bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on water resources optimal regulation of inter-basin water transfer project
Authors: Ma Jigang , Wang Haofang , Zhao Libin , Wei Song
Published: December 2018

Water resources optimal regulation is an important means to mitigate the shortage of water resources and promote social and economic sustainable development in regions or watershed. With the rapid development of urban population and industrial and agricultural production in recent years, the shortage of water is becoming more and more serious in Jiaodong area. The four regions with serious water shortage including Weifang, Qingdao, Yantai and Weihai in Jiaodong area are the typical research areas. In combination with the water transfer project of Yellow river to Qingdao and the south-to-north water transfer project, the water diversion is carried out to alleviate the contradiction between water supply and demand of Jiaodong area. The year of 2014 deemed as the base year and the years of 2020 and 2025 are the planning years. Based on the supply and demand analysis of water resources, an optimal regulation model is built with the minimum total water shortage considering the constraints of water supply capacity of project, water distribution capacity and minimum water supply of bleeds and so on. The optimal regulation schemes are obtained by solution model using MATLAB programming. The results show that water shortage rate of the four cities decreases significantly in annual regulation. For different planning years, guarantee rate of 50%, 75% and 95%,the total water shortage rate will be reduced by 15.35%、15.75% and 16.85% respectively in 2020, and in 2025the total water shortage rate will be reduced by 13.27%、13.26% and 14.19% respectively. Therefore the water resources optimal regulation of inter-basin water transfer project can effectively mitigate water scarcity and the contradiction between water supply and demand in Jiaodong area.
The influence of Three Gorges Reservoir high water level on the rainfall runoff
Authors: Wu Biqiong , Zheng Wei , Ren Xinkai , Xu Tao , Guo Xiao
Published: December 2018

After Three Gorges Reservoir building up, the natural river course and the near hillside inside the backwater region are inundated to form a fairly wide man-made lake which affects the hydrological characteristics and floodwater transmission to different degrees. When the reservoir impound to high water level, the conflux time is obviously shortened, the flood-peak discharge increase, and the peak type became sharper. The change of runoff yield and concentration makes the forecast scheme unable to be applied well. Based on the practice of Three Gorges Reservoir operation, the rainfall-runoff characteristics of the backwater region under the condition of high water level are analysed and summarized, then a set of unit hydrographs suitable for rainfall-runoff calculation are recalibrated, which has great reference value for hydrological forecasting of Three Gorges region.
Discussion on Core Technique and General Software Platform of River Water Resources Regulation in China
Authors: Gan Zhiguo , Cai Siyu , He Xianhao
Published: December 2018

Due to the aggravation of human activities and global climate changes in recent decades, catchment water cycle has experienced strong variation. The world is faced with profound water crisis, and water problems are especially severe and water disasters are of high frequency in China. Water problems have become significant obstacle factors for realizing sustainable development, which greatly threatens national economy and ecological safety. Given the scientific background of catchment water cycle evolution and water resources comprehensive regulation, we propose the method of solving water problems through water resources operation based on dualistic water cycle theory and discuss the developing status and existing problems of current water resources operation in China. On this basis, we also put forward the technical framework and key process of water resources regulation, which integrates the six links of monitoring, simulation, evaluation, forecasting, regulation and control. Furthermore, aiming at the background of the second phase of National Water Monitoring Capacity Building Project, we introduce a nationwide general software platform for water resources regulation. This platform will realize business collaboration and information sharing among three-scale platform of Ministry of Water Resources, basin authorities and provincial level, so as to overall improve the ability of water resources regulation and decision-making.
Modeling of joint water-supply scheduling with multi-source in Beijing under uncertain conditions
Authors: Dou Xiaojun , Wang Hejia
Published: December 2018

After the Middle Route of South-to-North Water Transfer Project (SNWTP) finished, a pattern of joint water-supply including SNWTP water, the surface water of Miyun reservoir and underground water has been formed in Beijing. In view of the uncertainty in water-supply scheduling, this study takes 2020 as the planning year, and the influence of uncertain factors on the system cost was fully considered by interval two stages planning method. In order to minimize the total water-supply cost, a joint water-supply scheduling model in Beijing has been established, which reflects the actual situation of the joint watersupply system with multiple sources. The results illustrate that the minimum water-supply cost of Beijing will be [14.6, 25.4] billion yuan in 2020, and the optimal water-supply of Miyun reservoir, groundwater and SNWTP water expected to be 0.54, 2.05 and 0.95 billion m³, respectively.
Self-optimization system dynamics simulation of reservoir operating rules
Authors: Jia Benjun , Zhou Jianzhong , Chen Lu , He Zhongzheng , Yuan Liu , Chen Xiao , Zhu Jingan
Published: December 2018

