水科学进展

Study on the influence of polluted river on its offshore groundwater environment

WANG Chao, LI Yong, BAO Zhen-qi

2002, 13(5): 535-541.

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It has great academic and practical significance to study the influence of polluted river on its offshore groundwater environment where surface water is seriously polluted.Based on the field observation experiments in Kui River in Jiangsu province,the time-and spatial distribution rule on physical,chemical and biological change of pollutants such as COD_Cr,NH₄⁺-N,NO₃^--N, Cl^- infiltrating into groundwater is discussed.And the ability of river offshore soil and groundwater to remove pollutants is analyzed.The field data shows that the efficiency of river sediment and its offshore soil to remove COD_Cr is high, to remove NH₄⁺-N and NO₃^--N is higher, to decrease the concentration is low due to the transform of NH₄⁺-N and NO₂^--N into NO₃^--N, and to remove Cl^- is very low due to its conservative character.As a result, the influence of conservative pollutant on river offshore groundwater must be considered.

Study on effect of hydrodynamic characteristics on reaeration progress

LI Ran, LI Jia, LI Ke-feng, FU Xiao-ying

2002, 13(5): 542-546.

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The reaeration progress for turbulent water is studied by the flume reaeration experiment and the interfacial mass transfer coefficients are obtained by employing the oxygen-flux theory.The expression of the interfacial mass transfer coefficient related with velocity and kinetic energy is developed by using the numerical model to simulate the turbulence characteristics of the flow field.The examination with the experimental data of different cases shows the validation of the theory.

A study on the non-point source pollution model

ZHANG Jian-yun

2002, 13(5): 547-551.

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Non-point source pollution, also called diffuse source pollution, mainly caused from the soil erosion and sedimentation, livestock wastes, and agricultural land (pesticide and other poisonous chemical components).In this article, the physical process of soil erosion was described, the main factors which would affect the soil erosion process were discussed, and the non-point source pollution (NPSP) model, which consists of the rainfall-runoff sub-model, the soil erosion sub-model (American USLE), and the livestock wastes sub-model, was constructed.Finally, the experiences and conclusions of the NPSP application in the Dodder Basin of Ireland was introduced.

Effect of regulation project along north bank of Jianshan bend in Qiantang Estuary on environment

LU Xiang-xing, HAN Zeng-cui

2002, 13(5): 552-556.

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Based on the analysis of field observation data, the mathematical calculation and the physical modeling, this paper studies and compares effect of the meandering channel and straight channel evolved in the Jianshan bend on the important environmental factors such as riverbed variation in the upper reaches of Qiantang Estuary, tide, current, tidal bore and salt water intrusion etc.It is more reasonable to adopt the meandering alignment according to the principle of reducing tidal influx and raising the ratio between river flow and tidal discharge, overall development of the multiple purpose, and eliminat ing the unfavorable factors which was shown in harnessing process of Qiantang Estuary.

Study on algalbloom in Hanjiang River

DOU Ming, XIE Ping, XIA Jun, SHEN Xiao-li, FANG Fang

2002, 13(5): 557-561.

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The characters of three algalbloom phenomena in Hanjing River in the nineties of 20th century are summarized.The causes and mechanisms of algalbloom occurrence are analyzed from the point of water quality condition,air temperature,hydrological condition.To counter the influences of water pollution control and water quantity distribution of Hanjiang River on algalbloom,the preventing measures are discussed.The conclusions are that administering eutrophication pollution of Hanjiang River as soon as possible is the key to solve the issue and some assistant measures must be taken for decreasing the losing of projects to the minimum,considering the disadvantage influence caused by Three-Gorges and water Transfer Project from Ruth to North (middle route) on water environment of Hanjiang River.

Study on sediment transport in the lower Yellow River during flood period

XU Jiong-xin

2002, 13(5): 562-568.

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Based on the data from 144 flood events during the periods 1950-1960 and 1969-1985,this paper deals with sediment transport in the lower Yellow River.The results show that the channel sediment delivery ratio (SDR) decreases with the increases in the event-averaged sediment concentration and the "incoming sediment coefficient" expressed as sediment concentration divided by water discharge.There is an optimal flood discharge of 4000 m³/s,at which the SDR reaches its maximum.The event SDR is negatively correlated with the event maximum sediment concentration C_max;when C_max is larger than 300 kg/m³,the SDR is smaller than 0.50,indicating that the SDR of hyperconcentrated flows is rather low.The SDRs of floods coming from different source areas are different.The floods whose runoff mainly came from the clear water area above Hekouzhen had a SDR larger than 0.60;those from the "fine sediment producing area" had a SDR larger than 0.50;those from the "coarse sediment producing area" had a SDR smaller than 0.50.The SDR of a given flood event is found to be related with the combination of sediment and runoff from different source areas;when the sediment from the coarse sediment producing area made up of 50% of the total,or the sediment from the fine sediment producing area made up of 40% of the total,the SDR of the flood events reached its maximum.

