• 全国中文核心期刊
  • 中国科技核心期刊
  • 美国工程索引(EI)收录期刊

2004 Vol. 15, No. 4

Display Method:
Applications of the Monte Carlo method to potential flow
JI Qing-feng, ZHENG Bang-min
2004, 15(4): 415-419.
Abstract:
The Monte Carlo method is applied to simulate the flow with complex boundaries. In order to improve the simulation precision,a new Monte Carlo method with irregular random walk grid for solving the partial differential equation is presented. The sluice and spillway flow is solved by the Monte Carlo method. The numerical results agree well with the experiment data. Compared with the finite element method,the Monte Carlo method is more effective for linear problems such as potential flow. It can calculate the velocity and pressure respectively at any points in flow field.
Analysis of recent changing characteristics and tendency runoff and sediment transport in the upper reach of Yangtze River
XU Quan-xi, SHI Guo-yu, CHEN Ze-fang
2004, 15(4): 420-426.
Abstract:
This paper statistically analyses the runoff and sediment transport of the major stations in the upper reaches of Yangtze River. Compared with the annual runoff and sediment transport before 1990,there were three major changes of annual sediment transport in the term of 1991-2002:the Yichang station decreased about 1.3×108t;the Pingshan station at the Jinsha River increased about 0.35×108t,and the percentage(compared with Yichang station)also increased from 51.8% to 71.9%;and the Beibei station increased about 0.985×108t,and the percentage also decreased from 25.7% to 9.1%. Through several non-parameter statistical methods such as the moving average check,the Spearman order correlativity check and the linear regression check,the paper concludes that the trend of runoff evolvement at the Pingshan station is not distinct, and nor is that of the sediment transport increased;but trends of the runoff and sediment transport decreased are very distinct; the trend of runoff evolvement at the Yichang station is not distinct,and the trend of sediment transport increased is distinct. The major factors correlated with the runoff and sediment transport changes such as the rainfall,water-and-soil conservation measures,reservoir trap and artificial inducements of soil etc. are also introduced.
Flood-control level study of floodplain flow
QI Mei-lan, CUI Guang-chen
2004, 15(4): 427-430.
Abstract:
In this paper,flow boundary water levels along flood embankments in flood plain reach of the Songhuajiang River are studied by the physical model. Different modeling methods to the roughness of the flood plain were used. Based on the similar model,the relationships between the water levels along the flood embankments and the discharges are measured. The experimental results show that due to the complex resistance in the reach,the water levels along the embankments are different to the levels of the main channel at the same section,and the maximum difference between the two places is 0.3 m.
Research on large eddy simulation for water quality
ZHANG Chang-bing, XIONG Chao-kun, GUI lin, LIU hua, MO Zheng-yu
2004, 15(4): 431-435.
Abstract:
A large eddy simulation approach for the water quality based upon the weakly compressible flow is developed,and the relationship between the diffusion coefficients and the average velocity is established. The finite volume approach in space and predictor-corrector method in time is used,and "partial slip condition" is applied to the solid wall boundary condition. This model is employed in simulating the concentration distribution of the pollutant transport at the cross area between the Jialing River and the Yangtze River,and the results show that the transverse diffusion is weak and the bank-side pollutant zone appears when the discharge of the branch river is relatively small,on the contrary,the transverse diffusion is strong and the pollutant zone moves to the heart of the main river when the discharge of the branch river is relatively large.
Study on integrating geodatabase with municipal drainage system planning
LONG Ying, JIA Hai-feng, CHENG Sheng-tong
2004, 15(4): 436-440.
Abstract:
The geodatabase is the third generation geographic spatial data model. Its functions have been enlarged greatly compared with Coverage,the second generation data model. After the reviews of the content of municipal,the drainage system planning and the applications of GIS to this areas,the advantages of integrating geodatabase with municipal drainage system planning are analyzed,and one new solution to municipal drainage system planning is proposed. In the layout planning of the project,the Beijing sewage treatment plants,the method is applied successfully,and proved more efficient than the traditional planning platform-CAD,the second generation data model in municipal drainage system modeling,planning data management, planning efficiency,etc.
