• 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

2005 Vol. 16, No. 1

Display Method:
Experimental study on influences of sediment-laden flow with wide sediment concentration range on channel metamorphosis
ZHANG Ou-yang, MA Huai-bao, ZHANG Hong-wu, DONG Zhan-di, XU Xiang-zhou
2005, 16(1): 1-6.
Abstract:
River metamorphosis caused by river regime is one of the most important issues in fluvial geomorphology.In this issue,Schumm has proposed a famous qualitative relation.But the relation is quite different in China when it is applied to hyper-concentrated flows.To resolve this controversy,a process-response model experiment using secondary deposited loess with the median diameter of about 0.042mm as well as with a wide sediment concentration range conducted in an 11m×3m flume.The experimental results show that sediment-laden flows with the different sediment concentrations have different behaviors in fill-scour and the ways of channel adjustment.Because of the existence of the hyper-concentrated flow,the sediment-laden flow needs less energy dissipation to transport sediment.Therefore,the variations of the channel form exhibit complex relations with those of the sediment concentration.When the sediment concentration is low,the ratio of the width to the depth of the channel will increase and when it increases to a certain degree to the field of hyper-concentrated flow,the width-to-depth ratio will decrease with the increase of sediment concentration.So does the sinuosity.Thus,according to the experimental results and some case studies about the range of non-hyper-concentrated flow in China,Schumm's relation is correct and available,but to hyper-concentrated flow,Schumm's relation should be modified.
Study on the separation zone in open-channel junction
MAO Ze-yu, ZHAO Sheng-wei, LUO Sheng, ZHANG Lei
2005, 16(1): 7-12.
Abstract:
The separation zone develops immediately downstream of the open-channel junction when branch flow enters,resulting in contraction of channel cross-section This particular hydraulic characteristic influences significantly the local sedimentary processes,channel scour and sidewall erosion Based upon the experimental investigation and theoretical analysis,the shape and size of the separation zone are studied,and the formulations for both contraction coefficient and energy loss coefficients are presented,together with the comparisons with experiment results Both the analytical solutions and the experiment results indicate that for the given junction angle the shape of the zone remains essentially const ant The fine relationships show the both width and the length of the separation zone increase either as discharge ratio or junction angle increases.
Experiments on characteristic of vertical diffusion in open-channel stratified shear flows
CHU Ke-jian, HUA Zu-lin, WANG Hui-min, XING Ling-hang, ZHANG Hong-xing
2005, 16(1): 13-17.
Abstract:
Experiments to determination the vertical diffusion in the thermally stratified shear flows in open-channel are described in this paper.The mixing intensity and the interfacial vertical thermal diffusion coefficient near the outlet are analyzed based on the experimental data.The results indicate that apparent difference exists among the running modes of the mixed intensity according to the different fluid states and the different relative positions,the vertical thermal diffusion coefficient is proportional to the mixed intensity and exponential to the outflow densimetric Froude number.The experimental formula is put forward about vertical thermal diffusion coefficient,the mixed intensity and the outflow densimetric Froude number.
Energy dissipation and hydraulics characteristics of multi-horizontal submerged jets
ZHANG Jian-min, WANG Yu-rong, YANG Yong-quan, XU Wei-lin, LI Yan-ling, ZENG Xiong-hui, CHENG Hao
2005, 16(1): 18-22.
Abstract:
In this paper,the multi-horizontal submerged jets(MHSJ),a good design of energy dissipation,is presented.The MHSJ comes into being by the special ways with horizontal and parallel jets and a needed distance to the bottom of bed when jets enter into the still downstream basin.In this arrangement,the number of strong stress and the turbulence among water surface,the high speed flow and the bottom of basin are twice more than enlarge or shorten jump.Therefore,the MHSJ is a kind of efficient energy dissipation in the term of making use of the strong stress and the 3-D turbulence vortexes.The hydraulic characteristics and dissipated energy ratio are studied theoretically,and the formula to calculate the conjugate water depth and energy dissipated ratio are obtained.These results show that the MSBJ is a good dissipation energy type with less local precipitation,more dissipated energy rate,well applicability,and wide practicability.
