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Progress in studies of the climate of humid period and the impacts of changing precession in early-mid Holocene

Progress in Natural Science:Materials International 2008年第12期18卷 1459-1464页

作者： Jianbin Huang~a Shaowu Wang~a Xinyu Wen~a Bao Yang~b a Department of Atmospheric Sciences,School of Physics,Peking University,Beijing 100871,china b Laboratory for Desert and Desertification,cold and arid regions environmental and engineering research institute,Chinese Academy of Sciences,lanzhou 730000,china [a]Department of Atmospheric Sciences School of Physics Peking University Beijing 100871 China [b]Laboratory for Desert and Desertification Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China

Studies on the climate of humid period and the impacts of changing precession in the early-mid Holocene are reviewed in this paper. High-resolution proxy data indicated that the African Humid Period,strong summer monsoon from the Arabian Sea to South Asia, northward migration of ITCZ (lntertropical Convergence Zone) over the northern South America,and the humid period of china appeared in 10.5-5.5 kaBP,10.0-6.0 kaBP,10.5 5.4 kaBP,and 11.0-8.0 kaBP,*** studies proved that summer inso- lation over the Northern Hemisphere increased following the changes of precession in the early Holocene,which increased the land-sea temperature contrasts,intensified the summer monsoon circulation in the Northern Hemisphere,and finally induced a humid climate over the area under the influence of summer ***,modeling results underestimated the increase of precipitation and the degree of northward extension of monsoon rain belt compared with palaeo-environmental *** discrepancies between the modeling results and the palaeo-environmental data may be associated with the changes of North Atlantic circulation,sea ice and veg- etation ***,climate of the humid period was not stable,in which several droughts were inlaid on centennial *** this review,perspectives for further studies of the climate change of the humid period in the early-mid Holocene are also proposed.

关键词： Holocene Humid period Precession Summer monsoon

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Canopy and leaf gas exchange of Haloxylon ammodendron under different soil moisture regimes

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Science china(Life Sciences) 2010年第6期53卷 718-728页

作者： 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 1. 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

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 *** 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 ***.

关键词： canopy photosynthesis leaf photosynthesis desert plant Haloxylon ammodendron assimilation chamber

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Turbulent intensity and its similarity function over an Inner Mongolian grassland during spring

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Science china Earth Sciences 2010年第5期53卷 773-780页

作者： YUE Ping1,2,3, NIU ShengJie2, HU YinQiao4 & ZHANG Qiang1 1 Key Laboratory of arid Climate Change and Reducing Disaster of Gansu Province, Key Laboratory of arid Climate Change and Reducing Disaster of CMA, institute of arid Meteorology, CMA, lanzhou 730020, china 2 Nanjing University of Information Science and Technology, Nanjing 210044, china 3 Zhangye National Meteorological Observatory, Zhangye 734000, china 4 cold and arid regions environmental and engineering research institute, Chinese Academy of Science, lanzhou 730000, china 1. Key Laboratory of arid Climate Change and Reducing Disaster of Gansu Province Key Laboratory of Arid Climate Change and Reducing Disaster of CMA Institute of Arid Meteorology CMA Lanzhou 730020 China2. Nanjing University of Information Science and Technology Nanjing 210044 China3. Zhangye National Meteorological Observatory Zhangye 734000 China4. Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Science Lanzhou 730000 China

Macroscopic reason for the development of turbulences in fluid is the conjunction action of velocity and temperature shears. We use the 2008 spring flux observations in the surface layer over Inner Mongolian grassland, obtain the similarity functions of turbulent intensity under different stratification stability conditions, and calculate the clear day turbulent intensity in the spring, which is then analyzed and compared with the observed values of turbulent intensity. The results show that in the Inner Mongolian grassland, under the condition of spring unstable stratification of the surface layer, dependence of the similarity function of turbulent intensity on stratification stability follows a "2/3 power law". The structural function is a constant under the neutral stratification condition, and complicated under the stable condition. The calculated turbulent intensity has a close correlation with the observed one, which verifies the accuracy of the similarity functions and the suitability of the theorem of turbulent intensity in the grassland region.

关键词： turbulent intensity variance of velocity similarity function grassland

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Losses of Soil Organic Carbon and Nitrogen and Their Mechanisms in the Desertification Process of Sandy Farmlands inHorqin Sandy Land

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Agricultural Sciences in china 2003年第8期2卷 890-897页

作者： SU Yong-zhong and ZHAO Ha-lin(cold and arid regions environmental and engineering research institute, Chinese Academy of Sciences,lanzhou 730000 , P. R. china) cold and arid regions environmental and engineering research institute Chinese Academy of Sciences Lanzhou 730000 P.R. China

Soil organic carbon(SOC)and total nitrogen(N)concentrations from bulk soils and soil particle size fractions in the different extent of desertified farmlands(potential, light, medium, severe, and most severe desertified farmlands)were examined to quantitatively elucidate losses of carbon and nitrogen and its mechanisms in the desertification process. Particle size fractions(2 -0.1 mm, 0.1 - 0.05 mm, 0. 05 mm)in desertification process. The concentrations of C and N associated with sand(2 - 0.1 mm and 0.1 - 0.05 mm)significantly decreased with increase of desertified extent. Silt and clay associated C and N concentrations, however, were less changed, and in contrast, were higher in soils under most severe desertified extent than in soils under potential and severe desertified extent. The percentage of distribution in sand(>0.05 mm)associated C and N significantly increased with increase of desertified extent, suggesting that stability of SOC decreased in the desertification process.

