Abstract: A three-dimensional mathematical model for calculating the steady flow of multiple non-buoyant turbulent jets in a cross flowing is present in this paper.For closing the control equation,the k-ε turbulence model is used in the mathematical model.The wall-function method is employed to treat the wall boundary condition at the bottom plane.The closed control equations are discretized by using hybrid finite analytic method on a non-uniform staggered grid system.The two characteristics for this kind flow are present:one is maximum surface elevation,an other is the condition for transform of flow type.The minimum dilution of water surface is given also.The results are reasonable and useful to design for waste water discharging into river.
Abstract: In this paper a river water pollution dynamic control problem is proposed as inverse boundary and inverse time mixed control one based on inverse boundary and inverse time control theory.In order to calculating the effluent concentration and total sewage flows from single point sources and multi-point sources,a exact algebraie method is presented for one dimensional advection and dispersion differential equations inverse control problem.The new algorithm is shown to be very effective in solving the water pollution control problem.For example,it considers dilution mixed runoff volume along course,water quality dynamic standards,social economic variety etc.factors.In addition to it can derive an approximate value of the dynamic contorl exact solution.
Abstract: Considering the effect of water flow on the transportation of Fe and Mn and describing its processes of redox,sorption,desorption,deposition and re-suspension in the reservoir,a joint 3-dimensional mathematical model for the hydrodynamics and the transportation of Fe and Mn was developed.The model simulated both horizontal and vertical gradients of Fe and Mn in Arha Reservoir.It was found that Fe and especially Mn stratify in accordance with the stratification of DO during summer.The redox cycles across the water sediment interface play a principal role in the rise of Fe and Mn concentrarions in the overlying water.It was also found that Fe and Mn loads from the tributaries have a carryover effect on the water quality through a secondary contamination in the reservoir.
Abstract: "Channel" reservoirs whose profiles are characterized as being wide and shallow, do not demonstrate gradation phenomena, so it can be assumed that pollutes entering into "channel" reservoirs mix with water completely. In this paper, the flow simulation model for "Channel" reservoirs was developed by solving one-dimensional Saint-Venant equations in Preissman weighted four-points implicit scheme and the water quality simulation model for "channel" reservoirs was developed by solving water quality equations employing the concept of full mixed reactor. The flow/water quality simulation coupled model was used to simulate the water quality situation for "channel" reservoirs. The flow/water quality simulation coupled model is of clear concept, concise structure and was used in the Guating Reservoir("Channel" reservoir) to simulate the transaction of NH3－N with satisfied results. This model can be used for environmental impact assessment, water quality prediction and management in the Guanting Reservoir.
Abstract: From the viewpoint of system theory, the concept of complex large system for flood disaster is put forward, and some aspects of its characteristics such as high dimension, dynamics and complexity are discussed. Based on the comprehensive methodology with qualitative and quantilative integration, the comprehensive methodology of flood disaster analysis such as simulation, forecasting and evaluation as well as decision are investigated. Therefore, it will provide the scientific basis for investigating the methodology for the management and control on flood disaster, and it is helpful for improving the relationships among resource and environmant as well as social development.
Abstract: A quantitative method of remote sensing for monitoring soil losses introduced briefly and its operations and results of application to small valley of UNDP experimental region is described in this paper. Although form of the model for monitoring soil erosion losses in the method is the same as the RUSLE, the formula and algorithms for model factors are generated from loss data observed in our country. Therefore, it is more applicable to loss regions in our country, and suits personal computer to process data of GIS and remote sensing. The results of its application are more accuracy and useful than those of existing methods for the conventional survey and qualitative remote sensing. The monitoring results of UNDP experimental region show that the quantitative remote sensing method can not only use for big valley (e.g. county or province region), but also use for small valley (≥ 7km2).