Computation of resistance coefficient and conveyance capacity in compound channels
YANG Ke-jun, CAO Shu-you, LIU Xing-nian
2005, 16(1): 23-27.
Abstract:
Stage-discharge curves are particularly important in river basin management.For compound channel,it is difficult to produce the stage-discharge curve.In computing conveyance capacity,adopting either the single channel method or the conventional divided cross section method will result in enormous error.In this paper,a compound channel is divided into four subregions:the flood-plain-side-slope region,the flood-plain region,the main-channel-side-slope region and the main-channel region.By analyzing a large numbers of experimental data from the Science and Engineering Research Council Flood Channel Facility(SERC-FCF),the Darcy-Weisbach resistance coefficient relationships among them are established.The experimental data from SERC-FCF show that the resistance coefficient in main-channel region is related to the relative depth(Dr),the ratio between the resistance coefficient in flood-plain region and that in main-channel region varies exponentially with Dr,and the resistance coefficients in flood-plain-side-slope region and the main- channel-side-slope region can be expressed by those of the flood-plain region and the main-channel region.Finally,by computing the discharge in every sub region on the basis of the resistance coefficient relationships,the total discharge can be obtained.The experimental data show that the computed discharge is in close agreement with the measured one.
Discussion of velocity distribution and resistance under ice cover
WANG Jun
2005, 16(1): 28-31.
Abstract:
It is very import ant to calculating the flow resistance and to confirm the velocity distribution under ice cover or ice jam.Many researches have been made for many years to suppose the mean velocity of flow sections is equal to that of the ice cover area and that of the bed area,and the validity of such assumption is argued in this paper based on the Prandtal's semiempiristic turbulence theory and the formula of velocity of logarithm distribution.And it is also found that falsehood would be induced in calculating flow resistance in shallow rivers based on the assumption that the slope of energy in the ice cover area is equal to that in the bed area And the ways and means are proposed.
Application of artificial neural network to numerical wave prediction
QI Yi-quan, ZHANG Zhi-xu, LI Chi-wei, LI Yok-sheung, SHI Ping
2005, 16(1): 32-35.
Abstract:
The objective of this paper is to use an artificial neural network(ANN) model to train the output of a third generation wave model to better forecast the significant wave heights from buoy data.After training,the agreement between the wave model's output and the buoy data generally increases,but there is still significant disagreement when the wave height is at its peak.The significant wave heights bigger than 1.5m are selected to retrain,using the same ANN model,and the resulting improvement in the forecast is obvious since the root mean square error(RMS) between the ANN output and the buoy data decrease from 0.31 m to 0.29 m.The goal of this paper is to investigate the feasibility of using an ANN to improve a wave model's numerical wave prediction so as to develop a more accurate wave forecasting system.The results show that an ANN is an useful tool for this purpose.
Improved numerical model for nearshore wave breaking
LI Shao-wu, LI Chun-ying, GU Han-bin, SHI Zhong
2005, 16(1): 36-41.
Abstract:
This paper aims at proposing an improved numerical model based on the full nonlinear Boussinesq equations for simulating wave breaking in the surf zone.A new formula is proposed based on the concept of surface roller to determine the production term in the k equation of turbulent model.Consequently the eddy viscosity in the Boussinesq equations,which gives the attenuation effect of the waves in the surf zone,can be calculated by solving the k equation.The slot method is used in the model to simulate wave movement in the swash zone.The model is verified by the experimental data in terms of wave height and setup and setdown.Comparison of modeled results with measurements shows a reasonable agreement Modeled results of the turbulent production,the turbulent energy and the dissipation rate of turbulent energy indicate:(1) the turbulent production peaks at the breaking point and decreases gradually as the wave approaches the shoreline;(2) at the incipient regime of wave breaking,the advection and the diffusion effects play an important role in the transport process of the turbulent energy; and(3) as waves approach the shoreline,the turbulent production and the dissipation are almost balanced each other.
