• 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

2008 Vol. 19, No. 4

Display Method:
Influence of a nonionic surfactant on the relationships between capillary pressure and saturation in two-phase system
CHEN Jia-jun, ZHI Yin-fang, ZHENG Bing, WEI Bin
2008, 19(4): 453-459.
Abstract:
The objective of this study is to investigate the effect of a nonionic surfactant,Triton X-100(0.1%),on the capil lary pressure-saturation relationships in two-phase system.This paper sets out the relationships between the capillary pressure and the saturation of water-air and water-oil system with surfactant Triton X-100.Experimental results show that,compared with the system without surfactant,the values of capillary pressure of the system with surfactant are lower under the same saturation,which indicates that lower capillary pressure is enough to drive the same volume of wetting-phase liquid.The data fitting based on the van Genuchten model shows that,when the relationship between capillary pressure and saturation without surfactant is known,the fitting values with a scaling factor involving interfacial tension accord with the measured values for water-air system with surfactant; however,for the water-oil system with surfactant,the scaling approach making fitting values accord with the measured values dependeds on the porous media.
Estimation of non-point source pollution loading on Tongguan section of the Yellow River
LI Qiang-kun, LI Huai-en, HU Ya-wei, SUN Juan
2008, 19(4): 460-466.
Abstract:
According to the characteristics of rainfall and runoff in China's northern districts,the process of rainfall and runoff is divided into two stages in a annual:flood season and non-flood season based on the principle of the mean concentration method; meanwhile the pollution load in hyperconcentration of sediment flow will be divided into two parts:the dissolved pollution load in water and adsorbed pollution load in sediment; and the estimation model of non-point source pollution in sandy river is put forward.According to the measured water and sediment of Tongguan hydrological station in 1950-2005,combining the experiment determination water body with the sediment pollution concentration,three kinds different representatives of non-point source pollution load and the pollution load in 2006 are calculated in the Tongguan cross section.So they represent wet year(P=25%),normal year(P=50%) and dry year(P=75%) of Tongguan section.Results show that in Tongguan section the annal pollution load mostly occurs in flood season in the Yellow River,with the non-point source pollution as the main part in flood season.In the non-point source pollution load,the dissolved pollution load is taken as the main part in nitrate nitrogen and ammonia nitrogen,and the adsorbed pollution load as the main part in total nitrogen and total phos-phorus.The non-point source pollution of Tongguan section takes the proportion of the total as follows in wet year,nitrate nitrogen accounts for 63.09%,ammonia nitrogen 61.32%,total nitrogen 87.17% and total phosphorus 89.83%; in dry year,nitrate nitrogen accounts for 26.92%,ammonia nitrogen 24.62%,total nitrogen 67.60% and total phosphorus 71.73%.In 2006,the non-point source pollution load of the nitrate nitrogen,the ammonia nitrogen,the total nitrogen and the total phosphorus occupy 17%,14%,15% and 41% of the whole annual year proportion respectively.
Study on threshold of grouping sediment concentration about floods scouring and silting relative balance in the lower Yellow River
YAO Wen-yi, GAO Guo-ming
2008, 19(4): 467-474.
Abstract:
The important parameter of water sediment regulation is the threshold of grouping sediment concentration about floods scouring and silt ing relative balance in hyperconcentration river.The study on the threshold of flood grouping sediment content and incoming sediment coefficient is based on the more 200 flood data measured in the lower Yellow River The data shows that the riverbed scouring and silting can obtain relative balance when the floods have determinate grouping sediment content and incoming sediment coefficient.For the floods with the suspended sediment consisting of thin silt,the crit ical sediment content of watercourse scouring and silting are influenced by unit discharge of main riverbed,the average maximal daily discharge,the least bankful discharge in the lower Yellow River beginning from Huayuankou and the weight percentage of riverbed sediment whose median diameter d50 is bigger than 0.05mm; For those with the suspended sediment consisting of the middle coarse silt,the critical sediment content of watercourse scouring and silting is irrelative to the weight percentage of riverbed sediment whose median diameter d50 is bigger than 0.05 mm; For those with the suspended sediment formed by the coarse silt,the critical sediment content of watercourse scouring and silting are influenced by the unit discharge,the average maximal daily discharge,the least flat beach discharge in the lower Yellow River beginning from Huayuankou and the weight percentage of riverbed sediment whose median diameter d50 is less than 0.025mm and bigger than 0.05 mm The similar sediment content floods have the critical grouping incoming sediment coefficient,which means that different discharge can bring forth different scouring and silting outcome.The result can provide evidence for water-sediment regulation of Xiaolangdi reservoir on the Yellow River,and enrich the river dynamics research.