Abstract: The computational grid generation is the prime procedure of hydromechanical numerical simulation. The results of generation affect the numerical simulation obviously. The manual grid generation methods were used for a long time. In this paper, the authors intend to apply the newly developing technology of Geography Information System (GIS) to the grid generation, use the computer to generate the numberical grid automatically, and discuss the integrated GIS-based numerical simulation environment and its function.
Abstract: In this paper,based on the former studies and considering the propability theory and mechanical analysis method,as well as shelter-exposure effects,a pattern for calculating the probability of incipient motion in non-uniform bed material is established.And a simple model found on the pattern for multi-step predicting the process of scouring and armoring is proposed here in,it should be a useful tool for forecasting the armoring-layer size distribution and scouring depth,while uses many observed data to prove it and yields satisfactory results.
Abstract: This paper discussed the juntions group method initially put forth by Li Yitian in datail,and advanced a new method,which can be applied in wide practices and is worth being recommended.The advantage of the new method is that the coding works of junctions can be handed in each sub-area individually,and the water level equations of junctions group can be obtained directly by using the original relations among junctions suitable to the common gradation method.
Abstract: Based on the contrast experiments of the continuous and intermittent infiltration with the typical Helu soil in Gully region of Loess Plateau, the differences among infiltration rate, infiltration volume, redistrbution of soil moisture, driving velocity and depth of wetting front are analysed, and infiltration mechanism of intermittent infiltration is discussed.
Abstract: A design ideal and design method for the mobile bed erosion model of a new excavated channel are presented, it shows that the method of designing the mobile bed model of the natural channel is diffferent from that of the new excavated channel due to the evident difference between the undistrurbed soil and individual sand in threshold velocity and sediment discharge, furthermore, which has been verificated to be accuracy and has a practical application value by the Tai-zhou approach channel mobile bed erosion model.
Abstract: Based on a new incomplete simiarity assumption of the simiarity theory and the structure of the asymmetric passing flows, a generalized power-type velocity distribution formula is proposed for hydraulic smooth region, hydraulic transition rough region and hydraulic rough region wallturbulence. Corresponding to the generalized velocity distribution formula, a skin-friction law is derived. Both the velocity distribution formula and the skin-friction law are compared with the classic Nikuradre experimental data.
Abstract: A model of Fuzzy Optimization Neural Networks,which can reflect decision maker's viewpoint,is given in this paper.A satisfactory result is obtained by applying this model to decision making for the coordinate management between economy,water resources and environment of South of Jinzhou,Dalian.
Abstract: In this paper, An optimized method for parameter calculation of non-equilibrium was introduced. Based on this method, the best aquifer coefficient of transmissibility, coefficicent of storage and coefficent of permeability can be derived. The parameters calculation were optimized. The calculation can be completed automatically.
Abstract: The article discusses the present deficiency of water resource, as a result caused by violation of relationship between nature and man in the process of industrilization in 20th Century.Rapid population grwvth and urbanization are two factors which deteriorate the existed supply-demand balance of water on land. Only in case of recovering the harmony to nature-man system,the water problem would be solved consequently.This is naturally be possiblly realiiz,d in the up to come informatron society.
Abstract: According to the historical data of the drought and waterlogging of 527 years, this paper gives some statistical characteristics of the drought and waterlogging in Jinqu Basin as follows: (1) the 17th century is a frequent period occurred the drought and waterlogging in Jinqu Basin; (2) there are different period of the drought and waterlogging; (3) the drought and waterlogging has structure of time fractal; (4) the drought and waterlogging respond well to the sunspot action and the El Niño event.
Abstract: In this paper the present situation and existing problem of conjunctive ground water and surface water management is analgsised at home and abroad.At the same time the development of this research field is studyed and forecated.Then the prospect of this sphere is discussed.
Abstract: Based on a Large number of papers published in more than 20 kinds of Journal which deal with different aspects of water sciences,a review of advances on water sciences has made,showing that the outcome of science is enrich, but there are some shorts of that in scientific forward position especially in the aspects on the research of hydrological cycle and its sectional process.