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Temperature variations recovered from tree-rings in the middle Qilian Mountain over the last millennium

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Science china Earth {1. 2005年第4期48卷 521-529页

作者： LIU Xiaohong1.2, QIN Dahe1. SHAO Xuemei , CHEN Tuo1.& REN Jiawen1. 1. cold and arid regions environmental and engineering research institute,{1., lanzhou 730000, china 2. institute of Geographical sciences and Natural Resources research,{1., Beijing 1.01.1. china cold and {1. regions environmental and engineering research institute Chinese Academy of Sciences Lanzhou China institute of Geographical {1. and Natural Resources research Chinese Academy of Sciences Beijing China

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 1.00 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 δ1.O 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.

关键词： middle Qilian Mountain, tree-ring width chronology, temperature variations.

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

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Science china Earth {1. 2005年第4期48卷 538-548页

作者： KANG Ersi1. CHENG Guodong1. , SONG Kechao1. JIN Bowen1. , LIU Xiande3 2 3 & WANG Jinye3 1. cold and arid regions environmental and engineering research institute,{1., lanzhou 730000, china 2. State Key Laboratory of Frozen Soil engineering,{1., lanzhou 730000, china 3. academy of Water Resources Conservation Forest of Qilian Mountains, Gansu Province, Zhangye 734000, china cold and {1. regions environmental and engineering research institute Chinese Academy of Sciences Lanzhou China State Key Laboratory of Frozen nSoil engineering Chinese Academy of Sciences Lanzhou China academy of Water Resources Conservation Forest of Qilian Mountains Gansu Province Zhangye China

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 s

关键词： inland rivers, mountain vegetation zone, Soil-Vegetation-Atmosphere Transfer (SVAT) system, energyand water balance, simulation.

Sap-flow measurement and scale transferring from sample trees to entire forest stand of Populus euphratica in desert riparian forest in extreme arid region

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research in {1. and arid regions 2009年第3期1卷 258-266页

作者： JianHua Si 1. Qi Feng 1. HaiYang Xi 1. ZongQiang Chang 1. YongHong Su 1. Kai Zhang 1.2 1. cold and arid regions environmental and engineering research institute,{1., lanzhou, Gansu 730000, china. 2. institute of arid Meteorology, china Meteorological Administration, lanzhou, Gansu 730020, china. chinese Acad Sci Cold & Arid Reg Environm & Engn Res Inst 320 Donggang West Rd Lanzhou 730000 Gansu Peoples R China china Meteorol Adm Inst Arid Meteorol Lanzhou 730020 Gansu Peoples R China

Understanding how the transpiration of this vegetation type responds to environmental stress is important for determining the wa-ter-balance dynamics of the riparian ecosystem threatened by groundwater depletion. Transpiration and sap flow were measured using the heat-pulse technique. The results were then projected up to the stand level to investigate the stand’s water-use in relation to climate forcing in the desert riparian forest in an extreme {1. region. This study took place from April through October 2003 and from May through October 2004. The experimental site was selected in the Populus euphratica Forest Reserve (1.1.1.' E, 41.59' N) in Ejina county, in the lower Heihe River basin, china. The sapwood area was used as a scalar to extrapolate the stand-water consumption from the whole trees’ water consumption measured by the heat-pulse velocity recorder (HPVR). Scale transferring from a series of individual trees to a stand was done according to the existing natural variations between trees under given environmental conditions. The application of the biometric parameters available from individual tree and stand levels was proved suitable for this purpose. A significant correlation between the sapwood area and tree diameter at breast height (DBH) was found. The prediction model is well fitted by the power model. On the basis of the prediction model, the sapwood area can be cal-culated by DBH. The sap-flow density can then be used to extrapolate the stand-water use by means of a series of mathematical models.

关键词： sap flow heat-pulse technique sapwood area scale transferring extreme arid region Populus euphratica

The research of three-dimensional numerical simulation of groundwater-flow: taking the Ejina Basin, Northwest{1. as example

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research in {1. and arid regions 2009年第3期1卷 238-248页

作者： Qi Feng 1,2, HaiYang Xi 1, Wei Liu 1,3, JianHua Si 1,2, ZongQiang Chang 1,2, YongHong Su 1,2 1. cold and arid regions environmental and engineering research institute, chinese academy of sciences, lanzhou, Gansu 730000, china. 2. Alashan Desert Eco-hydrology Experimental research Station, lanzhou, Gansu 730000, china. 3. State Key Laboratory of Hydrosciences and engineering, Tsinghua University, Beijing 100084, china. chinese Acad Sci Cold & Arid Reg Environm & Engn Res Inst 320 West Donggang Rd Lanzhou 730000 Gansu Peoples R China Alashan Desert Ecohydrol Expt Res Stn Lanzhou 730000 Gansu Peoples R China Tsinghua Univ State Key Lab Hydrosci & Engn Beijing 100084 Peoples R China