Modeling water security in China and comparison of the strategies

ZHANG Qiao-xian, OUYANG Zhi-yun, WANG Ru-song, WANG Xiao-ke, MIN Qing-wen, FU Guo-bin, MIAO Hong

2002, 13(5): 569-577.

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A China water security dynamic model were built up based on the systematical analyses of characteristics and their interrelationship of sub-systems of water resource system in China.In modeling,four scenarios,as the business as usual,the technology and economic scenario,the institutional,value,and life style changes scenario and the towards sustainable development scenario,were simulated in terms of life security,economical security,food security,ecosystem security,environmental security and social security.The simulation suggested that the water security in China can be guaranteed by combined with accelerated water use technology innovation,new water management policy and management system reform,and ecological and economical awareness on water resource impnwement.

A dynamics model for evaluating operation benefit of water economic system

GU Qiang-sheng, SHI Bin, XIE Neng-gang

2002, 13(5): 578-582.

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A dynamics model for evaluating operation benefit of water conservancy economic system, which corresponds to energy-index in the engineering power system, is established according to the optimal control theory.The reasonableness and feasibility of the model are witnessed by computational results of Jiangsu water conservancy economic system.

A optimal operation model for multiple reservoir power with time-varying electricity price

MA Guang-wen, WANG Li, GUO Xia-ming

2002, 13(5): 583-587.

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This paper presents a optimal operation model for multiple reservoir power with time varying electricity price by using the genetic algorithm.The model has been implemented in Zipingpu power station in Sichuan province.The results indicate that the operation schedules from the model are significantly different from those obtained from a similar kind of model without time varying electricity price.It is shown that competitive relationship between water supply and power generation can be coordinated effectively, besides, that the firm power can be increased.The importance of the model and its effect on water resources uses and hydropower development are emphasized.

Study on round turbulent jet in a cross flow with PIV

JIANG Guo-qiang, ZHANG Xiao-yuan, LI Wei

2002, 13(5): 588-593.

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A particle image velocimetry (PIV) is used to measure and visualize the flow of a jet directed normal to a uniform and steady cross flow, there is a complex interaction between the two flows.The development and the trajectory of jet are given by the experimental data.The visualization of wake structure shows the significant differences between the jet and the cylinder as obstacles to the cross flow.

Determination of the correlation window sizes in correlation analysis of DPIV

WU Long-hua, YAN Zhong-min, TANG Hong-wu

2002, 13(5): 594-598.

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In the digital particle image velocimetry (DPIV) system, the digital image correlation is normally used to acquire the displacement information of particles at present.And in this method, it is very important to determine the correlation window size.Through the theory of correlation analyse, the new method for determining correlation window sizes is proposed based on the sampling theory.The measurements of velocity field in the flocculation pool show that this method is accurate and reliable.

Viscous-elastic-plastic constitutive model for sea ice dynamics in the Bohai Sea

JI Shun-ying, YUE Qian-jin, YAO Zheng

2002, 13(5): 599-604.

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The viscous plastic constitutive model for sea ice dynamics has been widely applied in sea ice numerical simulations of the polar regions and their marginal ice zones.This model,however,can't be used to simulate the ice rafting and ridging processes that occur over small temporal and spatial scales.This preBents a problem in the Bohai Sea where due to the dynamic conditions that exist,these processes are significant factors.To remedy this situation,the Kelvin-Voigt viscous elastic constitutive equation was introduced into the sea ice dynamics,and a viscous-elastic-plastic constitutive model was developed based on the viscous plastic model.In the numerical sea ice simulation,both the viscous elastic behavior under small strains and strain rates,and the viscous plastic behavior under high strains and strain rates can be properly modeled.The sea ice dynamic process of Liaodong Bay was simulated for 48 hours,and the results indicate that the viscous-elastic-plastic model is more accurate.

Interaction principle and general momentum equilibrium equation for fluid flow in multiphase media

SHAO Long-tan

2002, 13(5): 605-610.

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The interaction principle for equilibrium analysis of multiphase media is illustrated in this paper.Then a uniform differential momentum equation,which governs the pore fluid flow in multiphase media, e.g.either saturated or unsaturated soils,is deduced based on the principle.By assuming that pore water flowing is in laminar flow,i.e.,interaction between fluid phase and solid phase is proportional to water velocity,the Darcy's Law formula can be inferred.In this way,physical meaning of the Darcy's Law for saturated soil is explained.The formula expressing the relationship between the permeability and soil potential and water content in unsaturated soil is also derived.Mme permeability testing results of clay and siliceous powder in steady hydraulic gradient are presented in this paper.These results are well agreeable to the theoretical prediction by the momentum equation.

Distribution of soil macropores characterized by CT

FENG Jie, HAO Zhen-chun

2002, 13(5): 611-617.

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Undisturbed soil core which has many macropores and disturbed soil core which has macropore (its diameter is known) are probed by CT.The theory of CT scanning is stated.CT scanning images are dealt with by using software photoshop and geographical information system software ARC/INFO and Mapinfo.The size, number, shape and continuity of macropores in transverse and vertical section of soil are characterized.The results indicate that CT scanning is a nondestructive method for characterizing macropores in soils, which is a promising method.

