Multi-water Resources Research Articles

Multi-Water Resources Optimal Allocation Based on Multi-Objective Uncertain Chance-Constrained Programming Model

Owing to serious water shortages and frequent water waste, water crises have swept the world and become progressively severe. One major question is how to rationally allocate limited water resources to guarantee daily water requirements and achieve sustainable and coordinated development simultaneously. The combined use of different sources, such as diverted water and local water including reclaimed water, surface and ground water, within a region is an efficacious means to address the imbalance between water supplying and using. Aiming at managing complex uncertainties existing in water resource systems, this paper seeks for a reasonable distribution plan by a multi-objective uncertain chance-constrained programming (MUCCP) approach between multi-water resources and multiple water users. In this model, we adopt an uncertain variable as a new tool to manage the incertitude in parameters. Meanwhile, the likelihood that something will happen is quantified by the uncertain measure. This proposed MUCCP model sets the economic, social and environmental benefits as objectives with capacities of water supply and demand as uncertain chance constraints. Then, the solution to MUCCP model is obtained by solving its crisp equivalent version. Finally, the model is implemented for determination of optimal allocation policy in Handan City, Hebei Province. The results suggest that the MUCCP model could be employed by managers for practical problems to achieve a trade-off between system cost-effectiveness and default risk under uncertainty.

Economic Dispatch Optimization of Multi-Water Resources: A Case Study of an Island in South Korea

Ensuring stable and continuous water supplies in isolated but populated areas, such as islands, where the water supply is highly dependent on external factors, is crucial. Sudden loss of function in the water supply system can have enormous social costs. To strengthen water security and to meet multiple water demands with marginal quality, the optimized selection of locally available, diversified multi-water resources is necessary. This study considers a sustainable water supply problem of Yeongjong Island, 30 km west from Seoul, South Korea. The self-sufficiency of several locally available water resources is calculated for four different scenarios based on the volume and quality of the various water sources. Our optimization results show that using all the available local sources can address the water security issues of the island in the case of interruption in the existing supply system, which is fed from a single source of mainland Korea. This optimization framework can be useful for areas where water must be secured in the event of emergency.

Study on Comprehensive Water Price of Multi-water Resources in Ningjin County

Ningjin County is located in northwest Shandong Province in the North China Plain. The water shortage can be solved if the South-to-North Water Transfer Project is completed, but the project water price is higher than the price of local groundwater and Yellow River water, so it is urgent to make the comprehensive water price of multi-water resources in this area. The water demand of non-agricultural water users in the planning year of 2020 and 2025 is forecasted based on water supply and consumption in current year of 2017, and two water supply schemes are set up respectively, four schemes totally considering the factors whether Yangtze River water will be obtained. The water prices of four schemes are calculated using weighted average model. The results show that when the transferring water replaces partial underground water in 2020, the comprehensive water prices of scheme 1 and scheme 2 are 3.21 yuan/m3 and 2.11 yuan/m3 respectively. When the transferring water replaces all groundwater in 2025, the comprehensive water prices of scheme 3 and scheme 4 are 2.92 yuan/m3 and 1.44 yuan/m3 respectively. The compensation mechanism of water price is discussed finally.

Development of a coupled quantity-quality-environment water allocation model applying the optimization-simulation method

A river basin usually provides water for multiagent. Imperfect coordination mechanisms among these agents, however, usually lead to serious water shortage, pollution, and ecological degradation. Therefore, it is vital to conduct research on allocating different kinds of water resources among multiagent including the water quantity agent, water quality agent and environment agent within a river basin. This paper proposes an optimization-simulation method that takes into consideration engineering measures, including water transfer projects, reservoirs, canal heads, and pump stations; multi-water resources such as local surface water, transferred water, groundwater, and reused sewage; and multiagent for remitting serious water problems. In the proposed optimization-simulation method, the groundwater and reused sewage are first allocated according to the water resources allocation simulation module (Module 1). Then, local surface and transferred water are allocated based on the water resources allocation optimization module (Module 2), which comprises water quantity, water quality and environment agents’ objectives based on synergism. Finally, the instream water quality is simulated according to the water quality simulation module (Module 3). Results show that, compared to the current situation, the water quantity and environment agent guarantee rates can satisfy the design requirements in the planning year of 2020. The regulated instream water quality is also improved; although, it still remains relatively poor. Water quality in the downstream is worse than that in the upstream. In addition, the water quality shows a positive correlation with the instream streamflow. These results certify the proposed optimization-simulation method can provide support for efficacious multiagent water resources allocation.

