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| 1 | Recent glacial retreat in High Asia in China and its impact on water resource in Northwest China显示文摘Under the impact of climatic warming, the glaciers in the High Asia in China have been retreating continuously with negative glacial mass balance in recent several decades. The retreat became more intensive in the past 10 years. The spatial pattern of the glacial retreat in the High Asia in China is that the smallest magnitude of retreat is in the inland of the Tibetan Plateau, the magnitude increases from the inland to the margin of the Tibetan Plateau, and the largest magnitude at the margin of the Tibetan Plateau. The glacial retreat in the High Asia in China has an important impact on the water resource of the arid regions in Northwest China. This study shows that the glacial retreat in the 1990s has caused an increase of 5.5% in river runoff in Northwest China. In the Tarim River basin, the increase of river runoff is higher than 5.5%. | YAO Tandong 1,2 ,WANG Youqing 2 ,LIU Shiying 2,1 ,PU Jianchen 2,1 ,SHEN Yongping 2 & LU Anxin 2,1 1.Institute of Tibetan Plateau Research,Chinese Academy of Sciences,Beijing 100029,China 2.Cold and Arid Regions Environmental and Engineering Research Institute,Chinese Academy of Sciences,Lanzhou 730000,China | 2004 | Science China Earth Sciences2004,47,12: | 117 |
| 2 | Temperature variations recovered from tree-rings in the middle Qilian Mountain over the last millennium显示文摘Based on the cross-dated tree-ring samples collected from the middle Qilian Moun- tain, a standard ring-width chronology had been developed, which covered the period AD 1000 to 2000. The correlations between the chronology and climatic records from the nearby meteorological stations indicated that temperature was the dominant climatic factor for tree growth at upper timberline, and the most important climatic factor for the tree growth in the area was the mean temperature from previous December to current April. The temperature variations recovered from the ring-width data showed a cold period during the “Little Ice Age” and the con- tinuous warming during the twentieth century. Comparison between the ring-width chronology and δ18O records from the Dunde ice core in the Qilian Mountain indicated that there was a con- sistent trend in both time series. A significant correlation existed between our ring-width chro- nology and the Northern Hemispheric temperature, suggesting that the climate changes in the Qilian Mountain were not only driven by regional factors, but also responsive to the global cli- mate. | LIU Xiaohong1,2, QIN Dahe1, SHAO Xuemei , CHEN Tuo1 & REN Jiawen12 1. Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China 2. Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China | 2005 | Science China Earth Sciences2005,48,4: | 66 |
| 3 | Estimation on the response of glaciers in China to the global warming in the 21st century显示文摘Glaciers in China can be categorized into 3 types, i.e. the maritime (temperate) type, sub-continental (sub-polar) type and extreme Continental (polar) type, which take 22%, 46% and 32% of the total existing glacier area (59 406 km2) respectively. Researches indicate that glaciers of the three types show different response patterns to the global warming. Since the Maxima of the Little Ice Age (the 17th century), air temperature has risen at a magnitude of 1.3℃on average and the glacier area decreased corresponds to 20% of the present total glacier area in western China. it is estimated that air temperature rise in the 2030s, 2070s and 2100s will be of the order of 0.4-1.2, 1.2-2.7 and 2.1-4.0 K in western China. With these scenarios, glaciers in China will suffer from further shrinkage by 12%, 28% and 45% by the 2030s, 2070s and 2100s. The uncertainties may account for 30%-67% in 2100 in China. | SHI Yafeng & LIU Shiyin Laboratory of Ice Core and Cold Regions Environment, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China | 2000 | Chinese Science Bulletin2000,45,7: | 71 |