Operating rules have been used widely in the reservoir long-term operation duo to its characteristics of coping with inflow uncertainty and easy implementation. And implicit stochastic optimization (ISO) has been widely applied to derive reservoir operation rules, based on linear regression or nonlinear fitting method. However, the maximum goodness-of-fit criterion of fitting method may be unreliable to determine the effective rules. Therefore, this paper develops a self-optimization system dynamics (SD) simulation of reservoir operation for optimizing the operating rules, by taking advantages of feedback loops in SD simulation. A deterministic optimization operation model is firstly established, and then resolved using dynamic programming (DP). Simultaneously, the initial operating rules (IOR) are derived using the linear fitting method. Finally, the refined optimal operating rules (OOR) are obtained by improving the IOR based on the self-optimization SD simulation. China’s Three Gorges Reservoir is used as a case study. The results show that the SD simulation is competent in simulating a complicated hydropower system with feedback and causal loops. Moreover, it makes a contribution to improve the IOR derived by fitting method within an ISO frame. And the OOR improve effectively the guarantee rate of power generation on the premise of ensuring power generation.
Study on the Influence and Rapid Prediction of Wind on water level for Open Channel Water Transfer Project
Authors: Long Yan , Zhu Jie , Lei Xiaohui , Tian Yu , Li Youming
Published: December 2018

Taking the typical main canal of the Middle Route of South-to-North Water Transfer project as an example, the numerical simulation study on the variation law of water level before sluice under different wind conditions is carried out. First, based on numerical simulation, mathematical induction, and statistical analysis method, the influences of wind speed, wind duration and wind direction on water level fluctuation are put forward and the fast prediction formula of maximum water level fluctuation under wind influence is extracted. Then, the feasibility of the fast prediction formula is verified by the actual monitoring data. The results show that: (1) the duration of wind has little influence on the maximum water level variation, and the maximum error is 9.83 %; (2) the maximum water level amplitude increases with increasing wind speed and decreases with increasing wind source distance; (3) the whole water level variation is symmetrical about the angle α=180°, and 0° to 90° is a period of maximum water level variation; (4) the error between the calculation result of the fast prediction formula and the measured result is 1.25 %, which shows that the maximum water level prediction formula is relatively applicable to open channel water transfer project. These research results provide a scientific basis for routine dispatching of water conveyance projects.
Analysis of Complementary Characteristics of Wind/PV/hydro Power Based on the Bundled Output
Authors: Dou Yanhong , Ding Wei , Huang Yan , Hu Jing , Li Yu , Zhou Huicheng
Published: December 2018

There is complementarity among wind, photovoltaic, and hydro power (wind/PV/hydro power), which is closely related to the bundled installed capacity of wind/PV/hydro complementary power generation system and regulating ability of hydropower. This paper evaluates the complementary characteristics among wind, PV, and hydro power though the ability of the system to output power smoothly. First, the ratio of installed capacity of wind to PV power is determined by minimizing the volatility of wind/PV joint power generation. Second, an optimization model, with the objective of maximizing grid-connected and steady output of wind/PV/hydro complementary system in the dry season, to determine the bundled output of the system is proposed. Third, the complementary characteristics of wind/PV/hydro power are analyzed by the bundled output and the absorptive rate of new energy in the dry season. The implication in the Yalong River shows that: (1) The optimum ratio of installed capacity of wind to PV power is 0.7. (2) The bundled output of wind/PV/hydro system is 1.742GW, in which 6.3GW are bundled capacity of wind/PV/hydro power. (3) The complementarity of wind/PV/hydro power will be strengthened with the increase of runoff in the dry season and the decrease of the new energy installed capacity. The research can provide guidelines for the planning and design of the clean energy complementary base.
The Trend and Influencing Factors of Potential Evapotranspiration in the Yellow River
Authors: Dai Yanyu , Lu Fan , Zhu Kui , Song Xinyi , Xu Yiran
Published: December 2018

Based on the Penman-Monteith formula recommended by the World Food and Agriculture Organization (FAO) and the Mann-Kendall trend test method, the variation trend of potential evapotranspiration in the Yellow River Basin from 1952 to 2014 is analyzed. The results showed that the potential evapotranspiration of 43.3% of the 90 meteorological stations in the Yellow River Basin showed a significant upward trend. 30% of the stations showed a significant downward trend, and 26.7% of the stations had no obvious trend of change. In all the secondary areas of water resources, the stations above Longyangxia are basically marked upward. The Longyangxia to the northern part of Lanzhou, the Longmen to the east of Sanmenxia and the Sanmenxia to Huayuankou are all significant descending sites. The change trend of the sites below the Huayuankou is not obvious. In other partition three kinds of sites are distributed. Through the correlation analysis, it is found that the increase of temperature has a great influence on the stations where the potential evapotranspiration is significantly increased, and the decrease of wind speed is the main reason for the significant decrease of potential evapotranspiration in some stations.
Review and prospect about water resources operation research
Authors: Wang Yu , Liu Bojun , Peng Shaoming , Cai Siyu , Zhang Dawei
Published: December 2018