Preliminary study on utilizing groundwater storage

DU Han-xue, CHANG Guo-cun, ZHANG Qiao-sheng, ZHUANG Yan-ge

2002, 13(5): 618-622.

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The concept of ground water reserwir,storage principle and its theoretical basis,storage condidons and methods,as well as high economic effect of the storage are discussed in the paper.It is suggested that a rmdel engineering for the ground water reserwir storage should be set up and utilized to mitigate the serious crisis in some waterdeficient regions in Jilin pnwince.To utilize gmund water storage,the water conservancy project should be build in addition to basic hydrogeological condition,so,it is a cross and combine of hydrogeology and water conservancy engineering.In future,it will become an important branch of the water conservancy engineering,i.e.engineering of ground water reservoir storage.

Experimental study on the condensation water in arid area, Northwestern China

GUO Zhan-rong, HAN Shuang-ping

2002, 13(5): 623-628.

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The weighing method is adopted in condensation of the water observation.The condensation water for the different kinds of soil samples are observed during the freezing period and non-freezing period respectively.The necessary conditions and time occurring the condensation water,the main influence factors forming the condensation water,the condensation water under the accumulated snow circumstances,the amount of the condensation water and its variation,and the eco-environmental significance of the condensation water are all analyzed and discussed.The research achievements have great significance to recognize the formation mechanism of the condensation water and the eco-environmental benefit of the condensation water in the arid areas,NorthwesternOTina.

Measurement in situ of streambed hydraulic conductivities in the Platte River, Nebraska

SHU Long-cang, CHEN Xun-hong

2002, 13(5): 629-633.

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In quantitative study of the interaction between the river water and groundwater,the hydraulic conductivities of streambed are very important parameters.The traditional methods,such as laboratory analysis,numerical model,and so on,can't provide the hydraulic conductivity in situ.The standipe test can measure the hydraulic conductivities in situ.In this study,the artificial gradient method and the natural gradiem method were used for measuring the hydraulic conductivities in vertical,horiwntal and oblique direcdons of streambed of the Platte River.The average vertical hydraulic conductivity for 10 test locations is 30.51 m/d.The horizontal hydraulic conductivity is about 97.2 m/d for the Platte River.The ratio of horiwntal and vertical hydraulic conductivities is about 3.The results indicate that the streambeds material is slightly anisotropy and heterogeneity in horiwntal direction.

Risk analysis of retaining rockfill cofferdam for diversion based on the Monte-Carlo method

HU Zhi-gen, LIU Quan, HE Chang-hai, XIAO Huan-xiong, ZHOU Yi-hong, FU Zheng, LI Ding-kui, ZHENG Jia-xiang

2002, 13(5): 634-638.

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Risk of the construction diversion system is controlled by the real capacity of flood discharge and flood inflow,which has uncertain and dynamic pn}perties.The paper uses the Monte-Carlo method to simulate the flood during construction and discharge process of diversion structure,analyaes statistically water level change of cofferdam in upperstream,and obtains a distribution function of the water level change.Based on the computational results,the risk of the diversion system are determined.The case study shows that the simulation model and analytical method are reliable and reasonable.

Experimental research on hydraulics characteristics of energy dissipation in vertical stilling well

LIU Huan-fang, SU Ping, LI Qiang

2002, 13(5): 639-642.

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A hydraulic model experiment about the project of energy dissipation with vertical stilling well indicated that the vertical stilling well is a reasonable and feasible measure when the flow changes from the conduit to the open flow under the high head and small discharge conditions.The vertical stilling well can bear much high head of the conveyer conduit, which is relative to the control valve installed on the import conduit.The analysis of theory indicated that the greater part of the pressure head of conveyer conduit is consumed on the valve.The valve is a key place on the project of energy dissipation well.The opening of valve should adapt to the pressure head.The velocity distributions in the expert conduit of energy dissipation well are large on the external curve, and are small on the internal curve.

Review of effect of temperature on soil water movement

FENG Bao-ping, ZHANG Zhan-yu, ZHANG Jian-feng, WANG Zhi-rong

2002, 13(5): 643-648.

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Based on the recent research results about the relationship between temperature and soil water movement, the effect of temperature on soil water movement and the effect mechanics are reviewed, and the mathematical models for soil water movement and the experimental methods are summarized.In addition, the main questions in this field are proposed.

Advances in non-point source pollution prediction model

XUE Jin-feng, XIA Jun, MA Yan-tao

2002, 13(5): 649-656.

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Transfer and transform of pollutants is very complicated.In order to prevent and control runoff pollution,the complicated processes need to be analyzed,simulated and predicted.The development of recent overseas and inland non-point pollution models is introduced in this paper.It can be seen that integrating GIS,fuzzy set theory,uncertainty analysis and risk management into non-point source pollution model will be future development direction.However,it is stil behindhand with this field in China,and remains to be developed.

2002 Vol. 13, No. 5

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