| 4 | Impacts of permafrost changes on alpine ecosystem in Qinghai-Tibet Plateau显示文摘Alpine cold ecosystem with permafrost environment is quite sensitive to climatic changes and the changes in permafrost can significantly affect the alpine ecosystem. The vegetation coverage, grassland biomass and soil nutrient and texture are selected to indicate the regime of alpine cold ecosystems in the Qinghai-Tibet Plateau. The interactions between alpine ecosystem and permafrost were investigated with the depth of active layer, permafrost thickness and mean annual ground temperature (MAGTs). Based on the statistics model of GPTR for MAGTs and annual air temperatures, an analysis method was developed to analyze the impacts of permafrost changes on the alpine ecosystems. Under the climate change and human engineering activities, the permafrost change and its impacts on alpine ecosystems in the permafrost region between the Kunlun Mountains and the Tanggula Range of Qinghai-Tibet Plateau are studied in this paper. The results showed that the per- mafrost changes have a different influence on different alpine ecosystems. With the increase in the thickness of active layer, the vegetation cover and biomass of the alpine cold meadow exhibit a significant conic reduction, the soil organic matter content of the alpine cold meadow ecosystem shows an exponential decrease, and the surface soil materials become coarse and gravelly. The alpine cold steppe ecosystem, however, seems to have a relatively weak relation to the permafrost environment. Those relationships resulted in the fact that the distribution area of alpine cold meadow decreased by 7.98% and alpine cold swamp decreased by 28.11% under the permafrost environment degradation during recent 15 years. In the future 50 years the alpine cold meadow ecosystems in different geomorphologic units may have different responses to the changes of the permafrost under different climate warming conditions, among them the alpine cold meadow and swamp ecosystem located in the low mountain and plateau area will have a relatively serious degradation. Furthermore, from the angles of grassland coverage and biological production the variation characteristics of high-cold eco- systems in different representative regions and different geomorphologic units under different climatic conditions were quantitatively assessed. In the future, adopting effective measures to protect permafrost is of vital importance to maintaining the stability of permafrost engineering and alpine cold eco- systems in the plateau. | WANG Genxu1,3 , LI Yuanshou2 , WU Qingbai2 & WANG Yibo3 1. Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China 2. Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China 3. Resource and Environment School, Lanzhou University, Lanzhou 730000, China | 2006 | Science China Earth Sciences2006,49,11: | 41 |
| 5 | Numerical Simulation on Climate Effects of Freezing-Thawing Processes Using CCM3显示文摘A parameterization of soil freezing-thawing physics for use in the land-surface model of the National Center for Atmospheric Research(NCAR) Community Climate Model(CCM3) is developed and evaluated.The new parameterization scheme has improved the representation of physical processes in the existing land surface model.Numerical simulations using CCM3 with improved land-surface processes and with the original land-surface processes are compared against the NCEP reanalysis.It is found that the CCM3 version using the improved land surface model shows significant improvements in simulating precipitation in China during the summer season,the general circulation over East Asia,and wind fields over the Tibet Plateau.For the summer season,the improved model was able to better simulate the Indian summer monsoon components,including the mean northerly wind in the upper troposphere and mean southerly wind in the lower troposphere. | Chenghai Wang1,2*,Guodong Cheng3,Aijun Deng4,Wenjie Dong5 1.State Key Laboratory of Frozen Soil Engineering,Cold and Arid Regions Environmental and Engineering Research In-stitute,Chinese Academy of Sciences,Lanzhou Gansu 730000,China 2.State Key Laboratory of Cryosphere Sciences,Cold and Arid Regions Environmental and Engineering Research Insti-tute,Chinese Academy of Sciences,Lanzhou Gansu 730000,China 3.State Key Laboratory of Frozen Soil Engineering,Cold and Arid Regions Environmental and Engineering Research In-stitute,Chinese Academy of Sciences,Lanzhou Gansu 730000,China 4.Department of Meteorology,The Pennsylvania State University,University Park,PA 16802 5.State Key Laboratory of Earth Surface Processes and Ecology Resource,Beijing Normal University,Beijing 100875,China Chenghai Wang1,2*,Guodong Cheng3,Aijun Deng4,Wenjie Dong5 1.State Key Laboratory of Frozen Soil Engineering,Cold and Arid Regions Environmental and Engineering Research In-stitute,Chinese Academy of Sciences,Lanzhou Gansu 730000,China 2.State Key Laboratory of Cryosphere Sciences,Cold and Arid Regions Environmental and Engineering Research Insti-tute,Chinese Academy of Sciences,Lanzhou Gansu 730000,China 3.State Key Laboratory of Frozen Soil Engineering,Cold and Arid Regions Environmental and Engineering Research In-stitute,Chinese Academy of Sciences,Lanzhou Gansu 730000,China 4.Department of Meteorology,The Pennsylvania State University,University Park,PA 16802 5.State Key Laboratory of Earth Surface Processes and Ecology Resource,Beijing Normal University,Beijing 100875,China | 2008 | Research in Cold and Arid Regions2008,,1: | 44 |