The concept of water resources operation is expatiated and classified and the theories and methods with regard to water resources operation are also summarized. Research progress of water resources operation exists to analyse the problems and to take a look to the future of research directions in the field of water resources operation. In conclusion, the research on water resources operation needs a combination with the actual state of projects, climate change and increasing human activities, actually considering water resources demands and employing uniform control of water quantity and quality, which could ensure the sustainable utilization of water resources in China.
Regional Flood Risk Management Modeling and Application
Authors: Liu Bojun , Zhang Jinliang , Yang Libin , Cai Siyu , Zhang Dawei , Li Fusheng
Published: December 2018

China is one of the countries with frequent flood disaster, and it does fall often with more precipitation especially from June to October in the Yangtze River, which would very easily cause floods thereby seriously threating to the safety of each region along the Yangtze River. How to manage regional flood risk reasonably and efficiently under the new situation of the joint effects of climatic change and human activities deserves more researches. The regional flood risk management model is built and applied in the Jingjiang section of the Yangtze River to derive regional flood processes under the condition of floodwall break and assess the effects of flood on each factor in the region. The built model is reliable and practical with reasonable results, would support some sort of technical help for regional flood risk management, water resources protection and measure-making of flood prevention and disaster mitigation.
Quantifying the impact of release operations and weather conditions on the flow and temperature dynamics in the cascade-reservoir system
Authors: Chen Gang , Zhai Yue , Fan Hui , Fang Xing , Wang Chuanhai
Published: December 2018

The objective of this study was to investigate the flow dynamics and temperature characteristics under different reservoir operation scenarios and weather conditions in the river-reservoir system, which can be used to set scientific guidelines for river management and conservation planning strategies. The calibrated three-dimensional model provided simulated unsteady water surface elevation, temperature, velocity and discharge at different layers (depths) in different locations. A series of operation scenarios were modeled to understand and quantify formation, propagation, and disappearance of density currents that are resulted from combinations of daily repeated large release (DRLR) of different durations and solar heating. DRLRs (140 m3/s) with longer durations pushed the bottom cold water further downstream and maintained the bottom water temperature cooler. Variations of weather conditions (e.g., drops of air temperature and solar radiation) directly controled variations of bottom-layer water temperature. The daily drop rate of bottom temperature was related to the rate and duration of air temperature drop. Under the practice for the water turbines running at downstream, it clearly showed the shocking withdrawal and stopping effect from the downstream operation. The velocity for the whole cross-section were almost increased with same magnitude of about 0.1 m/s at GOUS and JML.
Simulation and Analysis of Accident Condition and Coping Operations of The Dian Zhong Water Diversion Project
Authors: Yan Yibo , Huang Huiyong , Wan Hui , Wu Yongyan
Published: December 2018

In this paper, according to the characteristics of Dian Zhong Water Diversion Project, as big flow, small cross section, and insufficient escaping capacity, a numerical model of the project is developed. In addition, with analysis, a worst accident condition and operations dealing with it are developed and simulated by the numerical model. With the simulation results, a checking condition is suggested to the structure design.
Identifying effective reservoir capacity, water supply, inflow for tradeoff between human and ecological demand
Authors: Shan He , Xin’an Yin , Yang Zhifeng
Published: December 2018

To protect the river ecosystem and sustain ecological flow regime, it’s vital to consider environmental flow management in reservoir operation. Many researches try to use more detailed environmental flow management strategies to improve ecological flow regime. However, ecological flow regime not only is influenced by environmental flow management strategy, but also by three kinds of parameters, including reservoir capacity, reservoir inflow and water supply yield. The aim of this paper is to illustrate how ecological flow regime is affected by different reservoir capacities, reservoir inflows and water supply yields and to find a proper reservoir capacity, reservoir inflow or water supply yield under which the optimal ecological flow regime is the best and could not be improved. In this paper, an environmental flow management strategy, which is Four-period release approach (FP), is developed. Besides, social benefit and ecosystem needs are satisfied simultaneously. The results show that changing reservoir capacity, reservoir inflow or water supply yield could improve ecological flow regime.
Online Model Identification Of Open-Channel System With High Order IDZ Model
Authors: Liao Wenjun , Guan Guanghua , Zhong Le , Xiao Changcheng , Zhong Ke , Huang Huiyong
Published: December 2018

