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    15 January 2017, Issue 1
      
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  • XIE Chong-bao , ZHANG Guo-hua , LU Shao-hua, LU Wen-juan, XIE Rui-huan
    China Rural Water and Hydropower. 2017, (1):  1-3. 
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    The traditional sprayer is fixed on the ground,affecting the mechanization of farming and harvest,not suited to the development needs of modern agriculture. In order to solve this problem,the equipment as buried self-rising spray irrigation,drip irrigation and pipe irrigation came into being. In the case that the buried self-rising water equipment is increasingly perfect,how to develop more and better sprayer for buried is very urgent. The flow channel of the existing buried sprayer is closed,which not only higher energy consumption,but also easily cause blockage under the conditions of inadequate filtration,affecting the sprinkler effect. Aiming at the problem,a buried self-rising openchannel sprayer is developed.
  • ZHANG Heng-jia, HUANG Cai-xia
    China Rural Water and Hydropower. 2017, (1):  4-8. 
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    An experiment is conducted to determine different irrigation amounts on photosynthetic performance and above-ground biomass ( AB) of spring maize. The leaf area duration ( LAD) ,relative growth rate of dry matter ( RGR) ,leaf area ratio ( LAR) ,crop growth rate ( CGR) ,net assimilation rate ( NAR) ,and AB are analyzed from maize subject to various irrigation water in Hexi oasis region. The results indicate that the difference is significant in AB performance under different irrigation amounts. The maximum AB is recorded in the traditional full irrigation,which is 16.2% ~ 41.1% higher than in the limited irrigation,while the minimum is marked in the plots subject to the same irrigation amount at different growth periods after 12-leaf stage,which results in a significant reduction in maize LAD,CGR,NAR,and AB. Contrarily,the above indexes are greatly improved for maize subject to various irrigation amounts under a suitable water stress. In addition, the LAR is significantly reduced by 10.5% ~ 20.3% in the plots subject to the least irrigation water,showing that the leaf photosynthetic and assimilation capacity is improved by limited irrigation on maize subject to a suitable water stress,which also provides a suitable water environment for the future dry matter formation and accumulation and AB improvement. Therefore,full utilization of irrigation water before 12-leaf stage and less water consumption regulated by proper water stress after 12-leaf stage should be equally emphasized to form and accumulate more dry matter for the former and promote the transportation and distribution of assimilation product for the latter.
  • ZHANG Yu-shun, LU Zhen-guang, WANG Min, QIN Hai-xia, WANG Yan-ping, HE Gang, QIU Xin-qiang
    China Rural Water and Hydropower. 2017, (1):  9-12. 
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    Irrigation water use efficiency is one of the assessment indexes of the“three red lines”in conducting the most rigorous water resources management system in China. Considering such factors as topography and geomorphology,soil type,irrigation water management level,water source type and cropping pattern,this paper applies the “head-tail calculation method”in 112 sampling irrigation districts of Henan Province in 2015,and concludes that the irrigation water use efficiency in these sampling irrigation districts is between 0.412 and 0.873; the average irrigation water use efficiency of various scale and type irrigation districts is 0.479 in large irrigation district,0.482 in medium irrigation district,0.559 in small irrigation district,and 0.709 in well-irrigated district; with the weighted average of the gross irrigation water consumption of various scale and type irrigation districts. According to calculation,the current irrigation water use efficiency of Henan Province is 0.601. The above calculation results serve as a reference for related sectors in conducting water resources management and formulating related policies.
  • HUANG Cai-xia, ZHANG Heng-jia
    China Rural Water and Hydropower. 2017, (1):  13-17. 
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    Soil water contents in oasis spring maize field were monitored continuously using soil neutron probe combined with drying-weighing method, and the temporal and spatial variations of soil moisture at various growth stages were analyzed. Meanwhile, the effects of different irrigation amounts on periodic water consumption and its percentage in total water use of maize, leaf area index, and grain yield were explored. The results indicated that profile soil water contents in various increments varied similarly with maize growth under different irrigation amounts, but the spatial variation of soil moisture was quite different, revealing an obvious hierarchy dynamics among soil increments. The periodic water consumption and its percentage in total water use both increased initially then followed by a decrease as maize grew, with the maximum both valued in silking to grain filling. In addition, leaf area indexes were greatly improved under full irrigation before maize filling, and grain yield was not reduced under reasonable limited water management with respectively 102mm water application during maize jointing, 93mm during11-leaf stage, 93mm during booting, 90mm during heading, 90mm during silking, 75mm during early filling and 75mm during middle filling, contrarily, significant water saving and yield increase were achieved.
