Abstract: A solute transport equation is presented,in which the reaction of ion exchange between,water and rock is considered.A new mathematical model of sea water intrusion is also presented.In this model,the exchange cation Na+ and Ca2+ are used as simulated factor and the cation exchange of Na+-Ca2+ between water and rock in aquifer during sea water intrusion is considered.This model is applied to simulate sea water intrusion in Huangheying areas,Longkou City,Shandong Province,the simulated result agree well with the observed data.This demostrate that the presented solute equation is correct and the presented model is reliable.
Abstract: In this paper,the flow and thermal transport equations for the accurate description of natural thermal advection in the process of heat transfer in aquifers are manipulated and presented.A nonlinear three-dimensional heat transfer model is established as well.According to the characteristics of the model,the DouglasBrian ADI finite difference scheme,the characteristic reverse-tracking technique,and the improved Picard iterative method are proposed to solve it,and the calculation steps are also provided.Finally,the model together with the numerical methods are applied to simulate a multi-well RTES(Aquifer Thermal Energy Storage) experiment which was performed in the second confined aquifer in Shanghai.The results are satisfying and the natural thermal advection in the experiment is well represented.This shows that the model is reasonable and reliable,and the proposed methods are quite effective.
Abstract: Empirical graphic separation methods with large uncertainties are routinely used for decades to obtain input data,e.g.,the unit hydrograph etc,for various hydrologic models of rainfall-runoff.During 1970's another tracer-based hydrograph separation which attempts to be more physically-based than the above method mostly involves a two-component mixing model for stream flow which relies on the simple mass balance equations of water and isotope is widely used abroad.Eight fundamental assumptions involved in this method and its reality are tested within experimental and representative basins since 1987.From thin work,it is concluded that due to the isotopic situation is much more complex than these assumptions envisioned,most of them seems to be unrealistic notions,it follows that the conclusions of most previous studies based on this kind of two-component mixing model e.g.,a much higher propotion of storm runoff is contributed by groundwater,should be reconsidered.It is also concluded from this work that our reyuisities towards appropriate hydrograph separation into two or more than two components natural basins should be considered.
Abstract: In this paper,the improved time differe nce finite analytic method has been proposed for calculating groundwater unsteady well flow equation.By this algorithm,the shortcoming of poor accuracy caused by finite analytic method for solving process of great change of hydraulic head can be overcome.It has good stability.
Abstract: Hydrologic observed data and investigated(or historical) data are always imprecise,and may be modeled by fuzzy numbers,which forms fuzzy sample(s).This paper studies the methodology of fuzzy hydrologic statistical analysis based on the concepts of fu-zzy number and fuzzy sample,and describes the fuzzy Bayesian analysis approach in detail.The methodology is briefly interpreted by examples.
Abstract: According to the characteristics of Huai He river basin,a flood routine numerical model is established in this paper.This model is based on hydrodynamics method of combination 1-D channel flow modeling with 2-D flood plain flow modeling,and hydrology method of no data areas modeling.The technology and skill of solving the combination 1-D flow wish 2-D flow and treating the runoff in no data areas are developed,which are key to successful modeling.It is showed in the 9 times floods modeling calculations that the model has high accuracy,practicality,flexibility and universality.The model is a advanced tool of Huai He river basin flood control planning and can be used in other basins.
Abstract: The Pangzhuang irrigation district is one of the large districts.According to the contradiction between water supply and water need and the characteristic of the district,a macroscopic decision model of water resources management is developed using a optimal method.The model is solved by a decomposition-coordination way of large-scale system.The result is satisfactory.
