Abstract: Due to the shortage and pollution of water resources,and the characteristics of hydrology,water resources,and water supply and demand in China,it is necessary to develop a real-time monitoring and management system for water resources in river basin. The emphases should be put on the rearrangement and improvement of the current hydrologic monitoring network,the check and modification of operation mode and technical parameters of reservoirs,the control and management of water resources in flood,groundwater recharge and the sewage treatment and reuse,the water demand for ecological environment protection,the unite regulating for flood control and benefit promote,the joint management of surface water and groundwater resources and so on. The benefit and risk analyses of the scheme of real-time monitoring and management for water resources and the standardization of the system should also be carried out.
Abstract: Water use quotas,such as those for irrigation and industrial water use,can not be simply used to appraise the rationality of water use in a region because different regions cultivate different crops with different water requirement,and different industrials require different water use quotas. Furthermore,regions with higher water stress may host water-intensive-industrials such as coal mining and electricity generation because of the location of coal reserve. So it's not fair to suggest that regions with higher water stress have higher water use efficiency. Generally,water use rationality should be appraised by indicator system under three equally important criteria:sustainability,justice and efficiency.
Abstract: A system of water resources sustainable development evaluation indicators is designed,which based on a regional/basin water resources characters and socio-economic development requirement,as well as differences of socio-economic development and science/technology levels.The system is referred to cognizing level of international sustainable development stan-dard and national other resources sustainable use,following scientific,practical and concise principles.The five-grade identification standard of water resources sustainable development capacity identification standard is proposed exploringly.
Abstract: In order to evaluate regional water resources sustainable ut ilization,the paper puts forward a new method on the basis of the fuzzy matter-element analysis and combined with the concept of Euclid approach degree,regarding the regional samples and the utilization phases as the object of mater-element and constructs the compound fuzzy mater-element with the evaluation factors and their fuzzy value of the object.Through calculating Euclid approach degree between the fuzzy matte-relement and the standard(the best)fuzzy matte-relement,the writer achieves on development and utilization phase of regional water re-sources and its optimum order,with the calculation of weight adopting the analytical hierarchy process method and the model applied to the evaluation of water resources sustainable utilization in Xi'an.It provides significant reference for sustainable development of water resources in Xi'an.
Abstract: The lower Tarim River has dried up for many years,resulting in the deterioration even disappearing of the Green Corridor. From May of 2000 to November of 2001,three times water transfers have been undertaken to improve the local hydrological situation and resumed the local ecological environment. Based on the loss rate of the flux and the velocity of the river water,the hydrologic factors,such as the flux,the distance,the time and the water quantity,have been simulated for all three water transfers,mainly for the second. The analyses and simulations are helpful to evaluate the hydrological effects and to choose the proper water-transfer plan. Although the study mainly focuses on the water transfer,it has close relationship with the eco-hydrological research on the lower Tarim River.
Abstract: The study of crop water-fertilizer production function is an important aspect of deficit irrigation theory and will provide the base for increasing use efficiency of soil water and nutrient. The Jensen model and the artificial neural networks (ANN)model are used to describe crop water-fertilizer production function. Both models are validated by field experiments of winter wheat. The results show that both the ANN model and the Jensen model are capable of predicting crop yield on the basis of water and fertilizer used in the field with acceptable precision.
Abstract: The water allocation network(WAN)is a special mass exchange network(MEN). This paper reviews the concerned study and research in literature and introduces the researching methodologies,i. e. targeting approach and mathematical programming method. It predicates that the further study of WAN should focus on the application of the mass integration,as well as holistic process integration combining energy and water allocation network,in order to realize clean production and sustainable development.
Abstract: The automatic detection of drainage networks from digital elevation the models(DEM)is affected by flat areas and closed depressions.A variety of methods have been proposed to treat these two features,but the flat areas and closed depressions are processed only after they have been created,so as to generate many spurious and parallel drainage courses.a new algorithm for treating the flat areas and closed depressions is proposed in the paper.It is known that the flat areas and closed depressions often arisen because of low quality input data,interpolation errors during the DEM generation et al.Therefore,they can be removed by adding elevation information to input topographic data. The proposed approach can lead to better match between observed and modeled flow structure and produce more realistic results in application.
Abstract: Aojiang River,situated in the south of Wenzhou city in Zhejiang province,is struck by the flood disasters frequently.A system of flood forecasting and dispatching decision support system in Aojiang River Basin is developed to enhance the flood management and disaster mitigation measures. This essay mainly introduces the design,function modules,logical structure,model organization and the method of applying hydrological and hydraulics models in simulating flood movement in the watershed of the system. It aims at establishing a frame of flood forecasting and dispatching decision support systems that is suitable for middle and small watersheds in Zhejiang province and Southeast China border on the sea and even the whole country.
