• 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

2006 Vol. 17, No. 6

Display Method:
Factors affecting the hydraulic characteristics of horizontal submerged jets
LI Yan-ling, HUA Guo-chun, ZHANG Jian-min, YANG Yongquan
2006, 17(6): 761-766.
Abstract:
Based on the 3-D numerical simulation and the model test,many factors affecting the flow pattern stability and the hydraulic characteristics of the horizontal Submerged Jets are studied. The results show that multi-lever and multi-strand horizontal submerged jets are a new energy dissipation type and have better stability of flow patter,lower velocity in the slab and higher dissipated energy rate than the single-lever and the multi-strand horizontal submerged jets. Connecting to the model test,some suggest ions,important for design,are put foward,for example,the chute width of intermediate outlet should be constant;the optimum height difference of drop between intermediate out let and surface outlet should be larger than the water depth at intermediate outlet;and the type of drop should be changed with the characteristics of certain project.
Numerical simulation of hydrodynamic pressure on vibrating plates through differential quadrature method with fluid-structure interaction
ZHANG Li-xiang, Y.Guo
2006, 17(6): 767-773.
Abstract:
Abstract:The differential quadrature(DQ)method is firstly applied to solve three dimensional incompressible Navier-Stokes equations in primitive variable form with the fluid structure interaction(FSI).The flow passage used in the present paper consists of four rectangular plates,two of which are elastic and others rigid,and the elastic plates are vibrating while the fluid are flowing. To compare the influences of FSI on the pressure fields,the size of the flow passage is designated to 1.5m×0.5 m×0.2 m as a working example. The DQ mesh sizes of 25×25×25 and 29×29×29 were used for Reynolds numbers of 7000 and 10 000,with and without FSI,respectively. The numerical results show that the developed DQ method with FSI is a suitable tool to analyze hydrodynamic pressure on a vibrating plate,and the effects of FSI on the flow fields are significant.
Relation of starting shear stress and physical and mechanical indexes of cohesive undisturbed soil
HONG Da-lin, MIAO Guo-bin, DENG Dong-sheng, XIE Rui, ZHANG Si-he, JI Chang-hui
2006, 17(6): 774-779.
Abstract:
Through the test of the undisturbed soil samples from Zhongyun River,Changxing Island of Yangtze River,and the water channel of Huaihe River to sea,it is considered that the critical starting condition for soil in different channes are different because of the difference of the formation conditions,qualities and structures,though the physical and mechanical proper ties of soil is similar. However,for the same river,the obvious regularity exists in critical starting condition and the physical and mechanical indexes:the critical starting condition of the muddy cohesive soil increases with the decrease of the shear strength and decreases with the increase of the moisture content;the critical starting condition of silty clay is the minimum, and the relation of the clay,the shear strength and the moisture content is nonlinear;and the critical starting condition of the cohesive soil increases with the increase of the shear strength and the moisture content.
Study on eco-environmental water use of soil and water conservation in loess plateau
DAI Feng-gang, CAI Huan-jie, MENG Yi, TIAN Yong-hong, WANG Hong-xing
2006, 17(6): 780-784.
Abstract:
From the point of view of realizing the sustainable socio economic development in loess plateau,this paper discusses the def init ion of the eco-environmental water demand and the framework for computing eco-environmental water demand in loess plateau,aiming at sustainable development of eco-environment.Taking Jinghe river basin in loess plateau as an example,the average yearly ecological water ewquirement for soil conservation measures is estmated as 6.5368×108m3 in 1970-1996.The research not only enriches the theory of the eco-environmental water demand,but also provides a scientific basis for the eco-environmental construction and the exploitation and utilization of water resources.
Geochemical character of rare earth elements in Longgan lake,East of China
ZHU Zhao-zhou, LIU Cong-qiang, WANG Zhong-liang, WANG Shi-lu, ZHOU Zhi-hua, LI Jun
2006, 17(6): 785-789.