| 6 | Study of spatial distribution of sandy desertification in North China in recent 10 years显示文摘Sandy desertification is a land degradation characterized by wind erosion, mainly resulted from the excessive human activities in arid, semiarid and part of sub-humid regions in North China. It is one of main kinds of desertification/land degradation as well as water-soil erosion and salinization in China. Rapid and continuous spread of sandy desertification during last 50 years has created a major environmental and socio-economic problem in North China. Remote sensing monitored results in 2000 showed that the sandy desertified land area has been 38.57×104 km2. The area of potential to slightly sandy desertified land is 13.93×104 km2, moderately land 9.977×104 km2, severely land 7.909×104 km2 and very severely land 6.756×104km2. Sandy desertification mainly occurs in the semi-arid mixed farming-grazing zone and its northern rangeland zone, semi-arid dryland rainfed cropping zone and arid oasis-desert margin zone. The average annually developmental rate of sandy desertified land increased from 2,100tion in North China is 'overall deterioration, while local rehabilitation'. Already achieved rehabilitation results and monitoring assessment show that about 60% of desertified land in North China can be restored under the conditions of rational land-use ways and intensity. | WANG Tao, WU Wei, XUE Xian, SUN Qingwei & CHEN GuangtingKey Laboratory of Desert and Desertification, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China Department of Environment Engineering, Peking University, Beijing 100871, China | 2004 | Science China Earth Sciences2004,47,z1: | 28 |
| 7 | Effects of sunspot cycle length and CO_2 on air temperature along Qinghai-Xizang railway and air temperature's trend prediction显示文摘There are well coherences between annual averaged air temperatures at every meteorological station along the Qinghai-Xizang railway, and its 10-year moving average correlation coefficient is 0.92. Thus, the regional averaged annual mean temperature series along the Qinghai-Xizang railway (Trw) from 1935 to 2000 are constructed. The investigation is suggested that: Trw had significant responses to the 5-year lagged sunspot cycle length (SCL) and 15-year lagged concentration of atmospheric carbon dioxide (CO2), and the correlation coefficients between them are -0.76 (SCL) and 0.88 (CO2), respectively. The future SCL is predicted by the model of average generated function constructed with its main cycles of 76a, 93a, 108a, 205a and 275a. The result shows that the SCL would be becoming longer in the first half of the 21st century, and then it could be becoming shorter in the second half of the 21st century. Based on the natural change of SCL and the effect of double CO2 concentration, Trw in the 21st century is forecasted. It could warm up about 0.50℃ in the first half of the 21st century compared with the last decade of last century. The mean maximum air temperature could be likely about 0.20℃ in July and from 0.40℃ to 1.10℃ in January. The annual air temperature difference would likely reduce 0.3-1.00℃. The probability of above predictions ranges from 0.64 to 0.73. | LI Dongliang, QUO Hui, WANG Wen & WEI LiCold & Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Science, Lanzhou 730000, China Department of Atmospheric Sciences, Lanzhou University, Lanzhou 730000, China | 2004 | Science China Earth Sciences2004,47,z1: | 28 |
| 8 | Protective mechanism of desiccation tolerance in Reaumuria soongorica: Leaf abscission and sucrose accumulation in the stem显示文摘Reaumuria soongorica (Pall.) Maxim., a perennial semi-shrub, is widely found in semi-arid areas in northwestern China and can survive severe desiccation of its vegetative organs. In order to study the protective mechanism of desiccation tolerance in R. soongorica, diurnal patterns of net photosynthetic rate (Pn), water use efficiency (WUE) and chlorophyll fluorescence parameters of Photosystem II (PSII), and sugar content in the source leaf and stem were investigated in 6-year-old plants during progressive soil drought imposed by the cessation of watering. The results showed that R. soongorica was char-acterized by very low leaf water potential, high WUE, photosynthesis and high accumulation of sucrose in the stem and leaf abscission under desiccation. The maximum Pn increased at first and then de-clined during drought, but intrinsic WUE increased remarkably in the morning with increasing drought stress. The maximal photochemical efficiency of PSII (Fv/Fm) and the quantum efficiency of noncyclic electric transport of PSII(ΦPSII) decreased significantly under water stress and