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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 sciences 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, 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 1. Cold and Arid Regions Environmental and engineering Research Institute Chinese Academy of Sciences 730000 Lanzhou China 2. state key laboratory of frozen nsoil engineering Chinese Academy of Sciences 730000 Lanzhou China 3. academy of Water Resources Conservation Forest of Qilian Mountains 734000 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.

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黄河源区景观格局与生态功能的动态变化

生态学报 2002年第10期22卷 1587-1598页

作者：王根绪郭晓寅程国栋中国科学院寒区旱区环境与工程研究所冻土工程国家重点实验室兰州730000

利用 2 0世纪 70年代、80年代与 90年代三期遥感资料 ,选取有代表性的 9个有关度量景观空间结构与景观异质性的定量指标 ,通过 FRAGSTATS计算方法 ,系统研究了黄河源区景观生态结构与景观格局变化 ,表明在近 30 a来 ,区域景观空间格局... 详细信息

利用 2 0世纪 70年代、80年代与 90年代三期遥感资料 ,选取有代表性的 9个有关度量景观空间结构与景观异质性的定量指标 ,通过 FRAGSTATS计算方法 ,系统研究了黄河源区景观生态结构与景观格局变化 ,表明在近 30 a来 ,区域景观空间格局趋于破碎化和多样化 ,其形成与发展的主要内在因素是高寒稀疏化草原草地、黑土化与杂类草草地和沙化草地等景观类型的迅速发展 ,其景观面积分别增加了 384 .1 6 %、6 6 .6 3%和 4 2 1 .0 9% ;选取景观生物生产力、景观土壤养分、景观植被覆盖度等景观功能的表征参数 ,提出了景观格局动态演变下分析景观功能变化的定量方法及其数学模型。在明确近 30 a来区域景观格局演变特征的基础上 ,研究了黄河源区不同时段不同景观类型间生态功能的转移流动特征及其区域生态环境效应 ,表明 :近 30 a来 ,黄河源区景观功能变化强烈 ;区域景观动态演变将形成区域内部景观功能向减退与增强两个方向的变化 ,两个方向的强度均衡将形成区域整体生态功能的特征。研究区域景观格局的动态变化所引起的区域生态功能演变特征。

关键词：黄河源区景观格局生态功能动态变化

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 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 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, 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

Heat transfer process of roadway embankments with different type and width of road surface in permafrost regions

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Progress in Natural Science:Materials International 2007年第3期17卷 314-319页

作者： YU Qihao, PAN Xicai, CHENG Guodong and BAI Yang (state key laboratory of frozen soil engineering, Cold and Arid Regions Environment and engineering Research Institute, chinese A-cademy of sciences, lanzhou 730000, china) [a]state key laboratory of frozen soil engineering Cold and Arid Regions Environment and Engineering Research Institute Chinese Academy of Sciences Lanzhou China

The stability of roadbed in permafrost areas has become a big concern with rapid development and construction of throughways, highways and railways in these areas under the current climate change since it is governed by the thermal condition, or in other words, the heat transfer process in the embankment. We carried out a finite element analysis to analyze the effects of different types of road surface and the effect of breadth of embankment on the embankment heat transfer process. The results indicated that the mean annual heat transfer rate at the bottom of the roadway embankment with asphalt surfaces is 3 times that with sandy gravel surfaces. This means annual heat transfer rate increased by 60% when the breadth of asphalt surface was doubled. The increased heat transfer rate was mainly located at the bottom of the embankment and resulted in the effect of thermal concentration,. leading to degradation of the permafrost by as much as 1.6 times. It was also found that increasing embankment height would not reduce these increases of the heat transfer rate. Therefore both asphalt road surface and increased embankment breadth can lead to an intensified heat transfer rate in roadway embankment, consequently degradating the underlying permafrost and embankment instability.

关键词： wide road surface roadway embankment permafrost regions process of heat transfer heat flux ground temperature field.

Effects of chlorothalonil and carbendazim on nitrification and denitrification in soils

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Journal of Environmental sciences 2009年第4期21卷 458-467页

作者： LANG Man, CAI Zucong state key laboratory of soil and Sustainable Agriculture, Institute of soil Science, chinese academy of sciences,Nanjing 210008, china [a]state key laboratory of soil and Sustainable Agriculture Institute of Soil Science Chinese Academy of Sciences Nanjing 210008 China

The effects of chlorothalonil and carbendazim on nitrification and denitrification in six soils in upland and rice paddy environments were investigated. laboratory aerobic （60% water holding capacity） and anaerobic （flooded） conditions were studied at 25℃ and fungicide addition rates of 5.5 mg/kg A. I. （field rate, FR）, 20 times （20FR） and 40 times （40FR） field rate, respectively. The results indicated that chlorothalonil at the field rate had a slight inhibitory effect on one soil only, and that soil did not nitrify much in the first place. But chlorothalonil at higher rates inhibited nitrification significantly in all soils. For soils JXP and JXU with a pH of less than 5.0, chlorothalonil almost completely stopped their nitrification at 20FR and 40FR during the whole 14 d incubation period. For soils HNP and HNU with a pH of greater than 8.0, chlorothalonil also significantly inhibit nitrification at 20FR and 40FR （p 〈 0.05）. However, NH4＋ that was added to the soil was also almost completely nitrified by the end of the incubation period in these two soils. The effects of chlorothalonil at 20FR and 40FR on the nitrification of JSP and JSU soils, with a pH of 5.4 and 7.2, respectively, were intermediate between the other soil types. Chlorothalonil had no effect on denitrification at the field rate and had little effect at the higher rates of application in some soils. Carbendazim had essentially no effect on nitrification and denitrification in soils assessed.