Variations of runoff and sediment load of the Jinsha river
CHEN Song-sheng, ZHANG Ou-yang, CHEN Ze-fang, PENG Wan-bing
2008, 19(4): 475-482.
Abstract:
Using statistic methods,this paper analyzes the hydrologic data,precipitation data,soil and water conservation data and reservoir data and the causes for the variations of sediment loads at different areas.The results show that the runoffs and the sediment loads of Jinsha river are originated from different source areas and the runoffs and sediment loads from different source areas have very different variation characteristics,and the effects of precipitation,soil and water conservation and reservoir on sediment production at different source areas are also different.The sediment production upstream Panzhihua is mainly caused by the freeze-thawing erosion and slope erosion,and the sediment yield is relatively low,only about 0.521×108t,and the sediment runoff modulus is about 200 t/(km2·a).But in recent years,the sediment yield increases.The area between Panzhihua and Pingshan station lies in famous fault zones with precipitous landform.There exist a lot of fracture belts,little vegetation cover and the intense neotectonic movement that loosen the surface materials.Thus,mass erosion such as the collapse,landslide and debris flow develop largely in this area.The sediment yield in this area is very large,it is 1.58×108t annually,and the sediment runoff modulus is about 2 200 t/(km2·a).From year 2001 to 2004,the sediment yield in this area largely decreases to 1.10×108t,mainly because of the soil and water conservation and sediment trapping of the reservoirs.
Experimental study on dispersion of instantaneous discharging sediment cloud in cross-flow
GU Jie, HUANG Jing, LI Chi-wai
2008, 19(4): 483-488.
Abstract:
The artificial instantaneous discharge of dredged sediments in flowing waters is usually subjected to cross-flow action In shallow waters the initial discharge and cross-flow conditions are significant for the deposition pattern.T he determination of the characteristics of this problem is thus important before environmental impact assessment can be made.In the present study,a series of laboratory experiments are carefully conducted to investigate the transport and mixing of an isolated sand cloud in cross-flow.The results show that the sediment cloud is dispersed under the forces of buoyancy,gravity,drag force and turbulence of cross-flow The cross-flow is the main driving source for the advection of sediment cloud.The turbulence of cross-flow increases the mixing of sediment cloud and the ambient flowing water,and destroys the double vortices occurring in the stagnant water Thus the vertical frontal position and longitudinal width increase The analysis of experimental data gives the empirical constants and their variance,which can be used to determine the relationships of non-dimensional vertical frontal position and time,longitudinal width and time,and vert ical frontal position and longitudinal width All these results can be used to assess the environmental impact of dumping projects.
Study of the measurement of suspended sediment concentration based on pulse-coherent acoustic doppler profiler observation
BAI Xiu-fang, GONG De-jun, XU Yong-ping, LI Si-ren
2008, 19(4): 489-493.
Abstract:
In order to investigate the suitability of using pulse-coherent acoustic Doppler profiler(PCADP) to estimate suspended sediment concentration(SSC),the acoustic backscatter intensity was corrected for spreading and absorption losses,then calibrated with OBS,finally converted to SSC.The results show that there is good correlation with R equal to 0.74 between SSC and backscatter intensity.The mean relative error is 22.4%.Then the time span of little particle size variation was analyzed to exclude the influence of size variation.The correlation improves with R equal to 0.81 and the error decreases to 18.9%.It can be seen that PCADP estimating SSC can reach the requirement of professional instruments with the precision of 20% to 50%,and can meet the need of dynamics study.
Effects of chemical agents on the overlying water during in-situ sediment treatment
ZOU Lian-pei, ZHANG Ping, QIAN Guang-ren
2008, 19(4): 494-499.
Abstract:
The zero valent iron(Fe0) or calcium nitrate was added into the sediment of Suzhou creck for 80 days in the anaer obic environment for in-situ sediment treatment.The effects of chemical agents on the overlying water were studied by DO,pH,Eh,CODCr and TOC measurements.The results show that DO is depleted dramatically by Fe0 added,resulting in anaero bic environment easily,whereas the consumption of DO is delayed by the added calcium nitrate.And Fe0 or calcium nitrate added will raise pH value and descend Eh value.Meanwhile,the effect on CODCr or TOC in overlying water by Fe0 added is lower than that of the calcium nitrate added.In addition,there are certain relations among DO,pH and Eh or between CODCr and TOC in overlying water as Fe0 or calcium nitrate is added respectively.
Advection-diffusion models establishment of water-pollution accident in middle and lower reaches of Hanjiang river
WANG Qing-gai, ZHAO Xiao-hong, WU Wen-jun, YANG Mu-shui, MA Qiang, LIU Kun
2008, 19(4): 500-504.