Long term distribution of disaster-caused typhoon storm surges in the coastal area
DONG Sheng, HAO Xiao-li, LI Feng, LIU De-fu
2005, 16(1): 42-46.
Abstract:
On the basis of observed tide level and the wave height series sampled from typhoon processes in Qingdao area since 1949,a Poisson Bi-variable Gumbel Logistic distribution(PBGL) is put forward for statistical analysis of storm events.The PBGL model,different from the traditional warning stage method,is more capable of describing the combined effect of environmental loads,such as tide level and the concomitant wave height.The return periods are estimated for several most serious typhoons occurring in the mentioned coastal area.The results indicate that the proposed model will be suitable for representing the joint probability distribution of correlated water level and wave heights occurring in typhoon processes.The final conclusions are presented for reference when the government departments make a storm-prevention program.
Numerical simulation of scouring on bedrock
DENG Jun, XU Wei-lin, YANG Zhong-chao, QU Jin-xue
2005, 16(1): 47-51.
Abstract:
The problem about scouring on bedrock is one of important issue in hydraulics engineering.In order to know about the probability of numerical simulation of scouring on river bed,experiments are done; a set of mathematical model is developed; and the scouring on bedrock is simulated.The calculated results accord with the experimental data,which shows that the numerical simulation of scouring on bedrock is reasonable and feasible under the condition of knowing the characteristic of bedrock material.
Evolvement of water outlet of Cao’e River and its dredging
FENG Li-hua, BAO Yi-xin
2005, 16(1): 52-55.
Abstract:
The factors offecting the water out let evolvement of Cao'e River are set forth:there are some nature and artificial factors of water outlet evolvement of Cao'e River,including mainly the deflection force of earth rotation,the runoff volume,the sediment volume,the human act ivities and such like.The water outlet of Cao'e River swings frequently,which is controlled to a great extent by the change of Q iantang River s main channel and its south channel.On the condition of flood control and reclamation of the tidal flats along two banks,the optimum alignment of the water outlet of Cao'e River is northeast.The dredging principle is put forward "to guide it along its course of development and bring the river under control by means of reclamation of the tidal flats".Blocking the south channel can stabilize the alignment of Qiantang River's River to the northeastwards,which at same time can enlarge the reclamation area of the tidal flats.
Study on monitoring drought in China with MODIS product
QI Shu-hua, LI Gui-cai, WANG Chang-yao, NIU Zheng
2005, 16(1): 56-61.
Abstract:
In this paper,the 16 days' composite Normalized Difference Vegetation Index(NDVI) and 8 days' composite land surface temperature product in China are used to establish NDVI-Ts,NDVI-ΔT and NDVI-ATI space.From these spaces,temperature vegetation dryness index(TVDI),difference temperature vegetation dryness index(DTVDI) and apparent thermal inertia vegetation dryness index(AVDI) are suggested respectively to evaluate drought in every three agricultural climatic regions in China.The measured topsoil moisture is used to compare with TVDI,DTVDI and AVDI.From NDVI-ΔT spaces,we found that the wet edges are all parallel to the abscissa and the wet soil has the same power to hold back temperature change with the vegetation non-water stress.In NDVI-ATI space,ATI increases with the increase of NDVI.After we compare the measured topsoil moisture with TVDI,DTVDI and AVDI,the result shows that TVDI has a more significant linear correlation with soil moisture than the other two,and TVDI is the most promising method in monitoring drought for large region; DTVDI still has the potential on monitoring drought while AVDI is not competent for monitoring drought.