  • JIN Yong-kui , LI Qiang, YUAN Yuan
    China Rural Water and Hydropower. 2017, (1):  18-22. 
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    Aiming at the problems of high maintenance cost and low management efficiency of the large-scale efficient water-saving irrigation system,this paper designs a kind of efficient water-saving irrigation informatization monitoring system. The system consists of the monitoring center and display system,video monitoring system,management information system,field intelligent irrigation control system,wireless data transmission system and efficient water-saving irrigation management website. It uses technologies of data acquisition,data transmission,control decision,video monitoring and data traffic control to monitor center exhibition and pumping station safety protection. Under the integration of management software,a set of the informatization systems with intelligent information collection,transmission,management,application and decision,has been built and used in practice. It enhances management,operation and maintenance,achieves yield increase,cost reduction,efficiency increase and innovation of management model,and has a good practical value and application prospect. 
  • LUO Lin, LI Xiao-xiao
    China Rural Water and Hydropower. 2017, (1):  23-26. 
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    Currently, the new agricultural management entities are developing rapidly, and gradually to participate in the construction and management of farmland water conservancy projects, which bring some influences of the traditional farmland water conservancy project investment, construction and management mechanism. Based on the analysis of the main forms and existing problems about the new agricultural management entities involved in the farmland water conservancy construction and management, this article put forward some suggestions about the new agricultural management entities participate in the farmland water conservancy construction and management. This could help the new agricultural management entities play an active role in the farmland water conservancy construction and management.
  • CAO Yu-tong, SHE Dong-Li , LIU Bin, XU Cui-Lan, DING Ji-Hui , SUI Xue-yan
    China Rural Water and Hydropower. 2017, (1):  27-32. 
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    Taking Jiangsu fifteen finished land consolidation projects as an example, the paper constructed index system of land consolidation comprehensive benefits, in order to evaluate the land consolidation benefits scientifically and roundly. Based on analysis and evaluation on the Jiangsu land consolidation benefits by using analytic network process- fuzzy comprehensive evaluation(ANP-FCE), a three-level system“target-rule-index”was established, which included Money into, Process management, Engineering implement, Comprehensive benefits. The results showed that the impact in Jiangsu was significant after implementation of land consolidation project, which was consistent with the actual situation. But there were still some problems, including procrastination of project progress, weakening of protection after construction and neglect of ecological environment construction. It was concluded that we should complete standard management system of land consolidation projects based on the establishment of long-term special project for farmland ecosystem construction and long-acting mechanism of final management and maintenance. The research methods and evaluation model in this paper provided a reference for other scholars to study land consolidation comprehensive benefits of similar areas.
  • HU Liang, LING Jie
    China Rural Water and Hydropower. 2017, (1):  33-36. 
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    Before our reform and opening to the outside world,the state and the collectivity have the full ownership of water in rural areas.The state and the collectivity carried out the guidance of the management of river and water distribution. Since the reform and opening to the outside world,because of the privatizing trend the right of cultivated land,the collectivity has abandoned the ability of mobilization,families have not concerned the maintenance of water conservancy facilities outside families' cultivated land. Many water conservancy facilities are unmanned,even discarded. Solving the current problem of water project construction and management needs the participation of governments,farmers and the third party. At the same time,to improve the water management regulations,we encourage the establishment of Farmers' Water Association,to play their major roles.
  • China Rural Water and Hydropower. 2017, (1):  37-42. 
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    In this contribution, on the basis of field investigation and experimental data, integrate conventional statistics and geostatistics based on GIS are used to study spatio-temporal variation of the surface soil salt content and soil moisture content in spring and autumn and analysis the main influence factors between the Ebinur lake wetland. The results show that soil salt and soil water shows strong spatial autocorrelation in dry and wet seasons in the study region; the soil salt content in the southeast of the study area is higher than northwest; soil moisture content is more than October in May, Spring is concentrated in the southeast, the fall is concentrated in the northeast.These results suggest that arid climate, topography, hydrogeology and human activity is the main reason of the spatial distribution of soil water and salt. We conclude that study soil moisture and soil salt space-time distribution characteristics and its driving mechanism, the arid area soil salinization has important theory and practice of practical significance.
  • NING Juan, DING Jian-li , YANG Ai-xia, DENG Kai
    China Rural Water and Hydropower. 2017, (1):  43-48. 