Application of GIS to nonpoint source pollution evaluation
ZHOU Hui-ping, GE Xiao-ping, XU You-peng, LUO Wei-jia
2004, 15(4): 441-444.
Abstract:
This paper established an evaluation system for nonpoint source pollution integrated Visual Basic with Map Info geographical information syseml(GIS)MapX and simulated BOD loads on annual average in the Yanjiang watershed in Zhejiang province in the case study. This study analyzed the application of GIS to nonpoint source pollution evaluation at the aspects of system frame and run process including data input,model parameters extraction,result visualization. This study indicated that integrating GIS technology with evaluation for nonpoint source pollution in watershed is effective in acquiring model parameters and enhancing the definition of data and evaluation result. It provided an effective method for nonpoint source pollution control in watershed.
Direct search-simulated annealing algorithm in the optimal planning of water pollution control system
SHEN Wei, GUO Zong-lou, LIU Guo-hua
2004, 15(4): 445-447.
Abstract:
A direct search-simulated annealing(DSA)which is memory-based is suggested and constituted to solve the optimum planning model. The algorithm is applied to the optimum planning for the waste treatment system of Urumqi,Xinjiang. Results show an improved performance in finding the global minimum when water quality requirements have been fulfilled. The DSA has been shown to be fast,efficient and stable.And the program is simple.It provides a new way to the optimal planning of water pollution control system and has great application prospects.
Nonlinear dispersion relations of wave
ZHANG Yang, LI Rui-jie, ZHENG Jin-hai
2004, 15(4): 448-453.
Abstract:
Based on the summarization and comparison of present nonlinear dispersion relations of wave,the general expression of the nonlinear dispersion relations and its explicit form are presented in this paper. The result of comparison shows that the explicit form has a considerably high precision and is good agreement with the implicit form. By use of the explicit form of nonlinear dispersion relation along with the mild slope equation taking into account weak nonlinear term,a mathematical model of wave transformation considering the effect of the nonlinearity is obtained. Comparison of the modified nonlinear relations is made in the model,and the computed results show that it is more accurate to use the latest nonlinear relation.
Parallel finite element method for 2D unsteady seepage flows
JIANG Chun-bo, AN Xiao-mi
2004, 15(4): 454-457.
Abstract:
The parallel groundwater model for 2D unsteady seepage flow with finite element method is established. The message passing interface is applied to simulate saturated unsaturated seepage flow on Windows NT. To solve the el iptic differential equation,the implicit numerical scheme is applied and a parallel generalized minimal residual algorithm is used to solve the large sparse linear system. In order to improve the performance of the parallel program,multiple techniques are used,such as load balance,communication improvement and global operations. To verify the model,the seepage flows through the coffer dam of Xiluodu hydropower station and two kinds of unsteady seepage flows are simulated The results obtained are reasonable. In the end,the speedup of the parallel comput ing model is evaluated. It can be seen that bet er parallel performance is achieved as the computat ional scale increases.
Fractal model for predicting effective diffusion coefficient of solute in porous media
LIU Jian-guo, WANG Hong-tao, NIE Yong-feng
2004, 15(4): 458-462.
Abstract:
An alternative method is explored to predict effective diffusion coefficient of solute in porous media by using the fractal approach. A fractal capillary tube model is established to be an improvement of the classical sinuous capillary tube model and a power law equation is derived. The power exponent is a function of pore volume fractal dimension and surface fractal dimension,which respectively characterize the hierarchical structure and the tortuosity of pores. Analytical comparison of the reported experimental data of fractal dimension of clayey soils with the corresponding effective diffusion coefficients indicates that the derived power law equation is valid to predict the effective diffusion coefficient of solute in porous media.
Model of crop response to water with influence of after-effect of water stress
GUO Xiang-ping, ZHU Cheng-li
2004, 15(4): 463-466.