关键词： Farmland desertification Soil organic carbon Total nitrogen Mechanisms of losses

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A land surface model incorporated with soil freeze/thaw and its application in GAME/Tibet

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Science china Earth Sciences 2006年第12期49卷 1311-1322页

作者： HU Heping1, YE Baisheng2, ZHOU Yuhua3 & TIAN Fuqiang1 1. Department of Hydraulic engineering, Tsinghua University, Beijing 100084, china 2. cold and arid regions environmental and engineering research institute, Chinese Academy of Sciences, lanzhou 730000, china 3. Department of Civil engineering, Massachusetts institute of Technology, USA 1. Department of Hydraulic engineering Tsinghua University Beijing 100084 China 2. cold and arid regions environmental and engineering research institute Chinese Academy of Sciences Lanzhou 730000 China 3. Department of Civil engineering Massachusetts Institute of Technology USA

Land surface process is of great importance in global climate change, moisture and heat exchange in the interface of the earth and atmosphere, human impacts on the environment and eco- system, etc. Soil freeze/thaw plays an important role in cold land surface processes. In this work the diurnal freeze/thaw effects on energy partition in the context of GAME/Tibet are studied. A sophisti- cated land surface model is developed, the particular aspect of which is its physical consideration of soil freeze/thaw and vapor flux. The simultaneous water and heat transfer soil sub-model not only reflects the water flow from unfrozen zone to frozen fringe in freezing/thawing soil, but also demon- strates the change of moisture and temperature field induced by vapor flux from high temperature zone to low temperature zone, which makes the model applicable for various circumstances. The modified Picard numerical method is employed to help with the water balance and convergence of the numerical scheme. Finally, the model is applied to analyze the diurnal energy and water cycle char- acteristics over the Tibetan Plateau using the Game/Tibet datasets observed in May and July of 1998. Heat and energy transfer simulation shows that: (i) There exists a negative feedback mechanism between soil freeze/thaw and soil temperature/ground heat flux; (ii) during freezing period all three heat fluxes do not vary apparently, in spite of the fact that the negative soil temperature is higher than that not considering soil freeze; (iii) during thawing period, ground heat flux increases, and sensible heat flux decreases, but latent heat flux does not change much; and (iv) during freezing period, soil temperature decreases, though ground heat flux increases.

关键词： land surface model,soil freeze/thaw,GAME/Tibet,simultaneous liquid,vapor and heat transfer.

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Multifield coupling model and its applications for pile foundation in permafrost

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Science china Earth Sciences 2005年第7期48卷 968-977页

作者： WU Yaping1,2, ZHU Yuanlin2, GUO Chunxiang1, SU Qiang1 & MA Wei2 1. School of Civil engineering, lanzhou Jiaotong University, lanzhou 730070, 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 School of Civil engineering Lanzhou Jiaotong University Lanzhou 730070 China State Key Laboratory of Frozen Soil engineering Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China

Importing the interface element which links the frozen soil base with concrete piles and considering the couplings of stress field, temperature field and moisture field, this paper es- tablishes the nonlinear visco-elastic plastic finite element model of pile-soil. For a practical bridge structure the stress field and displacement field of single pile in freezing process are calculated. This paper emphatically studies the process of the tangential frost heave stress field, freezing stress field and displacement field varying with time, and ulteriorly studies time variation process of single pile carrying capacity in freezing process.

关键词： permafrost pile foundation freezing process multifield coupling analysis model.

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THE BALANCE BETWEEN SUPPLY AND DEMAND OF WATER RESOURCES AND THE WATER-SAVING POTENTIAL FOR AGRICULTURE IN THE HEXI CORRIDOR

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Chinese Geographical Science 2002年第1期 24-30页

作者： GAO Qian zhao, DU Hu lin, ZU Rui ping(cold and arid regions environmental and engineering research institute, the Chinese Academy of Sciences, lanzhou 730000, P.R.china) cold and arid regions environmental and engineering research institute the Chinese Academy of SciencesLanzhou 730000P.R.China