In the control of open-channel, it is difficult to estimate wave propergation time because of the complexity of reflection, superposition and energy attenuation of shallow water waves. Although Saint-Venant equation have reasonable accuracy in describing the motion law of unsteady flow, mathematically it is the first order quasilinear hyperbolic partial differential equations which makes it difficult to be used as control model in the design optimized controller. The Channel Integrator Delay Zero (IDZ) model linearizes the Saint-Venant equation and ensures the accuracy of the response of water level and discharge in high frequency band. However, there is still a considerable difference between the theoretical value and the actual response. In order to avoid this difference caused by theoretical derivation, this paper uses the single channel model of Zhanghe Irrigation District to play online identification of the relevant parameters by using the existing periodic response process of the canal system. The reliability of model identification under step water intake is verified, and the effect of this method on periodic water intakes in long channel is verified. The results show that the identified model can catch most dynamic action of the canal system with water intakes, which ensures its validity to be used for controller design. Meanwhile, it is simple in application.
Water and sediment graded management to alleviate the “secondary suspended river” in the lower reaches of the Yellow River
Authors: Li Junhua , Jiang Enhui , Xu Linjuan
Published: December 2018

The “secondary suspended river” poses a huge threat to the safety of embankment in the lower reaches of the Yellow River. The formation of the “secondary suspended river” is mainly attributed to the “less water and more sediment, inconsistent water-sediment relationship” of the Yellow River. Through the analysis of the relationship between the evolution of the lower reaches of the Yellow River and the loss caused by disasters and flood and magnitude of sediment concentration, this paper thinks that the Yellow River must pay attention to the graded regulation of water and sediment. For small and medium-sized flood with small sediment concentration, according to the flood magnitude and the reservoir water volume in the upper and middle reaches, Impoundment and filling water to build the peak time at the right time is necessary and the flood processes which are less than 2600 m3/s should be avoided in the scheduling process. Based on the shape of river channel of high flow flood in floodplain and average flow flood in floodplain, and the difference between the sediment transport efficiency of flood and the difference between the loss to the lower floodplain area, the average flow flood in floodplain which is between 6000 m3/s should be avoided in the scheduling process as far as possible. In order to relieve the development trend of the “secondary suspended river”, the regulation of “brushing groove of silt beach” should be insisted on for large flood. But the high sediment concentration flood should be avoided because of its serious destructive effect on the lower reach. At the same time, it also calls for strengthening the research and popularization of reservoir sediment treatment and sediment resource utilization technology.
Theory and Practice of water and sediment regulation in flood season of Yellow River in 2018
Authors: Wang Yuanjian , Jiang Enhui , Li Xinjie , Wang Xin
Published: December 2018

In recent years, the water and sediment pattern of the Yellow River has changed significantly, and a preliminary water and sediment regulation system was constructed. Based on a summary of the regulation principles of water and sediment in the Middle Yellow River, this paper proposes three key technologies to determine the water and sediment control thresholds, the artificial creation of a long-distance density current, and an engineering regulation for water and sediment control of the Yellow River. Taking the actual flood and sedimentation regulation of the Yellow River Basin in 2018 as an example, the practical applications of these relevant technologies are analyzed. This study provides an important theoretical and practical reference for the flood and sediment regulation of sediment-laden rivers in arid and semi-arid areas during flood season.
Study on confirmation of water right in Yangyuan County, China
Authors: Zeng Meng , Liu Meiyu , Gong Aixi , Quan Weici , Man Zihao
Published: December 2018

In order to implement the reform of the water resources fee in Hebei Province, the right confirmation of water resources use is crucial. In this study, Yangyuan County of Zhangjiakou, Hebei Province was selected for the research and the regional situations of hydrology, social economy, water conservancy project distribution and water supply were analyzed. Then, rights of residential water use, industrial water use, ecological water use, reserve water amount and agricultural water use in study region were calculated. Furthermore, the corresponding scheme of water use rights was confirmed. The results could provide technical support to the optimization of water resources management for Yangyuan County and reference to other regions of Hebei Province.
The Application and Research of Dynamic Control the Flood Limited Water Level of Wuqiangxi Reservoir
Authors: Wu Xin , Zhong Ping
Published: December 2018

This paper briefly introduces the method, content and approval process of the dynamic control of the flood limited level in Wuqiangxi reservoir, and summarizes the benefits since the implementation of dynamic control. The relevant research results of this paper can be used as reference for production technology management personnel.
Runoff forecasting benefit evaluation for long-term power generation scheduling
Authors: Ding Xiaoling , Zhou Jianzhong , Mo Xiaocong , Wang Chao , Wang Yongqiang
Published: December 2018

Long-term runoff forecasting important reference significance for the long-term planning of cascade hydropower stations. The traditional forecast accuracy evaluation is based on the deviation between the predicted runoff and the measured hydrological sequence, but fails to consider the effect on long-term scheduling. In this paper, a runoff forecasting evaluation method for long-term scheduling is presented. First, a monthly distribution method based on the forecast value of annual runoff is proposed to describe the uncertainty of the forecast. Then, a power generation plan model with the maximum generation objective and an actual generation benefit evaluation model are established to study the effect of runoff forecasting in scheduling. At last two indexes of “Incremental generation” and “Incremental benefit” based on the comparison of actual benefit with and without a forecast plan are given to evaluate the performance of forecasting. The case study shows that the proposed evaluation method can reflect the actual benefit brought by the forecast information, which provide more practical guidance for the hydropower station.
Analysis on the Effect of Groundwater Overexploitation Control in Water receiving region of the First Phase of the South-North Water Transfer Project
Authors: Yuanyuan GAO , Jia LI , Qichen HAO , Chu YU , Suhua MENG
Published: December 2018