exhibited an obvious phenomenon of photoinhibition at noon. Drought stressed plants maintained a higher capacity of dis-sipation of the excitation energy (measured as NPQ) with the increasing intensity of stress. Conditions of progressive drought promoted sucrose and starch accumulation in the stems but not in the leaves. However, when leaf water potential was less than –21.3 MPa, the plant leaves died and then abscised. But the stem photosynthesis remained and, afterward the plants entered the dormant state. Upon re-watering, the shoots reactivated and the plants developed new leaves. Therefore, R. soongorica has the ability to reduce water loss through leaf abscission and maintain the vigor of the stem cells to survive desiccation. | LIU YuBing1,2, ZHANG TengGuo1, LI XingRong2 & WANG Gang1 1 School of Life Sciences, Lanzhou University, Lanzhou 730000, China 2 Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China | 2007 | Science China(Life Sciences)2007,50,1: | 27 |
| 9 | Indian monsoon influences altitude effect of δ^(18)O in precipitation/river water on the Tibetan Plateau显示文摘The δ 18O variation in precipitation acquired from 28 stations within the network of Tibetan Observation and Research Platform(TORP)is studied, with the focus on the altitude effect of δ 18O in river water during monsoon precipitation in an effort to understand the monsoon influence on isotopic composition in annual river water. It is found that δ 18O in precipitation on the Plateau is influenced by different moisture sources, with significant Indian monsoon influence on δ 18O composition in plateau precipitation and river water. The δ 18O of water bodies in the monsoon domain is generally more depleted than that in the westerly domain, suggesting gradual rainout of southwesterly borne marine moisture in the course of long-distance transportation and lifting over the Himalayas. The lapse rate of δ 18O in river water with altitude is the largest during monsoon precipitation, due to the increased temperature vertical gradient over the southern Plateau region controlled by monsoon circulation. The combination of δ 18O in river water in monsoon (wet) and non-monsoon (dry) seasons shows a larger lapse rate than that in non-monsoon (dry) season alone. As the altitude effect of δ 18O in precipitation and river water on the Tibetan Plateau results from the combined effect of monsoon moisture supply and westerly moisture supply, the δ 18O composition and its altitude effect on the Plateau during monsoon seasons should be considered in the reconstruction of paleoelevation of the Tibetan Plateau. | YAO TanDong1,2, ZHOU Hang1,3 & YANG XiaoXin1,3 1 Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100085, China 2 State Key Laboratory of Cryosphere Sciences, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China 3 Graduate University of Chinese Academy of Sciences, Beijing 100049, China | 2009 | Chinese Science Bulletin2009,54,16: | 28 |
| 10 | Simulation of energy and water balance in Soil-Vegetation-Atmosphere Transfer system in the mountain area of Heihe River Basin at Hexi Corridor of northwest China显示文摘In the mountain area of inland Heihe River Basin at Hexi Corridor of northwest China during the vegetation growing season from May to September, the Simultaneous Heat and Water (SHAW) model of Soil-Vegetation-Atmosphere Transfer (SVAT) system is applied to simulating and studying energy and water balance of the soil-residue-plant canopy layers in the Picea crassifolia forest and the grassland by the forest at the shaded slope and the grassland at the sun-facing slope. The simulation of energy balance indicates that net radiation of the grass- land at the sun-facing slope is more than that of the Picea crassifolia forest and the grassland by the forest at the shaded slope. The energy outgoing components are the first latent heat and next sensible heat from the grassland both at the shaded slope and the sun-facing slope, but those at the former are less. The energy outgoing components are the first sensible heat and next latent heat from the Picea crassifolia forest. The composition and distribution of energy in the soil-residue-plant canopy layers in the Picea crassifolia forest and the grassland by the forest at the shaded slope make the soil layer receive less energy, which therefore, especially the forest possesses the energy conditions for soil water conservation. The simulation of water balance indicates that the water loss of the grassland at the sun-facing slope is mainly caused by soil evaporation, while evapotranspiration of the Picea crassifolia forest and the grassland by the forest at the shaded slope is less than that of the grassland at the sun-facing slope. Half of the evapotranspiration of the Picea crassifolia forest and the grassland by the forest at the shaded slope is consumed by transpiration. After precipitation, the soil water storage is increased much more for the Picea crassifolia forest and also more for the grassland by the forest at the shaded slope. Therefore the shaded slope vegetation, especially the forest is favorable for soil water storage. | KANG Ersi1, CHENG Guodong1, , SONG Kechao1, JIN Bowen1, , LIU Xiande3 2 3 & WANG Jinye3 1. Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China 2. State Key Laboratory of Frozen Soil Engineering, Chinese Academy of Sciences, Lanzhou 730000, China 3. Academy of Water Resources Conservation Forest of Qilian Mountains, Gansu Province, Zhangye 734000, China | 2005 | Science China Earth Sciences2005,48,4: | 25 |
| 11 | Lightning activity and precipitation structure of hailstorms显示文摘By using the cloud-to-ground (CG) lightning location data from the lightning detection network of He- nan Province, surface Doppler radar data and standard orbit data of PR, TMI and LIS on TRMM satellite, the spatial and temporal characteristics of CG lightning flashes in 10 severe hailstorms are analyzed. The results show that the percentage of +CG lightning in these hailstorms is high with an average value of 45.5%. There is a distinct increase in CG flash rate during the rapid development stage of hailstorms. The hailstone falling corresponds to an active positive flash period, and the increase of +CG flash rate is generally accompanied with a decrease of –CG flash rate. The flash rate declines rapidly during the dissipating stage of hailstorms. The precipitation structure and lightning activity in two typical hail- storms are studied in detail. It is found that strong convective cells with reflectivity greater than 30dBZ mainly are situated in the front region of hailstorms, whereas the trailing stratiform region is in the rear part of the hailstorms. The maximum heights of echo top are higher than 14 km. Convective rain con- tributes much more rainfall to the total than stratiform rain, and the convective rain takes about 85% and 97% of the total in the two cases, respectively. Total lightning in the hailstorms is very active with the flash rate up to 183 fl/min and 55 fl/min, respectively. The results also indicate that most lightning flashes occurred in the echo region greater than 30 dBZ and its immediate periphery. The probability of lightning occurrence is 20 times higher in the convective region than in the stratiform region. The result suggests that the lightning information is helpful to the identification of convective rain region. The linear relationship between flash rate and ice water content is disclosed primarily. | FENG GuiLi1,2, QIE XiuShu3,1, YUAN Tie1 & NIU ShuZhen4 1 Laboratory of Lightning and Thunderstorm, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China 2 Shandong Research Institute of Meteorology, Jinan 250031, China 3 Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China 4 The Meteorological Observatory of Henan Province, Zhengzhou 450003, China | 2007 | Science China Earth Sciences2007,50,4: | 22 |
| 12 | Using lightning locating system based on time-of-arrival technique to study three-dimensional lightning discharge processes显示文摘A time-of-arrival(TOA) system based on GPS technology for locating VHF radiation sources from lightning has been developed and used in observation sites in the northern Shandong Province,China.The 3D images of the lightning progression have been obtained successfully for the first time in China.The 3D-channel evolutions of typical negative CG,positive CG and IC lightning flashes have been discussed together with the data of fast electric field change.It was found that significant differences existed between the negative and positive CG lightning flashes in terms of the initiation and propagation of the radiation sources.The preliminary breakdown of a negative CG lightning flash propagated at a speed about 5.2×104 m/s.The stepped leader of negative CG lightning flashes was trigged by negative initial breakdown.Thereafter,it propagated downward at a speed of 1.3×105 m/s.The initial process of the positive CG lightning flashes was also a propagation process of negative streamer.These streamers propagated dominantly horizontally in the positive charge region and accumulated positive charges at the origin of the lightning,and as a consequence,initiated downward positive streamers.A new type of lightning discharge that was triggered by a narrow bipolar pulse(NBP) is discussed in this study.The NBP was originated at altitude of about 10.5 km in the upper positive charge region.As a distinct difference from normal IC flash,its channels extended horizontally all around