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Integrating MODFLOW and GIS technologies for assessing impacts of irrigation management and groundwater use in the Hetao Irrigation District,Yellow River basin

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Science china(Technological Sciences) 2009年第11期52卷 3257-3263页

作者： XU Xu1,2, HUANG GuanHua1,2 & QU ZhongYi3 1 center for agriculture Water research, china agricultural university, beijing 100083, china 2 chinese-israeli international center for research and training in agriculture, china agricultural university, beijing 100083, china 3 Water Conservancy and Civil Engineering College, Inner Mongolia agricultural university, Hohhot 010018, china center for agriculture Water research China Agricultural University Beijing China chinese-israeli international center for research and training in agriculture China Agricultural University Beijing China Water Conservancy and Civil Engineering College Inner Mongolia Agricultural University Hohhot China

Due to severe water scarcity, water resources used in agricultural sector have been reduced markedly in Hetao irrigation district. Application of water-saving practices (WSPs) is required for the sustainable agricultural development. The human activities including WSPs and increase of groundwater abstraction can lower down the groundwater table, which is helpful to the salinity control. Meanwhile, an excessively large groundwater table depth may result in negative impact on crop growth and fragile ecological environment. In this paper, the Jiefangzha irrigation system in Hetao irrigation district was selected as a typical area, a groundwater flow model based on ArcInfo Geographic Information System (GIS) was developed and implemented to quantify the effect of human activities on the groundwater system in this area. The preand post-processing of model data was performed efficiently by using the available GIS tools. The time-variant data in boundary conditions was further edited in Microsoft Excel with programs of Visual Basic for Application (VBA). The model was calibrated and validated with independent data sets. Application of the model indicated that it can well describe the effect of human activities on groundwater dynamics in Jiefangzha irrigation system.

关键词： groundwater flow modeling MODFLOW GIS water-saving practices irrigation district

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Modified vegetation-erosion dynamics model and its application in typical watersheds in the Loess Plateau

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international Journal of Sediment research 2011年第1期26卷 78-86页

作者： CHEN Yuehong~1,WANG Feixin~2,LIU Guangquan~3,YU Xinxiao~4, JIA Guodong~5,and GAN Ping~6 china Institute of Water Resources and Hydropower research,beijing 100048 international research and training center on Erosion and Sediment research,beijing 100048,china beijing Forestry university,beijing 100083,china. Key Lab of Dredging Technology of CCGRP,Shanghai Waterway Engineering Design and Consulting Co., Ltd,Shanghai 200120,china. international research and training center on Erosion and Sedimentation china Institute of Water Resources and Hydropower research,beijing 100048 Northwest A&F university,Yangling 712100,china, beijing Forestry university,beijing 100083,china, beijing Forestry university,beijing 100083,china. china Institute of Water Resources and Hydropower research,beijing 100048,and international research and training center on Erosion and Sediment research,beijing 100048,china Assoc. Prof. Dr. China Institute of Water Resources and Hydropower Research Beijing 100048 international research and training center on Erosion and Sediment research Beijing 100048 China beijing Forestry university Beijing 100083 China Dr. Key Lab of Dredging Technology of CCGRP Shanghai Waterway Engineering Design and Consulting Co. Ltd Shanghai 200120 China Prof. Dr. International Research and Training Center on Erosion and Sedimentation china Institute of Water Resources and Hydropower research Beijing 100048 Northwest A&F university Yangling 712100 China Prof. Dr. Beijing Forestry University Beijing 100083 China Dr. Beijing Forestry University Beijing 100083 China Engineer China Institute of Water Resources and Hydropower Research Beijing 100048 and International Research and Training Center on Erosion and Sediment Research Beijing 100048 China

The vegetation-erosion model was applied in three typical watersheds of hilly and gully area in the Loess Plateau in northwestern china to study the dynamic relations between vegetation coverage and soil erosion rate and various *** model was improved by introducing rainfall and runoff *** the modified model was applied in the Luergou and Luoyugou *** calculation results with the modified model were compared with the results of the original *** precisions of simulated vegetation coverage and soil erosion rate with the modified model were greatly improved compared with the original *** erosion rate reduced with increasing vegetation coverage and the human disturbance caused high soil erosion.