Optimal Allocation Method of Irrigation Water from River and Lake by Considering the Field Water Cycle Process

At present, the shortage of water resources has become a serious constraint to the further development of social economy. The optimal allocation of multi-water resources is valuable for agricultural water management in arid and semi-arid regions. However, traditional deterministic programming does not solve the complex water resources allocation in irrigation systems. Furthermore, previous allocation methods of irrigation water seldom considered the water cycle process, especially for multi-sources of irrigation. In this study, we develop an inexact fuzzy stochastic simulation-optimization programming (IFSSOP) model for the irrigation water optimal allocation of two water sources. The model combines the crop water model and the field water cycle model with an uncertainty optimization model, which considers the contribution of groundwater to crop water consumption. As a case study, the developed model is used in an arid area with two irrigation water sources: a river and a lake. Accordingly, the total optimal allocation irrigation water amounts of river and lake water under different violation probabilities in various hydrological years were obtained. By comparing the IFSSOP model with the IFSSOP model without considering the contribution of shallow groundwater (IFSSOP-NG model), it can be shown that the system benefits of the developed model are higher. With the lake water source from flood water, the region can save 30–34% of the river water, maintaining the original crop water deficit irrigation ratio. Consequently, application of the IFSSOP model in irrigation scheduling will provide effective water allocation patterns to save more water in an arid region with shallow groundwater.

Chance-Constrained Dynamic Programming for Multiple Water Resources Allocation Management Associated with Risk-Aversion Analysis: A Case Study of Beijing, China

Water shortage and water pollution have become major problems hindering socio-economic development. Due to the scarcity of water resources, the conflict between water supply and demand is becoming more and more prominent, especially in urban areas. In order to ensure the safety of urban water supply, many cities have begun to build reservoirs. However, few previous studies have focused on the optimal allocation of water resources considering storage reservoirs. In this study, a multi-water resources and multiple users chance-constrained dynamic programming (MMCDP) model has been developed for water resources allocation in Beijing, China, which introduces reservoir and chance-constrained programming into the dynamic programming decision-making framework. The proposed model can distribute water to different departments according to their respective demands in different periods. Specifically, under the objective of maximal benefits, the water allocation planning and the amount of water stored in a reservoir for each season under different feasibility degrees (violating constraints or available water resources situations) can be obtained. At the same time, the model can be helpful for decision-makers to identify the uncertainty of water-allocation schemes and make a desired compromise between the satisfaction degree of the economic benefits and the feasibility degree of constraints.

An Integrated Method for Interval Multi-Objective Planning of a Water Resource System in the Eastern Part of Handan

In this study, an integrated solving method is proposed for interval multi-objective planning. The proposed method is based on fuzzy linear programming and an interactive two-step method. It cannot only provide objectively optimal values for multiple objectives at the same time, but also effectively offer a globally optimal interval solution. Meanwhile, the degree of satisfaction related to different objective functions would be obtained. Then, the integrated solving method for interval multi-objective planning is applied to a case study of planning multi-water resources joint scheduling under uncertainty in the eastern part of Handan, China. The solutions obtained are useful for decision makers in easing the contradiction between supply of multi-water resources and demand from different water users. Moreover, it can provide the optimal comprehensive benefits of economy, society, and the environment.

多水源优化调度技术研究

针对宜兴市目前以横山水库和油车水库为主水源，西氿水作为备用水源的格局，根据生活用水水厂和水源的分布，并同时考虑水厂的取水量和水源水水质的变化，探讨了不同情况下的多水源水量的切换、原水配送策略及原水应急处理措施的判断规则，制定出多水源常规调度和多水源应急调度，保障宜兴市的用水安全，为多水源供水系统的规划设计、运行管理等工作提供借鉴。 Hengshan reservoir and Youche reservoir were used as the main water source and Xijiu water was the emergency water source in Yixing city. According to the distribution of water source and waterworks, as well as the changes of water withdrawals and water quality, the judgment rule of multi-water resources switching, distribution of raw water and emergency management measure were discussion. At last，multi-water resources regular dispatching and multi-water resources emergency dispatching were formulated, which offered protection for the water security in Yixing City.

Life cycle assessment of water supply alternatives in water-receiving areas of the South-to-North Water Diversion Project in China

To alleviate the water shortage in northern China, the Chinese government launched the world's largest water diversion project, the South-to-North Water Diversion Project (SNWDP), which delivers water from water-sufficient southern China to water-deficient northern China. However, an up-to-date study has not been conducted to determine whether the project is a favorable option to augment the water supply from an environmental perspective. The life cycle assessment (LCA) methodology integrated with a freshwater withdrawal category (FWI) was adopted to compare water supply alternatives in the water-receiving areas of the SNWDP, i.e., water diversion, wastewater reclamation and seawater desalination. Beijing, Tianjin, Jinan and Qingdao were studied as representative cities because they are the primary water-receiving areas of the SNWDP. The results revealed that the operation phase played the dominant role in all but one of the life cycle impact categories considered and contributed to more than 70% of their scores. For Beijing and Tianjin, receiving water through the SNWDP is the most sustainable option to augment the water supply. The result can be drawn in all of the water-receiving areas of the middle route of the SNWDP. For Jinan and Qingdao, the most sustainable option is the wastewater reclamation system. The seawater desalination system obtains the highest score of the standard impact indicators in all of the study areas, whereas it is the most favorable water supply option when considering the freshwater withdrawal impact. Although the most sustainable water supply alternative was recommended through an LCA analysis, multi-water resources should be integrated into the region's water supply from the perspective of water sustainability. The results of this study provide a useful recommendation on the management of water resources for China.