The South-North Water Transfer Project is playing a more and more important role in ensuring economic and social development and maintaining a good ecological environment for north of China. However, long-term over-exploitation of groundwater has caused a series of ecological and environmental problems. The first phase of the South-to-North Water Transfer Project was successfully passed through in 2013 and 2014. The water supplied by this huge project provided critical water source for implementing groundwater overexploitation control. In order to promote the management and protection of groundwater resources, the overdraft areas had adopted comprehensive measures to reduce groundwater extraction, such as accelerating the construction of supporting projects, shutting down groundwater mining wells, improving the groundwater monitoring station network, and reforming the water resources fees and so on. The urban groundwater overexploitation control work has received good progress. Based on the investigation and statistics of groundwater overexploitation control in the water receiving region of the first phase of the South-North Water Transfer Project, it was found that since the first phase of the South-to-North Water Transfer Project passing though, the water groundwater withdrawal decreased by 15.23×108 m3 by making full use of the water from the South-North Water Transfer Project, including 2.36×108 m3 in Beijing, 0.67×108 m3 in Tianjin, 6.39×108 m3 in Hebei, 3.84×108 m3 in Henan, 1.62×108 m3 in Shandong, and 0.35×108 m3 in Jiangsu, respectively. The number of groundwater withdrawal wells closed was 15202, including 331 wells in Beijing, 582 in Tianjin, 4895 in Hebei, 6213 in Henan, 2012 in Shandong, and 1169 eyes in Jiangsu, respectively. In terms of groundwater level, the trend of continuous decline in groundwater level has been effectively curbed in most areas of the water receiving region, however, in some areas the groundwater level is still declining due to the too large cumulative over-exploitation of groundwater. Shijiazhuang City was selected as typical monitoring site to explain the groundwater overexploitation control effect on groundwater level. The analysis of the monitoring data of typical monitoring sites showed that groundwater overexploitation control has a great influence on the groundwater level change in Shijiazhuang urban area. This study also puts forward some problems and suggestions in promoting the groundwater overexploitation control in the water receiving region, and provides reference for the construction of ecological civilization and national water security.
Fast and high-precision simulation of hydrodynamic and water quality process in river networks
Authors: Lu Chengwei , Zhou Jianzhong , Hu Dechao , Yuan Shuai , Liu Yi
Published: December 2018

To realize a fast and high-precision simulation of unsteady flows and water quality process in river networks, a 1-D mathematical modelling system for free-surface flows and water quality process is developed. In the hydrodynamic model, aθsemi-implicit method is used to discretize the free-surface gradient term in the momentum equation while the Eulerian-Lagrangian method is employed to solve the advection term. To achieve good mass conservation, the finite-volume method is used to discretize continuity equation. Moreover, the resulting hydrodynamic model is unconditionally stable with respect to the gravity wave speed and flow advection. In solving the scalar transport equation, the forward difference is used for discretization in time while the centre-difference is in space. A sub-cycling is introduced to divide the computational time step and improve the stability of water quality model. Therefore, large time steps are allowed in both the hydrodynamic and the transport models. The coupling of the branches of the river networks is solved using a predictioncorrection method. Then, a Gaussian pulse test and a rectangular wave test are employed to demonstrate the accuracy and the efficiency of the system, which will also provide powerful supports for ecological operations of cascade reservoirs in drainage basins.
Optimization dispatch rule of the Three Gorges Reservoir considering ecological and power generation benefit
Authors: He Zhongzheng , Zhou Jianzhong , Lu Chengwei , Qin Hui , Jia Benjun , Zhu Jingan
Published: December 2018

This paper focus on optimization operation problem of ecology and power generation considering uncertainty of inflow on the Three Gorges reservoir. A model with constraint violation as objective is proposed to obtain ecological and power generation optimization dispatch rule of the Three Gorges Reservoir using stochastic dynamic programming. In the model, minimization of ecological water shortage and constraint violation and maximization of power generation benefit are taken as objective, simple discrete-time Markov chain and stochastic dynamic programming take into account the uncertainties of inflow. A case study shows that the proposed approach is feasible and efficient to produce a dispatch rule to balance ecological and economic benefits. Some conclusions of the influence of ecology and power generation are finally drawn.
Application of power matching deviation coefficient in drying stage production control of Dadu River cascade hydropower stations
Authors: Wang Fuzhi , Zou Zujian , Zhong Qingxiang
Published: December 2018