Abstract: The composition of sediment in natural rivers has non-steadiness and non-uniformity,and adsorption capacity of different grain sizes is different.Therefore,when self-purify abilities of sediment in natural waters for heavy metal pollutams are discussed,concurrent adsorption kinetics model of sediment with different grain sizes must be studied.This paper presents the concurrent adsorption kinetics model by sediment with different grain sizes through systematic laboratory experimenu.It indicates that there is no competition or interference among different grain sizes,the adsorption content of heavy metal pollutants by non-uniform sediment equals to the sum of the adsorption contens of each grain sizes under the same conditions,which can be used as the basis of predicting the adsorption of non-umform sediment in natural rivers,to some extent.
Abstract: Mechanism of formation of an anabranched estuary is discussed from the viewpoint of mechanics of sediment transport.It is suggested that the formation of the anabranched estuary is attributed to many factors,among which the bed-forming role of bedload is the most dominant one under suitable combination of boundary condition,flow and sediment transport.The diffusion and deceleration of flow due to abrupt change of estuarine boundary is necessry condition for the accumlation of bedloas and the development of estuarine bars.Morever,a very high clay content in suspended sediments which can ensure silting up and stability of estuarine bars also plays important role in the formation of anabranched estuaries.
Abstract: In this paper,based on the self adjusting theory of alluvial channel,the impact of the large scale hydroelectric projects on the Inner Mongolia reach of the Yellow River is analyzed.The reason of recent change of the river characters and the constraint relationship between the freedom of adjusted river bed and the energy allocation and dissipation of the river system are researched.The suggestion for the operations of large scale reservoirs on the upper reach of alluvial river are presented from the relationship of harmonized river with mankind activeties.
Abstract: The article indicated that in ancient China there existed a period of water controlling lasted almost 2000 years,marking the particular process of spreading agriculture from high land to plain.This magnificient historical event discriminates between China and the other famous countries of ancient civilization in the world and gives highest vitality to Chinese people for sustainable existence over several thousand of years.The prosperity of Chinese ancient civilization,including the more or less perfect Chinese form of primitive dialectic philosophy,as an active facfor in the development of science and technology,might originate from the hisrorically important water controlling engineering.The article points our that the basic principle of the relationship between the modern and water can be found in the water controlling in ancient time,despite they are in different stages of development for human society.
Abstract: To determine the uranium contents and discuss the degree of uranium polution in Er-Sea and Nanming River on Yannan-Guirhou Pltaeau,two kinds of water samples collected from the part with different degree of contamination in Er-Sea and Nanming River are radiated by slow neutron in a nuclear reactor.The tracks of uranium decay fragements in the water samples are produced in SSNTU and etched by NaOH.The number of fission tracks is counted under a microscope.the result shows that the uranium content in Nanming River is more greater than Er-Sea.The situation of uranium polution in Nanming River and other rivre at home and foreign is also discussed in light of comparison among them.
Abstract: According to collecting water observation data during three year,in the middle of Gansu province,the relationships between runoff coefficients and materials,slopes of collecting-water surface,rainfall intensities carer analysed.Combining with the every hour rainfall data recorded by rainfall recorders on the 19 meteorological stations that distributed on the east regions of the Yellow River within Gansu Province,the averaged runoff coefficient and its mean square deviation were estimated,which provides scientific basis for applying the collecting water techniyue to agricultnre.
Abstract: This article reviews the most recent research on esturary front abroad and discusses the mechanism of tidal mixing fronts,plume fronts and shear front.The estuary tidal mixing fronts are the results of horizontal density gradient being effected by the estuarine vertical circulent.The shear fronts are due to velocity shearing with different density of water body.
Abstract: A review of advances in regional evaporation research in recent years is presented,which includes four aspens:①measuring much more accurate point evaporatton,②obtaining surface meteorological and geographical information from remote sensing,③using CBL model for exchange of vapour between land surface and mixed layer,④improving land surface parameterization scheme in regional model for basin water and heat balance.These methods approach regional evaporation processes at different direction,which presents a more impressed understanding of regional evaporation.Because of the heterogeneity of land surface characteristics and complexity of evaporation processes,there are still some shortcomings and need improvement in these methods.