Abstract: Based on salinization of water channeled from Yellow River being stored in the Beidagang Reservoir and the mass transfer theory,it qualitatively analyzed that the main salinization mechanisms are the salinity transfer of saline soil,the evaporation concentrating and the agitation of wind.A simulation trial pond was built beside the reservoir and some researches were done Based on water and the solute balance in the simulative pond,the proportions of water salinization by salinity transfer of saline soil and the evaporation concentrating are calculated quantitatively.It was showed that the proportion of salinity transfer of the saline soil increased with time more than 30 days and that the proportion of salinity transfer of the saline soil remained 80% and evaporation concentration is 20% after 30 days.This indicates that salinity transfer of the saline soil is the most important one of all factors of the water salinizaion.
Abstract: In order to probe into the accumulation of heavy metal in the biofilm,and the infection and contribution of the biofilm in the courses of water-sediments exchange,this paper studies the adsorption of mercury and other heavy metal in the biofilm and sediments,and compares the changes of mercury species after the adsorption in these two mediums The result showed the species of mercury and other heavy metal in sediments are mainly the residual matter bound,while the percentage of carbonate bound,ion exchangeable bound and organic acids bound are little The organic matter in the biofilm is much higher than this in the sediments The growth time,illumination and temperature are important factors affecting the heavy metal's content in the biofilm It can be inferred that the stronger the illumination,the higher the temperature,the longer the growth t ime,and much more the content of the heavy metals in the biofilm.q
Abstract: The polder reservoir,storing fresh water,is one of the measures to solve water-deficient problems in the coastal areas.How to accelerate water desalination process is the most important problem in a polder reservoir.Pumping out the saline water near the bottom in the deepwater areas is one of the effective measures to accelerate this process In this paper,the pumping locations and scales are determined based on the salinity distribution and the volume of deepwater,and the Delft 3D model is employed to calculate the salinity variation during the period of 2004 to 2006 under the designed hydrologic conditions.After three-year operation,draining out the saline water near the bottom in the deepwater,the total residual salinity in the reservoir is only 40% comparing with without pumping Numerical results indicate that it greatly accelerates water desalination process in the polder reservoir.
Abstract: To protect the water environment of the Three Gorges Reservoir(TGR),it is very inportant to predict the change trend of eutrophication of the TGR.This paper mainly introduces an eutrophication model system,which is developed by considering the integration actions,nutrient(including P,N),climate(including temperature and light intensive) and hydrodynamics on the algal growth rate based on the feature of TGR.Takinge the Daning River,a branch largely effected from the storage of TGR,as a case,an empirical formula is presented firstly to describe the effect of hydrodynamics on the algal growth rate in the Daning River.The verification of the formula is conducted with the measurement data from the Daning River.It shows that the formula can simulate better the general feature of the algal growing and decaying in the Daning River after the storages water in TGR.
Abstract: The aims,principles and requirements of the water ecological planning for city environmental system are analyzed and the ways of water eco-structure designing for cities' environment are discussed in this paper.By applying the ecological theory and methods and studying planning of the eco-function and eco-analysis,the environmental water in cities is planned with the macroscopic and microcosmic view,on the basic of maintaining the balance and intactness of the eco-system on considering the geological locations,the different requirements of function,the different ways of applications,the different development potatials of the environment water.The structure designing of the eco-system makes the ecological functions and aims of environment water in cities come true and establisles a complete and sustainable water eco-system.
Abstract: In order to raise the precision of prediction model for water environment nonlinear time series,a high precision radial basis function(RBF) artificial neural network model is presented The delay time of water environment time series is analyzed with auto correlation technique.The input and output of this model are decided by this delay time.And this model is verified by two cases First,the training and test are given by the recorded data of 32 years of marine water temperature,and the result shows that the error of every training sample is 0.00,and the relative error is 0.3875% of forecasting marine temperature based on the RBF network model.Then,the water environment elements,such as hardness,the salts of permanganic acid,BOD5,NH3-N,DO,phenol,cadmium,chloral and sulfate,are predicted at Wangjianglou in Changjiang river for eight years.The prediction precision of this RBF model is higher than that of the threshold auto-regression model,the BP artificial neural network model and the ELMAN artificial neural network model.The convergent speed of this new model is also faster than that of the BP model It is a good nonlinear prediction model for water science time series.
