Distance Water Transfer Research Articles

Research on the protection of pipelines with multiple column separation and water hammer of cavities collapsing

In long distance water transfer project, pipeline fluctuation, easy to produce multiple column separation phenomenon, then the water hammer of cavities collapsing is greatest harm to the pipe. Summarizing the previous research results, mechanism analysis of water hammer of cavities collapsing and theoretical calculation model, and introduces the main protective equipment and boundary conditions. After long-term practice, constant speed buffer air valve and Two-way Surge Tower effect remarkable on water hammer of cavities collapsing.

Risk Identification and Assessment of the Accidents for Distance Water Transfer Project

For South to North Water Transfer Project (SNWTP) in China with a long open canal, the distance water transfer system is a complex river system communicating with rivers and lakes along the way. Water delivery safety is threatened by various potential accidents. In this paper, using check list method, the accident risk was identified and the accident types were distinguished. Then, using fuzzy opinion centralized decision method (FOCD) and analytic hierarchy process (AHP), the risk assessment system was established and the assessment model was developed. Finally, the accident risk and the influence degree of various types of accidents for SNWTP in Shandong Province were evaluated.

Sensitivity Analysis for the Inverted Siphon in a Long Distance Water Transfer Project: An Integrated System Modeling Perspective

Long distance water diversion projects are developed to alleviate the conflicts between supply and demand of water resources across different watersheds. However, the significant scale water diversion projects bring new challenges for the water supply security. This paper presents the flood risk of inverted siphon structure which is used for crossing transversally in the water diversion project through sensitivity analysis. Soboĺ and regionalized sensitivity analysis are used to investigate the sensitive parameters of the integrated model and the sensitive range of the parameters, respectively. The integrated system model consists of the hydrologic model, the sediment transport model and the siphon hydraulic model to determine the flood overtopping duration and volume, which are used to quantify flood risk in this study. The flood overtopping duration and volume indicators are used to quantify flood risk in the sensitivity analysis. The South to North Water Diversion Project in China is used as a case study. The results show the mean rainfall and roughness coefficient of the pipe are the most sensitive parameters in the integrated models, while the sensitive range of these two parameters are distinct. The sensitivity analysis of the inverted siphon provides an insight into the significant contributions to the flood risk. The analysis can provide the guidance for the system operation security.

Risk forecasting of pollution accidents based on an integrated Bayesian Network and water quality model for the South to North Water Transfer Project

For a long distance water transfer system, guaranteeing the safety of water transferred in a long open canal is a challenge. Potential pollution sources and locations are identified first. Bridges above the canal are considered as the typical location where pollution accidents could happen. Truck responses, road conditions, and human responses are the main factors resulting in sudden pollution accidents. A Bayesian Network model is developed to calculate the risk of water pollution and evaluate the effects of pollutants in water. The key causes (human judgment, truck condition) were determined to calculate the unfavorable accidental risk. Six types of hydraulic structures were included in this canal reach. MIKE 11, a one-dimensional hydrodynamic and water quality model, was used to simulate the fluid field and pollutants transportation process. The water quality situations of cyanide at four pollution loads (0.5t, 5t, 10t, 20t) were simulated. Emergent countermeasures and measures, including the management of diversion and check gate, have been proposed according to the calculate result.

Transformation of water resource management: a case study of the South-to-North Water Diversion project