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    Soil salinization is an important factor restricting economic development in arid areas, accurating obtain of soil salt information become the premise of governance soil salinization in arid . In this contribution, based on sensitive wave bands selected by the spectral correlation with soil salinity that measured by visible-near-infrared(VNIR) spectroscopy and the laboratory.Useing partial least squares (PLSR) analysis and support vector machine (SVM) method to establish models to estimate the soil salinity in the oasis arid areas of Weigan and Kuqa Rivers. In addition, predicting the spatial variability of the soil salinity through using Universal Kriging method.The results show that the support vector machine (SVM) model pre-processed with first order differential with relectance produces the highest estmation accuracy. The determination coefficient (R2) of support vector machine model is 0.853, the root mean square error (RMSE) is 0.381.The soil salinity has the strong spatial autocorrelation ,it belongs to medium spatial variation and the spatial structure less than 25%.The spatial variability of soil salinity shows a higher prediction precision. The determination coefficient (R2) of soil salinity predicted and measured values is 0.786 and the root mean square error (RMSE) is 0.528.This study demonstrates a new method to acquire spatial variability of soil salinity in the oasis arid areas with considerable success.
  • CHEN Ran-ran, FENG Jing-chun, XUE Song
    China Rural Water and Hydropower. 2017, (1):  49-53. 
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    Sewage treatment is very important for urban infrastructure construction. In recent years, the sewage treatment industry in our country is in rapid growth, this brings a lot of pressure to the construction of sewage treatment project both on technological and on financial aspect. The PPP model has been preliminarily promoted in our country and used in many projects successfully by now. Therefore, the introduction of PPP model in sewage treatment project can be very beneficial. However, the PPP model cannot be suitable for all the projects. As a result, the government should make decisions based on the scientific method. This paper analyses the qualitative and quantitative evaluation methods of value for money theory based on the characteristics of sewage treatment project. The research result can be guidance for the promotion of PPP model in China.
  • ZHAO Yi, LIU Zhi-hui, LU Wen-jun
    China Rural Water and Hydropower. 2017, (1):  54-57. 
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    The study focused on the start condition of under the low temperature two-stage aeration biological filter in the treatment of campus domestic wastewater. Self-made two-stage aeration biological filter,and natural enrichment culture hang membrane for hanging aeration biological filter membrane. The design time is 30 d to accomplished the forming bio-film and analyzed the removal efficiency of SS,BOD5,CODCr, NH3-N and TP,And water temperature is also monitored. The results show that: under the condition of low temperature in winter in Xinjiang,using self-made aeration biological filter with heat insulation function can make the water temperature stability in 22 ℃ around,normal operation of equipment. After 20 d,the SS and BOD5 removal efficiency can reach stability above 90%,the COD5 removal efficiency can reach stability above 85%,NH3-N removal efficiency can reach stability above 90%. This implies that two-stage aeration biological filter running to 20 d film can start successfully.
  • CHEN Rui-xing, LI Wei-dong, LUAN Mu, YIN Yang-yang, FENG Wen, XU Xiang-yang
    China Rural Water and Hydropower. 2017, (1):  58-62. 
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    Taking the characteristics of the study area into consideration,a comprehensive rainstorm model based on SWMM is developed, which contains flood and waterlogging control. It simulates urban waterlogging,analyzes the surface runoff under different return periods of rainfall process,manhole overflow and pipeline overload situation,evaluates drainage capacity. According to the current situation of drainage pipelines in the study area and reasons for the shortage of the drainage capability,a pipe network optimal design scheme is put forward, which improves the capacity of drainage system and alleviate waterlogging risk. SWMM model is used to simulate and analyze the effects of the retrofit scheme. Simulation method used in the research can be extended in other urban drainage system optimization retrofit schemes.
  • LUAN Mu, LIU Jun
    China Rural Water and Hydropower. 2017, (1):  69-72. 
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    the Old Town in Tonglu County of Zhejiang Province was selected as the study area to build SWMM model. Four kinds of LID measures containing rain barrel, vegetative swale, permeable pavement and green roof were adopted. According to local conditions, the combination of the LID measures was optimized. The model was run to analysis the waterlogging depth and scope under the traditional development scenarios and the LID scenarios in the case of the storm occurred every year, two years and five years. The results show that, LID measures are able to reduce the peak flow, peak current deferred time and significantly reduce waterlogging depth and scope. They are helpful in reducing waterlogging risk in old towns.
  • JI Jing, LIU Pan, JIANG Yan-sheng, LIU De-di , DENG Chao, LI Ze-jun, GUI Zi-ling, ZHAO Yan, PAN Zheng-ke, ZHANG Xiao-qi
    China Rural Water and Hydropower. 2017, (1):  76-79. 