The economic indicators of cascade hydropower stations are the main technical means in the current economic operation management, but there are management loopholes in various economic indicators. Aiming at the particularity of the operation of cascade hydropower stations in dry season and the new form of grid reform, combined with the characteristics of various economic indicators, the power matching deviation coefficient is proposed to hedge the loophole of comprehensive water consumption rate, and the price difference is used to balance the spread between cascade hydropower stations. This indicator can correctly guide production and operation personnel to tap potential and increase efficiency and ensure healthy competition while ensuring the overall economic operation. The evaluation system has a good effect in the actual use of the Dadu River cascade hydropower stations, and has obvious promotion effect on the production control of the cascade hydropower stations.
Study on Flood and Sediment Joint Operation of Dadu River Downstream Cascade Reservoirs
Authors: Lu Liyu , Tao Chunhua , Huang Weibin
Published: December 2018

There is large amount of high hardness sand in the water flow in Dadu river. The problem of sediment deposition is very prominent in the two early reservoirs, Gongzui reservoir and Tongjiezi reservoir. In order to decrease sediment deposition effectively and extend the service life of them, the sediment characteristics of Dadu river cascade hydropower stations are analysed, as well as changes of sediment deposition in Gongzui reservoir and Tongjiezi reservoir after Pubugou reservoir puts into operation. Flood forecast and pre-discharge operation theory are studied for utilizing the discarding water to improve sediment-flushing effect, and flood and sediment joint dispatching schemes of cascade reservoirs are proposed. In order to evaluate effects of joint dispatching schemes, SBED extended one-dimensional flushing sediment mathematical model of deposited reservoir is built, and the mathematical model is used for simulative computation of coming 20-years sediment-flushing effect. After that, the effects of different schemes are analyzed comparatively. Three conclusions can be drawn from the studying. Firstly, the sediment in Gongzui reservoir and Tongjiezi reservoir is obviously reduced after Pubugou reservoir puts into operation. Secondly, flood forecast, pre-discharge operation theory and creating sand-flushing conditions can obviously improve sediment-flushing effects and avoid wasting power generation water when the water levels and outflows of Pubugou reservoir, Gongzui reservoir and Tongjiezi reservoir are rationally controlled. Finally, the larger the inflows and the lower the water level of Gongzui reservoir and Tongjiezi reservoir is, the more obvious the sediment-flushing effects are. According to situations of power plant at the time, such as rules of flood controlling and operation requirements of flood discharge facilities, it is recommended that the inflow of Gongzui reservoir is controlled at about 4500m3/s, and timely lower the water levels of Gongzui reservoir and Tongjiezi reservoir to their dead water levels, when carrying out joint dispatching schemes.
Dynamic Economic Dispatch in Thermal-Wind-Small Hydropower Generation System
Authors: Liu Guangbiao , Zhou Jianzhong , Xiao Xiaogang , Mo Li , Yuqi Yang , Chengwei Lu
Published: December 2018

With the large-scale wind power integration, the uncertainty of wind power poses a great threat to the safe and stable operation of the system. This paper proposes dynamic economic dispatch problem formulation in thermal power system incorporating stochastic wind and small-hydro (run-in-river) power, called thermal-wind-small hydropower system (TWSHS). Weibull and Gumbel probability density functions are used to calculate available wind and small-hydro power respectively. An improved differential evolution algorithm based on gradient descent information (DE-GD) is proposed to solve the dynamic economic dispatch (DED) problem considering uncertainty of wind power and small-hydro power, as well as complicated constraints in TWSHS. Based on the traditional differential evolution algorithm, the gradient information of the objective function is introduced after the mutation process to enrich the diversity of the population, thus increasing the possibility of convergence to the global optimization. Generation scheduling is simulated on a TWSHS with the proposed approach. Simulation results verify feasibility and effectiveness of the proposed method while considering various complex constraints in the thermal-windsmall hydropower system.
Joint optimal flood control operation of large scale mixed reservoirs
Authors: Zha Gang , Zhou Jianzhong , Chen Lu , Wang Quansen , Lu Chengwei , Yang Xin , Dai Ling , Zhou Chao
Published: December 2018

With the reservoir construction gradually completed, joint operation of reservoir groups is an important measure to realize reservoir flood control potential,but when the river basin is large, the flood channel routing and time-lag cannot be simplified, in addition, the curse of dimensionality is very difficult for model solving With the expansion of the number of reservoirs. These factors restrict the application of joint operation of large scale mixed reservoirs.In this study, The DP-POA cyclic iterative algorithm which is based on large scale system decomposed-coordinating method was proposed to solve the optimal problem considering the flood routing and time-lag.The upper Yangtze River is selected as a case study. 6 reservoirs, including the Three Gorges Reservoir(TGR)、Xiangjiaba Reservoir(XJB)、Xiluodu Reservoir (XLD)、 Pubugou Reservoir (PBG)、Goupitan Reservoir (GPT) and Tingzikou Reservoir (TZK)are taken into accounts.Compared with current operation of reservoirs independent,results demonstrate that the method can effectively reduce the maximum operating water level of TGR and flood diversion in the lower reaches of the TGR. Therefore, the safety of the flood control points along the river has been largely improved based on the proposed method.
Analysis and study of water resources management system at home and abroad
Authors: Chunling JIN , Mengjuan WU , Li GONG , Linan HUANG
Published: December 2018

