteorological disasters in Qinghai Province, which has high frequency, long duration, wide disaster range and great impact on agricultural production. Severe drought often makes agricultural production greatly reduced, or evens no production. In order to study the effect of climate drought on grain output in Qinghai Province, first, based on the Lagrange interpolation method, how to calculate the "expected yield" of no drought is determined, and then calculate the loss due to drought. Then according to the relationship with the drought intensity of the different growth stages, scope and crops sensitive to drought etc., statistics and evaluation model of drought loss might be set up. Applying the model in grain output assessment of Qinghai Province from 2006 to 2010, one can see that the error was less than 5% for four years, but was-9.38% in 2006. It is demonstrated that the assessment method can evaluate the drought loss of grain output, which could be used to assess the actual grain output of Qinghai Province with better effect. The method is suggested to forecast and assess the grain output in Qinghai Province from now on.
Based on the equivalent of Druker-Prager (abbreviated DP) yield criterion and the Mohr-Coulomb (abbreviated MC) theory, by the simulation of ANSYS software, the influences of earthquake on the stability of landslide in Nanqiao village under the conditions of its weight and rainstorm respectively were estimated. The results show that on the different intensity level of seismic fortification by changing the reduction factor to calculate the maximum of the horizontal displacement and plastic strain. To distinguish the destruction of landslide based on the abrupt point occurs and the calculation does not converge and the plastic zone penetration. So the landslide stability factor of different seismic fortification intensity had been obtained. Under the condition of weight add earthquake and rainstorm add earthquake, the discrepancy of the stability factors is between 0.25 and 0.32, which offered the possible for the mutual verification and theoretical calculations of the two conditions. The comparative analysis of the Finite Element Strength Reduction and the Limit Equilibrium Method showed that the errors of less than 5% are primary, when considering earthquake the stability coefficient of landslide will decrease by 13% to 16%. And the accuracy and reliability of numerical simulation were verified further. The result of calculation is consistent with the actual results. So this research should be promoted in scientific research and the actual design.
The deep ice sheet coring (DISC) drill, developed by Ice Coring and Drilling Services (ICDS) under contract with the US National Science Foundation, is an electromechanical machine designed to take 122-mm diameter ice cores down to depth of 4 000 m. The drill system consists of mechanical drilling subsystem and surface supporting subsystems. The mechanical drilling subsystem is made up with a drill sonde, a cable, a tower and a winch. The drill sonde is the down-hole portion of the drill system and consists of the following six sections: a cutter head, a core barrel, a sieve tube, a motor/pump section, a control panel and an upper sonde, which includes anti-torques and drill cable terminations. The surface supporting subsystem is a surface power supply, a control system, core processing workbench, drill fluid processing system, sieve tube cleaning system, an ancillary equipment and safety equipment. The drill was successfully tested at the Summit Camp in Greenland in 2006 and collected the final ice core from the WAIS Divide, Antarctica, on December 31, 2011, which was extracted from the bottom of a borehole, 3 405 meters in depth. It proves that the DISC drill is able to satisfy all science requirements. However, the cutters cannot bore a lateral hole on the ice wall to extract new core as a replicated core in WAIS.
The applicability of four precipitation products to the upper reaches of the Yarkant River is compared. The four datasets are: CMORPH, TMPA 3B42 v6, APHRODITE and ITPCAS. The characteristics of the temporal and spatial distributions of the four precipitation datasets are analyzed for 2003-2009. The datasets are also used as the forcing data to drive the variable infiltration capacity semi-distributed hydrology model. It is found that the spatial distribution of ITPCAS agrees reasonably with glacier distribution, followed by TMPA 3B42 v6 and APHRODITE. Among the four datasets, only CMORPH can roughly follow the seasonal variation of the mean gauge precipitation estimation. Runoff simulations suggest that CMORPH precipitation shows a potential as hydrological model input data for the Yarkant River, while the other precipitation datasets seem to possibly underestimate the precipitation in the catchment.