Abstract:
Water stress has after-effect which would affect water requirement of crop in different growing stages. The field experiment indicated that the after-effects caused by stress in earlier stages might result in decrease(or increase)of crop leaf area index(LAI)and water requirement. A correction coefficient of after-effect of water stress expressed as variation of relative leaf area index is introduced to improve the present Jenson model of crop response to water(MCRW).The improved model can separate the effects of water stress from after-effect of water stress on grain yield and thus avoid the appearance of "false water deficit". It can also explain reasonablely why water requirement increase in later growth when water stress is exposed in earlier stage and why relative high grain yield can be maintained under some stress treatment. The simulated results fit well in with the farm data with fairly high accuracy,indicting the model being reasonable. Disadvantages of the model are also discussed in the paper.
Flow characteristic in conjunction area after confluence of debris flow and main river
GUO Zhi-xue, FANG Duo, CAO Shu-you, YU Bin
2004, 15(4): 467-471.
Abstract:
Some solid material will deposit in the conjunction area when debris flow is in conjunction with the main river. The transport discharge,deposit discharge,transport ratio and deposit ratio are defined.Based on the momentum theory,we study not only the heading up and sediment deposit principle within the conjunction area but also the varying rule of discharge,density and moment transportation relation within the conjunction area after the confluence. We also deduce the equation of Froude number,which can reflect the hydraulic relation and confluence characteristic in the confluence area after conjunction of main river and branch river.It is verified with the experiment data. If the parameters are used correctly,the calculation value will be very close to the one got through observation.
Impact of temporal and spatial variation of water environment on ecosystem of the Pearl River estuary
CUI Wei-zhong
2004, 15(4): 472-478.
Abstract:
The paper analyzes the variation features of water environment of the Pearl River estuary in recent 20 years and researches with the interrelation and interaction of water environment and aquatic biology of the estuary. The results indicate that the variations of morphology,geomorphy,hydrological regime and water pollutants have changed the perching conditions of aquatic living things of the estuary,decreased self regulation and restoration capability and homeostasis of ecosystem,influenced greatly on matter cycle,energy transfer,development,evolution and equilibrium in the ecosystem of the Pearl River estuary.
Theory and application of regional drought characteristics
ZHOU Zhen-min
2004, 15(4): 479-484.
Abstract:
Drought problem must be analyzed and solved at a regional level. Drought studies must focus not only on the hydrological characterization of the phenomena but also the results caused by drought. In this paper the concepts and methods to characterize droughts as regional process are presented. The concepts of risk,reliability,resiliency and vulnerability are applied to characterize regional droughts and provide a theoretical framework for dealing with drought problems. The paper divides the downstream Yellow River irrigated district into 6 sub-regions,and the multivariate stochastic model is used to generate a synthetic series of monthly precipitation at the six sub-regions. Thirty-three years of monthly rainfall data are used to calibrate the parameters of the model. The generated precipitation series is used to perform the study of regional droughts from the point of view of theoretical risk.
Flood sedimental characteristic and its mark on the middle reaches of Yangtze River
LI Chang-an, ZHANG Yu-fen
2004, 15(4): 485-488.
Abstract:
Flood record is a foundation studying flood happen law. In order to establish the identification mark of flood sediment in the flooded area at the middle reaches of the Yangtze River,We study the flood sediments in 1998,1999 and 2002. The results show that the flood sediments are obviously different from the normal channel deposits on sediment body shape, sedimental texture and sediment composition in the middle reaches of Yangtze River. The results of study can provide the feasibility and basis for the history flood events identification in the field.The sedimentary characters of the flooded deposits on crevasse splay sedimentary,flooded flat and shore side are studied and summarized in the paper.
Forest landscape pattern and its eco-hydrological effects of the Qilian Mountains in northwest China
YANG Guo-jing, XIAO Du-ning, ZHOU Li-hua
2004, 15(4): 489-494.
Abstract:
Abstract:Using the model of Arc GIS program and the hydroloyical databases for 1981 to 2001,we analyze the landscape pattern and hydrological features of Dayekou river catchment(DYK)and Haichaoba river catchment(HCB)which are located at the Qilian mountains in northwest China. The results show that grassland and Picea crassifolia forest in DYK are the main landscape elements,and more important work in eco-hydrological process,while shrubs and bare land in HCB are the main landscape elements and of importance in eco-hydrological process. In DYK,the evapotranspiration is 61% of the rainfall,and the runoff coefficient is 0.39% whereas in HCB,the evapotranspiration is of the rainfall 41%,and the runoff is 0.59%. The coefficient study indicates that different forest landscape pattern will bring on different eco-hydrological effects in the arid mountain areas.