Abstract:
The rare earth elements(REEs)in Longgan lake is studied by the solvent extraction or sequential extraction procedure and the Inductively coupled plasma mass spectrometry(ICP-MS)determination. The contents of the dissolved REEs in the lake vary widely from 35.14 to 129.81 ng/kg. The dissolved REEs have a flat shale-normalized pattern,this is because the dissolved REEs are mainly presence in the fine colloidal phase(as a result of 0.22μm filtration)in a macrophyte lake. The amount of REEs in the sequential extracted four fractions obeys the following order:residual>bound Fe-Mn oxides>>adsorbed-exchangeable-carbonate(AEC)or bound organic matter. The partitioning characteristics of REEs in the suspended matter are quite similar,with the main amount in residual forms. The normalized patterns of REEs in AEC,bound organic matter and Fe-Mn oxides are same,with middle REEs enrichment,but the residual forms have a flat pattern. The middle REEs are more difficult to be transferred than other REEs in the water of Longgan lake,but these have more potential activities.
Hyperspectral model for transparency of Chagan lake in semi-arid environment of Songnen plain
SONG Kai-shan, ZHANG Bai, WANG Zong-ming, DUAN Hong-tao, ZHANG Yuanzhi, LI Fang
2006, 17(6): 790-796.
Abstract:
The transparency,which can demonstrate the limpid or muddy degree of lake water also be used to evaluate water eutrophic state,is one of the water body visible degree indicators.The traditional transparency of surface water is observed with Secchi Disk.It is time-consuming and strenuous,and only represents some local information. The remote sensing technology, which can cover large area simultaneously and periodically,may deal with this kind of limitation effectively. In this paper,77 spectral reflectance data of different water sites in Chagan lake were collected during 6 field works,and the water transparency data were acquired simultaneously. the linear regression constructed with every single band of reflectance and derivative against the water transparency data;the band ratio model with the reflectance of 780 nm and 654 nm also established.Finally,ANN-BP model is established with diagnostic band reflectance and derivative as the input vector.The result shows that water trans-parency has an intimate relation with water reflectance,and correlation coefficient is about 0.5 in blue and green spectral region, it is about 0.6 in red spectral region;while it obtains the maximum value in short wave of near infrared region. As for derivative reflectance,it also obtains higher value in near infrared spectral region.The regression model established with single band gets the similar performance as that with band ratio as regression dependent variable. By comparison,the ANN-BP model performed best with determination coefficient(R2)of 0.98. It indicates that hyperspectral remote sensing models established for estimation Chagan lake water transparency can obtain the comparatively accurate result. The construction of hyperspectral models in Chagan lake will to help estimate the water body transparency with satellite images,and also provide a method for remote sensing monitoring of other inner water body with similar water status as that in Chagan lake.
Modeling solute transport in heterogeneous soil column using continuous time random walk
XIONG Yun-wu, HUANG Guan-hua, HUANG Quan-zhong
2006, 17(6): 797-802.
Abstract:
Solute transport in heterogeneous media always occurs in the non-Fickian process with early arrival and long-tail. We analyze the data of the breakthrough curves(BTCs)measured in a 1 250 cm long heterogeneous soil column with the continuous time random walk(CTRW)and the advection-dispersion equation(ADE). It is found that Fickian behavior occurs in the transport at the distances from the inlet to 100 cm with a β value larger than 2,which is attributable to relatively homogeneous packing. Within the distances from 200 cm to 700 cm,the transport has significant non-Fickian behavior with β=0.915±0.024,this is due to the highly heterogeneity when packing the column. While the moderate non-Fickian transport isfound within the distances from 800 cm to 1200cm,and theβvalue is 1.19±0.0691 Compared with the dispersion coefficient of ADE,βvalue is relative stable. Better simulation results are also obtained especially for the tails of BTCs by using CTRW with respect to ADE. It implies that CTRW is a useful method to describe the scale-dependent transport and non-Fickian trans-port.
Coupled reaction-transport simulation of U(Ⅵ) migration in groundwater at the uranium mill-tailing site and the analysis of the parameter
XIE Shui-bo, LIU Qi, ZHANG Xiao-jian, CHEN Ze-ang, LI Shi-you
2006, 17(6): 803-807.
