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Hyperconcentrated flows as influenced by coupled wind-water processes

Science china Earth sciences 2005年第11期48卷 1990-2000页

作者： XU Jiongxin Institute of Geographical sciences and Natural Resources Research, chinese academy of sciences key laboratory of water cycle and related land surface processes, chinese academy of sciences, beijing 100101, china key laboratory of water cycle and related land surface processes Chinese Academy of Sciences Institute of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences Beijing China

Using data from more than 40 rivers in the middle Yellow River basin, a study has been made of the influence of coupled wind-water processes on hyperconcentrated flows. A simple “vehicle” model has been proposed to describe hyperconcentrated flows. The liquid phase of two-phase flows is a “vehicle”, in which coarse sediment particles are carried as solid-phase. The formation and characteristics of hyperconcentrated flows are closely related with the forma-tion and characteristics of this liquid-phase and solid-phase. surface materials and geomorphic agents of the middle Yellow River basin form some patterns of combination, which have deep influence on the formation and characteristics of liquid- and solid-phases of hyperconcentrated flows. The combination of high percentages of relatively coarse material with low percentages of fine material appears in the area predominated by the wind process, where the supply of rela-tively coarse sediment is sufficient, but the supply of relatively coarse sediment is not. The com-bination of low percentages of relatively coarse material with high percentages of fine material appears in the area predominated by the water process, where the supply of fine sediment is sufficient, but the supply of fine sediment is not. In the area predominated by coupled wind-water processes appears the combination of medium percentages of coarse and fine materials, and thus both coarse and fine sediments are in relatively sufficient supply. The manner in which the mean annual sediment concentrations of liquid- and solid-phases vary with total suspended sediment concentration is different. With the increased total suspended sediment concentration, mean annual sediment concentration of liquid-phase increased to a limit and then remained constant; however, mean annual sediment concentrations of solid-phase in-creased continuously. Thus, the magnitude of total suspended sediment concentration depends on the supply conditions of relatively coarse sedime

关键词： river sediment, hyperconcentrated flows, liquid-solid two-phase flows, wind process, fluvial process, Yellow River

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Coupling the hydrological and ecological process to implement the sustainable water resources management in Hanjiang River Basin

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Science china(Technological sciences) 2009年第11期52卷 3240-3248页

作者： ZHANG Xiang1 & XIA Jun2 1 State key laboratory of water Resources and Hydropower Engineering Science, Wuhan University, Wuhan 430072, china 2.key laboratory of water cycle and related land surface processes, IGSNRR, chinese academy of sciences, beijing 100101, china State key laboratory of water Resources and Hydropower Engineering Science Wuhan University Wuhan China key laboratory of water cycle and related land surface processes IGSNRR Chinese Academy of Sciences Beijing China

Research on the combination of hydrological variation and ecological demands plays an important role in water availability assessment and sustainable management on basin scale. An integrative frame, consisting of hydrological regime modelling, ecological water demands estimation and renewable resources management, is given in this paper in order to support the implementation of the sustainable water resources management. The suggested integrative frame has been used to study the integrated water resources management in southern Hanjiang River Basin which is the water source of South-toNorth water Transportation Project in china. SWAT (soil and water assessment tool) model was used to simulate the monthly averaging streamflow and the amounts of ecological water demands in stream were also estimated in order to evaluate the available water resources for the local users and the transportation project. Then we formed the developing scenarioes by coupling the available water resources, the recovering rate of water resources in natural water cycle, the local water use rate and the amounts of the water transported to North, and used the Scheafer model to analyze their evolving trajectories. Eventually, the sustainable water resources management measures were assembled by the comprehensive evaluation of the scenarioes. The research indicates that the integrative frame provided a new way for the integrated water resources management in river basin.

关键词： SWAT (soil and water assessment tool) Scheafer model ecological water demands water resources availability sustainable water resources management

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Validity of the Bouchet's complementary relationship at 102 observatories across china

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Science china Earth sciences 2009年第5期52卷 708-713页

作者： YU JingJie1,2,ZHANG YongQiang3,LIU ChangMing1,2 1 Institute of Geographic sciences and Natural Resources Research,chinese academy of sciences,beijing 100101,china 2.key laboratory of water cycle and related land surface processes,chinese academy of sciences,beijing 100101,china 3 CSIRO land and water,PO Box 1666,Canberra ACT 2601,Australia Institute of Geographic sciences and Natural Resources Research Chinese Academy of Sciences Beijing China key laboratory of water cycle and related land surface processes Chinese Academy of Sciences Beijing China CSIRO land and water Canberra Australia