Advances in distributed hydrological modeling in the Yellow River basin
LIU Chang-ming, XIA Jun, GUO Sheng-lian, ZHENG Hong-xing, WANG Zhong-gen, WU Xian-feng, HAO Fang-hua
2004, 15(4): 495-500.
Abstract:
The recent advances in distributed hydrological modeling in the Yellow River basin are reviewed in this paper.The purpose of this study is to develop distributed hydrological models for the Yellow River basin,which is part of the National Key Project "Water Resources Evolution Law and Renewability Maintaining Mechanism"(also simplified as Yellow River "973" project,G19990436). The discussion involvs the framework of distributed hydrological models and the related technological tools such as DEM,GIS and RS. Furthermore,the advances in distributed hydrological modeling are also described and some proposals for further study on hydrological modeling are discussed.
GIS/RS based distributed hydrological modeling 1, model theories and structures
WANG Zhong-gen, ZHENG Hong-xing, LIU Chang-ming, ZHAO Wei-min
2004, 15(4): 501-505.
Abstract:
A geography information system(GIS)/remote system(RS)distributed hydrological model is presented for water resources management of watershed. The model includes a unit hydrological module and a routing module. The former concerns with hydrological processes such as canopy interception,snowmelt,evapotranspiration,slope flow,soil flow and ground flow. The topography index method taking into consideration the effects of topography is used to calculate water yield.For river network routing,the Muskingum method is usually used. The inputs and parameters of the model are prepared with the support of GIS and RS,which enhance the efficiency of hydrological modeling.
GIS/RS based distributed hydrological modeling,2, model test and application
ZHENG Hong-xing, WANG Zhong-gen, LIU Chang-ming, ZHAO Wei-min
2004, 15(4): 506-510.
Abstract:
GIS/RS is an important technology support for distributed hydrological modeling in a watershed. This paper carries out a case study on the Jinghe River which is the second grade tributary of the Yellow River. With the support of GIS,the watershed characters including slope,river networks and river length are extracted from the digital elevation model with a resolution of 100-by-100 meters. Also,soil and land use information are parameterized to each sub-watershed. And precipitation, temperature are interpolated to all sub-watersheds. By coupling all the distributed parameters,the hydrological processes of the Jinghe River basin are simulated. The results show that the errors of water balance are less than 5% for all 25 sub-watersheds. which indicates the rationality of the model. The potential evapotranspiration simulated is quite close to the observation. As for the four hydrological stations,the correlation coefficient between daily runoff observed and simulated is about 0.84~0.93.
Storm-runoff simulation of distributed hydrological model in the Yellow River basin
WU Xian-feng, LIU Chang-ming, HAO Fang-hua, WANG Guo-qiang, YANG Gui-lian
2004, 15(4): 511-516.
Abstract:
An Hours-interval distributed hydrological model with a loosely coupled structure aimed mainly at simulating floods is proposed in this paper.The model is established on the basis of the DEM and composed of five components:the distributed digital basin,the unit grid module,the river rout ing module adjustment of water storage by reservoir model and the graphical user interface(GUI).With the support of GUI,the model can be run as model input,parameter selections and result display. The model can be applied to semi-arid and semi humid basin area with little ef ect from human activities,and is used in the upper Luohe River between Xiaolangdi and Huayuankou of the Yellow River basin.
DEM-based distributed hydrological model and its application
XIONG Li-hua, GUO Sheng-lian, TIAN Xiang-rong
2004, 15(4): 517-520.
Abstract:
A digital elevation model(DEM)-based distributed model is proposed to simulate the saturation-excess mechanism of runoff generation. With the establishment of the relationship between the soil water storage capacity and the topographical index,the spatial distribution of the soil water storage capacity over the watershed is simulated in the model. The direction of the overland flow is determined by using the multiple-direction allocation method rather than the steepest slope method. The results show that the model is capable of simulating the observed hydrographs at nearly the same efficiency as those of the Xinanjiang model and TOPMODEL,and the simulated spatial distribution of the soil moisture content over the whole watershed is reasonably in accordance with the hydrological reality.
