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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 10003., china. [a] Prof. State Key Lab of Hydroscience and Engineering Tsinghua University beijing 100084 china [b] 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 10003. 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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水工建筑物抗震设计规范修编的若干问题研究

水力发电学报 2011年第6期30卷 4-10,15页

作者：陈厚群中国水利水电科学研究院北京100048

本文概述了我国水工建筑物抗震设计规范修编的依据,工程背景,指导思想,主要变动内容及关键问题。阐明了本次修编的必要性和可行性。修编遵循的指导思想为:水工建筑物抗震安全性评价包括地震动输入、结构地震响应、结构抗力三个相互配套... 详细信息

本文概述了我国水工建筑物抗震设计规范修编的依据,工程背景,指导思想,主要变动内容及关键问题。阐明了本次修编的必要性和可行性。修编遵循的指导思想为:水工建筑物抗震安全性评价包括地震动输入、结构地震响应、结构抗力三个相互配套部分;"防止遭遇最大可能的极端地震时,发生库水失控下泄、导致严重次生灾害的溃坝灾变"是大坝抗震设计的战略重点。修编中主要变动的内容,包括:增加渡槽、升船机两类建筑物和边坡;对重要大坝按最大可信地震下不发生地震灾变进行校核;对设计烈度7度及以上的1、2级土石坝,同时用有限元法对坝体和坝基进行动力分析,综合判断其抗震安全性;补充了各章的抗震措施;调整个别水工建筑物的结构系数等。对修编中就抗震设防水准框架、设计反应谱、大坝混凝土动态力学特性、土石坝的动力分析等几个关键技术问题,给出了对其进行了专题研究的主要结果、及对其中一些修编规定对不同工程的影响进行了抗震试设计检验的结果。

关键词：水工建筑物抗震设计规范指导思想修编内容:关键技术问题

Thresholds of geographic environmental elements in sediment yield of drainage basins

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Science china Earth Sciences 2005年第2期48卷 230-240页

作者： CHEN Hao, ZHOU Jinxing, CAI Qiangguo, LU Zhongchen & LI Zhongyan institute of Geographic Sciences and Natural resources research, Chinese Academy of Sciences, beijing 100101, china institute of Forestry Science, Chinese Academy of Forestry Science, beijing 100091, china research Center for Eco-Environment Sciences, Chinese Academy of Sciences, beijing 100085, china Computing institute of Science and Engineering, North china Electric Power University, beijing 102206, china 1. institute of Geographic Sciences and Natural resources research Chinese Academy of Sciences 100101 Beijing China 2. institute of Forestry Science Chinese Academy of Forestry Science 100091 Beijing China 3. research Center for Eco-Environment Sciences Chinese Academy of Sciences 100085 Beijing China 4. Computing institute of Science and Engineering North China Electric Power University 102206 Beijing China

Threshold of environmental elements in drainage basin sediment yield refers to, under effect of climate, underlying surface and human activity, a turning point of abrupt changes in drainage sediment yield related to environmental element characteristics. Previous studies on threshold of sediment yield of relevant drainage basins were mainly concentrated on impact of natural zones with a few researches on impact of other environmental elements. Particularly studies on compound environmental element threshold in drainage basin sediment yield remain blank today. Studies indicate that sediment yield in drainage basins is affected by compound interactions and complex actions. Based on single element analysis, the present paper gives quantitatively compound threshold of environmental elements affecting sediment yield of the drainage basin between Hekouzhen and Tongguan in the middle Yellow River by the method of multi-variant, polynomial formula regression analysis.

关键词： middle Yellow River, environmental element, sediment, sediment delivery mudule, threshold.

RAIN INTENSITY DISTRIBUTION IN THE SPLASH REGION OF ATOMIZED FLOW

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Journal of Hydrodynamics 2006年第3期18卷 362-366页

作者： DUAN Hong-dong LIU Shi-he LUO Qiu-shi HUANG Wei School of water Resource and hydropower Wuhan University Wuhan 430072China water resources and hydropower Planning and Design General institute MWR Beijing 100011 China

Atomized flow is an unnatural two-phase flow produced while water discharges in water release structures. This flow might threaten the normal operation of hydraulic and hydroelectric installations owing to the unnatural and high-density rain as well as the unnatural and dirty mist. The splash region, the region with the highest rain intensity, hence should receive much attention during the design and operation of the hydraulic and hydroelectric installations. In this paper rain intensity distribution in the splash region of the atomized flow is investigated experimentally, and the method of random simulation is used to predict the rain intensity distribution in the splash region.

