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Decrease trend of dust event frequency over the past 200 years recorded in the Malan ice core from the northern Tibetan Plateau

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chinese Science Bulletin 2005年第24期50卷 2866-2871页

作者： WANG Ninglian Key Laboratory of Cryosphere and Environment, cold and Arid regions environmental and {3. research institute, chinese academy of sciences, lanzhou 73.00, china institute of Tibetan Plateau research, chinese academy of sciences, Beijing 100085, china Key Laboratory of Cryosphere and Environment Cold and And Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 73000 China Institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing 100085 China

By analyses of the dust layers in the Malan ice core from the northern Tibetan Plateau, it was found that dirty ratio in this core might be a good proxy for dust event frequency. The variations in the dirty ratio displayed a de- crease trend over the past 200 years, which implies that dust events became less frequent during the study period. The decrease trend in the variations in dust event frequency might be caused mostly by the natural processes, including increasing precipitation and weakening westerly which might be related with global warming. Furthermore, significant negative correlation was found between the dirty ratio and δ 18O in the Malan ice core. This is highly important for studying the effect of atmospheric dust on climate change.

关键词：青藏高原马伦冰核气候变化扬尘事件发生频率

Impacts of permafrost changes on alpine ecosystem in Qinghai-Tibet Plateau

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Science china Earth sciences 2006年第11期49卷 1156-1169页

作者： WANG Genxu1,3., LI Yuanshou2 , WU Qingbai2 & WANG Yibo3.1. institute of Mountain Hazards and Environment, chinese academy of sciences, Chengdu 610041, china 2. {3. and Arid regions environmental and engineering research institute, chinese academy of sciences, lanzhou 73.000, china 3. Resource and Environment School, lanzhou University, lanzhou 73.000, china 1. institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu 610041 China 3. Resource and Environment School Lanzhou University Lanzhou 730000 China 2. cold and Arid regions environmental and {3. research institute Chinese Academy of Sciences Lanzhou 730000 China

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

关键词： permafrost environment, alpine cold ecosystem, statistics relationship, climate change, impacts, Qinghai-Tibet Plateau.

Impact of land-use change on hydrological processes in the Maying River basin, china

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Science china Earth sciences 2006年第10期49卷 1098-1110页

作者： WANG Genxu1,3. ZHANG Yu2, LIU Guimin2 & CHEN Lin3.1. institute of Mountain Hazards and Environment, chinese academy of sciences, Chengdu 610041, china 2. {3. and Arid regions environmental and engineering research institute, chinese academy of sciences, lanzhou 73.000, china 3. Resource and Environment School, lanzhou University, lanzhou 73.000, china 1. institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu 610041 China 3. Resource and Environment School Lanzhou University Lanzhou 730000 China 2. cold and Arid regions environmental and {3. research institute Chinese Academy of Sciences Lanzhou 730000 China

Since the 1960s, dramatic changes have taken place in land-use patterns characterized by the persistent expansion of cultivated land and a continuous decrease in natural woodland and grassland in the arid inland river basins of china. It is very important to assess the effects of such land-use changes on the hydrological processes so vital for water resource management and sustainable development on the catchment scale. The Maying River catchment, a typical arid inland watershed located in the middle of the Hexi Corridor in northwest china, was the site chosen to investigate the hydrological responses to land-use changes. The annual runoff, base flow, maximum peak flow, and typical seasonal runoff in both spring and autumn flood periods were selected as the variables in the hydrological processes. Statistical-trend analysis and curvilinear regression were utilized to detect the trends in hydrological variables while eliminating the climatic influence. The relationship between cultivated land-use and hydrological variables was analyzed based on four periods of land-use variation data collected since 1965. A runoff model was established composed of two factors, i.e., cultivated land use and precipitation. The impact of land use changes, especially in the large ar- eas of upstream woodland and grassland turned into cultivated lands since 1967, has resulted in a mean annual runoff decrease of 28.12%, a base flow decline of 3..3.%, a drop in the maximum peak discharge of 3..77%, and mean discharge decreases in spring and autumn of 3..05% and 24.87% respectively, of which the contribution of cultivated land expansion to the influence of annual runoff amounts to 77%-80%, with the contribution to the influence of spring discharge being 73.-81%, and that to the influence of base flow reaching 62%-65%. Thus, a rational regulation policy of land use patterns is vitally important to the sustainable use of water resources and the proper development of the entire catchment.

关键词： land-use change, arid inland river catchment, hydrological process, impact, Maying River.

Respondence and feedback of modern sand deserts to climate change ——A case study in Gurbantunggut Desert

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chinese Science Bulletin 2000年第12期45卷 1137-1142页

作者： WEI WenshouXinjiang institute of Ecology and Geography, chinese academy of sciences, Urumqi 83.011, china Open Laboratory of Ice-Core, {3. and Arid regions environmental and engineering research institute, chinese academy ofsciences, lanzhou 73.000, china Xinjiang institute of Ecology and Geography Chinese Academy of Sciences Urumqi 830011 China Open Laboratory of Ice-Core Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China

The research on the respondence and feedback of modern sand deserts to the climate change is an important component part in the studies on the global climate change. Deserts respond to the climate change, meanwhile, they affect the climate with their feedback of peculiar environment during the respondence. Many researches on desert climate have been carried out at home and abroad. However, there is little research on the respondence and feedback of modern fixed, semi-fixed and mobile deserts in arid areas to the climate change, in which the factor analysis as well as the parameter changing effects is especially the difficult problem all along. In this note, the parameters of the respondence and feedback of Gurbantunggut Desert to the climate change are measured and analyzed, some variable parameters of water-heat exchange are obtained, and a numerical model of desertification is developed according to a series of climate change of about 40 years and the variable relations of meteorological and physical

关键词： Gurbantunggut Desert climate change respondence and feedback numerical model.