Abstract: Based on the current measurement data from TOGA-TAO(ADCP) and the assimilation analysis results from SODA(simple ocean data assimilation analysis),this paper analyzes and researches seasonal and annual variations of the Equatorial Undercurrent(EUC) in the equator Pacific,which are related to the warm water eastward propagation along the equatorial Pacific,and reveals that the physics mechanism of the anomalous warm water propagates eastward in the El Nino annual event.The result indicates that the seasonal and annual variation of EUC are very obvious.The vertical depth of EUC is from the sea surface to 300-400 meters.The mean biggest velocity of EUC can reach to 100cm/s along the equator.The longitude change of the biggest center of EUC is basically maintained between 130°W-160°W.The annual change of EUC is very obvious too,and particularly in the period of El Nino event occurs,the EUC appears obvious strengthening phenomenon.Its the biggest zonal velocity components can reach above the 140 cm/s.The EUC in middle-east Pacific has began strengthen before the subsurface warm water eastward propagation from western Pacific warm pool,and its the biggest zonal velocity components center is constantly strengthened along thermocline with eastward propagation,leading the anomalous warm water form the warm pool area in the western Pacific eastward propagation.So,we can think that the relationship between the eastward propagation of the anomalous warm water from the warm pool area in western Pacific and the strength of EUC is very closely,also in other words in El Nino event,the variation of EUC is leading to the important mechanism that the subsurface anomalous warm water of the warm pool area in the western Pacific propagates eastward.
Abstract: Considered the fractal self similar characteristics of river system,ideal self-similar networks is constructed and then the corresponding width function is derived.Based on the width function,the basin geomorphological instantaneous unit hydrograph is derived The results of the test of 11 floods in Yandu River basin is satisfactory.
Abstract: The grade evaluation of water resource system is a hotspot and difficulty problem in water resource system engineering.The common evaluation methods require that the structure form of evaluation function should be presumed beforehand,which are very difficulty to be adapted to the complex and variable practical evaluation systems.For this reason,a new non-parametric evaluation method for grade evaluation of water resource system(NGEM) is presented.The NGEM does not require the structure form of the evaluation function,and the evaluation information can be got directly from the evaluation standard datas,the objective weights of evaluation indexes can be determined by using the accelerating genetic algorithm based projection pursuit,and the evaluation function can be established by using accelerating genetic algorithm based nonparametric regressive method.The calculation examples show that the NGEM is visual,simple,effective and general,which can also be applied to both prediction and simulation of different water resource systems.
Abstract: This article discloses the existing of the Pan-Valley and describes the characters of it,on the basic of which,the definition is induced to expound this hydrographic phenomenon.By bringing forward to some indexes such as river contribution rate,harmonious rate,water resources available rate,etc.,the me thods through which to manage the water resources are evaluated and the significance is obvious.At the end of the article,the author gives some suggestions that the study of the essential of the river should go fatherly,the categorized study should been carried out immediately,and the harmonious and continuous development is the only way for the better utilization of the water resources.
Abstract: The paper educes a reasonable compensation for emergent water dispatch using the game theory in order to solve the benefit conflict among the different sides.The three compensation modes,water rights trade,administrative intermediation and watershed negotiation,are offered and analyzed with the game theory respectively.Based on the Nash equilibrium,the compensation schemes of the two water resource collocating modes,the water rights trade and the administrative intermediation are gained,and the game properties of the watershed negotiation is analyzed,which can be used as references to the administrators.In practice,single or multiform modes can be used based on the especial facts.
Abstract: There is multi-correlation among the factors which impact the city water resources capacity The traditional least square method can distort and destabilize the multivariate regression model.The partial least-square regression(PLS) is applied to build the city water resources capacity model based on the main component analysis and typical correlation analysis.Through distilling component,the model is suggested to solve the interactive correlation among the independent variables.The author has analyzed the PLS1 model,the result is satisfactory.