关键词： atomized flow splash rain intensity

A distributed hydrological model with its application to the Jinghe watershed in the Yellow River Basin

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Science china(Technological Sciences) 2004年第z1期47卷 60-71页

作者： WANG Zhonggen1, ZHENG Hongxing1, LIU Changming1, , WU Xianfeng2 2 & ZHAO Weimin3 1. Key Laboratory of water Cycle & Related Land Surface Processes, institute of Geographic Science and Natural resources research, Chinese Academy of Sciences, beijing 100101, china 2. institute of Environmental Science, beijing Normal University, beijing 100875, china 3. water resources Conservation Committee of Yellow River, Zhengzhou 450003, china Chinese Acad Sci Key Lab Water Cycle & Related Land Surface Proc Inst Geog Sci & Nat Resources Res Beijing 100101 Peoples R China beijing Normal Univ Inst Environm Sci Beijing 100875 Peoples R China water resources Conservat Comm Yellow River Zhengzhou 450003 Peoples R China

For the purpose of water resources management in the Yellow River Basin with highly spatial difference, a daily distributed hydrological model was proposed, of which the determination of spatially-distributed parameters and model inputs processing were performed by means of GIS/RS. In the model, the computation of runoff yield was based on the topography index method and flow routing was modeled by Maskingum method. The operation of the model is followed by means of “command structure” technique based upon the topography of river network. A case study using the model was conducted for the Jinghe watershed, which locates at the middle Yellow River Basin. The simulation of the hydrological processes in 1996 has shown that water quantity balance errors were less than 5% and the Nash-Sutcliffe coefficient arrived at 0.7, indicating that the model structure is justifiable, and the precision of the model can satisfy the purpose of water resources management.

关键词： distributed hydrological model, structure and equation, GIS and RS, Jinghe Basin, Yellow River Basin.

EXPERIMENTAL INVESTIGATIONS ON BUBBLE COLLAPSE NEAR BOUNDARIES

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Journal of Hydrodynamics 1997年第2期9卷 78-85页

作者： Lu Lichina institute of water resources and Hydro. Power research, beijing 10003., P. R.chinaHuang Ji-tang, Xu Xie-qingTsinghua University, beijing 100084, P.R. china china Inst of water resources and Hydropower Research Beijing China

Collapse of a spark-generated bubble near rigid or deformable surfaces is studied experimentally with a high speed cammera. The formation of a bubble wall jet has been observed and discussed. Results from experimental... 详细信息

关键词： bubble collaps cavitation

Control of atmospheric CO_2 concentrations by 2050: A calculation on the emission rights of different countries

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Science china Earth Sciences 2009年第10期52卷 1447-1469页

作者： DING ZhongLi1, DUAN XiaoNan2, GE QuanSheng3 & ZHANG ZhiQiang4 1 institute of Geology and Geophysics, Chinese Academy of Sciences, beijing 100029, china 2 The General Office of Chinese Academy of Sciences, beijing 100864, china 3 institute of Geographic Sciences and Natural resources research, Chinese Academy of Sciences, beijing 100101, china 4 The Lanzhou Branch of the National Science Library, the Scientific Information Center for resources and Environment, Lanzhou 730000, china institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China The General Office of Chinese Academy of Sciences Beijing 100864 China institute of Geographic Sciences and Natural resources research Chinese Academy

This paper is to provide quantitative data on some critical issues in anticipation of the forthcoming international negotiations in Denmark on the control of atmospheric CO2 concentrations. Instead of letting only a small number of countries dominate a few controversial dialogues about emissions reductions, a comprehensive global system must be established based on emissions allowances for different countries, to realize the long-term goal of controlling global atmospheric CO2 concentrations. That a system rooted in "cumulative emissions per capita," the best conception of the "common but differentiated responsibilities" principle affirmed by the Kyoto Protocol according to fundamental standards of fairness and justice, was demonstrated. Based on calculations of various countries' cumulative emissions per capita, estimates of their cumulative emissions from 1900 to 2005, and their annual emissions allowances into the future (2006―2050), a 470 ppmv atmospheric CO2 concentration target was set. According to the following four objective indicators―total emissions allowance from 1900 to 2050, actual emissions from 1900 to 2005, emissions levels in 2005, and the average growth rate of emissions from 1996 to 2005―all countries and regions whose population was more than 300000 in 2005 were divided into four main groups: countries with emissions deficits, countries and regions needing to reduce their gross emissions, countries and regions needing to reduce their emissions growth rates, and countries that can maintain the current emissions growth rates. Based on this proposal, most G8 countries by 2005 had already expended their 2050 emissions allowances. The accu-mulated financial value based on emissions has reached more than 5.5 trillion US dollars (20 dollars per ton of CO2). Even if these countries could achieve their ambitious emissions reduction targets in the future, their per capita emissions from 2006 to 2050 would still be much higher than those of developing coun