关键词： Soil erosion Vegetation coverage Vegetation-erosion dynamics model Loess Plateau Modified model

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A preliminary study on vegetation-erosion dynamics and its applications

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Science china Earth Sciences 2005年第5期48卷 689-700页

作者： WANG Zhaoyin 1,2 , WANG Guangqian 1 , LI Changzhi 1 & WANG Feixin 1 1. Department of Hydraulic Engineering, Tsinghua university, beijing 100084, china 2. international research and training center on Erosion and Sedimentation, beijing 100084, china Department of Hydraulic Engineering Tsinghua University Beijing China international research and training center on Erosion and Sedimentation Beijing China

Vegetation-erosion dynamics is a new interdisciplinary science, studying the laws of evolution of watershed vegetation under the action of various ecological stresses. Introducing a qualitative expression of ecological stresses in this paper, the present authors establish the cou- pled differential equations for the vegetation-erosion process and derive a theoretical solution. The model is applied to the Anjiagou watershed on the Loess Pateau and the Xiaojiang water- shed and its sub-watersheds on the Yunnan Plateau. The calculated results agree well with the vegetation development processes. Abstracted from the differential equations the so-called vegetation-erosion chart is worked out, with which we can predict the development trend of vegetation under no human stresses. It is demonstrated that the erosion control is important for vegetation development and reforestation must be a long-term strategy. On the Yunnan Plateau with relatively high precipitation and temperature, vegetation can be greatly improved if erosion is controlled. On the dry and cold Loess Pateau suffering from high rate of soil erosion, however, vegetation can effectively control erosion but erosion reduction exhibits low effectiveness on vegetation development. Vegetation in the area is not stable and management is always needed to maintain the vegetation.

关键词： vegetation-erosion dynamics, human activities, coupled differential equations, erosion control, vigor ofvegetation.

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research progress on electrical signals in higher plants

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Progress in Natural Science:Materials international 2009年第5期19卷 531-541页

作者： Xiaofei Yana, Zhongyi Wang a, Lan Huang a, Cheng Wang b, Ruifeng Hou b, Zhilong Xu b, Xiaojun Qiao b a College of Information and Electrical Engineering, china agricultural university, beijing 100083, china b National Engineering research center for Information Technology in agriculture, beijing 100097, china College of Information and Electrical Engineering China Agricultural University Beijing 100083 China National Engineering research center for Information Technology in agriculture Beijing 100097 China

This review introduces the characteristics of electrical signals in higher plants and their corresponding physiological significance, and describes in detail the impact of environmental factors (e.g. light and temperature) on the electrical potential of the plants. Also, we evaluate the measurement techniques used for electrical signals in plants, including intracellular measurement, extracellular measurement, measurement of the ion channel based on the patch-clamp technique and on the non-invasive microelectrode vibrating probe technique. We also give a brief review of the applications of these methods for investigating electrical signals in plants. The ionic mechanism of electrical activity in plants is then discussed in terms of environmental response in higher plants, and this is used to provide a theoretical basis for quantitative description of the electrical signals in plants. A model for interpretation of the electrical signal mechanisms in higher plants is discussed, but further experiments are required for the verification of this model.

关键词： Ion channel Temperature-induced Light-induced Ion mechanism Measurement technology

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Representations of Real and Complex Stability Radii of 2-Dimensional LinearSystems

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international Journal of Minerals,Metallurgy and Materials 1999年第4期13卷 299-301页

作者： Lequan Min1.2 Ning Song1(l Applied Science School, university of Science and Technology’ beijing, beijing 100083, china2 china center of Advanced Science and Technology, beijing 100080, china) Applied Science School University of Science and Technology Beijing Beijing 100083 China china center of Advanced Science and Technology Beijing 100080 China

Rigorous proofs are given for the representations of real and complex stability' radii of 2-dimensional linear systems. This representations can be used to analyze the robustness of a nominal 2-dimensional linear system under pelturbation of the system parameters, in particular testing the effect of numerical algorithms which are used to calculate the real stability radii of higher dimensional piecewise-linear systems.

关键词： linear systems robustness stability radii

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EVALUATION OF WATER AND SEDIMENT QUALITIES AT RIVER MOUTHS IN THE HAIHE RIVER SYSTEM

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international Journal of Sediment research 2007年第4期22卷 318-326页

作者： Cheng LIU1, Zhao-Yin WANG1,2, Yun HE3, and Dongsheng CHENG3 1 Prof., Dr., international research and training center on Erosion and Sedimentation, beijing, 100044, china 2 Prof., Dr., Dept. of Hydraulic Engineering, Tsinghua university & international research and training center on Erosion and Sedimentation, beijing, 100084, china 3 Dr., Senior Engineer, china Institute of Water Resources and Hydropower research, beijing, 100044, china Int Res & training Ctr Eros & Sedimentat Beijing 100044 Peoples R China Tsinghua Univ Dept Hydraul Engn Beijing 100084 Peoples R China Int Res & training Ctr Eros & Sedimentat Beijing 100084 Peoples R China china Inst Water Resources & Hydropower Res Beijing 100044 Peoples R China

Water and sediment qualities are studied by analyzing samples taking from the mouths of the Haihe, Duliujian, New Ziya and Beipai rivers in the Haihe river basin in north china in 2005 and 2001, in order to find the changes of water and sediment pollutions. The concentrations of heavy metals, arsenic, total nitrogen (TN) and total phosphorus (TP) are analyzed and results have been compared for the two times. The in-situ measurement for Dissolved Oxygen (DO) and Sediment Oxygen Demand (SOD) rates were carried at the Haihe and Duliujian river mouths in 2006. The results show that the waters of the 4 river mouths are still seriously polluted, though much improved in the case of the Haihe and Duliujian rivers. The main pollutants are TP and TN in the New Ziya and Beipai rivers and mercury (Hg) at all 4 river mouths. Compared with those in 2001, the concentrations of almost all metals and arsenic in the 4 river mouths have decreased. Water quality at Haihe and Duliujian shows an improving trend, while the water quality at Beipai is similar to that of 2001. In contrast, water at the New Ziya river mouth is more severely polluted. The sediments in the 4 river mouths are not seriously polluted by heavy metals but are polluted by nitrogen and phosphorus. Most of the pollutant contents in the sediments show little change between 2001 and 2005. The in-situ DO and SOD measurement shows that the waters at the Haihe river mouth is in the state of oxygen depletion, and SOD is important consumer of DO at the river mouths. The overall analysis shows that increasing water pollution and eutrophication in waters far from cities are ongoing causes of concern.

关键词： River mouth Water quality Sediment quality Eutrophication Sediment oxygen demand

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Strategies for managing reservoir sedimentation

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international Journal of Sediment research 2009年第4期24卷 369-384页

作者： Zhao-yin WANG 1 and Chunhong HU 21 Prof., State Key Lab of Hydroscience and Engineering, Tsinghua university, beijing 100084, china. 2 Prof., Secretary General of international research and training center on Erosion and Sedimentation, beijing 100048, china and Vice President of china Institute of Water Resources and Hydropower research, No. A-1, Fuxing Rd, beijing 100038, china. Prof. State Key Lab of Hydroscience and Engineering Tsinghua University Beijing 100084 China Prof. Secretary General of International Research and Training Center on Erosion and Sedimentation Beijing 100048 China and Vice President of China Institute of Water Resources and Hydropower Research No. A-1 Fuxing Rd Beijing 100038 China

Sediment deposition in reservoirs has caused the loss of 66% of the reservoir capacity in china. The main sedimentation control strategies are: 1) storing the clear water and releasing the turbid water; 2) releasing turbidity currents; 3) Draw-down flushing and empty flushing; and 4) dredging. The paper summarizes these strategies with examples. Sediment transport in many chinese rivers occurs mostly during the 2-4 month flood season, that is, 80-90% of the annual sediment load is transported with 50-60% of the annual runoff. By storing the clear water after the flood season and releasing the turbid water during the flood season, less sediment deposits in the reservoir while the reservoir is still able to store enough water for power generation in the low flow season. The Three Gorges and Sanmenxia reservoirs apply this strategy and control sedimentation effectively. Turbidity currents have become the main sedimentation control strategy for the Xiaolangdi Reservoir. Empty flushing involves reservoir draw-down to temporarily establish riverine flow along the impound reach, flushing the eroded sediment through the outlets. Case studies with the Hengshan Reservoir and Zhuwo Reservoir are presented. Jet dredgers have been used to agitate the reservoir deposit so that the deposit is released from the reservoir with currents. The sediment releasing efficiency is 30-100% for storing the clear and releasing the turbid; 6-40 % for turbidity current; and 2,400-5,500% for empty flushing. Empty flushing causes high ecological stress on the ecosystem to the downstream reaches. Storing the clear and releasing the turbid is the best strategy to control reservoir sedimentation while achieving hydro-power benefit and maintain ecological stability.

关键词： Reservoir sedimentation Storing clear and releasing turbid Flushing Turbidity current Three Gorges Reservoir

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The age of synthesis:From cognitive science to converging technologies and hereafter

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chinese Science Bulletin 2011年第6期56卷 465-475页

作者： CAI ShuShan1,2 1 Department of Psychology, Tsinghua university, beijing 10084, china 2 center for Psychology and Cognitive Science, Tsinghua university, beijing 10084, china Department of Psychology Tsinghua University Beijing China center for Psychology and Cognitive Science Tsinghua University Beijing China

This paper describes the development of two of the most important scientific disciplines in the last quarter of the 20th century, cognitive science, which emerged in 1975, and nano-bio-info-cogno (NBIC) converging technologies, which emerged in 2000. In this century, we will achieve cross-disciplinary integration, innovation in comprehensive knowledge and comprehensive devel opment in human resources. NBIC converging technologies will greatly expand human cognition and communication, improve human health, enhance social outcomes, strengthen national security and unify science and education. Cognitive science and converging technologies will have major effects on the future human development. I argue that the 21st century represents an age of synthesis, reflected in the continual reintegration between scientific disciplines in recent times. This new age of synthesis will require innovations in thought and methodology that differ from those underlying the age of analysis in the 20th century. I predict that these developments will allow every individual to realize comprehensive development. Accordingly, the education system will be transformed, and a comprehensive human resources system will be created.