Temporal and spatial analysis of water demand of crops in Yellow River Delta based on remote sensing
PAN Zhi-qiang, LIU Gao-huan, ZHOU Cheng-hu
2005, 16(1): 62-68.
Abstract:
In this paper Yellow River Delta is selected as the research area,and the temporal and spatial analysis method for water demand of crops is brought out which based on the regional evapotranspiration(ET) retrieval using remote sensing method with the help of meteorological data.Firstly,the remote sensing method based on surface energy balance equation which is a function of net radiance flux,soil heat flux,sensible heat flux and latent heat flux is used to retrieve ET.Five NOAA AVHRR images and one landsat TM image are selected to retrieve ET from July to September of 1999,and the ET retrieval map of TM is used to improved the spatial resolution of the ET retrieval map of NOAA AVHRR,so less TM images and more NOAA AVHRR images can be used to retrieve regional ET,which can improve the practicability of ET retrieval method based on Remote Sensing.Secondly,the ET retrieved maps of the 6 images combined to the reference ET result which is computed using meteorological data are used for the temporal and spatial analysis of total water demand of crops in different irrigation regions of Yellow River Delta from July to September of 1999.
Effects of groundwater recharge using sand piles on solute transport in fallow croplands by sand tank model
YEH Yi-lung
2005, 16(1): 69-75.
Abstract:
The functions of paddy fields will shift from mere production to incorporate with ecological functions The retained water in paddy fields during fallow period can not only maintain ecological function,but also enhance soil moisture and recharge groundwater in field.In this paper,the sand tank model is used to investigate the effects of groundwater recharge with sand piles on solute transport in fallow croplands.The results show that the infiltration rate increases about 40 times with the sand piles piercing through hard pan than without sand piles.On the contrary,the sand piles also increase the solute transport rate between soil layers The effects are more conspicuous when the sand soil exists under hard pan.Therefore,the quality of irrigation water has to be inspected during retained process to prevent the soil and groundwater from being polluted.
Predicting reference evaportranspiration based on artificial neural network with genic arithmetic
CUI Yuan-lai, MA Chen-xin, SHEN Xi-zhong, MA Ji-gang
2005, 16(1): 76-81.
Abstract:
A model of Artificial Neural Network with Genic Arithmetic(GA-ANN) is established to predict reference evapotranspiration.This model integrates the merits of seeking for a global optimum solution by using genic arithmetic and the well-mapping capacity of the back propagation neural network.It can determinate the optimum model structure automatically.Eight groups of model input factors' composition are set up,and their correlative influence on the model's forecasting precision are studied.An optimum model structure for predicting short time period(daily and decade) reference evapotranspiration is present,in which only daily mean temperature,sunshine hours and the Julian day's ordinal number are considered as the input factors.A case study shows that the model overcomes the disadvantages in determinating the model structure when using back propagation neural network.And it has high precision with good adaptability and feasibility.
Adoption of water conservation practices in the society and comparison evaluation study
CHEN Ying, LIU Chang-ming, ZHAO Yong
2005, 16(1): 82-87.
Abstract:
This paper presents the recent developments in the field of water conservation that have substantial practical implications for water policies,programs,and projects.Water saving and developing water conservation society are the keys to realize both for wise water allocation and the sustainable utilization.In accordance to the scientific,practical,and simple principals,the paper sets up a hierarchy evaluation index system to estimate the advances in constructing water conservation society.Also,a comparing study is carried out in the provinces and cities in China to understand the situation and the impact on the practice of water conservation.The paper suggests that water conservation is a large systematic project that in vovles lots of sectors,industries and departments.
Water quality evaluation based on fuzzy artificial neural network
CHEN Shou-yu, LI Ya-wei
2005, 16(1): 88-91.