Abstract:
Based on the sub-models of MIKE 11 model Rainfall-Runoff model(RR model),Hydrodynamic model(HD model),Advection-Diffusion model(AD model),the corresponding three models used for the middle and lower reaches of Hanjiang river are established.Through the coefficients calibration and the model verification,the models receive a better simulation.The diffusing and moving processes of pollutants from the burst water-pollution accidents are timely simulated by using the above established models under the different hydrological status in winter and summer of 2003.These models can quantitatively predict the reaching time and concentrations of pollutants at any places in the middle and lower of Hanjiang river when water-pollution accidents burst out.
Annual maximum flood occurrence dates and magnitudes frequency analysis based on bivariate joint distribution
FANG Bin, GUO Sheng-lian, XIAO Yi, LIU Pan, WU Jian
2008, 19(4): 505-511.
Abstract:
Annual maximum flood occurrence dates and magnitudes both can provide important information for the hydraulic engineering design and the reservoir operation.The existing literatures only consider the distribution of flood magnitudes,but ignors the flood occurrence dates.In this paper,Von Mises distribution and Pearson Type Ⅲ distribution are used to describe the occurrence dates and magnitudes of annual maximum flood respectively.A bivariate joint distribution with Von Mises distribution and Pearson Type Ⅲ distribution margins is developed based on the Gumbel Archimedean Copula and used to describe the annual maximum flood series.The approaches for calculating conditional probability,joint probability and bivariate return period are presented.Case study shows that the bivariate joint distribution can fit both occurrence dates and magnitudes of annual maximum flood series well.It can mine more flood information and provide a new way for flood frequency analysis.
Sustainable development mechanism of regional water resources complex system
CONG Fang-jie, ZHOU Hui-cheng
2008, 19(4): 512-518.
Abstract:
The regional water resources complex system develops with S-type pattern,so the process can be described with Logistic curve(L-curve) and Gompertz curve(G-curve).The analysis of differential eguations shows that the growth period and the golden period of L-curve,and the growth-period,the golden-period and the autumn-period of G-curve are the sustainable development period.The analysis of diffefence equation of L-curve shows that the development speed is the key factor for the sustainable water resources utilization Lower speed will obstruct the society development,and higher speed can lead to the unsustainable development Furthermore,the process of the sustainable development can be described with combined S-type curve,which contains the start period,growth period and golden period of L-curve and G-curve.At the end,a fitting is made with an example,and the result shows that the development processes of Dalian water resources complex system and Yantai water resources complex system from 1996 to 2005 are both the combined L-curve with two layers.
Analysis of dynamic characteristics for the regional water resources system
XU Jian-xin, HAO Zhi-bin, JIANG Xiao-hui, GAO Feng, SHANG Chong-ju
2008, 19(4): 519-524.
Abstract:
The dynamic characteristics for water resources system of water receiving district in Henan province of the middle route project of south-to-north water transfer is analyzed in this article,the qualitative relationship between the dynamic characteristic indexes and water cycle in each subsystem is given,and the fractal characteristic,complex extent and evolution rules are revealed.The results show that there are obvious fractal structure and chaotic characters in the system,which is the non-liner and there is a strange attractor during evolution,and its opening extent and resistance capacity reduce gradually from the water cycle system of precipitation-surface water-groundwater-deep underground water,and it mees the normal rules of water resources system from the cycle of precipitation.surface water-groundwater.The results provide an important reference for finding chances and means to improve the behavior of the water resources system.
Experimental study on effect of water flow on seepage
XIE Li-quan, YU Yu-zhen, SHAN Hong-wei
2008, 19(4): 525-530.
Abstract:
The seepage in riverbank generally induces the bank-collapse so it is one of the key points in the research of this area.The seepage analysis now is based on the assumption that the flows inside and outside the bank slope are too slow to be considered,which ignored the fact that the flow velocity in the river is rather high,eg.2.5~4.5 m/s in the Yangtze River,China.A new experimental equipment is developed to invest igate the effect of flow velocity on the seepage in riverbank A series of tests are performed by combining various flow velocities and seepage heads.The test results indicat that the flow velocity obviously affects the seepage in the sand soil.When the seepage gradient at the seepage exit is lower than a certain value,the flow will weaken the seepage discharge; if the seepage gradient is higher than the certain value,the flow will increase the seepage discharge.The research will benefit the safety evaluation of the constructions along rivers.
High resolution two-dimensional numerical model of scalar transport based on unstructured grid finite volume method
WANG Zhi-li, LU Yong-jun, GENG Yan-fen
2008, 19(4): 531-536.