In order to enhance the effectiveness of China’s water resources management, China has implemented the most stringent policies in recent years, such as the most stringent water resources management system, the full implementation of the “River Administrator” system, and the “Lake Administrator” system. In this article, we studied the water management systems of six foreign countries, including United States, Canada, Japan, the United of Kingdom, France, and Australia, with exploring and analyzing the operating modes of their management system, to summarize their distinct advantages and common problems, provide reference for the development and perfection of China’s water resources management system, and to better support the sustainable management of China’s water resources and water environment to support the sustainable economic development of the basin and strict water resources management systems and water Implementation of pollution prevention action plans.
Assessing the adequacy of bias corrected IMERG satellite precipitation estimates using extended mixture distribution mapping method over Yangtze River basin
Authors: Ma Qiumei , Xiong Lihua , Xu Chong-Yu , Guo Shenglian
Published: December 2018

Satellite precipitation estimates (SPE) product with high spatiotemporal resolution is a potential alternative to traditional ground-based gauge precipitation. However, SPE is frequently biased due to its indirect measurement, and thus bias correction is necessary before applying to a specific region. An improved distribution mapping method, i.e., Extended Mixture Distribution (EMD) of censored Gamma and generalized Pareto distributions, was established. The advantage of EMD method is that it describes both moderate and extreme values well and carries on the traditional censored, shifted Gamma distribution to combine the precipitation occurrence/non-occurrence events together. Then the EMD method was applied to the Integrated Multi-satellitE Retrievals for GPM product (IMERG) as statistical post-processing over Yangtze River basin. The Version-2 Gridded dataset of daily Surface Precipitation from China Meteorological Administration (GSP-CMA) was taken as reference. The adequacy of bias corrected IMERG precipitation was assessed and the results showed that (1) the Root Mean Squared Error and Relative Bias between bias-corrected IMERG precipitation and reference are significantly reduced relative to the raw IMERG estimates; (2) the performance of extreme values of IMERG in Yangtze River basin is enhanced since both the under- and over-estimation of the raw IMERG are compromised, due to the generalized Pareto distribution introduced in EMD which is enable to describe the extreme value distribution. This highlights the improved distribution mapping method, EMD is flexible and robust to bias correct the IMERG precipitation to obtain higher accuracy of SPE despite the coarse resolution of reference.
Instream ecological flow and reservoir ecological operation in the upper reaches of Irtysh River
Authors: Li Jian , Xia Ziqiang , Yin Wei , Jia Haiyan
Published: December 2018

Instream ecological flow (IEF) and flow-related variations were important for healthy river systems. However, water conservancy projects such as reservoirs altered the processes of IEF and thereby posed considerable threat to the health of river systems and aquatic lives. To that end, in this study the effects of reservoir construction on IEF in the upper reaches of the Irtysh River were analyzed using an improved hydrological method. The computed results were in turn used to determine the maximum (MaxIEF), minimum (MinIEF) and optimal (OptIEF) instream ecological flows of the river. Based on the study, reservoir impoundments limited IEF in wet seasons but enhanced it in dry seasons. It also narrowed suitable flow range for reproduction and growth of aquatic life. Reservoirs could be used to regulate Irtysh River discharge. For healthy instream processes in wet years, OptIEF could be set as the lower limit and MaxIEF as the upper limit. For much the same reasons, MinIEF could be set as the lower limit in dry years and OptIEF as a suitable target in normal years.
Joint optimization of cascades in Yalong River and the middle and downstream of Jinsha River
Authors: Zhang Hairong , Li Peng , Ren Yufeng , Liang Zhiming , Chen Yufan , Li Chunlong
Published: December 2018

The main tributaries of the upper reaches of the Yangtze River are not only the strategic base for China’s water resources, but also an important hydropower base for the “West-East Power Transmission Strategy”. With the completion of these reservoir groups, a large-scale mixed reservoir system across the different basins has been formed, which makes the requirements for joint optimization and scheduling of large-scale hydropower system getting higher and higher. This paper focuses on the key problems faced by the joint optimization of large-scale hydropower system in the basin. Taking the Yalong River and the middle and downstream of the Jinsha River as the research area, the hybrid optimization method is introduced herein to solve the joint optimal scheduling model. The results reveal that the power generation by joint optimal scheduling is much more than separately scheduling, and the total power generation increased by 2.84% on average. As Mid-Jinsha cascade and Yalong River cascade has a 690 million kW·h and 190 million kW·h decrease in power generation respectively, the downstream Jinsha River cascade has a power generation increase of 4.31 billion kW·h.
A random gradient based Harmony search algorithm for long-term hydropower scheduling in the lower of Jinsha River Basin
Authors: Feng Yu , Xu Jijun , Chen Jin , Wang Yongqiang , Hong Xiaofeng
Published: December 2018