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    Critical precipitation is an important indicator during the process of preventing flash flood disasters. However,how to determine the value especially in ungauged basins is always challenging. Because the parameters of hydrological models used to calculate the critical precipitation cannot be calibrated. When we derive design storm and its corresponding design flood,the rainstorm isograph method is widely used in ungauged basins in engineering practice. Therefore,the design storm and its corresponding design flood are employed to calibrate the hydrological model parameters in our study,and the critical precipitation was determined when the disaster flow is input into the model. With a case study of Dianjun District,Yichang City,Hubei Province,Xin'anjiang and SCS model are selected to assess critical precipitation respectively. The results indicate that the proposed method is conducive to determining the critical precipitation in ungauged basins. Both selected hydrological models are feasible to calculate the critical precipitation,but the Xin'anjiang model has better performance than the SCS model in our case study.
  • LI Wei-dong, ZHOU Hong, CHEN Rui-xing, YING Yang-yang, CAO Yu-hang, XU Xiang-yang
    China Rural Water and Hydropower. 2017, (1):  80-83. 
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    In order to resist the potential threat of the design storm with high return period in the flood season to Valley Dry Ash Yard and prevent the erosion damage to the ash field caused by the invasion of the flash floods,according to the relevant design standards and specifications of the power plan,based on rainstorm and flood characteristics of small watershed,this thesis focuses on the calculation method suitable for Valley Dry Ash Yard design flood. A typical Valley Dry Ash is taken as an example,on the basis of analyzing and research on the different calculation methods in small watershed design flood,this paper uses the inference formula method to design flood calculation and analyze the ash field drainage scheme,and carries on dam flood regulation and storage convergence calculation combined with MIKE model HD module. The results show that compared to the single inference formula method,the result after regulating calculation by model is reasonable, in line with Valley Dry Ash Yard features of design floods and can serve as a design basis for the construction of power plants,which has a certain reference value.
  • GUAN Yi-hong, LvMou, WANG Can, YANG Ting-ting
    China Rural Water and Hydropower. 2017, (1):  84-87. 
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    In order to study the stormwater control effect and the water quality simulation of different development model in Jiaozhou New District, the SWMM model was used to compare the difference of status, conventional model and low-impact development model (LID). The results indicated that runoff coefficient, peak flow and organic emissions in the conventional model had increased compared with the status, and the low-impact development mode had decreased with status and conventional model; For the stormwater control effect of different LID model, Combination LID> Permeable Paving> Rain Gardens; The stronger the rainfall intensity was, the sooner and greater maximum organic emissions in low-impact development model was. Dealing with the initial rainwater had become an important research direction in low-impact development model.
  • QIN Jian-ming, CHEN Yang-bo, WANG Huan-yu
    China Rural Water and Hydropower. 2017, (1):  88-93. 
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    This paper proposed the precipitation interpolation method for estimating the cell areal precipitation of Liuxihe Model, and set up the Liuxihe Model for Tiantoushui Watershed, optimized the model parameter with PSO algorithm, simulated six flood events, the results show that the method works well for Liuxihe Model. Studied the impact of rain gauges network density on precipitation estimation, parameter optimization and flood simulation of Liuxihe Model, and find that there exists a threshold rain gauge network density. When the rain gauge network density is higher than the threshold, the flood simulation results changes little.
  • FAN Qiang, TIAN Zhong, LI Nan, DING Can, TANG Nan-bo, WANG Qi-yan
    China Rural Water and Hydropower. 2017, (1):  94-96. 
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    This paper discussed the settlement planning issues of the city flood refuge under the influence of the mountain river using typical p - median method, and put forward a optimization model of p- median method combined with weighted scoring method. In this paper, the traditional p- median method has been further improved and innovated, which successfully solves the optimization problem of the traditional p- median method, and provides a beneficial reference for city flood control evacuation settlement planning. The presented theory is universal, which provides a reference for other domestic analysis of flood submerged area.
  • JIN Cong, ZHANG Xing-nan , XIA Da-zhong
    China Rural Water and Hydropower. 2017, (1):  97-102. 
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    Distributed hydrological model is an effective tool to study the regulation of water resources evolvement in the changing environments. Taking Xinxing River Basin as the study area,the distributed hydrological model SWAT was built based on GIS platform by integrating the watershed underlying surface information and weather data. Parameter sensitivity analysis and model calibration were done by using historical runoff data from 1990 to 2003 of Yaogu hydrological station in order to validate the applicability of the model in this basin. On the basis of the calibrated model,the effects of climate change on the runoff was analyzed by using the incremental scenario method. The results show that the relative errors of total runoff are within ±10% and the Nash-Sutcliffe coefficients are above 0.90 in both calibration and validation periods,the overall simulation accuracy of SWAT model is pretty good; The changes of precipitation and air temperature have different effects on runoff of the basin,and the response of runoff to precipitation change is more sensitive than that of air temperature. Through runoff simulation,SWAT model can provide an effective reference for water resources planning and management of the Xinxing River Basin in the changing environments.