Bouchet in 1963 hypothesized that for large homogeneous land surface with minimum advection of heat and moisture,there exists a 1:1 complementary relationship of potential and actual evaporation coupled through land-atmosphere *** complementary relationship has been widely used to estimate regional actual evaporation and explain the pan evaporation *** examine the standardized potential evaporation(potential evaporation divided by wet environment evaporation) at 102 observatories at different elevations across ***,the relationship is appropriate at the low elevations(<1000 m).With the increase of elevation,vapor transfer power becomes much less than radiation energy budget because of lower vapor pressure deficit and stronger global solar *** a result,at the high elevations(over 1000 m),the excess energy resulted by limited moisture availability is not enough to be converted into drying power of the *** result suggests that the complementary relationship is asymmetric at the high elevations.

关键词： evaporation complementary relationship elevation china

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STATISTICAL RELATIONS BETWEEN GEOMORPHIC PARAMETERS——A CASE STUDY OF THE YUNNAN REACH OF THE LANCANGJIANG RIVER IN SOUTHWESTERN china

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International Journal of Sediment Research 2007年第2期22卷 131-141页

作者： Suiji WANG1, Shaohong WU2 and Erfu DAI31,3 key laboratory of water cycle and related land surface processes, Institute of Geographical sciences and Natural Resources Research, chinese academy of sciences, beijing, 100101, china, 2.key laboratory of water cycle and related land surface processes, Institute of Geographical sciences and Natural Resources Research, chinese academy of sciences, beijing, 100101, china, chinese Acad Sci Inst Geog Sci & Nat Resources Res Key Lab Water Cycle & Related Land Surface Proc Beijing 100101 Peoples R China

The properties of rivers and their catchments can be expressed by statistical relationships between geomorphic parameters. These statistical relationships may reveal some inherent differences in geomorphic evolution for different reaches or different order tributaries of a river basin. A case study was undertaken of the Yunnan reach of the Langcangjiang River. The catchment area, channel length and gradient of the first-, second- and third-order tributaries all with catchment areas larger than 100 km2 in the Yunnan reach were the main geomorphic parameters evaluated. The correlation between catchment area and channel length as well as between catchment area and channel gradient with respect to the total tributaries, different reach tributaries, and different order tributaries were revealed using statistical methods. In general, the channel length as a function of catchment area, was best expressed by a quadratic function where channel length increases with increasing catchment area (half parabola), while the channel gradient as a function of catchment area is best expressed by an exponential decay function. Comparison of the best-fit formulas revealed the following phenomena: the lower Yunnan reach tributaries and the first-order tributaries have a dominant effect on geomorphic parameters of the total tributaries. In addition, the statistical relationships indicate that the river geomorphic system in the upper and lower Yunnan reaches evolved differently. This study method used to differentiate river characteristics by determining statistical relationships between geomorphic parameters may be extended to other rivers and their catchments.

关键词： River catchment Geomorphic parameter Correlation River characteristics

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SEDIMENT YIELD MODELING FOR SINGLE STORM EVENTS BASED ON HEAVY-DISCHARGE STAGE CHARACTERIZED BY STABLE SEDIMENT CONCENTRATION

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International Journal of Sediment Research 2007年第3期22卷 208-217页

作者： Mingguo ZHENG1, Qiangguo CAI2, and Qinjuan CHENG3 1Assistant professor, key laboratory of water cycle and related land surface processes, Institute of Geographic sciences & Natural Resources Research, CAS, beijing 100101,china. 2 Professor, key laboratory of water cycle and related land surface processes, Institute of Geographic sciences & Natural Resources Research, CAS, beijing 100101,china. 3 Doctoral candidate, key laboratory of water cycle and related land surface processes, Institute of Geographic sciences & Natural Resources Research, CAS, beijing 100101,china. Graduate School of the chinese academy of sciences, beijing 100039, china. chinese Acad Sci Inst Geog Sci & Nat Resources Res Key Lab Water Cycle & Related Land Surface Proc Beijing 100101 Peoples R China

The relation between runoff volume and sediment yield for individual events in a given watershed receives little attention compared to the relation between water discharge and sediment yield, though it may underlie the event-based sediment-yield model for large-size watershed. The data observed at 12 experimental subwatersheds in the Dalihe river watershed in hilly areas of Loess Plateau, North china, was selected to develop and validate the relation. The peak flow is often considered as an important factor affecting event sediment yield. However, in the study areas, sediment concentration remains relatively constant when water discharge exceeds a certain critical value, implying that the heavier flow is not accompanied with the higher sediment transport capacity. Hence, only the runoff volume factor was considered in the sediment-yield model. As both the total sediment and runoff discharge were largely produced during the heavy-discharge stage, and the sediment concentration was negligibly variable during this stage, a proportional function can be used to model the relation between event runoff volume and sediment yield for a given subwatershed. The applicability of this model at larger spatial scales was also discussed, and it was found that for the Yaoxinzhuang station at the Puhe River basin, which controls a drainage area of 2264km2, a directly proportional relation between event runoff volume and sediment yield may also exist.