and produced a lot of radiation sources.The source power of the NBP could approach 16.7 kW,which is much greater than that of normal lightning discharge ranging between 100 mW and 500 W.The 3D propagation of this new type of lightning discharge was observed and obtained for the first time in China.The possible initiation mechanism of this new type of light-ning is discussed here. | ZHANG GuangShu1,WANG YanHui1,QIE XiuShu2,ZHANG Tong1,ZHAO YuXiang1,3,LI YaJun1 & CAO DongJie11 Laboratory for Climate Environment and Disasters of Western China,Cold and Arid Regions Environmental and Engineering Research Institute,Chinese Academy of Sciences,Lanzhou 730000,China 2 Laboratory for Middle Atmosphere and Global Environment Observation(LAGEO),Institute of Atmospheric Physics,Chinese Academy of Sciences,Beijing 100029,China 3 Department of Physics,Tianshui Normal College,Tianshui 741001,China | 2010 | Science China Earth Sciences2010,53,4: | 21 |
| 13 | Soil Organic Carbon,Carbon Fractions and Nutrients as Affected by Land Use in Semi-Arid Region of Loess Plateau of China显示文摘Cropland (CP),native grassland (NG) and two shrub land treatments which were converted from cropland in 1985:seabuckthorn (Hippophae rhamnoides L.) (ST),and branchytamarisk (Tamarix ramosissima) (BT) were investigated to evaluate effects of land use conversion on soil organic carbon (SOC) and soil nutrients in the semi-arid region of the Loess Plateau of China.Total organic carbon (TOC),light fraction organic carbon (LFOC),heavy fraction organic carbon (HFOC),total N (TN),nitrate nitrogen (NO 3-N) and nitrite nitrogen (NO 2-N),ammonium nitrogen (NH + 4-N),total P,and available P (AP) were measured.The results showed that SOC in NG,ST and BT were 12.7%,27.7% and 34.8% higher than that of the cropland,respectively.LFOC,light fraction (LF) dry matter,ratio of TOC to TN (C/N) and the ratio of TOC to AP (C/P) were higher in the shrub land or native grassland than in the cropland.Cropland had the highest TN,the sum of NO 3-N and NO 2-N,TP and AP due to the use of chemical fertilizers.TOC significantly correlated with LFOC,HFOC and C/N.LFOC significantly correlated with dry matter of the LF and C/N.TN,the sum of NO 3-N and NO 2-N and AP were significantly negatively correlated with TOC and LFOC.Therefore,land use conversion from cropland to shrub land,or maybe grassland,contributed to SOC sequestration and improved soil nutrients stabilization. | LIU Xun,LI Feng-Min,LIU Da-Qian and SUN Guo-Jun Key Laboratory of Arid and Grassland Ecology of the Ministry of Education,School of Life Sciences,Lanzhou University,Lanzhou 730000 (China) | 2010 | Pedosphere2010,20,2: | 19 |
| 14 | Variations in air temperature during the last 100 years revealed by δ^(18)O in the Malan ice core from the Tibetan Plateau显示文摘By comprehensive analyses, it was found that the variations in d 18O recorded in Malan ice core from theKekexili Region on the Tibetan Plateau could represent thechanges in air temperature during the summer half year (from May to October) over the Kekexili Region and the northern margin of the Tibetan Plateau. The general increase trend in d18O in this ice core during the past century indicated climate warming, and it was estimated that air temperature during the summer half-year rose about 1.2C over there then. However, this ice core record documented that the study area has been cooling while most of the world has been dramatically warming since the late 1970s. A teleconnection was foundbetween the variations in d 18O in the Malan ice core and the North Atlantic Oscillation. Moreover, the variations in d 18O in this ice core were similar to that in the summer half-year air temperature over the southern Tibetan Plateau on thecenturial time scale, but opposite on the multidecadal timescale. | WANG Ninglian, YAO Tandong, PU Jianchen, ZHANG Yongliang, SUN Weizhen & WANG Youqing Key Laboratory of Ice Core and Cold Regions Environment, Cold and Arid Regions Environmental and Engineering Research Institute, ChineseAcademy of Sciences, Lanzhou 730000, China | 2003 | Chinese Science Bulletin2003,48,19: | 19 |