Abstract:
Based on the analysis of the historical data of the uranium mill-tailing site in southern China,the actual conditions are generalized,and a coupled reaction-transport numerical model is set up to simulate the representative radionuclide-uranium (Ⅵ)adopting the PHREEQC-Ⅱ code. This work is carried out with the various parameters such as dispersion coefficient,the diffuse coefficient,pH,the mixratio,and the retardation coefficient. The sensitivities for the parameters are also analyzed in this paper. The results of this simulation accord with the actual information observed on site1 So the simulation,which can be a reference for analogical research,can provide theoretical base for environment assessment and treatment after the decommis-sion of uranium mill-tailing sites.
Calculating method for wellhead protection zoning:Krijgsman-Lobo-Ferreira method and its application to Zhangji area,Xuzhou city
MAO Yuan-yuan, WANG Lian-sheng, FANG Rui, JP Lobo Ferreira, Manuel M. Oliveira
2006, 17(6): 808-811.
Abstract:
In this paper,A method for delineating wellhead protection areas,Krijgsman-Lobo-Ferreira method,is introduced and the formulas for calculating the protection distances of upgradient,downgradient and perpendicular to the direction of the groundwater flow are derived. The applicability and some complications about the formulas are also discussed. The method is applied to Zhangji area,Xuzhou city. The results show that it is a simple and effective method for identifying the wellhead protection area,and can be applied to other areas in China.
Fractal dimensionality dependence of microstructural parameters and permeability in fractal porous media
LIU Jun-liang, TIAN Chang-an, ZENG Yan-wei, DONG Biao
2006, 17(6): 812-817.
Abstract:
According to the fundamental notions of the fractal geometry,the rigorous relationships between the fractal dimen-sionality and the microstructural parameters including porosity as well as permeability in random fractal porous media are established in the present paper. The physical significances of microstructural characteristics,the cumulative pore number-size distribution and the porosity formula of the fractal porous media are discussed in detail using the model of the Sierpinski solid and the pore mass fractals In addition,the permeability-fractal dimensionality relat ionships built up on two different models and their dif erences are quantitatively analyzed.
Water cycle in substrate-vegetation-atmosphere system of rock slope
SUN Hai-long, LI Shao-cai, YANG Zhi-rong, HE Lei, CUI Bao-shan
2006, 17(6): 818-823.
Abstract:
The substrate-vegetation system is the primary functional component of eco-engineering for the rock slope protection. The water cycle in the system can influence the engineering and achievement. In this paper,Festuca arundinacea Schreb is selected to study water cycle in substrate-vegetation-atmosphere system with the time domain reflector to investigate in situ for one year stimulating slope with the different surface treatments and the different gradients. The results show that the gradient is the main limiting factor of water cycle in substrate-vegetation-atmosphere system. A rise in gradient leads to a decrease in the actual precipitation receiption of slope and a change in substrate water input. The evapotranspiration from the system decreases with the gradient improving,but the rangeability is small. Under weather conditions of the experiment area,the natural precipitation is sufficient for the vegetation with slopes of 45° and 60°,whereas deficient for the vegetation on a slope of 75°. Runoff happens when the substrate is fully filled with water due to its favorable moisture physical properties. The effect of the precipitation characteristics and the water content of the initial stages in the substrate on the process of runoff is small. Under the same space-time condition,water content in the substrate varies slightly in different treatments. They fallow in the order of spraying concrete slope>limestone>sandstone. The modified engineering measurements of eco-engineering are suggested from the point of water cycle,and provide necessary technical and theoretical support.
World’s greatest known point rainfalls and their enveloping curve formula
WANG Guo-an, LI Bao-guo, WANG Jun-liang
2006, 17(6): 824-829.
Abstract:
This article presents a large number of extreme values of the point rainfalls around the world and derive a new envelope curve formula for enveloping the world's greatest known point rainfalls,R=491D0.452 (R is the rain,D is the duration of rainfal).In the end,it gives a brief explanat ion to characterize the regional distribution of the world's greatest point rainfalls, the causes of storms and the use of extreme values point storms in the probable maximum precipitation estimation.
Spatial-temporal change of 20 cm pan evaporation over the Yangtze River basin
WANG Yan-jun, JIANG Tong, XU Chong-yu
2006, 17(6): 830-833.