关键词： international negotiations on climate change cumulative emissions per capita emission allowance

Indoor imitation experimental study on driving factors of rainfall-runoff process

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Science china Earth Sciences 2005年第3期48卷 417-428页

作者： ZHANG Shifeng1, LIU Changming 1, XIA Jun1, TAN Ge 1, LI Lin1, LIU Caitang1, ZHOU Changqing 1 & GUO Lei2 1. institute of Geographic Sciences and Natural resources research, Chinese Academy of Sciences, beijing 100101, china 2. College of water resources and hydropower Engineering, Wuhan University, Wuhan 430072, china 1. institute of Geographic Sciences and Natural resources research Chinese Academy of Sciences 100101 Beijing China 2. College of water resources and hydropower Engineering Wuhan University 430072 Wuhan China

The driving actions of rainfall-runoff process can be attributed to two aspects. The first is the influence of precipitation process, and the second is that of the ground pad. The re- search results of 179 indoor experiments conducted to imitate rainfall-runoff process indicate that both precipitation duration and intensity play important roles in affecting confluence lag time, which is obviously inconsistent with the traditional hypotheses. The nonlinear relationship is of great significance to the confluence curve especially when the precipitation duration is less than the total confluence time or the precipitation intensity is small. Therefore it can be concluded that the unit hydrograph (UH) can be applied to rainfall-runoff process imitation in the humid areas in the south china region. However, the UH application should be strictly modified in accordance with precipitation conditions in the arid and semiarid region of north china where the precipitation duration is short and the intensity is unstable. It will be hard to get ideal imitation results if the UH is applied blindly without considering specific conditions in the north china region. This also explains the unsatisfactory imitation results caused by using various hydrological models in the north china region. When the precipitation duration is short, and the watershed has not reached total watershed concentration, the characteristics of confluence change greatly, which reflects the actual situation in the north china region. Therefore necessary nonlinear corrections should be made when UH is applied. If the duration is longer than the total confluence time and the balance between pondage and discharge is stricken, the imitation research results will be applicable to both rainfall-runoff relation with longer duration in the south china region and the basic theoreti- cal research on runoff generation and concentration. On conditions of adequate rainfall, peak discharge is in linear relationship with inten

关键词： rainfall-runoff, driving factors, indoor imitation, experiment.

Changes in hair arsenic concentration in a population exposed to heavy pollution:Follow-up investigation in Chenzhou City,Hunan Province,Southern china

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Journal of Environmental Sciences 2010年第2期22卷 283-289页

作者： Bin Wu,Tongbin Chen Center for Environmental Remediation,institute of Geographic Sciences and Natural resources research,Chinese Academy of Sciences,beijing 100101,china. [a] Center for Environmental Remediation Institute of Geographic Sciences Natural resources research Chinese Academy of Sciences Beijing 100101 China

Follow-up investigation on hair arsenic concentration was conducted in an arsenic heavily polluted area of southern china in 2002 and 2006. The results showed that the geometric mean of hair arsenic concentration decreased from 2.95 mg/kg in 2002 to 1.78 mg/kg in 2006, when the percentage of the population with levels over 1 mg/kg only decreased from 93.4% in 2002 to 80.5% in 2006. Over this four-year period, the population with high arsenic concentrations decreased significantly while there was no obvious change in hair arsenic concentration for people who had relatively low concentrations. In terms of age distribution, young and old people had higher hair arsenic concentrations than the middle-aged. All of these results showed that it is difficult to reverse the negative impact of arsenic pollution on human health. Arsenic pollution has a long-term continuous influence on the health of local residents.

关键词： arsenic human health soil contamination hair arsenic