Water transformation plays a crucial role in the rational allocation and avoiding over-exploitation of natural resources. Mega water transformation project will not only bring opportunities for ecological and economical use of water resources, but also contribute towards regional industrial and societal transformations. The scarcity of water is a serious issue for north China, accordingly the Chinese government decided to implement the South-to-North Water Diversion project in order to transfer water from the water rich south China to China's northern region. The South-to-North Water Diversion project is the largest water diversion project in the world involving significant long distance and inter-basin water transfer features. The management of this mega project faced a number of significant challenges as it had to contend with a variety of issues including politics, the economy, society, local culture, the environment and the local ecology. This project has also drawn global attention to the question of how to coordinate, manage and implement the world's largest water resource project. This study focuses on management practices of the South-to-North Water Diversion project by investigating the project's eastern and central routes. The three project management approaches that were used in this project, i.e. project owner direct management, project consignment management, and agent construction management (Daijianzhi) were investigated. Management regulations, control measures and common issues associated with the South-to-North Water Diversion project were also examined. These included: land acquisition and resettlement, bidding and tendering, construction supervision, quality management, cost management and schedule management. A questionnaire survey was conducted with key project participants in order to identify the key factors that contribute towards cost overruns and delays in the project. This is one of very limited number of studies which have in-depth investigation of mega water transformation projects in a systematic manner. The findings are expected to assist both academics and industry practitioners gain a better understanding of management practices in this mega water transformation project. This is particularly useful as the project team has to deal with a variety of sustainability related issues apart from traditional project management duties. Similarly, the lessons learnt from this case study will provide a valuable reference for the management of mega engineering projects and act as useful inputs for an international benchmarking exercise.

Water quality model parameter identification of an open channel in a long distance water transfer project based on finite difference, difference evolution and Monte Carlo

A new method is proposed based on the finite difference method (FDM), differential evolution algorithm and Markov Chain Monte Carlo (MCMC) simulation to identify water quality model parameters of an open channel in a long distance water transfer project. Firstly, this parameter identification problem is considered as a Bayesian estimation problem and the forward numerical model is solved by FDM, and the posterior probability density function of the parameters is deduced. Then these parameters are estimated using a sampling method with differential evolution algorithm and MCMC simulation. Finally this proposed method is compared with FDM-MCMC by a twin experiment. The results show that the proposed method can be used to identify water quality model parameters of an open channel in a long distance water transfer project under different scenarios better with fewer iterations, higher reliability and anti-noise capability compared with FDM-MCMC. Therefore, it provides a new idea and method to solve the traceability problem in sudden water pollution accidents.

Discussion on the Harm and Protection of Water Hammer of Cavities Collapsing during Long Distance Water Transfer Project

In long distance water transfer project, the pipeline pressure caused by the change of hydraulic impact on pipeline is the most dangerous, which cavities hammer boost up to the general water several times, the tube explosion phenomenon is most caused by water hammer of cavities collapsing. After long-term practice, two-way surge tower and constant speed buffer air valve effect remarkable on water hammer of cavities collapsing.

Simulation and analysis of ice processes in an artificial open channel

The Middle Route Project for South-to-North Water Transfer, which consists of a long artificial open channel and various hydraulic constructions, is a big water conveyance system. A numerical modeling of water conveyance in the ice period for such large-scale and long distance water transfer project is developed based on the integration of a river ice model and an unsteady flow model with complex inner boundaries. A simplified method to obtain the same flow discharge in the upstream and downstream of the structure by neglecting the storage effect is proposed for dealing with the inner boundaries. According to the measured and design data in winter-spring period, the whole ice process, which includes the formation of the ice cover, its development, the melting and the breaking up as well as the ice-water dynamic response during the gate operation for the middle route, is simulated. The ice characteristics and the water conveyance capacity are both analyzed and thus the hydraulic control conditions for a safety regulation are obtained. At last, the uncertainties of some parameters related to the ice model are discussed.

Modeling, Simulation and Automatic Control of Long Distance Water Transfer in Winter

In order to automatically control the long distance water transfer in winter, mathematic models, modes of water transfer in winter, operation methods and control models of long distance canal system are introduced. After receiving the cold current forecast, the discharges must be reduced so as to decrease the flow velocity. When the flow velocities are all below 0.4m/s, ice flowers will accumulate and form ice cover. Then the canal system successfully achieves transition from normal open flow state to icing model state. This paper points the present research process and the further research issues.