Abstract:
This paper andyzes the trends of 20 cm pan evaporation over the Yangtze River basin from 1951 to 2000 using Mann-Kendall trend test and IDW interpolation methods.The significant negative trends of annual,summer and autumn pan evaporation characterize the trends of pan evaporation since 1951,especially in the 1990s. The annual and summer pan evaporation in the 1990s is the lowest for the recent 50 years;the annual and summer pan evaporation anomalies in the 1990s are -25.9 mm and -36.1 mm,respectively. But this trend is much more significant in the middle and lower reaches than that in the upper reaches in the Yangtze River basin,especially in the Poyanghu basin.
Remote sensing model for evapotranspriation over the eastern part of northwest China using satellite data retrieval
CHEN Tian-yu, CHEN Qian, LI Bao-zi
2006, 17(6): 834-840.
Abstract:
In this study,a satellite remote sensing model of deducting sensible heat from surface energy balance algorithm for land(SEBAL)is used. The regional distribution maps of the daily evapotranspiration(ET)during April to August over the eastern part of Northwest China(33-38°N,102-108°E)is estimated,combining NOAA-16 AVHRR data with the microme teorological observations over a wheat field at Dingxi arid meteorological and ecological environment experimental station and regular observations data of 127 weather stations. Based on land use,we evalute the average and standard deviat ion of the de rived ET for irrigate fields,short grass,spring and winter wheat rainfed fields,pine and broadleaf forest,evergreen forest and marsh fields. It is shown that the ET distribution feature is decreasing from the south humid evergreen forest though the semiarid rainfed agriculture region to the north arid desert during the variant plants growing periods. The mean relative error (MRE)is 16.6% evaluated through the derived ET and the measured values estimated using the evaporation dish at 54 stations. The MRE is only 16.2% between the derived results and the measured of L1 7500 CO2/H2O gas analyzer at Dingxi station The results show that the derived results is in good agreement with measured values over experimental regions.
Application of cluster computing in the digital watershed model
LI Tie-jian, LIU Jia-hong, HE Yang, WANG Guang-qian
2006, 17(6): 841-846.
Abstract:
With the development of the computing technology,the high performance/price ratio parallel computing,represented by the Message Passing Interface(MPI)standard,is applied widely to the more traditional professional fields. The massive computing is required since that the digital watershed model discussed in this paper is aimed to simulate the distributed hydrological and sediment process in a large-scale watershed. The parallel computing of the digital watershed model has its proper advantage including the cell partition mode based on the watershed division and the technical coding method of the drainage network. This paper presents a typical parallel scheduling flow to accomplish dynamically task assignment in rainfall-runoff and discharge routing computing. The application experiment on the MPI computing cluster constructed in this paper indicates that the cluster computing improves the computing efficiency of the digital watershed model. The paper presents the future development of this cluster computing flat as well.
Application of a coupled atmospheric-hydrological modeling system to real-time flood forecast
LU Gui-hua, WU Zhi-yong, LEI Wen, ZHANG Jian-yun
2006, 17(6): 847-852.
Abstract:
A coupled atmospheric-hydrological modeling system is established over the Huaihe River Basin for predicting severe precipitation and real-time flood forecast. This system is the high-resolution regional atmospheric MC2(Canadian Mesoscale Compressible Community)model that is one-way coupled to the Xinanjiang hydrological model. The system was tested for the July 4 to 15,2005 severe flood event in real-time over the basin. The MC2 precipitation is first evaluated using observations from rain gauges over the Wangjiaba sub-region. The Xinanjiang model flood forecast is then validated with the observed hydrograph at the Wangjiaba Station. MC2 performs reasonably well in predicting severe precipitation with the forecast lead time up to 96-h. The flood forecast using MC2 precipitation shows a good result of flood timing and peak discharges at the Wangjiaba Station. The encouraging result obtained in this study demonstrates the potential of using mesoscale model precipitation for real-time flood forecast,which provides a longer flood lead time compared to many traditional methods.
Impacts of environmental change on runoff in Fenhe river basin of the middle Yellow River
WANG Guo-qing, ZHANG Jian-yun, HE Rui-min
2006, 17(6): 853-858.