The Hexi Corridor is an important base of agriculture development in Northwest china. According to recent statistics, there are 65.94×108m3 of water resources available in the Hexi Corridor. At present, net consumption in development and utilization is 43.33×108m3. Water supply and demand reach a balance on the recent level of production, but loss of evaporation and evapotranspiration is as much as 25.69×108m3. So net use efficiency of water resources is 59%. Based on analyzing balance between water and land considering ecological environment at present, there exists the serious water shortage in the Shiyang River system where irrigation lands have overloaded. There is a comparative balance between supply and demand of water resource in the Heihe River system; and the Sule River system has some surplus water to extend irrigation land. Use of agriculture water accounts for 83.3% and ecological forest and grass for 6.9%. The Hexi Corridor still has a great potential for water saving in agriculture production. Water saving efficiency of irrigation is about 10% by using such traditional technologies as furrow and border dike irrigation and small check irrigation, and water saving with plastic film cover and techniques of advanced sprinkler and drip/micro irrigation etc. can save more than 60% of irrigated water. Incremental irrigation area for water saving potential in the Hexi Corridor has been estimated as 56%-197% to original irrigation area. So the second water sources can be developed from water saving agriculture in the Hexi Corridor under Development of the Western Part of china in large scale. This potential can be realized step by step through developing the water saving measures, improving the ecological condition of oasis agriculture, and optimizing allocation of water resources in three river systems.

关键词： water resources balance between supply and demand water saving potential of agriculture Hexi Corridor

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On efficiency of sand-controlling system along the Tarim Desert Highway in Taklimakan Desert

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Journal of Geographical Sciences 2000年第2期10卷 141-150页

作者： WANG Xun-ming, DONG Zhi-bao, CHEN Guang-ting, HAN Zhi-wen (cold and arid regions environmental and engineering research institute, Chinese Academy of Sciences, lanzhou 730000, china)

As the longest desert highway in china. the 447-kin-long Taklimakan Desert Highway which goes across the Taklimakan Desert was fully opened to traffic in 1996~[1]. The sand-controlling system along the Desert Highway enables the Highway itself to operate properly and creates enormous socio-economic benefits. However, due to delivery time pressure, the sand-controlling system was built in a haste. Lack of studies on sand-controlling system brought deficiencies on design and construction of the sand-controlling system. And with the lapse of time, troubles such as sand deposition on the roadbeds and erosion on roadsides came to surface and caused more serious problems for the traffic routes[1.2]. This paper discusses two forms of the sand-controlling system-the upright fence and the send-covered sand barrier, then analyzes the general benefits of the sandcontrolling system along the Desert Highway.

关键词： sand-controlling system, desert highway Taklimakan Desert

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Vertical quantitative and dominant population distribution of the bacteria isolated from the Muztagata ice core

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Science china Earth Sciences 2005年第10期48卷 1728-1739页

作者： XIANG Shurong1, YAO Tandong1, 2, AN Lizhe1, 3, WU Guangjian2, XU Baiqing2, MA Xiaojun 3, LI Zhen1, WANG Junxia1 & YU Wusheng1 1. Key Laboratory of Ice Core and cold regions Environment, cold and arid regions environmental and engineering research institute, Chinese Academy of Sciences, lanzhou 730000, china 2. institute of Tibetan Plateau research, Chinese Academy of Sciences, Beijing 100085, china 3. College of Life Science, lanzhou University, lanzhou 730000, china Key Laboratory of Ice Core and cold regions Environment Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou China institute of Tibetan Plateau research Chinese Academy of Sciences Beijing china College of Life Science lanzhou University lanzhou china

Vertical distribution of the main bacteria isolated from the Muztagata ice core (about 22.4 m) was investigated by means of cultivation and 16S rRNA sequence analysis. The results showed that the amount of culturable bacteria fluctuated with ice core depth, and was more in dirty layer than in clean ice, which suggested the close corresponding relationship between high input of the bacteria deposited by wind and snowflow and dirty layer. Most of the bacteria were psychrophiles and psychrotolerants, including α- and γ-proteobacteria, Cryobacterium psychro-philum, CFB (Cytophaga-Flavobacterium-Bacteroides) group, high-G+C gram-positive bacteria (HGC). Acinetobacter sp. and HGC repeatly occurred in different ice depths, and their quantita-tive distribution was consistent with the change of the total amount of culturable bacteria with depth, which suggested the main bio-indicator; while Flavobacterium, Cryobacterium psychro-philum, and α-proteobacteria, also functioned as a secondary indicator of climatic and environ-mental changes. This study is the first report concerning continuous quantitative variation and pattern of the main culturable bacteria in ice core section.

关键词： Pamirs Plateau, ice core, pattern of bacteria, bio-indicator.

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Recent glacial retreat in High Asia in china and its impact on water resource in Northwest china

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Science china Earth Sciences 2004年第12期47卷 1065-1075页

作者： 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 1. Chinese Academy of Sciences Institute of Tibetan Plateau Research 100029 Beijing China 2. Chinese Academy of Sciences Cold and Arid Regions Environmental and Engineering Research Institute 730000 Lanzhou China

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%.

关键词： High Asia, glacial fluctuation, impact on water resource.

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