关键词： Sediment yield Peak flow Flow-sediment relation Loess Plateau

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Ecological hydraulic radius model to calculate instream flow requirements for transporting sediment in the western water transfer region

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Science china(Technological sciences) 2009年第11期52卷 3401-3405页

作者： MEN BaoHui1 & LIU ChangMing2 1 Renewable Energy Institute, North china Electric Power University, beijing 102206, china 2.key laboratory of water cycle and related land surface Process, Institute of Geographical sciences and Natural Resources Research, chinese academy of sciences, beijing 100101, china Renewable Energy Institute North China Electric Power University Beijing China key laboratory of water cycle and related land surface Process Institute of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences Beijing China

Transporting sediment is a natural function of the river. To maintain the normal evolution of the river certain amount of water flow is required, which is called the instream flow requirements for transporting sediment (IFRTS). We defined the permitting flow velocity by the conception of IFRTS, and also put forward the ecological hydraulic radius model (EHRM) to estimate IFRTS. The calculating process of EHRM is explained by the example of Daofu Hydrological Station on Xianshui branch of Yalong River in the west line first-stage construction of South-North water Transfer Project. The result shows that the IFRTS occupied 29.7%―59.5% of annual mean discharge in flood season, the average of IFRTS was about 100.2 m3/s during 1966―1987, it is close to the IFRTS 90 m3/s calculated by IFRTS conception. Hence, it is feasible to use EHRM to calculate IFRTS.

关键词： ecological hydraulic radius model (EHRM) instream flow requirements for transporting sediment (IFRTS) permitting flow velocity ecological hydraulic radius for transporting sediment

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An ecological hydraulic radius approach to estimate the instream ecological water requirement

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Progress in Natural Science:Materials International 2007年第3期17卷 320-327页

作者： LIU Changming and MEN Baohui ( key laboratory of water cycle and related land surface Process, Institute of Geographical sciences and Natural Resources Research, chinese academy of sciences, beijing 100101, china key laboratory of water and Sediment sciences, Ministry of Education & water sciences College, beijing Normal University, beijing 100875, china Department of Hydraulic and Hydropower Engineering, North china Electric Power University, beijing 102206, china) key laboratory of water cycle and related land surface Process Institute of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China key laboratory of water and Sediment sciences Beijing Normal University Beijing 100875 China Department of Hydraulic and Hydropower Engineering North China Electric Power University Beijing 102206 China

This essay defines the concepts of ecological flow velocity as well as ecological hydraulic radius (EHR) and proposes an ecological hydraulic radius approach (EHRA) which considers both the watercourse information (including hydraulic radius, roughness coefficient and hydraulic gradient) and the required stream velocity necessary for maintenance of certain ecological functions all together. The key parameter of EHRA is to fix the watercourse cross-sectional flow area corresponding to EHR, by which the relation between parabola shaped cross-sectional flow area and hydraulic radius is deduced. The EHRA not only meets the requirement of flow velocity for adequate fish spawning migration, but also is applicable to the ecological flows in regard with other ecological issues (such as the calculation of the instream flow requirements for transporting sediment and for pollution self-purification, etc.). This essay has illuminated the computational process taking the estimation of ecological water requirement of Zhuba Hydrologyical Station watercourse in Niqu branch of the Yalong River as an example. Additionally, we compare EHRA with Tennant approach. The result shows that the Zhuba Hydrological Station ecological water requirement calculated by EHRA lies between the minimum and favorable ecological water requirement calculated by the Tennant approach. This is due to the fact that the ecological flow velocity (such as the fish spawning migration flow velocity) was taken into consideration, producing results applicable to the practical situation.

关键词： ecological flow flow velocity cross-sectional flow area ecological hydraulic radius (HER) instreamecological water requirement.