The long-term hydropower generation scheduling (LHGS) is one of the most important problems which aim to obtain a suitable scheme to maximize electrical benefits. In this paper, a gradient based Harmony search algorithm (GHS) is employed on the optimization of the cascade hydropower stations in the Jinsha River. Firstly, the original Harmony search algorithm (HS) is firstly improved by a dynamically adjustment strategy and global pitch adjustment strategy. Then random gradient strategy is adopted to improve the search speed of HS. In case study, the proposed GHS is used to solve the LHGS problem in the Jinsha River. Results show that GHS is effectiveness when dealing with LHGS problems.
Numerical Simulation of Flow Field of DN2400 Hedge Dissipator
Authors: Tan Huipan , Sun Jianghe , Liao Zhifang , Zhang Baiyun , Tang Zherun , Jiang Jin
Published: December 2018

The distribution of water resources in China is uneven. Long distance water conveyance projects have effectively solved this problem. In the water delivery system, the energy dissipator plays an important role in pressure regulation and regulation. Therefore, the design and structure of the energy dissipator affect the working efficiency and stable operation of the whole water delivery system, and it is of great significance to study the internal flow field of the energy dissipator. Based on a emergency project, this paper studies the internal flow field of the energy dissipation valve in A location and B location in the design conditions, accident conditions and water separation conditions to verify the DN2400 hedging energy dissipation. The rationality of the structural design of the device provides a reference for the design and improvement of the energy dissipator in the future.
The Study on Transport Characteristic and Impact Factors of Spilled Oil on Open Channel of Water Transfer Project
Authors: Mu Jie , Liu Xiaoqing , Ma Chao , Shen Ruozhu , Zhang Dawei , Ma Jianming , Cao Daling
Published: December 2018

In order to quickly respond to oily pollution incidents in water transfer projects, the author has adopted the two-dimensional hydrodynamic model, oil spill numerical model, combined with physical model test, to carry out quick prediction on the characteristic parameters of oil spill transport and impact factors. The research results show that: in the case of sudden outbreak of oil spill pollution on the open channels of water transfer projects, the oil slick transports about 1.15 times as fast as the central flow velocity; the change rate of the longitudinal length of the oil slick is 0.5 times of the central flow velocity at the cross section; in the case of sudden pollution, neither the transport distance of the oil slick nor its longitudinal length change rate is affected by oil spill quantity; the wind field has a greater influence on the transport distance of oil slick: when the wind direction is parallel with the flow, the wind field has little influence on the change rate of the longitudinal length of the oil slick; when the wind direction is perpendicular to the flow, the oil slick will be banked under the action of the wind field; According to the physical model test, different oil spill types will lead to different the change rate of the longitudinal length of the oil film. The research results of this paper can be used to realize quick prediction of the pollution range in the case of oil spill on open channel of water transfer project, and provide support for decision making in emergency treatment pollution control.
Studies on Cooperative Emergency Regulation of Over-level Floods of Cascade Reservoirs
Authors: Hua Yue , Ma Guangwen , Yang Gengxin
Published: December 2018

Affected by global climate change, the frequency of extreme weather events increases in China, and the suddenness, harmfulness and unpredictability of the flood disaster exceeding the designed level are more serious. As a result, emergency response problems facing cascade reservoirs are increasingly prominent, among which the dam break or consecutive break is the greatest threat to cascade reservoirs. In case of floods exceeding the designed level, cooperative emergency regulation of cascade reservoirs is an effective method to develop the comprehensive benefit of reservoirs. In this paper, the criterion of minimizing the highest water level is chosen as the objective function of the cooperative emergency regulation model in cope with floods exceeding the designed level, with the progressive optimality algorithm adopted to solve the function. Moreover, the related emergency regulation plan is conductively explored. In addition, the Pubugou Reservoir, Shenxigou Reservoir, and Zhentouba I Reservoir on the Dadu River are taken as examples to regulate and calculate the flooding process, which verifies the validity and reliability of the preceding model. According to the results, by means of cooperative emergency regulation of cascade reservoirs, each reservoir pre-discharges water in the early flood to maximize the storage capacity, thus coping with the possibly coming flood, minimizing the water level of each reservoir, and effectively ensuring flood control safety for cascade reservoirs. The research results are of great theoretical significance and engineering practice value for establishing the emergency regulation mechanism to cope with floods exceeding the designed level for cascade reservoirs in each river basin.

CLC number: TV321 Document code: A