Abstract:
Runoff in many rivers in China have presented decreasing trend over the past decades. How to identify the effects of climate change and human activities in the trend variation are a current hot topic,a difficulty problem as well. An assessment method to quantitatively distinguish the effects of climate change and human activities was put forward in the paper. SIMHYD rainfall runoff model was briefly introduced and calibrated with "natural" hydro-meteorological data in Fenhe River basin. Based on simulation of natural runoff in human-disturbed period with hydrological model,causes of runoff variation were analyzed. And results show that SIMHYD rainfall runoff model has good performance for natural monthly discharge simulation. On average,35.9% and 64.1% of total annual runoff reduction from 1970-1999 were induced by climate change and human activities respectively. Human activities are main reasons of runoff reduction in Fenhe River basin.
Deduction of symbolic target for regional water resources and water environmental protection
LIU Ning
2006, 17(6): 859-864.
Abstract:
The paper discusses the protection and treatment research concept of the regional water resources and the water environment protection based on the water-based system,and establishes the definition of the symbolic target for the evolvement of acertain size water-based system which is durative,disciplinary and variable. The author sets up the water usage and drainage control relation for the regional water resources and water environment based on water resources and water environment’s holding capacity,develops the framework of learning and training for the water quantity and water quality coupled process and the adjusting effect of water price by applying the brainpower method of the BP artificial neural network,and then,explores the steps and methods to decide the symbolic target of the protection and the treatment of the regional water resources and water environment.
A case study on the evolutionary law of water resources in Sanchuan river basin
QIU Ya-qin, ZHOU Zu-hao, JIA Yang-wen, QING Da-yong, WANG Hao, YAN Deng-hua, JIANG Nai-qian, WANG Guo-qing
2006, 17(6): 865-872.
Abstract:
We apply the distributed hydrological model(WEP-L model)with physical mechanism to simulate hydrological cycle under the different conditions of Sanchuanhe basin as a case study,and analyze the quantitative influence of the different factors such as precipitation,water use and underlying surface on the evolution of water resources on the basis. Eight cases are described:Case I,the precipitation data in 1956-1979,the underlying surface data in 2000 and the zero water use;case 2,the precipitation data in 1980-2000,the underlying surface data in 2000 and the zero water use;case 3,the precipitation data in 1956-2000,the underlying surface data in 2000 and the zero water use;case 4,the precipitation data in 1956-2000,the underlying surface data in 2000 and the real water use;case 5,the precipitation data in 1956-2000,the underlying surface data in 1956-2000 and the zero water use;case 6,the precipitation data in 1956-2000,the underlying surface data in 2000 and the zero water use;case 7,the precipitation data in 1956-1979,the underlying surface data in 1956-1979 and the zero water use;and Case 8,the precipitation data in 1980-2000,the underlying surface data in 2000 and the real water use. The comparison of case 1 and case 2 show that 4.5% reduction of precipitation causes the decrease in water resources in all forms:18.4% surface water resources and groundwater resources,15.8% not overlapped with surface water resources,18.3% special water resources,2.1% precipitation effective utilization and 4.6% general water resources. In case 4,the surface water resources reduce by 4.6% but the not-overlapped groundwater resources and surface water increase by 113.5%,and the special water resources decrease by 0.4% but the general water resources increase by 0.7%,and 0.9% increase of the precipitation effective utilization compared with that in case 4. Comparing with the water resources in case 5,the special water resources decrease by 4.3% with 4.3% and 2.8% decrease of not-overlapped surface water resources and groundwater resources,while the general water resources increase by 5.13% with 7.1% increase of the precipitation effective utilization in case 6. In case 8,the general water resources decrease by 25.8% with 30.6% decrease of surface water and 114.5% increase of not-overlapped the groundwater and surface water,and the precipitation effective utilization and the general water resources increase by 7.1% and 5.3% compared with that in case 7. The research achievement can be referenced in other basins.
3-D particle tracer model and its application in Jiaonan sea area
ZHANG Xue-qing, SUN Ying-lan
2006, 17(6): 873-876.
Abstract:
Considering the intertidal belt in the estuary and coastal sea area,a variable boundary mass transport model is needed. In this paper,based on the established ECOM model,a variable boundary particle tracer model is developed,and is applied in Jiaonan sea area. This paper discusses the transfer character of the particle forced by M2 tide in 3-D space. This model can be applied to the management of the marine environment in the estuary and coastal sea area.