| 15 | Relationships between δ ^(18)O in summer precipitation and temperature and moisture trajectories at Muztagata, western China显示文摘Based on summer observations of stable isotope of precipitation at Muztagata, western China, during 2002―2003, this paper presents the relationship between δ 18O in precipitation and air temperature, and discusses the effect of moisture transport on δ 18O in precipitation. Results show that air temperature correlates positively with δ 18O in precipitation, and the temperature effect controls the δ 18O of precipitation in this area. The Muztagata region exhibits high δ 18O values in summer precipi-tation, similar to those shown at stations in adjacent regions. According to the results of our model set up to trace the moisture trajectories, the westerlies and local moisture circulation contribute to varia-tions of oxygen isotopes in precipitation. In addition, the impacts of the moisture transport distance, the moisture transport level, and the incursion of the polar air mass also influence the variations of δ 18O in precipitation. The moisture origins and transport mechanisms also contribute to the variation of δ 18O in precipitation at Muztagata. | YU Wusheng1,2, YAO Tandong1,2, TIAN Lide1,2, LI Zhen2, SUN Weizhen2 & WANG Yu2 1. Laboratory of Environment and Process on Tibetan Plateau, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100085, China 2. Key Laboratory of Cryosphere and Environment, Jointly Established by Cold and Arid Regions Environmental and Engi-neering Research Institute and Institute of Tibetan Plateau Research, Chinese Academy of Sciences and Chinese Academy of Meteorological Sciences, China Meteorological Administration, CAS, Lanzhou 730000, China | 2006 | Science China Earth Sciences2006,49,1: | 18 |
| 16 | Effect of climatic change on snowmelt runoffs in mountainous regions of inland rivers in Northwestern China显示文摘Climatic change has significant impacts on snow cover in mid-latitude mountainous re- gions, in the meantime, spatial and temporal changes of snow cover and snowmelt runoffs are con- sidered as sensitive indicators for climatic change. In this study, the upper Heihe Watershed in the Qilian Mountains was selected as a typical area affected by snow cover and snowmelt runoffs in northwestern China. The changes in air temperatures, precipitation, snowfall and spring snowmelt runoffs were analyzed for the period from 1956 to 2001. The results indicate that climatic warming was apparent, particularly in January and February, but precipitation just fluctuated without a clear trend. The possible changes of snowmelt runoffs in the upper Heihe watershed in response to a warming of 4℃ were simulated using Snowmelt Runoff Model (SRM) based on the degree-day factor algorithm. The results of the simulation indicate that a forward shifting of snow melting season, an increase in water flows in earlier melting season, and a decline in flows in later melting season would occur under a 4℃ warming scenario. | WANG Jian1 & LI Shuo2 1. Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China 2. College of Geography, Nanjing Normal University, Nanjing 210097, China | 2006 | Science China Earth Sciences2006,49,8: | 18 |
| 17 | Eco-environment range in the source regions of the Yangtze and Yellow rivers显示文摘Based on geographical and hydrological extents delimited, four principles are identified, as the bases for delineating the ranges of the source regions of the Yangtze and Yellow rivers in the paper. According to the comprehensive analysis of topographical characteristics, climate conditions, vegetation distribution and hydrological features, the source region ranges for eco-environmental study are defined. The eastern boundary point is Dari hydrological station in the upper reach of the Yellow River. The watershed above Dari hydrological station is the source region of the Yellow River which drains an area of 4.49×10 4 km 2 . Natural environment is characterized by the major topographical types of plateau lakes and marshland, gentle landforms, alpine cold semi-arid climate, and steppe and meadow vegetation in the source region of the Yellow River. The eastern boundary point is the convergent site of the Nieqiaqu and the Tongtian River in the upstream of the Yangtze River. The watershed above the convergent site is the source region of the Yangtze River, with a watershed area of 12.24×10 4 km 2 . Hills and alpine plain topography, gentle terrain, alpine cold arid and semi-arid climate, and alpine cold grassland and meadow are natural conditions in the source region of the Yangtze River. | DING Yongjian,YANG Jianping,LIU Shiyin,CHEN Rensheng,WANG Genxu,SHEN Yongping,WANG Jian,XIE Changwei,ZHANG Shiqing(Cold and Arid Regions Environmental and Engineering Research Institute, CAS, Lanzhou 730000, China) | 2003 | Journal of Geographical Sciences2003,13,2: | 18 |