Abstract:
By the non interposition flux reconstructed and limiter,one high-order transport model is constructed based on arbitrarily unstructured shallow flow model and finite volume method.The stability and non-oscillatory condition are analyzed,its scalar transported in the circle flow is simulation,which shows that this model is of high order and non oscillatory.At last,the model simulates the salt transport of the Oujiang estuary,and the results show shat the water levels,velocity and salt are agree ment with the measured ones.
Optimal control problems in unsteady flow computation and their variational solutions
LAI Xi-jun, FU Guo-sheng, SUN Bo
2008, 19(4): 537-545.
Abstract:
Dynamical equations,observations and their statistics are all important information for presenting the states of unsteady flows.Under the framework of inverse problems,a variational model is developed to fuse all available information for improving the computation of unsteady flows.In the paper,the appropriate optimal control problems are firstly defined for controlling possible numerical errors from inaccurate initial conditions,boundary conditions and unknown physical parameters.Then,the general variational method and its numerical algorithm are suggested to solve these optimal control problems of unsteady flows.Also,we derive the adjoint equations of one-and two-dimensional shallow equations with the forms for practical purpose.It directly serves for real engineering applications.With the proposed variational model,the tidal flows in one reach of the Pearl River are investigated.Results show that the model can well reconstruct tidal flow states when data are unavailable at some boundaries,unlike the direct model.
Horizontal 2-D flow model with variable grid for simulating surges due to landslide in reservoirs
YUAN Jing, ZHANG Xiao-feng, ZHANG Wei
2008, 19(4): 546-551.
Abstract:
A horizontal 2-D numerical model in moving generalized non-orthogonal curvilinear coordinate is established to simulate surges generated by landslide in reservoirs.Comparing with the models using fixed grid,the difficulty in computing the action of the sliding mass on the water body is overcome.Taking a physical model test as an example,the numerical model is used to simulate the change process of the flow,and in the model,the action of the sliding mass on the water body is calculated by the method of variable grid,and the grid covered by the sliding mass slides down along with the sliding mass.Through the comparison between the numerical results and flume test,it is shown that the numerical results are in good agreement with the laboratory data,which indicates that the numerical model with variable grid can simulate the surge process well and offers a new method for computing and forecasting surge generated by landslide in reservoirs.
Numerical simulation of reactive solute transport in saturated column of different soils
ZHANG Cong-zhi, ZHANG Jia-bao, XU Shao-hui, ZHANG Hui
2008, 19(4): 552-558.
Abstract:
Physical chemistry reaction in saline soils has some important effect on saline solute transport,and ion exchanges are the common chemical reactions observed in soil.Indoor leaching experiment were conducted to explore effects of the two reaction solute on single component/multi-component saline solute transport.The traditional convection-dispersion equation(CDE) regardless of chemical reactions was simulated by CXTFIT,and the reaction solutes coupled with adsorption,and ion exchange were simulated by PHREEQC,a hydrologic geochemical software.Results show that soil texture has important effect on single component saline solute transport,the effects between components are important in saline solute transport,and the effect coupled physical and chemical reaction is more precise in simulation.
Variation of water and salinity in sodic saline soil during frozen-thawing season
LUO Jin-ming, DENG Wei, ZHANG Xiao-ping, LI Xiu-jun, SUN Guang-you
2008, 19(4): 559-566.
Abstract:
By the in-situ observation and analysis in the laboratory,the variation of water and salinity in micro scale(a 32 m-long transect) of sodic saline soil region are discussed during the frozen-thawing season.Results show that vast groundwater is transported and stored in the frozen layer of saline meadow soil in frozen period,which results in the significant enriched soil moisture,the moisture at 30-40 cm layer increases most obviously(increase from 20% before frozen to 50%),and the groundwater level descends abruptly from 1.2 m to 2.5 m below.The enrichment of soil moisture in sodic saline soil isn’t significant; nevertheless,salinity is enriched significantly,the enrichment degree in white crust sodic alkaline soil reaches 80%.The variation of salinity is mainly composed of the increased content of bicarbonate,carbonate,sulfate and sodium.The vastsalinity accumulat ion in surface layer results in the graduall aggravated saline degree during thawing season.
Study of water-demand regulations and water use efficiencies for water-saving rice cultivation patterns
XIAO Xin, ZHAO Yan-wen, HU Feng, SHI Guo-qing
2008, 19(4): 567-573.