Real Time Temperature Simulation on Caohe River Aqueduct in South to North Water Transfer Project During Construction Period

The cracking control standard of water delivery structure is quite strict especially for middle-route of south-to-north water transfer project with long distance water transfer, large discharge, the crack prevention standard is extraordinary strict and must be reached. Early crack during construction period will affect safe operation of aqueduct, and diurnal variation of air temperature has significant effect on temperature field of thin-walled structure. Construction process simulation and temperature filed calculation during construction period about Caohe river landing rectangle aqueduct of Beijing-Shijiazhuang emergency water supply engineering of middle-route of south-to-north water transfer project are carried out by FEM , and compared with the monitoring temperature. The comparison result shows that temperature field during construction can be accurately simulated by calculation, which is helpful for guiding construction and choosing construction scheme, and worthy to popularize to other similar projects. From the calculation and monitoring, the maximum temperature difference is less than the standard, so there will be no serous cracks during construction in Caohe river aqueduct.

Water import and transfer versus desalination in arid regions: GCC countries case study

The scarcity of water resources and the increasing gaps between demand and available supply in the Gulf Cooperation Council (GCC) countries is a major challenging issue facing the development sectors. GCC countries have extremely dry climates with rare rainfall, high evaporation rates and limited non-renewable groundwater resources. At present all GCC countries except Oman fall in the critical water scarcity category which is about 500 m3 of renewable water/cap/year. In addition, governmental policies with regard to increasing the level of food self-sufficiency through subsidies and other incentives, have contributed to a major expansion in and unrestricted use of non-renewable groundwater resources. This coupled with a lack of defined policies and strategies geared toward optimizing and managing the scarce water supplies within the GCC region, have contributed to wasteful and uneconomic practices, as well as to the inefficient mining of non-renewable supplies. To meet the present and future water demands of the region the available options are limited to either long distance water transfer and import from other countries or investing in large scale seawater desalination installations. In this paper the economical, technical, sustainability and the political criteria affecting the two alternatives have been evaluated. Economic analysis revealed that the cost of long distance water transfer can escalate to more than 0.83 US$ per cubic meter. When sustainability considerations are taken into account this figure may reach up to 2.35 US$ per cubic meter. While these figures were competitive with the cost of seawater desalination 20 y ago, the situation has been recently shifted in favor of seawater desalination which dropped from 5.5 US$ in 1979 to less than 0.55 US$ in 1999 using the RO technology. It is concluded that sustainable development of GCC countries will depend in the future on large scale desalination. This fast growing technology should replace or at least be considered a viable alternative to presently planned water transfer projects. Expanding desalination capacity in the next 20 y will be possible by building new plants or upgrading the existing facilities in GCC countries. This process, however, will require high economic investment.

Water transfer versus desalination in North Africa: sustainability and cost comparison

AbstractThe North African region is experiencing water scarcity that is getting more severe with time. The regional annual average per capita water availability has been reduced from 2285 cubic meters in 1955 to 958 cubic meters in 1990 and is expected to reach 602 cubic meters by the year 2025. To meet the present and future water demands of the region the available options are limited to either long distance water transfers from the southern aquifers to the coastal areas or to investing in large scale seawater desalination technology. Economic analysis revealed that the cost of long distance water transfer can escalate to more than 0.83 US Dollars per cubic meter. When sustainability considerations are taken into account this figure may reach up to 2.35 US Dollars per cubic meter. While these figures were competitive with the cost of seawater desalination twenty years ago, the situation has been recently shifted in favor of seawater desalination which dropped from 5.5 US Dollars in 1979 to less than 0.55 US Dollars in 1999. It is concluded that sustainable development of North Africa will depend in the future on large scale desalination as a last resort. Presently, planned water transfer projects should be substituted by this fast growing technology as the best option.

Long Distance Water Transfer (A Chinese Case Study and International Experiences

Long Distance Water Transfer (A Chinese Case Study and International Experiences

Long distance water transfer: the Chinese plans

The demand for water has been increasing steadily with increases in population and standard of living. The food and energy crises of the Seventies have made water resources development a priority issue in many countries. Agriculture currently accounts for 80 % of all global water consumption but hydroelectric generation does not consume any water. Since irrigation and hydropower generation are compatible uses of water, most recent water developments include both these uses. Quantity of water available to any country is limited, but demands are continually rising. Accordingly, water use has to be made more efficient and options like interregional water transfers have to be explored. The paper outlines the problems and prospects associated with long distance water transfer projects and discusses the latest plans for this type of development in the People's Republic of China.