Abstract: This paper presents an experimental study of 2-Dturbulent jets discharged vertically through a rectangle submerged pipe into flowing non-stratified water of finite depth.The experiments were carried out in laboratory facilities of a closed system capable of maintaining steady-state conditions,and the condition for the transform of flow type is presented. The relat ionship between the velocity ratio and the position of vortex located in the near of the jets and the separated point is given also. The velocity vector in the center plane and the rate of centerline velocity are obtained by the Micro ADV system for 3 kinds typical jets Based on the data of velocity,the streamline contours in center plane for the jets are obtained by the software of Teck plot 7.5. There is a fall off of the upstream streamline near the jets. The vector of jets with velocity ratio,8 is showed for com paring with the numerical simulation.
Abstract: Currently the costal water pollution problem is more serious with the increase of waste discharge into inshore region. According to the characteristics of inshore regions with large scale of area,the rational grids distribution construction is important to improve computational enfficiency and precision for inshore regions. Based on the idea of the quadtree grid structure, the nested adaptive quadtree grids for the inshore water region is distributed according to demand of different research areas in this paper. The grid is densified scattered in the coastal pollution region,and the pollutant zone is focused to simulate. A numerical model is established by using the flux difference splitting(FDS)scheme of Godunov-type,and applied to simulation of flow and concentration fields for Haizhou Bay.Then the relationship curve between the waste discharge amount and the area of pollution zone is gained under the given condition of tidal range. The pollution control plan for cutting down waste discharge amount are obtained according to the limit area of pollution zone by environment protection department.
Abstract: Ammonia pollution becomes one of most crucial factors in the decline of the surface water quality and the deterioration of the aquatic ecosystems in China. This paper studies the impact principles on the quality of river water and the sorption and retention characters from the riparian reed,on the basis of site comparison experiments.Theoretical analysis had been per formed and some conclusions had been obtained that the conflux of rainstorm at the beginning stage had the worst influence on the quality of river water,and the sorption abilities of ammonia by riparian reed zone were influenced by growing stage of the plants,the concentration of ammonia in rivers,the rate of water flow and some meteorological conditions. Furthermore differences of the attenuation coefficient and decrease amount of ammonia under the conditions of existing riparian reed zone and non-reed zone had been achieved through numerical simulation and parameters optimize method. The changing principles and impact factors of them had also been found,which would provide scientific foundations for aquatic ecosystem restoration and water quality prediction.
Abstract: The vertical turbulent mixing process of point source and linear source in nature rivers are studied in this paper. According to the vertical turbulent mixing process near the discharge point in large rivers,the new concept of part depth of homogeneous mixing is presented.The basic equations of vertical mixing process are developed.The fundamental relationship between the part mixing depth and the vertical mixing distance is obtained.The distance of vertical homogeneous mixing in whole depth can be calculated by the theory equation,which is deduced in the paper.The equat ion is also verified by the measure data in the Yangtze River.On the base of the law,a 2-D water quality numerical model which is mixed through part depth homogeneous is developed,and used in the concentration field calculation.By use of the measure data of Rhodamine-Btracer in the Yangtze River estuary,the comparison of the value calculated with the data measured is made.The value calculated by the new model is more precise than that calculated by the traditional 2-D model,and it is more efficient than 3-D model.
Abstract: Abstract:The ecological environment in lakes has been changed due to inflow of large amount of organic pollutants,as a re sult,the food chain in ecological system has been damaged,forming the dominant species of algae and producing eutrophication.This article describes a research method to partially change again the ecological environment in small scale by reproducing large amount of rotifers to eat algae,so as to revive the ecological system.After a partial small ecological system has been revived,the equipment can be moved to another area for revival.In the way,the eutrophication in lakes can be finally harnessed.
Abstract: Based on the elliptic mild slope equation and the Message Passing Interface(MPI),a paral ellsolution method is proposed for the simulation of nonlinear wave transformation over a topography with mild slopes,and implemented numericaly on a personal computer(PC)cluster.The nonlinear wave transformation over a typical topography with mild slopes is simulated.A comparison of numerical results with experimental data shows that the application of the nonlinear dispersion relation to the el iptic mild slope equation can ef ectively take the nonlinear effect into account.It can also be seen from the parallel efficiency and speedup rate that the parallel solution method proposed in the present paper can effectively increase the efficiency of numerical simulations.
Abstract: Vortex ripple is widely formed in the coastal region,and the dynamics of vortex is responsible for the sediment transport In this paper,a 2-D Large-Eddy-Simulation method(LES)was used to predict the flow structure and the dynamics of vortex in the bot om layers under the action of the wave.The numerical simulation results show a complete process of vortex formation,evolvement and disappearance.The bed shear stress distribut ion and the length of the separation bubble with different scale vortex ripple also were studied.