A Study on Type of Smart Water Grid Pipeline System (multi waterloop system) and Application Method

In these days, water-loop system using multi water resources is lively discussed. This system distributes water effectively by using multi water resources instead of new water resources development. Multi water resources consist of surface water, rainwater, reclaimed water, seawater etc. This system would be distributing sanitary water stably, and able to economical maintain the related facilities. Also, this system has an emergency reaction ability when system is faced with accident. Especially, if multi water loop system is constructed by using the city’s securable water, nation’s water resources will be utilized effectively and water resources will be developed or reused on a small scale. The neces elements of water-loop system design are suggested in this research. The elements are the followings; Model of connected water-loop pipe networks, platform model of multi water resources loop system, range of technology, difference with existing systems and direction of construction.

Theoretical Considerations of Joint Optimal Model for Water Allocation and Pipe Placement

Water shortage emerges and restricts the urban construction and the social-development due to the rapid expansion of the cities. Recent research mainly focuses on the water resources management or water distribution network management separately. In this paper, a joint optimal model for water allocation and water distribution network management is developed. In the first phase, a multi-objectives linear programming is used for the optimal allocation on multi-water resources for multi-users, in which cost and water conservation are regards as objectives. In the second phase, a non-linear model is proposed, which is solved by single-objective GA linking to EPANET hydraulic solver. The result of the first phase is a parameter of the objective in the second phase.

The Optimal Allocation of Large-Scale Water Resource

Large-scale water resource system with multi-water resources and multi-users consists of several independent supply and drainage network systems. It is hard to solve the problem well of large-scale water resource system with traditional planning method. We model the problem of optimal allocation of water resource using the principles of biological evolution, and eliminate the inferior by judging the optimization degree of each generation individuals, then produce a new generation, thus the optimal allocation of water resource is accomplished through iteration repeated. The disadvantage is that MOGA solution out of the quasi-global optimal solution, rather than the true optimal solution.

Research on the Influence of Rainstorm Duration Distribution to the Multi-Water Resources Allocation of Artificial Lake

With the development of the people's living standard, artificial lake has already become the important part of the urban ecological construction. The artificial lake needs a certain amount of water resources as a support, however, conventional water resources fail to meet the water demand of the artificial lake in the water shortage area. According to the water demand of meeting the artificial lake's ecological function, the paper has established the urban artificial lake multi-water resources optimal allocation model which based on the water quantities and water quality constraints. And under the different rainstorm duration distribution conditions, the model has been applied to settle the multi-water resources which include the conventional and unconventional water resources optimal allocation problem of the Tianjin Meijiang artificial lake and analyze the influence of rainstorm duration changes to the allocation. The results can provide a good foundation for the multi-water resources reasonable optimal allocation of the urban artificial lake.

Inexact fuzzy two-stage programming for water resources management in an environment of fuzziness and randomness

A standard lower-side attainment values based inexact fuzzy two-stage programming (SLA-IFTSP) approach is proposed for supporting multi-water resources management under multi-uncertainties. The method improves upon the existing inexact two-stage stochastic programming by the introduction of a standard average lower-side attainment values based fuzzy linear programming. Multi-uncertainties such as intervals, probabilistic and/or possibilistic distributions and their combinations in water resources management can be directly communicated into the water allocation process. The risk of infeasibility caused by the random water availabilities can be analyzed by imposing economic penalties when the designed water allocations would not be satisfied after the occurrence of random seasonal flows. Based on the standard average lower-side attainment index, the fuzzy random relationships representing various subjective judgments in the model can be transformed into corresponding deterministic ones without additional constraints, and thus guarantee a higher computational efficiency. A hypothetical case regarding two-source water resources management is adopted for demonstrating its applicability. Reasonable solutions have been generated. They provide desired water allocations with maximized system benefit under different water availability levels. The solutions of intervals with different probabilities can be used for generating decision alternatives. Comparisons between the solutions from SLA-IFTSP and those from ITSP are also undertaken. They show that SLA-IFTSP can generate more reasonable water allocation patterns with higher net system benefits than ITSP.