Lake shrinkage and expansion is an indicator of global climate change. In this study, variation in lake area and water level of the Paiku Co in southern Tibetan Plateau was examined by Landsat ETM images from 2003 to 2011 and ICESat altimetry data from 2003 to 2009. The results are as follows: 1) the monthly variation of the lake area is apparent. However, seasonal fluctuation of it is small, based on which further calculating is feasibility; 2) the lake area had decreased obviously from 2003 to 2011, with the rate of 0.52 km2·a-1 in winter, 0.35 km2·a-1 in spring and 0.61 km2·a-1 in autumn; 3) the lake level had decreased 1.17 m from 2003 to 2009 with the rate of 0.05 m·a-1; 4) from 2003 to 2009, the water storage had decreased 0.35×108 m3·a-1in winter, 0.21×108 m3·a-1in spring and 0.37×108 m·a-1in autumn; 5) spatially, the most obviously retreating parts were the northeast corner, the southeast corner and the southwest corner. Meteorological analysis shows that the increase of air temperature in summer will be the dominant factor for the reduction of the lake in autumn, while the decrease of precipitation in winter will induce lake shrinking in winter and spring.
Based on the data of temperature, precipitation and runoff of the Kensiwate Hydrological Station, the climate changes and the processes of summer flood during the period of 1957-2010 under the background of Extreme Weather were analyzed. The results showed that the mean annual temperature is increasing obviously in recently 51 years. The turning point of the average annual temperature from downward trend to increase is in 1979. While the jump point of the average annual temperature rising is in 1989, and the extreme high temperature increased after 1978, mainly occurred in July. The trend of the annual precipitation is decreasing fluctuate at Manas River during 1957-2007. The precipitation has increased since 1986, but only restored to the average annual precipitation level. The precipitation mainly concentrated in April to August, and which accounted for about 70% of the annual precipitation. The months of the higher temperatures and more precipitation are not entirely consistent. Such as it is cold in May, but the precipitation is great; the highest temperature is in July, but the maximum precipitation is in June; it is hot in August but with less precipitation. The annual runoff mainly concentrated in June to September in Manas River, which accounted for 80% of the total annual runoff. The runoff in June is the maximum, accounted for around 28.8% of the total annual runoff. The maximum flood runoff is increasing significantly during 1957-2010. The turning point from decrease to increase is in 1993. While the maximum flood runoff during 1994-2010 remained at a high level fluctuate. The proportion of the maximum flood runoff on 15 successive days accounted for the annual runoff is 23.7%, and up to 35.04%, indicating longer duration flood and flood water is more concentrated. The maximum flood runoff usually occurred in July and early August. The summer runoff is low correlation with summer temperatures and precipitation, which indicated that the frequent occurrence of summer floods since 1993, especially the times and magnitude of the exceeding standard flood increased mainly due to the increased of the extreme high temperature and extreme precipitation in summer.
Based on the past 50-a runoff and precipitation data at Shaliguilanke and Xiehela Hydrological Stations in the Aksu River, variation trend and correlation in various time scales between precipitation and runoff from the above two stations were analyzed by using the Z index method, t-test, non-parametric test and wavelet transform. It is found that: 1) the runoff and precipitation at the two hydrological stations had an increasing trend. Runoff increased abruptly at the two stations in 1993, whereas abrupt change point of precipitation occurred in 1985 at Shaliguilanke Station and in 1986 at Xiehela Station; 2) the high-low flow index of runoff and precipitation at the two stations changed from dry and normal grades before the abrupt change point to normal and flooded grades after the abrupt change point; 3) the main period of runoff variation at the two stations was 7 a and 6 a, respectively, and that of precipitation variation was 7 a and 4 a, respectively; 4) runoff and precipitation had positive correlation mainly at Shaliguilanke Hydrological Station and negative correlation at Xiehela Hydrological Station. However, runoff and precipitation presented non-significant positive correlation at two hydrological stations in the period longer than 20 a.