关键词： fungicide nitrification denitrification chlorothalonil carbendazim

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.

Study on ground temperature change and characteristic response of engineering geology of permafrost along Qinghai-Tibet Railway

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Science china(Technological sciences) 2003年第z1期46卷 78-90页

作者： PAN Weidong, WANG Quancai, YU Shaoshui & ZHANG Xiaoyan Department of Mechanics, School of Physical Science and Technology, lanzhou University, lanzhou 730000, china Institute of Mountain Hazards and Environment, chinese academy of sciences and Ministry of Water Resources, Chengdu 610041, china state key laboratory of frozen soil engineering, Cold and Arid Regions Environment and engineering Research Institute, chinese academy of sciences, lanzhou 730000, china Sichuan Provincial Communications Department, Chengdu 610041, china lanzhou Univ Dept Mech Sch Phys Sci & Technol Lanzhou 730000 Peoples R China chinese Acad Sci Inst Mt Hazards & Environm Chengdu 610041 Peoples R China Minist Water Resources Chengdu 610041 Peoples R China chinese Acad Sci State Key Lab Frozen Soil Engn Cold & Arid Reg Environm & Engn Res Inst Lanzhou 730000 Peoples R China Sichuan Prov Commun Dept Chengdu 610041 Peoples R China

Along with the global warming in the recent scores of years, comparatively big changes have taken place in the weather and other environmental conditions of the permafrost area in the Qinghai-Tibet Plateau, and very big changes have also occurred in the engineering geological conditions of the permafrost area. Based on a large volume of field survey data, this paper discusses the regularities of horizontal and vertical distribution of permafrost, with its focus of analysis on the temperature change characteristics of the soil in different frozen-soil zones, as well as presents simulation analysis and research for the engineering geologic characteristic response changes that would occur in the future when the temperature of the frozen soil in different zones rises by 1 and 2.6℃ respectively, which will have a tremendous impact on the stability of constructional work.

关键词： Qinghai-Tibet Railway, permafrost, ground temperature, engineering geological characteristic.

Processes and modes of permafrost degradation on the Qinghai-Tibet Plateau

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Science china Earth sciences 2010年第11期53卷 150-158页

作者： 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 1. state key laboratory of frozen soil engineering Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China

Climate warming must lead the mainly air temperature controlled permafrost to *** 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 *** on the Qinghai-Tibet Plateau (QTP) is generally considered a relic from late Pleistocene,and has been degenerating as a whole during *** to spatial-temporal compensation,the present thermal state discrepancy of permafrost in different areas on the QTP may correspond with their degradation *** 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 *** 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 *** are two modes of perennially frozen ground thawing,thawing from top to bottom and thawing from bottom to top *** 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 *** 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 *** the other hand,the disappearance of permafrost may be delayed by "thermal offset" and "seas

关键词： Qinghai-Tibet Plateau permafrost degradation process degradation stage degradation mode

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A constitutive model of frozen soil with damage and numerical simulation for the coupled problem

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Science china(Physics,Mechanics & Astronomy) 2010年第4期53卷 699-711页

作者： ZHU ZhiWu, NING JianGuo& MA Wei 1 School of Mechanics and engineering, Southwest Jiaotong University, Chengdu 610031, china 2 state key laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081, china 3 key laboratory of frozen soil engineering, CAREERI, CAS, lanzhou 730000, china 1. School of Mechanics and engineering Southwest Jiaotong University Chengdu 610031 China2. State Key Laboratory of Explosion Science and Technology Beijing Institute of Technology Beijing 100081 China3. Key Laboratory of Frozen Soil Engineering CAREERI CAS Lanzhou 730000 China

Based on the microcosmic mechanics of composite materials, an elastic constitutive model for frozen soil with damage is presented. For frozen sandy soil with a range of ice contents and under a range of temperature conditions, quantitative results determined by this constitutive model agree with practically measured stress-strain curves. After numerically simulating the coupled water, temperature and stress fields of channel frozen and frozen roadbed using a self-developed finite-element routine, more accurate and practical calculation results for the temperature field coupled with stress, displacement and strain fields are obtained; the results match predictions and tests undertaken by earlier researchers. Our results support the reliability of our routine for calculating interdependent physical quantities of frozen soil and for describing the relationships between them. Our program can offer necessary constraints for engineering design and construction in permafrost regions.

关键词： frozen soil microcosmic mechanics roadbed coupling stress field