Review of several problems on the study of eco-hydrological processes in arid zones

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chinese Science Bulletin 2002年第5期47卷 353-360页

作者： ZHAO Wenzhi & CHENG Guodongcold and Arid regions environmental and {3. research institute, chinese academy of sciences, lanzhou 73.000, china State Key Laboratory of Frozen Soil {3., chinese academy of sciences, lanzhou 73.000, china cold and Arid regions environmental and {3. research institute Chinese Academy of Sciences Lanzhou China State Key Laboratory of Frozen Soil engineering Chinese Academy of Sciences Lanzhou China

Ecosystem degradation is a common and cardinal environmental problem in arid zones. The change in the eco-hydrological processes is the basic cause responsible for such a problem. The study on the eco-hydrological processes in arid zones has become a forefront and focus of the eco-environmental research. Recent studies on eco-hydrological processes in arid zones show that the primary vegetation pattern and its eco-hydrological effect are of the most stable state of the ecosystem in arid zones. Special water absorption ways of plants in arid zones and the hydraulic lift and reverse hydraulic lift functions of some plants are the key mechanisms to maintain the stability of the ecosystem in arid zones. In the case of water shortage, ensuring ecological water requirement and maintaining proper ecological ground- water table are the prerequisite to keep healthful operation of the ecosystem in arid zones. The paper reviews some advances in the study of eco-hydrological processes in arid zones. It puts

关键词： arid zone vegetation pattern eco-hydrological effect hydraulic lift plant water source ecological water requirement.

Dynamic calculation model and seismic response for frame supporting structure with prestressed anchors

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Science china(Technological sciences) 2010年第7期53卷 1957-1966页

作者： DONG JianHua1’2, ZHU YanPeng1, ZHOU Yong1 & MA Wei2 1 College of Civil engineering, lanzhou University of Technology, lanzhou 73.050,{3. 2 State Key Laboratory of Frozen Soil engineering, cold and Arid regions environmental and engineering research institute, chinese academy of sciences, lanzhou 73.000,{3. 1. College of Civil engineering Lanzhou University of Technology Lanzhou 730050 China2. State Key Laboratory of Frozen Soil Engineering Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China

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, 3. 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.

关键词： frame supporting structure with prestressed anchor slope dynamic calculation model seismic performance seismic design

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 73.000, china 2. institute of Tibetan Plateau research, chinese academy of sciences, Beijing 100085, china 3. College of Life Science, lanzhou University, lanzhou 73.000, 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{3. 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.

Effects of sunspot cycle length and CO_2 on air temperature along Qinghai-Xizang railway and air temperature's trend prediction

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Science china Earth sciences 2004年第z1期47卷 131-141页

作者： LI Dongliang, QUO Hui, WANG Wen & WEI Licold & Arid regions environmental and {3. research institute, chinese academy of Science, lanzhou 73.000, china Department of Atmospheric sciences, lanzhou University, lanzhou 73.000, china 1. cold & Arid regions environmental and {3. research institute Chinese Academy of Science 730000 Lanzhou China2. Department of Atmospheric Sciences Lanzhou University 730000 Lanzhou China

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 193. 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, 93., 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.

关键词： Qinghai-Xizang railway, annual mean air temperature, sunspot cycle length (SCL), atmospheric carbon dioxide concentration (CO2), prediction.

LANDSCAPE ECOLOGICAL CONSTRUCTION IN RURAL china:THEORY AND APPLICATION

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chinese Geographical Science 2001年第2期11卷 104-114页

作者： XIAO Du-ning (cold and Arid regions environmental and {3. research institute, the chinese academy of sciences, lanzhou 73.000, P.R.china institute of Applied Ecology,the chinese academy of sciences, Shenyang 110015,P.R.china ) cold and Arid regions environmental and {3. research institute the Chinese Academy of Sciences Lanzhou P.R. China institute of Applied Ecology the Chinese Academy of Sciences Shenyang P. R. China

In landscape with overpopulation, intensive management for economic production, and where even small natural-vegetation patches are scarce, ecological conservation generally must be developed in the course of economic development. Thus “landscape ecological construction” has evolved in china. This approach adds spatial elements and alters landscape pattern to strengthen inter-ecosystem linkages, improve functioning of damaged ecosystems, and increase productivity and stability of the whole landscape. Five examples of managed landscapes in china are presented: dike-pond systems in a river delta; multi-pond system in a rice paddy landscape; field-grass-wood grid system on unstable sand dunes; shelterbelt network in a crop field area; and field-grass-wood mosaic system on highly erodible hilly farmland. These indicate that ecological conditions can be improved along with increased economic production. Altering landscape structure and ecological flows by introducing small landscape elements in distinct spatial patterns is considered a key to the results. This reshaping of the land has focused on changing patch size, regularity of arrangement, biological and hydrological corridors, and networks, the matrix and grain size. It suggests that such changes can increase negative feedbacks and increase stability. Finally, planning and design principles are pinpointed for the landscape ecological construction process.

关键词： landscape planning ecological construction rural china