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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.

Discussion 1 Morphological Changes and Disasters

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International Journal of Sediment Research 1999年第2期14卷 39-39页

作者： Brad Hall and wang guangqian

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冲刷致岸堤稳定的衰变

清华大学学报（自然科学版） 2010年第9期50卷 1346-1349页

作者：孙即超王光谦清华大学水利水电工程系水沙科学与水利水电工程国家重点实验室北京100084

四川"512"地震堰塞湖及由此导致的后期人工开挖的泄流槽冲刷问题的核心是不能预测河流冲刷下泄水槽的稳定性。该文展开室内试验,对试验获得的图片进行扭转平移,进而直接测量实验获得的图片,得到岸堤的坍塌开裂露头位置。提出路径损伤的... 详细信息

四川"512"地震堰塞湖及由此导致的后期人工开挖的泄流槽冲刷问题的核心是不能预测河流冲刷下泄水槽的稳定性。该文展开室内试验,对试验获得的图片进行扭转平移,进而直接测量实验获得的图片,得到岸堤的坍塌开裂露头位置。提出路径损伤的理论,根据路径损伤公式,计算得出冲刷下岸堤的路径损伤;并拟合出岸堤损伤的演变公式,通过此公式可以对岸堤的损伤坍塌进行预测。

关键词：河道稳定岸堤坍塌稳定性图像处理

Characterization and quantification of within-year variation of snow-cover elevation in mountainous regions, eastern Tibet

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Research in Cold and Arid Regions 2011年第5期3卷 400-407页

作者： Jie Gao XuDong Fu TongLiang Gong guangqian wang Hao wang State Key Laboratory of Hydroscience and Engineering Tsinghua University Beijing 100084 China Tibet Bureau of Water Resources Lhasa 850000 China Hydropower and Water Resources Planning ＆ Design General Institute Beijing 100120 China

Fluctuating snow-covered elevation （FSCE） was conceptualized and proposed to characterize within-year variation of the border between snow-covered and snow-free area in mountainous regions. Two parameters, namely median of snow flee period （Tm） and snow free duration （AT）, were defined to quantify FSCE. A regression model of FSCE was developed for the Lhasa River Basin, Niyang River Basin, and Changdu region in eastern Tibet. Statistical analysis of the snow-products data with a spatial resolution of 25km×25km shows that：（1） Tm correlates weakly with geographical and topographic factors, having the yearly mean value of July 31; （2） △T correlates significantly with the average elevation of the snow-products cell, having the yearly mean value of nearly five months （i.e., 151 days）; （3） the region begins snow disappearance in late April and finishes snow coverage in mid November, being snow-free from late June to mid September and snow-covered from December to March in the next year. In addi- tion, snow-products with higher spatial resolution will be helpful to characterize FSCE in smaller spatial scales.

关键词： fluctuating snow-covered elevation (FSCE) eastem Tibet median of snow-flee period duration of snow-flee period

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水权交易机理分析

水力发电学报 2005年第4期24卷 104-109页

作者：李海红王光谦清华大学水沙科学教育部重点实验室北京100084

在我国,随着经济的发展,水资源的供需矛盾日益突出。本文从水资源的特点出发,提出由于水资源的生命性、竞争性以及负外部性,基于明确产权的水权交易是实现水资源的合理高效配置、解决供需矛盾的有效手段。本文对水权交易的前提、基础、... 详细信息

在我国,随着经济的发展,水资源的供需矛盾日益突出。本文从水资源的特点出发,提出由于水资源的生命性、竞争性以及负外部性,基于明确产权的水权交易是实现水资源的合理高效配置、解决供需矛盾的有效手段。本文对水权交易的前提、基础、依托、原则、形式等进行了探讨,加之实例分析,进而解析水权交易的机理。

关键词：水资源配置稀缺性市场经济水权交易

Effects of arbuscular mycorrhizal fungi on carbon assimilation and ecological stoichiometry of maize under combined abiotic stresses

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Journal of Plant Ecology 2024年第2期17卷 74-88页

作者： Qiong Ran Songlin Zhang Muhammad Arif Xueting Yin Shanshan Chen guangqian Ren School of Management Chongqing University of TechnologyChongqing 400054China Key Laboratory of Reservoir Aquatic Environment Chongqing Institute of Green and Intelligent TechnologyChinese Academy of SciencesChongqing 400714China Key Laboratory of Eco-environments in Three Gorges Reservoir Region(Ministry of Education) State Cultivation Base of Eco-agriculture for Southwest Mountainous LandSchool of Life SciencesSouthwest UniversityChongqing 400715China Institute of Environment and Ecology Academy of Environmental Health and Ecological SecuritySchool of the Environment and Safety EngineeringJiangsu UniversityZhenjiang 212013China