  • JIANG Shan-hu, REN Li-liang, LIU Shu-ya, YUAN Fei, YANG Xiao-li
    China Rural Water and Hydropower. 2017, (1):  107-112. 
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    In this study, the hydrological modeling uncertainty analysis and ensemble simulation based on the Bayesian Model Averaging (BMA) method were set up in Mishui basin, South China. The Xinanjiang model, hybrid rainfall-runoff model, and HYMOD model were first calibrated by two parameter optimization algorithms, namely the Shuffled Complex Evolution (SCE-UA) method and the Shuffled Complex Evolution Metropolis (SCEM-UA) method. Then, the input uncertainty was quantified by utilizing a normal distributed error multiplier. Lastly, the ensemble simulation sets calculated from the three models were combined using the BMA method. Both the SCE-UA and SCEM-UA resulted in good and comparable streamflow simulations. Specifically, the SCEM-UA implied parameter uncertainty and provided the posterior distribution of the parameters. In terms of the precipitation input uncertainty, the precision of streamflow simulations did not improve remarkably. Fortunately, the BMA combination did not only improve the precision of streamflow prediction, but also quantified the uncertainty bounds for the simulation sets. The prediction interval calculated using SCEM-UA based BMA combination appears superior to that calculated using SCE-UA based BMA combination. In summary, the overall results suggest that the comprehensive uncertainty analysis concerning model parameters uncertainties and multimodel ensembles by using the SCEM-UA algorithm and BMA method are advantageous and very practical for streamflow predictions and flood forecasting.
  • WANG Jian-jin, SHI Peng, QU Si-min, XIAO Zi-wei, DAI Yun-qiu, CHEN Ying-bing, Chen Xing-yu
    China Rural Water and Hydropower. 2017, (1):  113-117. 
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    It has proposed a BP neural network coupling correction algorithm, In order to improve the accuracy of flood forecasting. This method combines the stability of hydrological model forecasting and the accuracy of neural network forecasting. The single period coupling correction test and real-time Xin'anjiang model calculation river channel local inflow correction were performed by using the observed discharge and coupled with Muskingum concentration model. The results in real-time correction were compared with AR(2) model. Actual watershed validation results show that:the improved BP neural network coupling correction algorithm is stable and can improve the accuracy of flood forecasting. It converges quickly without losing the forecast lead period and overall effect of real-time correction is superior to the AR(2) model.
  • QIU Yun-xiang , LIU Guo-dong, WANG Liang, LI Shi-yu
    China Rural Water and Hydropower. 2017, (1):  118-121. 
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    It is necessary to estimate the search range of parameters,when intelligent optimization algorithm is applied to Theis's model. In order to reduce the difficulty in estimating the search range,IWO algorithm is applied,which has the advantage of wide search for Theis's model. Through analyzing the limitation of using Theis's equation with the application of IWO algorithm in the case of wide search area,the static settings of standard deviation is changed to dynamic modulation,the model of using Theis's equation with the application of the modified IWO algorithm is proposed. This model is applied to deal with three different scale unsteady flow pumping tests. The results prove that using Theis's equation with the application of the modified IWO algorithm in the case of wide search area can efficiently obtain the transmissivity and storativity,which are close to the actual values.
  • JIANG Li-feng, ZHANG Feng, CUI Jian-guo, LI Hong-yan, CUI Jia-li, JI Wen-jing
    China Rural Water and Hydropower. 2017, (1):  125-129. 
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    The electrochemical oxidation research on drinking water containing bromide is conducted by using the anode of Ti /RuO2 -IrO2 - TiO2 and the cathode of titanium. The formation mechanism of bromate when this two electrode occur electrolysis is studied by monitoring the concentration of bromide ions,active bromine,bromate; Cyclic voltammetry scanning and RNO faded experiment. The influence law of the bromate formation is analyzed by the reaction conditions of current density,pH value and bromide ion initial concentration c0 ( Br - ) . The results show that the bromate is more easily formed when the BDD electrode has electrolysis compared with Ti /RuO2 -IrO2 -TiO2 electrode. The reason of the above phenomenon is that the BDD electrode has stronger generative capacity of active substances such as -OH. The bromate is more easily formed with the greater current density or the higher bromide ion initial concentration. At the neutral pH condition,the bromate is more easily formed compared with strong acid or alkali condition.