Global glaciers are ablating with the maximal rate on record in more and more areas all over the world. This phenomenon determines the potential loss of glacial microbial resources without being discovered. Taken snow samples from the glacial ablation zone and terminus, soil samples from glacial terminus as research objects, the variation of dominant bacterial community in glacial snow with adaptation to non-snow environment in response to the retreat of Laohugou Glacier No. 12 in the Qilian Mountains was investigated, using culture and molecular methods, as well as physiological and biochemical indexes. The result demonstrates that the dominant population of Pedobacter, represented by 1BW1 and 1BW2, in snow sample from the glacial terminus is unable to isolate from snow sample from the glacial ablation zone and soil sample from the glacial terminus. Moreover, dominant population of Acinetobacter, represented by 2BW, in the snow sample from the glacial ablation zone is more than that in the snow sample from glacial terminus and is less in the soil sample from the glacial terminus. Strains with high 16S rRNA sequence similarity in different sampling sites are more different in physiological and biochemical characteristics. Therefore, the dominant populations in glacial snow may probably become extinction owing to unable to adapt the new environment after glacial retreat. The research is a basis for the utilization and protection of bacterial resources in glaciers.
The diversity and vertical distribution of archaea community within the permafrost active layer in the proglacial environments of the Glacier No. 1, Tianshan Mountains are described by PCR-DGGE fingerprinting in the present study. Of the total 34 DGGE bands selected for sequencing, none of the sequences are the same as reference sequences from cultured taxa. 29 are identified as representing of non-thermophilic Crenarchaeota (Thaumarchaeota), while the remaining five are assigned as representing of Euryarchaeota, and clustered with members of the Halobacteria and Thermoplasmata. No sequences from methanogen are observed. Particularly, members of Thaumarchaeota Group 1.1b are present within the permafrost active layer in the proglacial environments of the Glacier No. 1, Tianshan Mountains (though lacking the defined structure) and Euryarchaeota communities are present only in the upper 10~100 cm of the layer, suggesting the relative abundance of Euryarchaeota decreasing with depth. In addition, some of phylotypes, which belong to Thaumarchaeota Group 1.1b, are closely related to ammonia-oxidizing Nitrososophaera. These results suggest that Thaumarchaeota Group 1.1b are active contributors to the N cycle throughout the permafrost active layer in the proglacial environments of the glacier, of which the contribution to community structure and ecology are necessary to study in the future in this area.
In this paper, the input-output of Zhangye Municipality, located in the middle reaches of the Heihe River, is analyzed. Combining the traditional financial input-output table and the physical input-output table of water resources utilization, the direct and indirect water consumption coefficients, the water consumption multiplier and the comprehensive water consumption characteristics in various sectors of the local economy in Zhangye Municipality have been calculated. It is found that the greatest water consumer is agriculture sectors, whose water utilization benefit and water utilization efficiency are lower than another sectors, which is the main cause of the excessive dependence on water resources in Zhangye Municipality. Thus, for solving water crisis in Zhangye Municipality, it is important to adjust industrial structure, upgrade the industries, implement the efficiency water-saving measures, reduce properly proportion of agriculture, especially planting, at the level of regional economy. These measures will contribute to make reasonable industry structure and water saving measures, and will be useful to improve the macro-benefit of the regional water resources utilization.
Initial water rights allocation is an indispensable part of water rights system. It can effectively achieve the explicit purpose of water rights, as well as provide basis and conditions for the development of water rights transaction. The Ganzhou District, Linze County and Gaotai County of Zhangye Municipality, in the middle reaches of the Hehei River, are taken as the research areas in this paper. On the basis of initial water rights system principle and index system, 2020 is selected as the planning level year, for which the multilevel and multi-objective fuzzy optimization is adopted to assign initial water rights for basins. Then 2009 is selected as a reference year, for which different water rights allocation models are applied, and then compared to verify the rationality of the allocation models. It is found that follow the rational model, in 2020, Ganzhou District will have an allocation ratio of 35.8%, Linze County will have an allocation ratio of 30%, and Gaotai County will have an allocation ratio of 34.2%. In addition, after the reasonable inspection, the comprehensive distribution model based on the principles is believed more practical, fairness, efficiency, sustainability and policy.