Water is a primary controlling factor for economic development and ecological environmental protection in the inland river basins of {1. western china. And it is groundwater, as the most important component of total water resources, that plays a dominant role in the development of western china. In recent years, the use-ratio of surface water has been raised, the groundwater recharge rate from surface water has been reduced, and groundwater has been exploited on a large scale. This has led to the decline of ground-water levels and the degradation of eco-environments in the Heihe watershed. Therefore, the study on the change in groundwater levels in recent years, as well as simulating and predicting groundwater levels in the future, have become very significant for im-proving the ecological environment of the Heihe River Basin, to coordinate the water contradiction among upper, middle and lower reaches of Heihe River Basin and to allocate the water resources. The purpose of this study is to analyze the groundwa-ter-level variations of the Ejina region based on a large scale, to develop and evaluate a conceptual groundwater model in Ejina Basin, to establish the groundwater flow model using the experimental observation data and combining Modular Three-Dimensional Groundwater Flow Model (MODFLOW) and GIS software, to simulate the regional hydrologic regime in re-cent 1. years and compare various water-delivery scenarios from midstream, and to determine which one would be the best plan for maintaining and recovering the groundwater levels and increasing the area of Ejina oasis. Finally this paper discusses the pos-sible vegetation changes of Ejina Basin in the future.

关键词： groundwater flow model Ejina Basin MODFLOW Heihe River

Estimation on the response of glaciers in china to the global warming in the 21.t century

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chinese Science Bulletin 2000年第7期45卷 668-672页

作者： 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 Laboratory of Ice Core and cold {1. Environment Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou China cold and {1. regions environmental and engineering research institute Chinese Academy of Sciences Lanzhou China

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. {1.es indicate that glaciers of the three types show different response patterns to the global warming. Since the Maxima of the Little Ice Age (the 1.th 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 21.0s 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 1.%, 28% and 45% by the 2030s, 2070s and 21.0s. The uncertainties may account for 30%-67% in 21.0 in china.

关键词： modern glacier global warming Little Ice Age glacier type temperature rise in the 21.t century estimated glacier shrinkage.

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 {1. regions environmental and engineering research institute, chinese academy of sciences, lanzhou 730000, china State Key Laboratory of Frozen Soil engineering, chinese academy of sciences, lanzhou 730000, china cold and {1. regions environmental and engineering 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 {1. 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 {1. zones has become a forefront and focus of the eco-environmental research. Recent studies on eco-hydrological processes in {1. zones show that the primary vegetation pattern and its eco-hydrological effect are of the most stable state of the ecosystem in {1. zones. Special water absorption ways of plants in {1. 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 {1. 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 {1. zones. The paper reviews some advances in the study of eco-hydrological processes in {1. 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 {1.) 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 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 College of Civil engineering Lanzhou University of Technology Lanzhou China State Key Laboratory of Frozen Soil engineering Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 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, 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.

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

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 {1. 2004年第z1期47卷 131-141页

作者： 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 cold & {1. regions environmental and engineering research institute Chinese Academy of Science Lanzhou China Department of Atmospheric sciences Lanzhou University Lanzhou China

There are well coherences between annual averaged air temperatures at every meteorological station along the Qinghai-Xizang railway, and its 1.-year moving average correlation coefficient is 0.92. Thus, the regional averaged annual mean temperature series along the Qinghai-Xizang railway (Trw) from 1.35 to 2000 are constructed. The investigation is suggested that: Trw had significant responses to the 5-year lagged sunspot cycle length (SCL) and 1.-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, 1.8a, 205a and 275a. The result shows that the SCL would be becoming longer in the first half of the 21.t century, and then it could be becoming shorter in the second half of the 21.t century. Based on the natural change of SCL and the effect of double CO2 concentration, Trw in the 21.t century is forecasted. It could warm up about 0.50℃ in the first half of the 21.t 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 1.1.℃ 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.

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 830011, china Open Laboratory of Ice-Core, cold and arid regions environmental and engineering research institute, chinese academy ofsciences, lanzhou 730000, 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.