Abstract: In order to know the characteristics of water-rock interaction and the sources of the contaminants in the ground water system of the karstic area,we carry out a study on the water geochemistry of the surface and ground water in Guiyang,the capital city of Guizhou Province,China.The waters are characterized mainly by the HCO3 and SO4 type,as well as their mixed type.The solutes of the studied waters are mainly derived from the weathering of the carbonate and clastic sedimentary rocks,among which the sulfate ions are probably from the dissolved gypsum and the oxidation of the sulfide minerals in coal- containing strata.Most of K+,Na+,Cl-,SO42-,and NO3- are anthropogenic in origin.The results of this work are applicable to the assessment of water quality and human impacts on the ground water system,and can be used as the data-base for the protection and exploitation of water resources from the surface/ground water system in the karstic area.
Abstract: This paper is to explore the issues of scale effect of water saving,caused by the returning f lows and their reuse in the water resource system Taking the rice-based irrigation system,Zhanghe Irrigation System(ZIS),as an example,we analyzed the components of water balance and their roles at different scales,and point out that the situation would be become more complicated and the scale effect could be obvious with the increas of scale Based on the experimental and long-term historical data in ZIS,we consider water use at different scales——the fields,the middle scale,a main canal-commanded area scale and the irrigation system The results demonstrate the higher water productivity under water saving irrigation practice at the field scale and in the ZIS.And there are real water saving and the considerable increase in water productivity over time.
Abstract: According to the characteristics of flow-sediment transport in the middle-lower reaches of the Yangtze River system,a numerical model is established with combination of the 1-D and 2-D unsteady flow and the sediment model to simulate the transport of the flow-sediment and the bed scouring silt ing processes of the middle-lower reaches of the Yangtze River,Dongting Lake and their network Some relevant problems are discussed,including the moving-boundary in the network,the computation patterns of flow-sediment diversion at channel bifurcations,the moving riverbed resistance and the exchange pattern of water-sediment among the rivers and the lake Based on the hydrologic and topographic data of the middle-lower reach of the Yangtze River,the model verification shows good results for the flow transport characterist ics and the riverbed variation patterns for the middle-lower reaches of the Yangtze River,Dongting Lake and their network.
Abstract: In order to compare the effect of different impervious scheme in the second phase cofferdams in the Three Gorges Project(TGP),the finite element method is employed to analyse three arrangement style:double concrete cofferdam,single low plastic concrete cofferdam combining with geomembrane inclined core and single-thick cofferdam.The 2D and 3D models are used to simulate seepage field of non-safety working station in stable and unstable cases,such as cracking in impervious elements,sudden drop of the water level.The numerical simulation gives out the contour lines of water potential energy in these cases.It shows that the double concrete cofferdam has better impervious effects than the other two schemes The cracking of the concrete cofferdam affects only on the down stream.From the unstable numerical analyses,the dropping depth of water level should be less than 2 meters per day in order to keep the safety of the cofferdam.
Abstract: Based on the third-order central weighted essentially non-oscillatory(CWENO) reconstruction,a high-resolution semi-discrete central-upwind difference scheme for solving the 2-D shallow water equations is presented by using the dimension-by-dimension approach.The reconstruction is chosen to improve the accuracy and guarantee the non oscillatory behavior of the present scheme.The optimal third-order SSP(Strong Stability Preserving) Runge-Kutta method is used for time discrete Since no Riemann solvers are required and characteristic decomposition can be avoided,the resulting scheme retains all the advantages of central scheme.For the numerical treatment of source terms,the Simpson’s quadrature rule is used.The simulated results are shown to be in good agreement with numerical results obtained by other methods These results demonstrate that the present method is efficient and stable.
