• 全国中文核心期刊
  • 中国科技核心期刊
  • 美国工程索引(EI)收录期刊

2001 Vol. 12, No. 1

Display Method:
Effect of Fine Material on Transport of Bed Material Load in Hyperconcentrated Flow
ZHONG De-yu, WANG Shi-qiang, WANG Guang-qian
2001, 12(1): 1-6.
Abstract:
In this paper a transport rate equation of bed material load is proposed with the consideration of the effect of fine material's flocculation.The equation indicates that the transport of suspended bed material load in hyperconcentrated flow can be increased significantly due to the reduced settling velocity and Rouse number by the presence of fine grains generally behaving as wash load.Since the fine material mainly comes from upstream watershed,the introduction of fine material's concentration in the calculation of transport rate of bed material load reflects the impact of watershed on sediment transport.Comparison of field data in the Yellow River and the calculation result of present equation shows that the equation can reproduce the phenomenon that the more the fine sediment comes from upstream,the more the coarse sediment is transported in the Lower Yellow River under the same flow conditions.
Self-Organization and Stability of Form Evolution of River Bends
WANG Fu-quan, CAO Shu-you, DING Jing
2001, 12(1): 7-16.
Abstract:
The evolution equations of river bends are proposed by using the self-organized theory and method which are the Fokker-Planck equation and the Langevin equation.And the qualitative achievements,such as the evolution laws of river bends, symmetry damaged, form transition, and developing trend,are got by detailed analysis of analytic solution of the Fokker-Planck and the Langevin equations and it's dynamic inferences.Finally, we analyze the evolution features of some really river bends.The theoretical results tally with the observed results.
Preliminary Research on the BP Networks Foreasting Model of Watershed Runoff and Sediment Yielding
ZHANG Xiao-feng, XU Quan-xi, PEI Ying
2001, 12(1): 17-22.
Abstract:
In this paper,considering the radical principle of neural networks and acting rainfall condition as the main affecting factors,a back propagation (BP) networks model of watershed runoff and sediment yielding is discussed.The model has satisfactory learning and generalization performance,and it may be used to value the human-action influence on runoff and sediment yielding in a watershed.The results identified by Xihanshui, Datongjiang and Xiangcihe basins's observed data indicate that the model are satisfactory.
Study on the 3-D Numerical Modeling Near-Field Behavior of Waste Water in Side-Discharge, 1, The Mathematical Model and Its Verification
HUAI Wen-xin, CHEN Xue-feng, CHEN Da-hong
2001, 12(1): 23-27.
Abstract:
The 3-D mathematical model and its calculation method for the near field of waste water in side-discharge are given in this paper, and the buoyant effect is considered in the mathematical model.The model and its numerical method are used to calculate the flow of thermal pollution in the steady state.Through the comparision between the calculated and experiment data of Chu, the method is feasible and effective.
Study on the 3-D Numerical modeling Near-Field Behavior of Waste Water in Side-Discharge, 2, The Prediction on the Near-Field Behavior
HUAI Wen-xin, CHEN Xue-feng, CHEN Da-hong
2001, 12(1): 28-32.
Abstract:
This is the second part of study on the 3-D numerical modeling near field behavior of waste water in side-discharge.Based on a series of numerical calculations, the effect of the exit densimetric Froude number F0 on the near-field are mainly discussed.Furthermore, it is possible to determine if the side discharged jets attached again by using a simple criterion and the corresponding formula is also given.
Efficient Improvement of Crank-Nicolson Scheme
ZHANG Xiao-feng, ZHANG Hong-wu
2001, 12(1): 33-38.
Abstract:
Using the undetermined coefficient method developed by authors, accuracy of the Crank-Nicolson scheme is improved effectively.The improved one, named as HAUC2 scheme, is a three order scheme and agrees well with exact solution of pure convection equation.Conservative form of the new scheme is also pressented, which enhances its applicability in the engineering.
Inverse Problem on Amount of Pollutant into Natural Channel
HAN Long-xi
2001, 12(1): 39-44.
Abstract:
By simulating one dimensional water quality of natural channel,three groups of the basic solutions calculated from the initial pollutant concentration,the boundary pollutant concentration and the pollutant amount into channel,can be obtained respectively.Basing on the basic solutions,the pollutant concentration in any section of channel is expressed mathematically by a linear function of the pollutant amount.The optimization model for pollutant amount control is set up,in which the restraint conditions of the model are deduced from river's environment plan and the object function of the model from the function of pollutant treatment fee.The genetic algorithm is used to solve the optimization model successfully.