关键词：认知科学融合技术化学合成教育系统人力资源人类健康生物信息综合知识

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DEVELOPMENT OF STEP-POOL SEQUENCE AND ITS EFFECTS IN RESISTANCE AND STREAM BED STABILITY

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international Journal of Sediment research 2004年第3期19卷 161-171页

作者： Zhao-Yin WANG, Jiang XU and Changzhi LI Professor, Dept. of Hydraulic Engineering, Tsinghua university, beijing & Chairman of Advisory Council, international research and training center on Erosion and Sedimentation, 100084, china, Email: zywang@***.M. Phil., Dr. & Post Doctorate research fellow, Dept. of Hydraulic Engineering, Tsinghua university, beijing, 100084, china Dept. of Hydraulic Engineering Tsinghua University Beijing & Chairman of Advisory Council International Research and Training Center on Erosion and Sedimentation 100084 China Dr. & Post Doctorate research fellow Dept. of Hydraulic Engineering Tsinghua University Beijing 100084 China

Experiments were conducted and field investigations were performed to study the development of step-pool sequence and its effects on resistance to the flow and stream bed stability. Step-pool sequence develops in incised channels as a result of streambed erosion, which is compared with sand dunes and armor layer of the role in resistance and streambed protection. The tight interlocking of particles in steps gives them an inherent stability which only extreme floods are likely to disturb. That stability suggests that step-pools are a valid equilibrium form, especially when coupled with their apparent regularity form and their role in satisfying the extreme condition of resistance maximization. The development degree of step-pools, SP, is proportional to the streambed slope. If the incoming sediment load is equal to or more than the sediment-carrying capacity of the flow, there is no bed erosion and thence there are no step-pools. If the flow depth increases and is over the step-height the resistance caus

关键词： Step-pool Streambed stability Erosion Resistance Rate of energy dissipation Manning’s roughness n

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SHRINKAGE OF THE ESTUARINE CHANNELS OF THEHAIHE DRAINAGE SYSTEM AND ITS INFLUENCES ON FLOOD HAZARD

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international Journal of Sediment research 1999年第2期14卷 65-76页

作者： HU Shixiong WANG Zhaoyin and DING Pingxing (international research and training center of Erosion and Sediment, P.O.Box 366, beijing 100044, china) (The State Key Laboratory of Estuarine and Coastal research, East china Normal university, Shanghai, 20

The reductions of runoff and sediment load in the Haihe River Basin and the causes of the shrinkage of the estuarine channels are analyzed in this paper it is concluded that the modern Yellow River sediment can be transported to the south part of the Bohai Bay, but rarely to the north part and the Tianjin Harbor. Sediment from the mid of the Bohai Bay does not affect the estuarine channels. The sediment caused the estuarine channels shrinkage are from the modern and ancient Yellow and the Haihe River deposit removed by wave. tidal current, and beach erosion. The influences of the estuary shrinkage on the flood discharge capacity of the river mouth channels and the flood hazard are discussed. The maximum capacity of the reservoirs and pools is about 20 billion m3in the south part of the basin while the capacity in the north part is only 7.5 billion m3. Two 100 years floods occurred in the watershed in 1963 and in1996 with total runoff about 30 billion m3each. The economic loss in 1996 is about $6 billion, nearly two times of that in 1963 in the south part of the area. One of the main reasons is that the discharge capacity of the channels in the area had reduced by 50%. If another 100 years flood occurs in the south part again, the economic loss will be similar to that in 1996. If a 100 years flood occurs in the north part, the economic loss will be much higher than that in 1996. Because the storage capacity of reservoirs and pools in the area is much less than that in the south area. and discharge capacities of the north estuarine channels decreased more sharply than that of the south. Strategies for controlling estuary shrinkage are suggested. Physical and mathematical models show that trailer dredging combined with scouring with runoff or tidal water is economical and practical. Guiding dikes at the river mouths to prevent turbidity water entering into the estuarine channel will be a major strategy. Building a new gate combining the harbor may also mitigate the sed

关键词： Shrinkage of the estuarine channel the Haihe Drainage System Flood hazard

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