  • MENG Zhao-fang, JIANG Jin, LI Yan-hui, FU Xiang-qian
    China Rural Water and Hydropower. 2017, (1):  130-134. 
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    It is hard to simulate the filling process of empty pipes and draining process of liquid-filled pipes in gravity flowed system with traditional characteristics method, because of the changing position and time of corresponding boundary conditions. In this research, Lattice Boltzmann method, as a new 3D transient simulation method, was used to study the filling and draining transient processes of gravity flowed pipes. Different from the traditional one-dimensional analytical method of a system, the Lattice Boltzmann method, which was based on mesoscopic model, built the lattice model of time-space discrete dynamics in gravity flowed pipes according to the essential feature of fluid microscopic movement. Distribution and movement of the mesoscopic fluid particles obeyed the dynamic statistical law, and the fluid macroscopical motion variables could be obtained by statistically averaging a large number of particles in the flow field. Thus this method could deduce visually the changing liquid levels of the filling and draining processes in pipes, fully filling and draining time, changing flow field in the opening gate valves that were respectively at inlet and outlet, as well as the change curves of pressure and velocity at monitoring points behind the valves. At the same time, traditional 1D calculation of the pipe system was used to be compared with the 3D simulation result and make verification. It is an innovative research orientation to use CFD technology to analyze flow field of pipes in system level, which greatly improves the accuracy of results and visually analyzes the transient process of flow field in key location in system as well.
  • LI Pan, ZHANG Jian-min, LI Jun-ning
    China Rural Water and Hydropower. 2017, (1):  135-138. 
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    Air flux through ventilation facilities in a flood tunnel were sensitively determined by its Shapes and Internal flow patterns so that the air quantity is hardly to calculate. An experimental model, a flood tunnel with the mid-gated chamber, was employed to measure air flux through ventilation shafts. It was found that under the given water head and vent area, air flux increase first and then decrease with the increase of the gate’s relative opening . When the gate’s relative opening equals 0.5, the air flux adds up to the maximum. Air flux decrease weakly following the increase of the vent area. When the vent area rise to 400% , the air flux only reduce less than 20%. Based on the theory of hydraulic jump, a formula to calculate the air flux was derived and is able to be used under the condition of short flood tunnel with submerged outlet. The results agree well with the experimental data. The research will able to be referred in projects.
  • ZHANG Xiao-ying, LI Lin, TAN Yi-hai, WU Yang-feng
    China Rural Water and Hydropower. 2017, (1):  143-147. 
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    A series of tests were conducted to observe the behavior and pattern of the gas-liquid two-phase flow in a tilted siphon installed in middle pipeline; the pipeline was installed at 6 m high and its slope and water head were changed in the experiment. The porosities in the flow at the annular electrode in the pipeline were measured. The experimental results show that as the slope angle of the pipeline (a positive slope or a negative slope) increased, pseudo-cavitation in the pipeline gradually weakened and the sizes and quantities of voids and bubbles decreased. The pattern of the two-phase flow in the siphon was not associated with the direction (positive or negative) and slope angle of the middle pipeline; changes in slope angle only affected the stability of siphoning. It was found that both the maximum and average values of porosity in the pipeline declined as the slope angle decreased.
  • KANG Duan-gang, MA Xiao-yi, ZHAO Long
    China Rural Water and Hydropower. 2017, (1):  152-155. 
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    In order to improve the accuracy of the measurement of canal water level in the irrigation district,this paper designs a kind of water level meter based on the magnetostrictive effect. According to the water level of the canal measurement requirements,this paper carries out the optimization design of the hardware circuit of the following: NE555 integrated chip is used to generate excitation pulse signals,treatment of weak echo signal by using simple passive filter,high precision instrumentation amplifier AD620,integrate active filter LTC1562-2 and voltage comparator LM397. There is a 16 bit ultra- low power microcontroller ( MSP430F169) design of timing and data processing circuit. The water level meter designed in this paper has the characteristics of high precision,corrosion resistance,convenient installation,stable and reliable work.
  • China Rural Water and Hydropower. 2017, (1):  156-159. 
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    The paper, based on the characters of mountain streams and results of field survey and typical medium and small river improvement projects in Guangdong Province, investigated the current situations and put forward general principles of medium and small river governance in the province since mountainous areas in it suffered from medium and small river torrent disasters frequently. By analyzing the core problems of the mountainous river channels, such as sedimentation and steep gradient, practical channel improvement engineering measures were proposed. The paper discussed the application scope and advantages and disadvantages of common revetment protection methods and suggested some new ones out of the engineering practices of the author for the reference of medium and small river governance in mountainous areas.