Abstract:
The artificial neural network(ANN) and the fuzzy recognition(FR) are all information process systems to simulate biological mechanism.And the two theories are widely applied to many fields currently.Taking each strong point into consideration,this paper proposes a fuzzy artificial neural network recognition model(FANNR) combining ANN and FR; thereby,the flexible recognition ability of the network is enhanced.Finally,the model is used to evaluate the water quality of the Tuo river,and the result shows that FANNR model is objective and practicable.
Application of extended waterbody diffusion formulate to environmental risk assessment
SHI Jian-rong
2005, 16(1): 92-102.
Abstract:
Based on various waterbody diffusion model and the strict mathematic deduction,a modeling system(quantitative estimation model) is developed to identify and estimate the harm effect on the accidents in water environment,whose contents include the identification of dangerous source,the est imation of the thick degree line of the characteristic endangered area and endangered period of an accident,and estimation of the endangered period for backward position of the accident,and the like,and the calculation of any concentration isoline's rigor time-space location and specific pot location.As the extended formulate of the various waterbody diffusion model,it has the same conditions,and is easy to use with exact results.It can be applied broadly to the dangerous engineering design and engineering insurance,the environmental risk assessment and management,the environmental impact assessment,the environmental planning,etc.
Study on carrying capacity of urban water environment
ZUO Qi-ting, MA Jun-xia, GAO Chuan-chang
2005, 16(1): 103-108.
Abstract:
In this paper,the carrying capacity of urban water resources and water environment are discussed in several aspects,such as the concept,the connotative meanings and the computation model.A computation method and the model relevant to urban water carrying capacity are put forward which are called "the Control Object Inversion Model"(COIM).including the equation of total drainage from urban area,the equations of annual runoff volume and concentration of contaminant at the control cross section,and the control objective equation,and the computation model of carrying capacity of urban water environment.With a case study of Zhengzhou city,the application of the model is presented and some countermeasures against water environment deterioration are proposed.
Study on water resources carrying capacity based on regional development goals
YAO Zhi-jun, LIU Bao-qin, GAO Ying-chun
2005, 16(1): 109-113.
Abstract:
This paper discusses and analyzes the essence of water resources carrying capacity(WRCC) of the radical carrying capacity questions.The WRCC,unlike other carrying capacity being the objective and internal value,is affected by the regional development goals,and alters under the different development goals.Accordingly,the study on WRCC must be carried out under concrete regional development goals.Therefore,this paper employs goal programming as the quantitative method of WRCC and takes Beijing as a study case,and calculates and analyzes the WRCC and goals realization under the expected development goals.The results show that the expected economic,social and environmental development goals in 2005 can not be achieved totally because of the condition restriction of water resources.The expected development goals in 2010 can be achieved basically due to the improvement of local water resources exploitation and utilization and water supply from the middle route water transfer project of the south-to-north water transfer projects,and the social and economic sizes can be consolilated by means of water resources 11 833 thousand people and 473.27 billion RMB GDP.To solve the inconsistency between water resources carrying capacity and development goals,the population,on the one hand,should be controlled; the water consumption effectiveness should be improved; and the industrial structure should be optimized.On the other hand,the expected development goals should be adjusted according to actual situation.
Systematic risk evaluation model for flood-control system
CHENG Wei-shuai, CHEN Jin
2005, 16(1): 114-120.
Abstract:
The systematic risk evaluation of flood-control system is one of the most difficult and important issues in the domain of flood-control study.According to the system reliability theory,a failure sequence of flood-control system is defined,based on which,a systematic risk evaluation model for flood-control system is established.A general method for identifying the main failure sequences is advanced in algorithm form,and the main fault tree of flood-control system is built.Moreover,according to the characteristics of the systematic risk evaluation model,the identification algorithm is improved through the effective bounding measures,and the computational efficiency is improved largely.Finally,through an example,the study shows that the systematic risk attributed to an important structure is much less than the risk of the stucture itself because of the natural risk transfer and the artificial risk transfer.
Analysis of ice-flood in Sikeshu River basin on the north slope of Xinjiang Tianshan mountain
JIA Bing, LIU Zhi-hui, MAO Hua-sheng
2005, 16(1): 121-126.