Distributed hydrological modeling based on nonlinear system approach
WANG Gang-sheng, XIA Jun, ZHU Yi-zhong, NIU Cun-wen, TAN Ge
2004, 15(4): 521-525.
Abstract:
The distributed rainfall-runoff model has the advantage of being physically-based. However,this model is difficult to apply because of the demands on the input data,much of which is not directly measurable,and computational time. This fact has led to the development of simplified distributed models,such as the Distributed Time Variant Gain Model(DTVGM), by a combination of physical or conceptual processes with a nonlinear system approach. In the Banqiao Basin of Yellow River, considering the spatial variation of precipitation,the DTVGM makes positive response to the distributed input data and obtains higher precision in streamflow simulation than that of the lumped model. In Chaobaihe River basin of North China,by analyzing the variation of the time variant factor G for different land use types,the response trend of runoff to the land use and cover change is preliminarily showed:in case of the same soil moisture condition,the value of G decreases,which means that the surface runoff generation ability decreases with the increase of the forest cover.
Research development and some problems discuss on acid rain in China
WANG Jia-quan, WU Jin-bing, LI Ru-zhong, QIAN Jia-zhong, PAN Tian-sheng
2004, 15(4): 526-530.
Abstract:
By describing briefly the acid rain research history in China and abroad,the paper analyzes acid rain study in China,and put forward some further research problems. In the past years,great progress in acid rain researches have been made in China.But due to the development of acid rain form and the complexity of acid rain movement,many problems still need to be further researched in China.For instance,(1)Set up models to prognosticate acid rain with the change of energy structure; (2)Study the ecology remediation technique damaged by acid rain from the point of ecology system;(3)Find the way to control waster SO2 and desulfurizing technic in different industry;(4)Constitute countermeasure to control acid rain which is suitable the development of our economy;(5)Combine new technique such as GIS with acid deposition approach,acid deposition model and programming critical charge of acid deposition.
Review of indices for precision irrigation decision-making
CAI Jia-bing, LIU Yu, LEI Ting-wu, XU Di
2004, 15(4): 531-537.
Abstract:
According to the theory of soil-plant-atmosphere continuum,there are three types of indices for precision irrigation decision-making,including soil moisture,plant water status and weather conditions. This paper reviews the researches and developments in these regards. The technologies for soil water monitoring and measurement have lately made great progress,such as time domain reflectometry,microwave,near infra-red radiation,etc. The plant water status,indicated by the leaf ture,shrinking or swelling of stems or fruits,the capacitance or resistance of crop stem,etc,has been used as indicators for irrigation decision-making. And the temperature difference between canopy and its ambience,including the sap flow of plant, will be a better method to study the crop water status from the literature reviews. The crop reference evapotranspiration,estimated from meteorological data with methods such as the Penman-Monteith method recommended by FAO,is useful for precision irrigation decision-making. And it is concluded that the combination of the applied multi-indices can be used for irrigation management. In this paper,the development of precision irrigation control,as an important part of precision agriculture,is also discussed. The factors,which should be considered for irrigation application at the "proper time" and "adequate quantity" for these purposes,are crop,soil moisture and weather conditions.
Mechanism and application of a third generation wave model SWAN for shallow water
XU Fu-min, ZHANG Chang-kuan, TAO Jian-feng
2004, 15(4): 538-542.
Abstract:
Research status and existing problems of wave numerical models for shallow water at the coastal and estuarine zone are generalized,the developing history of forecasting waves with energy balance equation is also discussed.The third generation wave model Simulating waves Nearshore(SWAN),based on the most advanced wave study achievements,is described in great detil here.In additiion,the applicability,numerical characteristic,functionality and limitation of the model are interpreted. The action balance equation,its discrete demand,the method dealing boundary condition,and source terms(the wind input,the energy dissipation and nonlinear wave-wave interactions) are detailed discussed,and special emphasis is put on the triad wave-wave interactions. The SWAN model is applied to simulate the significant wave height and average period at the Haian bay,and the influence of nonlinear wave-wave interaction term on the simulation results is analyzed. Finally,the application foreground and study tendency of the model is discussed,too.