Abstract: According to the experimentation and the theory,research on gas properties and current rush to interception airmass in the delivery pipeline system are made.The studies indicated that the gas thermal insulation coefficient determining primary properties of the air-mass changes apparently instead of a single constant when hydraulic transition process happens So four appropriate processes are given,namely sub process 1 of compressing,sub-process 2 of inflating,sub-process 3 of inflating,and sub process 4 of compressing.In the sub-process 2 of inflating and sub process 4 of compressing,the gas thermal insulation coeff icient is 1.4~1.6,and is 1.15 in other two processes The value of gas thermal insulation coefficient has definitely influence on the result of the analytic root of current rush to interception air-mass in the delivery pipeline system The more small gas thermal insulation coefficient is,the more great the press of current rush to interception air mass is,and and vice versa.
Abstract: We analyze the feasibility of application of the supply chain management to the South-to-North Water Transfer Project(SNWTP) supply chain management,and validate the Pareto Optimization as the objective of SNWTP supply chain management.Combining with real experience,the corresponding contracts are designed based on the principle agent model,which are immediately implementable in the East Route water resources system of SNWTP.In addition,the concept of "Information Transformation Effect" in the SNWTP supply chain is defined; the existence,quant ification and control of "Information Transformation Effect" are analyzed.The results of this paper suggest that it has significant development and implementation potentials to apply the theories and methodologies of the supply chain management in the complex water resources system and water resources allocation and dispatching.
Abstract: Land subsidence is a kind of geological calamity caused by human activities.Shanghai is the earliest and the most effective city which applied various methods to control or arrest its land subsidence in China.Although the land subsidence has been arrested effectively,the tendency of land subsidence exists still in Shanghai because of its coastal environment and the continuous withdraw of underground water.This paper evaluates its possible losses based on the analysis of the factors which affect the economic losses induced by the land subsidence in the future.According to our risk evaluation,the economic losses caused by the land subsidence in Shanghai from 2001 to 2020 will be about 24.57 billion($2.97 billion).
Abstract: The existing reservoir water-supply operation rules focuses on the single water supply,paying little attention to multipurpose water supply with different priority and reliability.This paper proposes a reservoir operating rule for the multipurpose water supply,which can deal with the different water supply respectively,make sure no severe shortfall happens and achieve the operating objective of minimizing the total water-supply shortage.A model combining simulation and genetic algorithm is used to optimize the parameters of the proposed operation rule,and the genetic algorithm is proved to give good performance in searching the optimal parameter combination.The case study justifies this operating rule for multipurpose water supply.
Abstract: The purpose of this paper is to examine the water deficit in Xi'an area,the ancient city in China.This paper analyzes the hydrologic characteristic of surface water in Xi'an area by the monthly flow time delay curve and the transcendental probability curve,and evaluates the water supply level in Xi'an city with the water-supply guaranteed rate and the shortage index as the evaluating index,through the joint operations among the reservoirs and the operation without reservoir.The results show that the needs of the present water can not be met without the reservoir operation in Xi'an city,and the mean annual surplus water will still reach 200 million m3 in 2030 with the joint operation among the three reservoirs,which proves that the water resource developing is still of certain potential.
Abstract: Freezing soil is a natural phenomina in cold and mountain areas,which has great impact on the regional climate,water cycle,and water balance.The land surface process in the condition of soil freezing and thawing is one of the most important process in the area.This paper firstly reviews the present study on land surface process in the condition of soil freezing and thawing,especially the development after the the hydrological land surface model introduced into the study of General Circulation Model,then introduces the undergoing international research project,such as Project for Intercomparison of Land-surface Parameterization Schemes and Cold Land Process Field Experiment by NASA,and finally analyses and puts forward the future research field and topics.
Abstract: The Soil water and the solute transport are a hotspot in the research of the soil-water environment,and it is the problem that has no better solutions.It is a new ideal and method that the soil water and the solute are studied with the fractal theory to settle the complex problems in this area.Based on the expounding in briefly that soil structure is measured with fractal theory,a series of results in the soil water and the solute transport mechanisms with the fractal theory are reviewed particularly,including its basic parameters the non-Fick phenomenon of the soil solute transport and the scale effect of dispersion coefficient.It is hoped that the Fractal theory will be used in the future to research the soil water and the solute transport process.