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Differential Hydrological Grey Model (DHGM) with self-memory function and its application to flood forecasting

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Science china(Technological sciences) 2009年第4期52卷 1039-1049页

作者： CHEN XiangDong1, XIA Jun1,2 & XU Qian3 1 key laboratory of water cycle and related land surface processes, Institute of Geographic sciences and Natural Resources Research, chinese academy of sciences, beijing 100101, china 2 State key laboratory of water Resources and Hydropower Engineering Science, Wuhan University, Wuhan 430072, china 3 School of Hydrology and water Resources, Hohai University, Nanjing 210098, china key laboratory of water cycle and related land surface processes Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing China State key laboratory of water Resources and Hydropower Engineering Science Wuhan University Wuhan China School of Hydrology and water Resources Hohai University Nanjing China

This paper addresses a problem of flood forecasting with the self-memory function. Considering flood forecasting’s uncertainty and updating demand, a hybrid hydrological model, namely Differential Hy- drological Grey Model with self-memory function (DHGM-SM), is developed. The model has two fold features. One is to establish a self-memorization equation linked with DHGM, that could extract useful information from past data series and realize updating of hydrological dynamic process. The other is that this model has higher efficiency relative to original hydrological model without self-memory func- tion. This approach was applied to river flow forecasting of two representative basins in Tunxi of South china and Daqinggou of North china. It is shown that this hybrid method has satisfactory forecasting accuracy by examination of both calibration and validation.

关键词： differential grey model the self-memorization principle real-time forecasting faded-memory recursive least square method

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Spatial-Temporal Changes of Soil Organic Carbon During Vegetation Recovery at Ziwuling, china

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Pedosphere 2005年第5期15卷 601-610页

作者： LI Yu-Yuan SHAO Ming-An ZHENG Ji-Yong ZHANG Xing-Chang key laboratory of water cycle and related land surface processes Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 （China） State key laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Institute of Soil and Water Conservation Chinese Academy of Sciences and Ministry of Water Resources Yangling 712100 （China）

To probe the processes and mechanisms of soil organic carbon (SOC) changes during forest recovery, a 150-yearchronosequence study on SOC was conducted for various vegetation succession stages at the Ziwuling area, in the centralpart of the Loess Plateau, china. Results showed that during the 150 years of local vegetation rehabilitation SOC increasedsignificantly (P land, grassland, shrubland and forest were 4.46, 5.05, 9.95, and 7.49 kg C m-3,respectively. The decrease in SOC from 60 to 150 years of abandonment implied that the soil carbon pool was a sink forCO2 before the shrubland stage and became a source in the later period. This change resulted from the spatially variedcomposition and structure of the vegetation. Vegetation recovery had a maximum effect on the surface (0-20 cm) SOCpool. It. was concluded that vegetation recovery on the Loess Plateau could result in significantly increased sequestrationof atmospheric CO2 in soil and vegetation, which was ecologically important for mitigating the increase of atmosphericconcentration of CO2 and for ameliorating the local eco-environment.

关键词： soil organic carbon density spatial-temporal change vegetation recovery vegetation succession

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water Security Problem in North china: Research and Perspective

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Pedosphere 2005年第5期15卷 563-575页

作者： XIA Jun LIU Meng-Yu JIA Shao-Feng key laboratory of water cycle ＆related land surface processes Institute of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 （China） State key laboratory of water Resources ＆ Hydropower Engineering sciences Wuhan University Wuhan 430072（China） Center for Agricultural Resources Research Institute of Genetic and Developmental Biology Chinese Academy of Sciences Shijiazhuang 050021 （China）

This paper addresses the emergence of water security problems in North china with the aim of highlighting key waterresources management and water security issues for the long-term development of North china. Three key problemsrelated to water resources and security issues in North china in the 21st century are addressed, namely 1) the watercycle under environmental change, 2) agricultural water saving, and 3) water security. Development of internationalresearch related to these issues is also reviewed. The research plan developed recently by the chinese academy of sciences(CAS) is discussed and suggestions on research and development of water resources science in North china are *** to focus on experimental catchments and dedicated research stations, a detailed knowledge of the water cycle onNorth china farmland has been compiled. A range of techniques that include isotope tracers has been used to acquirehydrologic data. Much research has been devoted to developing distributed hydrological models at different scales. In thewell irrigation district, five different water saving irrigation regimes have been investigated, and these regimes have hadwidespread application, and reduced water use 60-150 mm while they increased water use efficiency (WUE) by 20%-30%.Furthermore, preventing water pollution is the most essential step to ensure North china’s water security.

关键词： environmental change North china water cycle water resources water security

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