Abstract:
The study of water-demand regulations and water use efficiencies(WUE) under conditions of different water-saving rice cultivation patterns were carried out through the field-scale experiments.The results show that the evapotranspiration of rice or rape reduced by a wide margin,and the water requirement and requirement intensity and coefficient at every stage change greatly with the growth regulation function and the compensation effect on crop of water-saving rice cultivation patterns.Thus,the new water requirement rules of water-saving rice cultivation patterns are formed.Compared with the conventional double cropping rice puttern,the water requirement intensities of the watersaving irrigation pattern of the double cropping rice(WSIPDCR),the flood-drought cultivation pattern of double cropping rice(FDCPDCR),and the water-saving rice cultivation pattern of rice and rape rotation(WSRCPRRR) decrease by 0.76 mm/d,1.15 mm/d and 0.71 mm/d,respectively; The leakage intensities of WSIPDCE,FDCPDCR,and WSRCPRRR decrease by 0.12 mm/d,0.16 mm/d and 0.19 mm/d,respecitively.The WUE of WSIPDC,FDCPDCR,and WSRCPRRR increase by 30.14%,47.95% and 17.81% respectively.
Variation of permeability with depth and lithology in a formation of fractured sandstone-mudstone media
JIANG Xiao-wei, WAN Li, Bill X. HU
2008, 19(4): 574-580.
Abstract:
In this paper,the spatial variation of permeability with depth in a formation of the fractured sandstone mudstone media is analyzed The permeability value is represented by unit absorption ω obtained from the packer permeability test.The variability of permeability is so significant that the value of ω spans 3 to 4 orders of magnitude at different depths By taking mean value of log ω at different depths,the pattern of permeability versus relative depth is easy to discover We found that the variation of permeability with relative depth obey the exponent ial law; After subtract ing the linear trend of log ω with depth,the residual of log ω can be well correlated with the distribution of mudstones In addition,the linear trend of log ω with depth is caused by the fractured sandstone.The spat ial structure of permeability in the study area is clearly and quantitatively characterized by the methods proposed in this paper,which can be utilized for researches on similar studies areas.
Analysis of spatial variability of nitrate content in groundwater and its factors in Huaitai county in North China plain
CHEN Shu-feng, HU Ke-lin, LIU Zhong-lan, LI Wei, PAN Zhi-yong, ZHANG Jun-lian
2008, 19(4): 581-586.
Abstract:
584 observed wells were sampled in Huantai County in North China Plain and the NO3-N content in every phreatic water were measured.The geostatistics and GIS technique are used to analyze the data.The results indicate that NO3-N concentration shows a lognormal distribution.The Kriging method is used to estimate the unobserved points and the distribution map of NO3-N concentration is generated.The areas of NO3-N content in phreatic water for each category are calculated according to the National Quality Standard for Ground Water in every town of Huantai County.The correlative analysis shows that there is a significant correlation between the annual total nitrogen input,wastewater irrigated and NO3-N concentration in phreatic water.It is showed that the wastewater irrigation contributed much to NO3-N content in phreatic water and the total nitrogen input should be considered in the region evaluation.
Isotope tracer in watershed hydrological modeling
QU Si-min, BAO Wei-min, Jeffrey J. McDonnell, YU Zhong-bo, SHI Peng
2008, 19(4): 587-596.
Abstract:
The objectives of this study are is to present the applications and assumptions and problems in the application of isotope tracer in watershed hydrological modeling and promote new advances and new research directions.An evaluation and review of the application of isotope tracer in watershed hydrological modeling are presented in the paper.It is motivated by new and emerging interests in isotope tracer application in hydrological modeling and the need to classify different directions.The review is focused on three issues including:(1) isotopic hydrograph separation,(2) mean residence time and mixing,and(3) coupled with hydrological model.Additionally,the review provides a critical analysis of unresoloved issues when applied in watershed hydrological modeling.These issues include:(1) temporal and spatial variation of isotopic concentration of precipitation,(2) sampling of different runoff,(3) spatial variation of isotopic concentration of different runoff,(4) the distribution function of mean residence time,and(5) coupled hydrological and isotopic model.
Recent development in simulation of river ice jam
WANG Jun, ZHAO Hui-min
2008, 19(4): 597-604.
Abstract:
The ice jams in river in northern often cause severe winter flood.Centring around the experimental study,the proto-type observation and the numerical simulation of river ice problems,the scholars both at home and abroad engaged in a lot of research in order to prevent the disaster of ice-induced flooding.the study results from the scholars in one-dimensional,two-dimensional numerical simulation of river ice are reviewed and the description focuses on Shen's one-dimensional river ice numerical model and the two-dimensional model which simulate ice jam breakup,as well as their application in practical problems; Base on the review of the characters of all models,we try to give the future development direction of the numerical model for river ice.