Ground resistivity technique measurement for ice jam early warning at freeze-up period of the Yellow River
CONG Pei-tong, WANG Rui-lan, LI Cui-xia
2006, 17(6): 877-880.
Abstract:
The terrain landform and the topographic feature in the Yellow River val ey vary considerably. Affected by the cold air flow from the areas of Siberia and Mongolia,the noteworthy icing arises to various extents in the main and branch streams in winter and spring. The fierce violence of the formed ice jam flooding and abruptness in increment of water level could easily result in crevasse and cause natural calamity. It is,therefore,very important to carry out studies on ice jam early warning system. The amount of ice flows under the ice cover and the growth of ice bodies in the freeze up period of the Yellow River are the key factors for the Yellow River ice jam early warning In the study,we measure the two phase resistivity of ice water with the ground resistivity measurement technology,plot the resistivity diagrams,digitalize the parameters of the ice jam formation, and the evaluate the growth of ice bodies and the accumulation of ice bulks,which provides valuable information for the ice jam protection and the natural disaster reduction. The results indicate that,at the stable stage of ice flow,the threshold is around 10Ω·m fol owing the decomposition of the resistivity cure by wavelet analysis During partial blockage of ice jam,the threshold increases up to about 100Ω·m. The apparent difference in the thresholds can be a criterion for judging the ice jam early warning. A practical method for ice jam early warning is,therefore,proposed the based on dif erences shown on the ground resistivity curves.
Instabilities of free surface in open-channel flows and development of roll waves
WANG Yu-hai, YU Guo-hua, HU Yan-jun
2006, 17(6): 881-886.
Abstract:
Roll wave often develops as the free surface loses its stability in an open-channel steady,uniform flow. They can bring about a series of unfavorable affects,such as the spilling,the mixing gas,the excessive pressure or the stress on hydraulic engineering projects,etc. Roll waves have the characteristics of shallow long waves. Considerable progresses are made in terms of theoretical,experimental and numerical studies by using the shallow-water equations. To build better mathematical model needs to takes into account viscosity,the vertical velocity acceleration,the shock profile,etc. and study the occurrence and evolution of the roll waves in sedimentladen flow over the movable bed(including bed deformation).It is of great importance in engineering practice and theoretical research.
Review of river system in responses to flow and sediment regime variation
SUN Zhao-hua, LI Yi-tian, HUANG Ying
2006, 17(6): 887-893.
Abstract:
As the anthropogenic disturbance on large river systems become common,the riverine function's degradation is of ten mentioned in the contemporary river management studies and form one of the major challenges in the fields of watershed exploitation. This paper intends to review the current status of the river system adjustment mechanism. The discussion starts with the analysis of the characteristic of the interact ion between water-sediment regime and river system adjustment,including hydro-hydraulic character and geo-ecosyste. It gives us the description that the different changes of a river system are the reflections of the certain variation of a water sediment regime. The paper then reviews the process of the recognition of the riverine functions and focuses on the techniques to estimate river systems in response to the changing inputs. The paper finally gives some suggestions to advance the research and achieve the higher levels of the water-sediment regulation of the sustainable river management.
Advances in research on soil moisture probability density functions obtained from models for stochastic soil moisture dynamics
LIU Hu, ZHAO Wen-Zhi
2006, 17(6): 894-904.
Abstract:
This paper reviews on several typical models for the stochast ic soil moisture dynamics and the corresponding soil moisture probability density functions(PDFs)derived analyticaly,and analyses the effects of random fluctuations,climates, soil,plants and terrain characteristics on soil moisture PDFs based on the modeling results Meanwhile,some experiments are cited in the paper to validate the results obtained from the models. It is showed that the soil moisture PDFs,which response remarkably to all those mentioned factors,is an instrumental tool for revealing soil moisture dynamics and explaining ecohy drolical phenomena. The last part of this paper suggests areas worthy of further research:developing more realistic stochastic models,quantitative describing water stress on plants with stochastic models;coupling soil moisture dynamics and nutrient dynamics,and building soil moisture PDFs for a region and directing the related eco hydrolical work and research with the estab lished soil moisture PDFs.