Abstract: The construction of the Three Gorges Reservoir may brings about a new problem to the Lujiahe shallow reach,and chamfering the Shihong(the right thalweg)is one of the measures suggested Based on the model experiment,the effect of chamfering has been studied,proving that chamfering can solve the problem of lag in depth in the navigation channel of shahong(the left thalweg)and escarpment and riffle as well,and improve the navigation condition of the whole reach completely Meanwhile,chamfering will make the main flow translocation with the lateral branch in dry season,and decrease the discharge diverting ratio of the Songzihe River(an important tributary of the Yangtze River in this reach)from the Yangtze River,etc However,the extra descendent of water stage of the upper reach resulted by the chamfering may foreclose the normal navigation condition of the Gezhouba Ship Lock,etc.
Abstract: The density of deposit in rivers increases under the action of water pressure and soil pressure,which results in large changes on the physical and mechanical properties of the soil. A large difference occurs when the threshold velocity is calculated by the empirical formula So,in this paper,the experiments on the threshold velocity for muddy loam are studied in special rectangular pipes. From the experiments,the frictional velocity is obtained at the critical condition Changed into the velocity for the natural river by resistance relationship and compared with the flow dynamic conditions of the river,it can be proved that the experimental results are effective and reasonable,providing a new method to solve the critical condition for the threshold velocity of deposit in rivers.
Abstract: In this paper a normal principle of the river system is introduced.Based on the analysis of water-sediment model of single reach,a numerical model for calculation of normal river system is established and tested with the observed data of the Jingjiang River and the Dongting Lake. The result shows that the computed data and the observed data fits well,which indicates that it is suitable to describe the complex boundary of the Jingjiang-Dongting,and the model is applicable.
Abstract: Based on the field data of velocity profile observed at 23 measuring points distributed over the Yangtze River estuary in March and September,1996,the momentum coefficients are calculated and their distribution characteristics are obtained through statistical calculations. For different typical time intervals and different places in the Yangtze River estuary,the results of linear regression show that the momentum coefficients are larger for flood than forebb,and for flood season than for dry sea son,that they increase from spring tide,mean tide to neap tide on temporal distribution,and that they increase from the out side of the month to inside the month for the North Branch,and increase at first and then decrease from outside the month to inside the month for the South Branch,the maximum value appearing near the month where riverflow crosses tide on spatial distribution Through analysis,the feature of frictional resistance in the motion of tide is better understood,and an easy approach is provided for choosing the Manning coefficient for numerical simulation of plane 2-D tidal current.
Abstract: The impacts of human activities can be regarded as an integrated variable,and should be calculated comprehen-sivelg. Based on the theory of geodynamics and GIS,a universal model of the impacts of human activities on the water resources is presented and applied to the western of Jilin province. The results show that the method is practicable.
Abstract: A new in-situ remediation technology for groundwater contamination(permeable reactive barrier)is introduced in the paper,including the configurations,medium selection,mechanism,utilization situation and existed problems of reactive barrier. In practice,the permeable reactive barrier configurations can be changed according to the local hydrogeologic conditions and the characteristics of groundwater contamination in order to effectively catch the contaminated plume.Comparing with pump-and-treat system,the permeable reactive barrier is cheap and durable,with a good effect on the treatment of DNAPLs-contaminated plume.
Abstract: The 502year complicate process of the hydrological basin study of PRC is reviewed,and the concept of experimental hydrology and the hydrological experimental system are introduced,proposing that the hydrological experimentation appears the best way for the improvement of hydrology which has not yet consolidated as a science itself. It is neccessary to make efforts on the recovery of the basin study interrupted during recent decades. For this purpose,some points related to the strategy of basin study are discussed.
Abstract: At present,the main circulatory pattern of Qiongbei compound aquifer system of Hainan(area of 4300km2)is inter-supplying and inter permeating in vertical. The subsidiary circulatory pattern is runoff in horizontal,and the system inter-cepts the groundwater runof to the sea with maximum limitation. Two condit ions are demanded for the sea and the compound aquifer system to exchange water:(1)existing passage for water to be exchanged,and(2)existing potential difference(the difference of location head and pressure head and the gravity potent ial head produced by the different density of salt and fresh water)Since groundwater resources of Qiongbei compound aquifer system has been continually exploited for many years,the level of the hydraulic has already been reduced under the sea level for fifteen to twenty years ago.Up to now no obvious sign of the sea invading has been found.
Abstract: The Evolution of flood losses of the United States in the 20th century,the flood impact on national economy,and the responses after the great floods are explored in the paper. The comparative analysis of flood losses between the US and China in the 1990s is discussed. Some conclusions are obtained to provide the referees for the policy on flood control and disaster reduction in China as follows. Flood losses in the United States continued to rise slowly to US $5.56 billion of average annual damages in the 1990s at a ratio of 1.58 percent and the ratio of flood losses to GDP continued to drop gradually from 0.334 percent in the 1930s to 0.068 percent in the 1990s;many key policies involving flood were triggered by destructive floods to head the way from flood contain and control to flood management;with the comparative analysis of flood losses between the United States and China in the 1990s,average annual damage in China in the 1990s is estimated about RMB 134.34 billion accounting for a proportion of flood losses to GDP of 2.386 percent in contrast,average annual damage US $5.56 billion in the United States accounting for the ratio of 0.068 percent.