Abstract:
Sikeshu River on the north slope of Xinjiang Tianshan mountain is a calamitous river.Besides summer flood the bursting ice-flood causing disaster in the winter is more remarkable.Starting with the analysis of its condition of physical geography,this paper elaborates the particular characteristics of the ice-flood,and analyzes the cause of formation of ice-flood combined with air temperature and terrain factors.Formation of ice-flood is related to the changes of air temperature and terrain When air temperature rise gradually or suddenly,the force of combination of ice-dam framework decline.While the water pressure caused by ice-dam exceed the support force of ice-dam framework,a certain loose ice-dam of the upper reach burst,ice-water flow swift to the lower reach,thus brought out a series of collapsed ice-dam and forming ice-flood.Moreover,the ice-flood evolvement and the reasons of the notable difference of ice-flood volume,nonuniformity of annual change of ice-flood and no ice-flood in stable period of ice-cover or melting period etc are also analyzed.
Vertical water cycle and its ecological effect in inland basins,Northwest China
ZHOU Ai-guo, MA Rui, ZHANG Chen
2005, 16(1): 127-133.
Abstract:
The inland basins in northwest China are of the four great regions short of hydrological cycles in China.By the vertical circle in the water saturation,the water in aeration zone,the water in aerosphere near surface,and the water in plant body(‘Four Waters'),the groundwater systems have indispensable adjective effects on maintaining the balance among water,heat and salt in shallow surface,the surface ecological balance,the long-term availability of soil resources and the relative stability of the local climate.At present,the related study pays more attention to the statistical analysis of corresponding relation-ship between groundwater and vegetation types,but less to the mechanism of water fluxion.Although more and more research on soil-plant-atmosphere continuum(SPAC) system has been carried out,little improvement has been achieved in the ecological effect of groundwater because of the hard scale-transform and the ignorance of the effect of groundwater in simulation.In contrast to SPAC system,the groundwater-soil-plant-atmosphere continuum(GSPAC) system is more integrated.To make clear the ecological effect of groundwater on arid inland basin and guide the exploitation of water resources,such studies should be carried out:(1) the dynamic course and the mechanism of the vertical circle between ‘Four Waters',especially the dynamic transition model about water,steam and heat through interface between saturated zone and aeration zone; and(2) the evolution characters of groundwater system under human activities,which is the key to the transform from microcosmic SPAC system to macroscopic water resources management.
Advances in effects of dams on river ecosystem
MAO Zhan-po, WANG Yu-chun, PENG Wen-qi, ZHOU Huai-dong
2005, 16(1): 134-140.
Abstract:
River systems are the major transport channel between land ecosystem and aquatic ecosystem,but the constructed dams fragmented the river ecosystems,that can change their physical,chemical and biological characteristics.The detail effect of the dams are reviewed on the hydrological and hydrodynamic characteristics,the nutrients transportation,the structure and functions of the river ecosystem,and the corresponding measures for the ecological restoration.With larger dames as major component of the hydrological cycle,their effects on the watershed ecosystem health is increasing.We need to study their negative effects on the ecosystem and the corresponding restoration measures.
Application of fractal theory to hydrology and water resources
ZHANG Shao-wen, WANG Wen-sheng, DING Jing, CHANG Fu-xuan
2005, 16(1): 141-146.
Abstract:
This paper deals more systematically with the application of fractal theory in many aspects to hydrology and water resources,including the structure of river network,the topography of basin,the surface geometry of river bed,the distribution of rainfall in time and space,the variation of flood in time and space,the process of runoff,the movement of ground water and infiltration.The characteristics which occur in the practice of the application of the fractal theory to hydrology and water resources shows the activity thinking and the creation in methodology for hydrology.Attention should be paid to the verification of the reasonable basis for such application based on a great deal of data.