  • SU Xiao-li, LIU Han-sheng, FAN Xiao-dan
    China Rural Water and Hydropower. 2017, (1):  160-162. 
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    The working gate is located at the end of the spillway tunnel. Its safe operation assists in discharging flood safely. Water hammer is developed in the closing process of working gate of spillway tunnels. At present,there is no attention to water hammer phenomenon generated in spillway tunnels. The method of characteristics is used to calculate unsteady flow pressure in spillway tunnels in the closing process of working gate. Fortunately,we have drawn some important conclusions. First,the way of working gate running at a constant speed gives rise to water hammer wave in spillway tunnel. Water hammer takes place after working gate is closed,and water hammer pressure amplitude decreases based on the exponential law. Second,the running way of working gate has influence on water hammer in spillway tunnels. If the closing speed is fast-slow,the amplitude of water hammer pressure and the possibility of working gate vibration are both reduced effectively. Therefore,water hammer can be eliminated,and working gate vibration caused by water hammer can be completely avoided only if working gate runs at appropriate and constant acceleration. Thus,the flood discharge safety hazard is ruled out.
  • LI Nan, TIAN Zhong, FAN Qiang, WANG Wei, TANG Nan-bo
    China Rural Water and Hydropower. 2017, (1):  163-166. 
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    The cavitation characteristics of the middle-piers in discharge tunnels with pressure were experimentally investigated in the vacuum tank, under different conditions with three head shapes of middle-piers and three discharges. The comprehensive analysis for cavitation characteristics were performed by three ways: visual observation method, maximum sound pressure level (SPL) differences method and noise energy ratio method. The results show that there is no cavitation occurring for the three shapes of middle-piers, and the elliptical head of the middle-pier is optimal, and the semi-circular one is worse. Cavitation takes place easily at the head of the middle-pier, comparing with the middle part and the tail part.
  • China Rural Water and Hydropower. 2017, (1):  167-170. 
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    Water rights trading is effective measure to solve water shortage problem, implement the most stringent water management system and optimize water resources allocation. A technical scheme of water rights trading pilot was design for agricultural water transferring to industry in Ningxia. The scheme includes water-saving potential analysis and trading water quantity calculation. Other content includes subject and object, contract period, cost prices, procedures, supervision and management of water right trading. The scheme will provide theoretical basis and technical reference for water rights trading practices between agricultural and industry in yellow river basin.
  • XU Chang-xin, LIN Jian-ting
    China Rural Water and Hydropower. 2017, (1):  171-174. 
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    Taking industrial water consumption and economic development over the past decade of Jiangsu province as the background, on the basis of mechanism of industrial water consumption and economic development, this paper built decoupling model. Then this paper further improved the Tapio decoupling model using identity and LMDI, recounting the driving factors of the decoupling relationship, and put forward relevant suggestions.
  • WANG Kai, JIANG Ling-lin, ZHANG Zi-xu, CHEN Kun
    China Rural Water and Hydropower. 2017, (1):  180-184. 
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    Impeller,radial guide-vane and volute of a two-stage self-priming centrifugal pump were designed with velocity modulus method.
    The two-stage self -priming centrifugal pump was made and the hydraulic characteristic experiment and self -priming experiment were measured.The results show that efficiency of the pump reaches 60.58% at the design flow rate. The range of high efficiency area is broad.
    Efficiency of the pump is always above 58% from flow rate of 52 to 85 m3 /h. In addition,the self-priming time of the pump is 154 s when the self-suction height is 4 m
  • CHEN Rong-jie , KAN Kan, QIN Ying-cong, ZHANG Xin, JIA Shao-hua
    China Rural Water and Hydropower. 2017, (1):  185-188. 
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    In order to analysis the distribution of stress of shaft-extension tubular type pump blade root after it is thickened, numerical simulation of three dimensional steady incompressible turbulent flow fields through a shaft-extension tubular type pump was conducted on the basis of Reynolds equations closed by SST k-ω turbulence model with general coordinates by using computational fluid dynamics software CFX. With the help of ansys workbench platform and taking static pressure on blade surfaces gained from numerical simulation of turbulent flow fields as load boundary conditions of the blade finite element calculation, the equivalent stress and the distribution of total deformation of four kinds of different degree of thickening of blades under design conditions. The results show that by thickening the area of stress concentration on blade root, the stress concentration could be eased and the maximum equal stress could reduced in these areas, so as to suppress and prevention the occurrence of cracks at the roots of blades. However, the thickened blade root has no effect on total deformation of impeller blade, at the same time a method of thickening the connecting part of impeller blade root and shaft is proposed. The result of this study provide the reference for the structural design optimization and Safety stability study of the same-type pump impeller.