Arbuscular mycorrhizal fungi(AMF)enhance plant tolerance to abiotic stresses like salinity and improve crop ***,their effects are variable,and the underlying cause of such variation remains largely *** study aimed to assess how drought modifed the effect of AMF on plant resistance to high calcium-saline stress.A pot experiment was performed to examine how AMF inoculation affects the growth,photosynthetic activity,nutrient uptake and carbon(C),nitrogen(N)and phosphorus(P)stoichiometric ratio(C:N:P)of maize under high calcium stress and contrasting water *** results showed that high calcium stress signifcantly reduced mycorrhizal colonization,biomass accumulation,C assimilation rate and C:N stoichiometric ratio in plant ***,the adverse effects of calcium stress on photosynthesis were exacerbated under *** inoculation profoundly alleviated such reductions under drought and saline ***,it barely affected maize performance when subjected to calcium stress under well-watered ***,watering changed AMF impact on nutrient allocation in plant *** well-watered conditions,AMF stimulated P accumulation in roots and plant growth,but did not induce leaf P accumulation proportional to C and N,resulting in increased leaf C:P and N:P ratios under high calcium *** contrast,AMF decreased N content and the N:P ratio in leaves under ***,AMF inoculation improved maize resistance to calcium-salt stress through enhanced photosynthesis and modulation of nutrient stoichiometry,particularly under water defcit *** results highlighted the regulatory role of AMF in carbon assimilation and nutrient homeostasis under compound stresses,and provide signifcant guidance on the improvement of crop yield in saline and arid regions.

关键词： arbuscular mycorrhizal fungi compound abiotic stresses C:N:P stoichiometry induced systemic resistance calcium-salt stress

大型渠道糙率系数设计取值的不确定性及影响分析

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应用基础与工程科学学报 2008年第6期16卷 870-878页

作者：王开魏加华王光谦清华大学水沙科学与水利水电工程国家重点实验室北京100084

大型调水工程糙率系数的设计取值与其它许多水利水电工程问题一样,存在着相当大的不确定性.本文在综述国内外大型调水工程糙率选取的基础上,综合考虑南水北调中线工程总干渠的渠道参数,建立了长距离渠道输水能力校核模型,并就总干渠综... 详细信息

大型调水工程糙率系数的设计取值与其它许多水利水电工程问题一样,存在着相当大的不确定性.本文在综述国内外大型调水工程糙率选取的基础上,综合考虑南水北调中线工程总干渠的渠道参数,建立了长距离渠道输水能力校核模型,并就总干渠综合糙率在一定范围内发生变化后对水面线及过流能力的影响进行了分析,研究结果对调水工程的糙率系数选取具有重要的指导作用.

关键词：调水工程糙率系数敏感性输水能力南水北调

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水权交易中的水价估算

清华大学学报（自然科学版） 2005年第6期45卷 768-771页

作者：李海红王光谦清华大学水利水电工程系北京100084

水权交易是实现水资源有效配置的手段,而交易水价的估算又是进行水权交易的重要依据。选定反映水资源稀缺程度和经济发展水平的水资源影子价格作为水资源价值量化手段,提出在水权交易中的水资源影子价格递减效应、递增效应等概念,分析... 详细信息

水权交易是实现水资源有效配置的手段,而交易水价的估算又是进行水权交易的重要依据。选定反映水资源稀缺程度和经济发展水平的水资源影子价格作为水资源价值量化手段,提出在水权交易中的水资源影子价格递减效应、递增效应等概念,分析了水权交易中水资源影子价格对交易水量的递减(买方)、递增(卖方)效应,以及对时间的递增效应等对交易水价的影响,并据此推导了水权交易的水价估算方法以及最佳交易水量的确定方法。通过中国甘肃省与宁夏回族自治区之间进行的水权交易实例计算,阐述了具体实现方法。

关键词：水资源配置水权交易影子价格递增效应递减效应最佳交易水量

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黄河流域降雨时空分布特征

清华大学学报（自然科学版） 2018年第11期58卷 972-978页

作者：王远见傅旭东王光谦清华大学水利水电工程系北京100084 水沙科学与水利水电工程国家重点实验室北京100084

对于黄河流域降雨时空分布规律的探究，有助于从细部区分不同区域和时段的降雨变化对黄河干支流产流产沙的影响，对于黄河水循环的科学研究和治黄工程措施均有重要意义。利用黄河流域内分布的67座气象站点，使用多种时间序列分析方法，... 详细信息

对于黄河流域降雨时空分布规律的探究，有助于从细部区分不同区域和时段的降雨变化对黄河干支流产流产沙的影响，对于黄河水循环的科学研究和治黄工程措施均有重要意义。利用黄河流域内分布的67座气象站点，使用多种时间序列分析方法，对过去59年（1959-2017年）的黄河流域降雨序列的时空分布特征进行探究。结果表明：黄河流域具有7种典型的降雨空间分布类型；其中，源区（III区）全区域的年降雨量均有显著的增加趋势，是缓解黄河流域用水紧张的积极自然因素；多沙粗沙区（IV区）的年中大雨日数有显著的减少趋势，这可能是黄河下游近年来沙量锐减的原因之一。进一步的降雨序列频谱分析结果，一方面证实了2-4年的短周期是黄河流域多数站点降雨普遍最显著的周期，另一方面也部分佐证了分区的合理性。

关键词：降雨时间序列分析空间分布黄河流域