Abstract: In this paper the behavior of intersection fissure flow is studied using finite element method to solve Navior-takes Equation.Comparing the result of finite element method with that of conventional network hydraulics method and experiment results,it is demonstrated that the accuracy of conventional network method in analysis of rock seepage completely satisify the requirement of engineering accuracy.When analyzing and calculating the network rock seepage,it is not requisite to separately consider the deflection flow problem of crevice water.
Abstract: This paper introduces a procedure to solve steady 3-D incompressible N-S equations in primitive variables using HFAM with FAS-FMG.The complex flows in cavities are used as the standard problems for testing the numerical codes.The calculation results illustrate that the algorithm developed in this paper exhibits grid-independent convergence properties and that it is can asymptotically optimal iterate method.
Abstract: In this eater,the measuring and estimating methods of frequently used param eters(such as specific yield,coefficient of recharge from precipitation and coefficient of phreatic evapaolration) in shallow groundwater resources assessment are described and it is dissected by practical examples.Through analysis,weobtain some new knowledge,that is:(1)The value of specific yield is related to the conditions of injected and released water.In the practical situation,the maximum value of specific yield may occur around the ground surface since the surface soil of farm land is loo se and is effected by cro ps.(2) By using the pumping test technique to measure the specific yield,its value is varied from well to well,we adopt the mean value of it in the domain of mainly affected radius and this is a new attempt;(3) The coefficient of recharge from precipitation is not only related to the construction of soil but also related intimately to specific yield and its regular pattern of distribution is decided by the size of specific yield.Generally,there is a tendency that the coefficient decreases with increasing depth from ground surface to water level;(4) The coefficient of phreatic evaporation varies according to different seasons and croes and the parameters in the calculating formula varied as well.
Abstract: The solving method of water quantity and water quality model in channel networks based on the method named ‘channel-junction-channel' behaves high efficient.But,so far,there is not a good method being relative to above water quality model to calculate water environmental capacity in channel networks.In this paper,through carefully analyzing the proceeding of above water quality model in channel networks and bringing forward a new concept named ‘ermissive input pollution of junctions',a method named ‘jnnction-hannel-junction' which is relative to above water quality model and can be used to calculate unsteady water environmental capacity in a large river networks is developed and established,and is used in Taihu river networks successfully.This method can be used to the pollution analysis and water quality planning in river net.
Abstract: This paper presents a new method,called genetic algorithm(GA),for the parameter optimization of Streeter-phelps model.It is comparable in performance to existing mathematical programming methods.The GA uses a population of points at a time in contrast to the single-point approach by the traditional optimization ones,and will guarantee to find the global optimum.The optimal solution by GA is no longer dependent on initial search values.The GA uses randomized operators and works on coded variables.It does not require problem derivative.
Abstract: This paper bases on hydrology and hydraulic characteristics to simplify convection disperse functions reasonably and gives a dynamic analytic solutions under instantaneous suddenly draining sewage conditions.This paper also develops a river water quality model with arid region characteristics including three basic water quality factors,carbonized BOD5,ammoniated nitrogen,and dissolved oxgen,deduces a water quality modeling matrix,and applies it to simulate and estimate the water quality dynamic process in the Shui Mohe River in the arid Urumqi region.
Abstract: This paper indicates that the water resource in the Northwest arid region is in comparable with that in the other regions of China,if "the total water resource" of hydrological statistics is used as an index.A more reasonable result may be obtained only in case of including the soil water as an important component of water resource,because of that the soil water can maintain the growth of wild vegetation and the evaporation from earth surface in the eastern regions of China,while in arid regions such water consumption come only from "the total water resource".
Abstract: The main courses of sediment transport in Huang Mao bay are obtained by the relationship which is calculated by the fuzzy mathematical theory and cluster of the samples data determined by neutron activation method.The samples as sediment sources are selected based on actual conditions and analysis of sediment so urces characteristics.And the sediment depositional range from each source can be determined by the least-squares method.
Abstract: By utilizing Davies form ulations on ion str engthen calibration,the chemical stability constants of fluorine ion pairs obtained under laboratory conditions are corrected in the ion streng then equal to the salinity of 35‰.A iteration computation method has been employed to calculate the chemical forms of fluorineion pairs:free fluorine ion makes up of 49.9%,MgF+ 46.8%,and the others are CaF+ and NaF0.
Abstract: In arid and Semi-arid areas,the locally isolated flood events can not be collected efficiently due to the rare hydrological stations density.Since the 1970s,a lot of simple flood investigating site-fixed on rivers in a broad region have been set up to record the annual maximum discharge in Gansu province and Ning xia Hui Auto nomous regions.A new statistical approach suitable for this kind of data has been put forward in this paper.The statistical region of which is a district with many stations.The design flood for the given site can be obtained through the frequency transformation from area to point.A case study shows the successful application of the proposed method to the upper reach of the Jinhe River basin in Gansu province,and several problems have beed discussed.
Abstract: Based on Muskingum method,an advanced model of flood routing,considering the flood diversion and flood retarding areas,has been designed.The practical calculation method of the dividing discharge into the flood diversion areas is put forward and discussed.The application in the Huaihe River from Wangjiaha to Loutaize channel shows that the proposed method is reasonable and the calculated results have a high accuracy.
Abstract: This paper introduces the estimating and forecasting methods of daily reference crop and rice evapot ranspiration and presents the real-time irrigation scheduling models for general use.The procedures and informations are suggested to provide a real-time irrigation scheduling service.The case study shows that the menudriven worksheet program is rigorous and simple to apply.
Abstract: This paper mainly deals with water delivery models in the irrigation sy stems.First,Crop pattern in the irrigation area was categorized into paddy and upland croes.Based on water balance and soil moisture simulation theory,the irrigation water delivery models both for paddy and upland croes were established.Secondly,the parameters in the models such as hydrometeorology,soil and croes were obtained through historic data analysis or field measurement.The studied models can be calculated in real-time basis,and can forecast and revise next irrigation schedule,cording to real data.Finally,the optimum real-time irrigation schedule were achieved.The optimum canal discharge and irrigation rotation schedule were also studied in the models.
Abstract: This paper presents a dynamic programming model of qualitative and quantitative mixture system in canal profile-scross section design.The shape of the cross-section,the section parameters,lining etc.of earth canal reach,as well as the parameters of appurtenant pumping station and work site can be considerd.
Abstract: Combing the simplified soil infiltration curve with the soil evaporation declining curve resulted from the nonlinear relationship between soil evaporation and soil moisture content leads to a mathematical model of excessing runoff producing in this paper,the model was tested against the data of Chuxian Country runoff experimental station and the results show a good simulation.
Abstract: This paper discusses necessity of thewatershed hydrology model,limitation of present watershed hydrology model,and problems of using the watershed hydrology model in hydrological forecasting.Some suggestions are proposed for advancing research of the watershed hydrology model.