| 18 | Dynamic calculation model and seismic response for frame supporting structure with prestressed anchors显示文摘A dynamic calculation model of frame supporting structures with prestressed anchors for the slope stability is proposed. The frame and soil are closely contacted in the role of prestressed anchors and they cannot be separated along the whole slope. The lateral displacement of frame and soil is nearly in phase. The movement characteristic satisfies the theory of elastic foundation beam. The frame is treated with elastic foundation beam in this model. The influence of prestressed anchors is simplified as linear spring and damped system related with velocity. Under the condition of horizontal earthquake excitation, the equation of vibration response is established by using the model of dynamic Winkler beam and the analytical solutions are obtained for simple harmonic vibration. This method is applied to a case record for illustration of its capability, in order to verify the method, 3D nonlinear FEM (ADINA) is used to analyze the seismic performance of this case, the comparative results show that the design and the analysis are safe and credible by using the proposed method. The calculation model provides a new way for earthquake analysis and seismic design of slope stability supported by frame structure with prestressed anchors. | DONG JianHua1’2, ZHU YanPeng1, ZHOU Yong1 & MA Wei2 1 College of Civil Engineering, Lanzhou University of Technology, Lanzhou 730050, China 2 State Key Laboratory of Frozen Soil Engineering, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China | 2010 | Science China(Technological Sciences)2010,53,7: | 16 |
| 19 | Processes and modes of permafrost degradation on the Qinghai-Tibet Plateau显示文摘Climate warming must lead the mainly air temperature controlled permafrost to degrade.Based on the numerical simulation,the process of permafrost degradation can be divided into five stages,i.e.,starting stage,temperature rising stage,zero geothermal gradient stage,talic layers stage,and disappearing stage,according to the shape of ground temperature profile.Permafrost on the Qinghai-Tibet Plateau (QTP) is generally considered a relic from late Pleistocene,and has been degenerating as a whole during Holocene.According to spatial-temporal compensation,the present thermal state discrepancy of permafrost in different areas on the QTP may correspond with their degradation stages.On the QTP,permafrost in the high and middle mountains belongs to temperature rising stage,the permafrost thermal state is transiting from late rising temperature stage to zero geothermal gradient stage that is distributed in the middle-low-mountains.Permafrost that is in a zero gradient stage mainly appears in the high plateau and valley,whereas the transition from zero gradient stage to talic layers stage of permafrost is located in the vicinity of the lower limit of permafrost,and permafrost is disappearing from margin of perennially frozen ground.There are two modes of perennially frozen ground thawing,thawing from top to bottom and thawing from bottom to top respectively.During the temperature rising stage,when the heat flux in the perennially frozen soil layer is less than that in the unfrozen soil underlying frozen soil layer,the geothermal flux is partly used to thaw the base of permafrost,and permafrost thaws from bottom to top.With the decrease of thermal gradient in the perennially frozen ground,the heat that is used to thaw permafrost base increases,and geothermal heat will be entirely consumed to thaw the base of permafrost until the temperature gradient reaches zero thermal gradient state.On the other hand,the disappearance of permafrost may be delayed by 'thermal offset' and 'seasonal offset' effects in the upper of permafrost layer.When ground surface temperature rises to the level that can counteract the thermal offset effect,heat accumulation in the active layer would start,and the thickness of the active layer increases until a talic layer to appear.This process can be intensified by the 'seasonal anti-offset effect'. | WU JiChun,SHENG Yu,WU QingBai & WEN Zhi State Key Laboratory of Frozen Soil Engineering,Cold and Arid Regions Environmental and Engineering Research Institute,Chinese Academy of Sciences,Lanzhou 730000,China | 2010 | Science China Earth Sciences2010,53,1: | 16 |
| 20 | Canopy and leaf gas exchange of Haloxylon ammodendron under different soil moisture regimes显示文摘In order to reveal the drought resistance and adaptation of the C4 desert plant Haloxylon ammodendron under artificially controlled soil moisture regimes,representative plants were selected to measure canopy photosynthesis using canopy photosynthetic measurement system.The results showed that appropriate soil moisture significantly enhances the canopy and leaf photosynthetic capacity,and extremely high soil moisture is not conducive to the photosynthesis of H.ammodendron. | GAO Song,SU PeiXi,YAN QiaoDi & DING SongShuang Linze Inland River Basin Research Station,Plant Stress Ecophysiology and Biotechnology Laboratory,Cold and Arid Regions Environmental and Engineering Research Institute,Chinese Academy of Sciences,Lanzhou 730000,China | 2010 | Science China(Life Sciences)2010,53,6: | 15 |