Direct Calculation of Pressure by Lattice Boltzmann Model
CHENG Yong-guang, SUO Li-sheng
2001, 12(1): 45-50.
Abstract:
The basics and the d2q9 (two-dimensional nine-point) model of the lattice Boltzmann method are introduced, and the advantage of its direct pressure calculation is demonstrated.A more efficient model for simulating pressure fields, namely d2q9p, an improved version of d2q9, is presented.Using the model, 2-D steady and unsteady viscous flows past a circular cylinder are simulated.Good agreement between results of the LB and those of other methods shows that LB method is a simple, efficient and accurate approach to simulate pressure fields.
The Effect of Hydrological Regime on Phytoplankton Community
WU Hong-juan, GUO Sheng-lian
2001, 12(1): 51-55.
Abstract:
Phytoplankton is an important one of primary production and the indicator of the environment in the ecosystem of reservoir.The effect of hydrological regime on phytoplankton community was regarded as necessary for management of water quality.This study is, at present, mainly the effect of water retention, water level on the species component, standing crop, spatial pattern (including vertical and horizontal distribution) and succession of phytoplankton community.
Hysteresis in Process of Rainfall-Infiltration-Runoff on Hillslpoe in Loess Area
LIU Xian-zhao, KANG Shao-zhong
2001, 12(1): 56-60.
Abstract:
The observed data of hillslope under natural rainfall-infiltration-runoff condition on small watershed in Loess Plateau are simulated by the models considered and unconsidered hysteresis, respectively.The simulated results shows that the hysteresis increases the infiltration rate and reduces the runoff volume during the process of rainfall-infiltration-runoff.The predicted soil water content and runoff volume are approximate to the measured values.From this, we know that the hysteresis has a considerable influence on soil moisture, infiltration rate, runoff process and runoff volume.It is very necessary to consider the effects of hysteresis in the study on water exchange in the future.
A Model for Groundwater Quality Assessment Based on the Maximum Entropy Theory
HE Ling, CHEN Xiao-hong
2001, 12(1): 61-65.
Abstract:
The system of water quality is a grey system due to its partially uncertainties.There exist several methods for the assessment of water quality, i.e.the index method, the fuzzy mathematical approach and the grey clustering method.However, the resolutions are low in the results of the present methods.Based on the Jaynes maximum entropy theory, a new model for assessing water quality is put forward in this paper.A case study is given by using this model.The results compared with those of the grey clustering approach shows that the model established in this paper is not only strictly derived, but also has higher resolution and sensitivity and reliability.
Study on Water Resource Safety Strategy for China in the 21th Century
JIANG Wen-lai
2001, 12(1): 66-71.
Abstract:
The water resource safety strategy for China in the 21th century discussed in this paper includes:(1)to Increase water resource utilization efficiency, (2)to Integrate water resource management, (3)to set up efficiency water resource manage mechanism, (4)to pay more attentive to stratagem water resource and save up technology, and (5) to Develop water resource trade for home and abroad market.
Optimal Water Operation for the Water Transfer Project from South to North (Middle Route)
WANG Yin-tang, HU Si-yi, ZHOU Quan-lin, WEN Dan, WANG Fang-qing, Wu Ze-yu
2001, 12(1): 72-80.
Abstract:
In this paper, the principle and methods of hierarchical analysis for large-scale system are applied to solve the problems of optimal water operation for the water transfer project from south to north (middle route)and the three-level hierarchical model is established.Having satisfied the total system water supply objects, the optimal regulation diagram of reservoir is determined by simulation technique combined with the optimization methods.It could provide science bases for the project's operation and decision-making in actuality operation condition in the future.
Analysis on China’s Water Management Problems and Adoption of Integrated Water Management Pattern
ZENG Si-yu, FU Guo-wei
2001, 12(1): 81-86.
Abstract:
Based on explaning the integrated water management pattern and analyzing present problems in China's water management, we draw conclusion that the integrated water management pattern should be adopted in China, and give a brief discussion on what should be done to operate this management pattern in China.
The Great Flood of 1999 and Further Flood Control Measures in the Taihu Basin
WANG Tong-sheng
2001, 12(1): 87-94.
Abstract:
In 1999, the great flood occurred in Taihu Basin.The highest flood stage in Taihu Lake reached a new historical record, 5.08m.In this paper, the characteristic of rainfall and flood are analyzed.The flood control function and disaster mitigation benefit of the Taihu flood control project are illustrated.Also the further harnessing measures are discussed.