  • TANG Hong-bing, ZHU Jian, LI Chong-hao, YANG Kai-bin , GE Zhao-xia
    China Rural Water and Hydropower. 2017, (1):  189-193. 
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    This paper is focused on the long-term prediction of April-May runoff at Tianyi hydropower station,which is under the management of China Southern Power Grid,the inter-annual incremental approach has been applied to prediction model in this study. The original runoff series include both inter-annual and decadal signals,while the inter-annual runoff increment is mainly occupied by inter-annual signals. As a result,predicting the runoff increment may be much easier than predicting the original runoff. Based on the correlation analysis,more significant factors against the runoff increment than that of original runoff are chosen. The hindcast assessment shows that,by the incremental approach,the accordance rate of“flood or dry”is 80%,and it can catch the continuous drought phenomenon during 2010-2013. The pass rate of“relative error”“ is 70%. Particularly,the incremental approach can reproduce the increasing trend during 1991-2005 and decreasing trend during 2006-2013. The possible reason for the good ability is the incremental approach can catch the inter-annual signal and keep the observed decadal signal.
  • YANG Bing, HU Yan-long, HUANG Wei-bin
    China Rural Water and Hydropower. 2017, (1):  194-198. 
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    Hydropower development can provide peak FM,flood control,irrigation,and other ancillary services,has significant social benefits; at the same time,can effectively reduce the emission of greenhouse gas emissions and sulfur dioxide,nitrogen oxides,soot and other pollutants,has significant environmental benefits. However,the current pricing mechanism of China's water and electricity pricing has not been included in the positive external benefits,which is not conducive to the fair competition between hydro-powers and other power supplies. Based on this,the paper puts forward a green pricing model based on the social benefits and environmental benefits of hydropower,and carries out an empirical study of the model. The research results show that the green pricing model can effectively realize the quantification of the external benefits of hydro-powers,and guide the orderly development of hydropower. 
  • ZHENG Xiao-dong, WAN Li-piao , WU He-gao, WANG Jian-guo , FU Shan
    China Rural Water and Hydropower. 2017, (1):  199-202. 
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    In accordance with the layout of water diversion and power generation system in Iranian QIANGMUXI hydropower station, the shape of its biggest four-girder reinforced trifurcation is designed by using the calculation program based on the theory of cone intersecting with cone and the relationship of plane geometry, then APDL of ANSYS and stress control criterion of DIN19704 are used to calculate and analyze the trifurcation. The results show that increasing the width of inner part of U-shape girders can decrease the stress of reinforced girder and its section height so as to achieve the goal of decreasing the manufacturing difficulty of trifurcation and reducing the size of construction and transportation tunnel. The design thought and method proposed can provide a reference for the popularization and application of four-girder reinforced trifurcation.
  • HU Kang , TAN De-cai , CHEN Hua
    China Rural Water and Hydropower. 2017, (1):  203-207. 
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    The pattern of the management and operation for hydropower station has transformed from the single reservoir to the cascade reservoirs. The joint operation of cascade hydropower stations is being more and more complex, so that it is urgent for us to study the key techniques of the joint operation system of the cascade hydropower stations. In this study the advanced network developing techniques have been applied to design, and develop a new cascade operation system in the Baishuijiang catchment, which integrates the synthetical management methods, the scheduling optimization algorithms and the data collaborating and protecting techniques. The joint operating system has been successfully run on the Baishuijiang Cascade Hydropower Stations, which shows that it is user-friend, safe and efficient. The joint operating system will provide a strong support for the management and operation of the cascade hydropower stations system.
  • MEI Jia-peng, NIE Si-min, WANG Hong-yuan
    China Rural Water and Hydropower. 2017, (1):  208-211. 
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    Pumped storage power stations have two kinds of working conditions,such as power generation and water pumping,and therefore the inlet and outlet flow characteristic two-way flow,the inlet and outlet of the body design of the hydropower efficient and economic operation have a greater impact. In this paper,Jurong Pumped Storage Power Station,by analyzing the physical model of the plant in the original proposal side inlet and outlet of each channel flow distribution,velocity distribution section,the hydraulic characteristics of head loss coefficient,test results show that the original plan to reach the design specification requirements through analysis,by using a water outlet on the roof height and spread angle to optimize the adjustment program. The test results indicate that the optimum flow characteristics shape better than the original size,to meet regulatory requirements.