The Total Sand Flushing Funnel and Application
ZHOU Zhu, QIU Xiu-yun, HOU Jie, WANG Shun-jiu
2001, 12(1): 95-98.
Abstract:
This paper introuduces a new desilting works mainly,the funnel total sand flushing works.This works can drain bed sediment of coarse grain and suspended sediment of fines.The desilting rate for coarse grain which diameter more than 0.5 mm is 100 percent,and for fines which grain diameter less than 0.5 mm is 90 percent,the water consum ption is only 2-3 percent of channel diversion.
Fractal Models for Predicting Unsaturated Soil Hydraulic Parameters
LIU Jian-guo, NIE Yong-feng
2001, 12(1): 99-106.
Abstract:
The soil structures, including soil particle mass(size) distribution, pore volume distribution and solid-ore interface roughness, are fractals in lin ited length-scales and m ay be represented by mass fractal dimension, pore volume fractal dimension and surface fractaldimension.The functional equations consistentwith the CampbellLaw have been established between fractal dimensions and the hydraulic properties of soils in literatures reviewed.The equations disclose thephysicalmechanign of theCampbellLaw andmay be used to predict soil water retention and hydraulic conductivity of unsaturated soil.
Study on Characteristics of Soil Water and Salt Transport under Drip Irrigation
LÜ Dian-qing, WANG Quan-jiu, WANG Wen-yan
2001, 12(1): 107-112.
Abstract:
Much research of characteristics of soil water and salt transport under drpirrigation, an important basis to develop salt-affected land, has been conducted at home and abroad.In the paper, the related research results about factors affecting point-source infiltration, characteristics of infiltration models and water distribution, shape of wetted wne, wetting front movement and soil salt transport are reviewed in order to provide some informations and opinions to study soil water movement and salt transport for salt-affected soils.
A Perspective on Hydrology from the 20th Century to 21th Century
LIU Su-xia
2001, 12(1): 113-117.
Abstract:
Based on the related sessions on the 22th A ssembly of International Union of Geodesy and Geophysics which was held in July 1999 in Birmingham,there are three basic characteristics of hydrological research from the 20th Century to 21th Century.Firstly, the effects of human activities on hydrological cycle both in water quantity and water quantity are stressed very much,which includes inpact of land-use change on nutrient loads from diffuse sources; inpacts of urban growth on surface and groundwater quality, riverine ecological response to changes in hydrological regine, sedinent transport and nutrient loading, and interactions between surface water and goundwater in quality and quantity.Secondly, the hydrological research in regional scale is focused.The hot topics at present are to establish a global hydrological data bases, to explore new methods which are suitable for regional study over continental regions.The study on the interaction between ahnosphere and land surface greatly promotes regional hydrological research also.Finally, linkage among tracer techniques, advanced hydrometric and remote sensing is very helpful for understanding hydrological processes in catchment.
State-of-the-Art of the Flood Control Operation of Multi-Reservoir System
WANG Dong, XU Sheng-bin
2001, 12(1): 118-124.
Abstract:
The state-of-the-art of flood control operation of multi-reservoir system is reviewed systematically in thispaper.The current research methods in this subject are induced, classified,and evaluated.Finally the future study is discussed as the remarks.
Uncertainty and Study Present of Economic Evaluation of Hydroelectric Engineering
TU Yan-ning, XIAO Huan-xiong
2001, 12(1): 125-129.
Abstract:
The economic evaluation of hydroelectric engineering are effected by many intricate factors.This paper makes a briefreview about the method of risk analysis and risk combination of several key risk factors which are partitioned in order to study conveniently.Furthermore, the development of multiple objective risk decision of hydroelectric engineering investment is introducted briefly.
On the Condition of Water Resources in the North of China and Its Moisture Background
ZHANG Jia-cheng, ZHANG Yuan
2001, 12(1): 130-133.
Abstract:
The article indicates that if the soilwater is considered, the agriculture would be corespondent with the moisture condition both in South and North of China, without the urgent demand of water transfered from the South to the North of China, as the earlier literature shows.Only the fast growth of population and the development of industry and urbanization make thewater deficiency in North is becoming seriousmore andmore.However, thewaterproblem may be resolvedon the spot, not necessarily to transferwater from outside.
2001, 12(1): 134-134.
Abstract:
2001, 12(1): 135-136.
Abstract: