Scenario Optimisation of Pumping Schedules in a Complex Water Supply System Considering a Cost–Risk Balancing Approach

The optimisation of water pumping plant activation schedules is a significant issue when managing emergency and costly water transfer under a drought risk. This problem needs specific optimisation tools to deal with complex multi-reservoir supply systems and to consider different alternative scenarios. The effectiveness of emergency transfers alleviating droughts requires early warning and activation; on the other hand, the high operating costs of pump stations require system managers to take a robust approach that defines activation rules. The proposed optimisation procedure combines scenario optimisation analysis with a cost-risk balancing approach. The model searches for the identification of optimal decision rules by balancing the risk of water shortages and the operating costs of pumping stations. Scenario optimisation provides ‘barycentric’ values that define the activation threshold by comparing hydrological synthetic series results. A multi-objective approach is also required in order to balance energy cost minimisation requirements and a reduction of damage needs that can be caused by water shortages. Consequently, a scenario optimisation has been developed considering the multi-objective and cost-risk balancing problem. A model application has been developed optimising water management and energy costs in a real water system with shortage risks in the South Sardinia (Italy) region.     

考虑湖泊调蓄的引江济淮工程旬水量调度方案

为挖掘引江济淮工程沿线湖泊调蓄能力在保障供水、降低泵站输水能耗方面的潜力,开展考虑湖泊调蓄的 跨流域调水工程旬水量调度研究,构建考虑湖泊调蓄的泵站-湖泊多目标旬水量优化调度模型,并采用遗传算法进 行求解,以制定满足用水单元缺水量最少、泵站能耗最小和湖泊不平衡量最小的泵站-湖泊联合调度方案。分析 引江济淮工程调度运行的不同典型运行工况,以自流引江工况为例讨论考虑湖泊调蓄的旬水量调度方案的优势。 结果表明,考虑湖泊调蓄的调度方案能有效提高供水保证率、降低泵站总输水能耗,可为引江济淮工程运行调度 提供决策支撑。     

南水北调来水调入密云水库调蓄工程梯级泵站机组选型设计与研究

南水北调来水调入密云水库调蓄工程,通过沿京密引水渠建梯级泵站将南水北调来水调入密云水库,解决来水与北京市用水过程不匹配问题,提高供水可靠性。本文通过重点分析调蓄工程梯级泵站特点,理论和试验相结合地选择合理的超低扬程供水泵站泵型,选用合适的水力模型优化了流道设计,提高了泵站水力性能和泵站装置效率。研究成果可为类似调蓄工程超低扬程泵站设计提供参考。     

大中型长距离梯级有压管道供水泵站水泵系统设计关键问题总结探讨

大中型、长距离梯级有压管道供水泵站的水泵系统设计不仅需综合考虑泵站梯级设置、泵站水锤防护、梯级泵站流量平衡等系统设计的关键问题,还需解决泵站的变工况计算、水泵调节工况计算、节能运行方式等问题。就东莞市东江与水库联网工程中的主体工程-供水水源工程探讨长距离梯级有压管道供水泵站的水泵系统设计应注意的关键性技术问题。     

新疆泵站工程机电设计浅析

针对近年来新疆大中型泵站规划设计中遇到的典型问题，通过工程技术经济反复比较论证的方法，对干旱、沙漠、高寒、高海拔地区建设泵站工程机电专业设计方面的若干特点进行了探讨。干旱区域引调水泵站工程的建设，解决了部分绿洲经济系统与荒漠生态系统水资源供需矛盾，加速了新疆社会经济快速发展。     

含翻水线的两库系统联合调度优化方法研究

丰水地区水库和泵站系统水资源优化调度的目标应该是解决系统季节性缺水、弃水、补水共存的矛盾。针对含有翻水线的两库系统,对系统的联合调度控制参数设计正交试验,然后采用动态规划对子系统模型进行求解,可以同时获得两座水库最优的供、弃水量过程和两座泵站最优的提水量过程。将该方法应用于江苏省南京市六合区山湖水库与泥桥水库及其翻水线的联合调度方案中,以2016年为例,在满足系统需水的前提下,可以减少25. 7%的系统年总补水量,节约245 h的泵站运行时间,降低了系统的运行成本。     

南水北调东线工程江苏段多目标优化调度研究

考虑南水北调东线工程供水目标、经济成本以及系统稳定性特点,本文以受水区生活、工业以及农业用水供水量最大,梯级总抽水量最小以及调水峰值最小5个目标为优化目标,构建了南水北调东线工程江苏段水资源优化调度模型。在此基础上,针对传统多目标蛙跳算法(MOSFLA)存在多样性差,后期易陷于局部最优解等缺点,本文提出了一种改进的多目标蛙跳算法(MQSFLA),通过引入实数量子编码、采用改进的量子旋转门局部更新策略以及基于动态外部档案集维护Pareto非劣解的方式,改善传统MOSFLA。分别基于MQSFLA和MOSFLA求解3种典型来水条件下的多目标优化模型,分析不同目标之间的关系,提出调蓄湖泊群联合优化调度和水量调配方案。结果表明:MQSFLA在多样性和收敛性方面都优于传统的MOSFLA,能得到更多高质量的非劣解集,更有效协调供水以及抽水的矛盾,满足不同来水条件下多水源相互补给的多目标优化调度,为南水北调东线工程江苏段的运行管理提供理论依据和科学支撑。     

南水北调东线工程金湖站厂房布置研究

金湖站位于南水北调东线长江至洪泽湖段输水线上，其主要任务是供水、排涝和防洪，设计流量150m^3／s，安装灯泡贯流式机组5台套。该站采用堤身式布置型式，具有挡洪水位高，机组安装位置低，单机设计流量大，供排水扬程悬殊，周边地势低洼等特点。为协调好站区内外部环境，提供良好的运行管理条件，现从金湖站工程的具体条件出发，提出了四个厂房布置方案进行研究，经技术、经济比较，选择了地下式厂房的布置方案。     

Strategic optimization for implementing the Jordanian National Water Master Plan

The Jordan National Water Master Plan integrates multiple efforts to address the national water shortage, but suffers problems in implementation. The systems analysis-based approach proposed here involves stakeholders in defining: study areas/issues, flow limits (based on infrastructural, sustainability and management reasons), and the optimization objective function. The approach includes using a newly developed computer optimization model to speed analysis of stakeholder proposals. The optimization model calculates multi-period water distribution and allocation strategies, minimizing unsatisfied demand or optimizing economic effect. Implementing the approach would identify opportunities for improving water supply, conveyance and demand management, and help investment planning and international negotiations. It is transferable to other countries.     

Applying Genetic Algorithm and Neural Network to the Conjunctive Use of Surface and Subsurface Water

The conjunctive use of surface and subsurface water is one of the most effective ways to increase water supply reliability with minimal cost and environmental impact. This study presents a novel stepwise optimization model for optimizing the conjunctive use of surface and subsurface water resource management. At each time step, the proposed model decomposes the nonlinear conjunctive use problem into a linear surface water allocation sub-problem and a nonlinear groundwater simulation sub-problem. Instead of using a nonlinear algorithm to solve the entire problem, this decomposition approach integrates a linear algorithm with greater computational efficiency. Specifically, this study proposes a hybrid approach consisting of Genetic Algorithm (GA), Artificial Neural Network (ANN), and Linear Programming (LP) to solve the decomposed two-level problem. The top level uses GA to determine the optimal pumping rates and link the lower level sub-problem, while LP determines the optimal surface water allocation, and ANN performs the groundwater simulation. Because the optimization computation requires many groundwater simulations, the ANN instead of traditional numerical simulation greatly reduces the computational burden. The high computing performance of both LP and ANN significantly increase the computational efficiency of entire model. This study examines four case studies to determine the supply efficiencies under different operation models. Unlike the high interaction between climate conditions and surface water resource, groundwater resources are more stable than the surface water resources for water supply. First, results indicate that adding an groundwater system whose supply productivity is just 8.67 % of the entire water requirement with a surface water supply first (SWSF) policy can significantly decrease the shortage index (SI) from 2.93 to 1.54. Second, the proposed model provides a more efficient conjunctive use policy than the SWSF policy, achieving further decrease from 1.54 to 1.13 or 0.79, depending on the groundwater rule curves. Finally, because of the usage of the hybrid framework, GA, LP, and ANN, the computational efficiency of proposed model is higher than other models with a purebred architecture or traditional groundwater numerical simulations. Therefore, the proposed model can be used to solve complicated large field problems. The proposed model is a valuable tool for conjunctive use operation planning.     

引江济淮工程（河南段）多目标水量优化调度

引江济淮工程（河南段）涉及河道、闸泵、管道和调蓄水库,约束条件复杂,常规的优化调度算法难以搜索可行解,求解效率低。选用受水区缺水率平均值最小、泵站总抽水量最小和受水区缺水率标准差最小作为目标函数,从供水保障、供水成本和公平性角度构建多目标水量优化调度模型。基于可行搜索思路,结合逆序演算和顺序演算过程对约束条件进行处理,引入决策系数,通过映射关系使搜索空间保持在可行域中,结合多目标非支配排序遗传算法（non-dominated sorting genetic algorithms,NSGA-II）进行求解,得到Pareto最优解集,并采用熵权法进行方案优选。结果表明,基于可行搜索的NSGA-II算法能够有效求解复杂调度系统的多目标优化问题,综合考虑多个目标的最优方案相对单目标方案更加合理,结果可为引江济淮工程（河南段）运行管理提供决策支撑。     

基于改进 GRA-NARX 模型的不同预见期 泵站水位预测

基于超参数自动率定的 GRA-NARX（grey?relation?analysis-nonlinear?autoregressive?model?with?exogenous?inputs） 模型是 GRA-NARX 模型的一种有效改进。以南水北调东线一期工程洪泽泵站为例，使用基于超参数自动率定的 GRA-NARX 模型，针对 1?h 和 2?h 时间间隔的输入数据，分别预测 3 个短预见期（2?h、4?h、6?h）和 1 个长预见期（12?h） 的泵站站前水位，并与 GRA-BP（grey?relation?analysis-back?propagation）模型的预测结果进行比较。结果表明：不同 预见期（2?h、4?h、6?h、12?h）下，基于超参数自动率定的 GRA-NARX 模型的相关系数、均方根误差和平均绝对误差 等指标均相差不大，预测精度高，且皆优于 GRA-BP 模型；采用 1?h 时间间隔的输入数据预测结果优于 2?h 时间间 隔的输入数据结果。研究成果可为不同预见期泵站站前水位预测提供理论参考。     

Distributed Simulation‐optimization Model for Conjunctive Use of Groundwater and Surface Water Under Environmental and Sustainability Restrictions

Evolving optimal management strategies are essential for the sustainable development of water resources. A coupled simulation-optimization model that links the simulation and optimization models internally through a response matrix approach is developed for the conjunctive use of groundwater and surface water in meeting irrigation water demand and municipal water supply, while ensuring groundwater sustainability and maintaining environmental flow in river. It incorporates the stream-aquifer interactions, and the aquifer response matrix is generated from a numerical groundwater model. The optimization model is solved by using MATLAB. The developed model has been applied to the Hormat-Golina valley alluvial stream-aquifer system, Ethiopia, and the optimal pumping schedules were obtained for the existing 43 wells under two different scenarios representing with and without restrictions on stream flow depletion, and satisfying the physical, operational and managerial constraints arising due to hydrological configuration, sustainability and ecological services. The study reveals that the total annual optimal pumping is reduced by 19.75?% due to restrictions on stream flow depletion. It is observed that the groundwater pumping from the aquifer has a significant effect on the stream flow depletion and the optimal conjunctive water use plays a great role in preventing groundwater depletion caused by the extensive pumping for various purposes. The groundwater contribution in optimal conjunctive water use is very high having a value of 92?% because of limited capacity of canal. The findings would be useful to the planners and decision makers for ensuring long-term water sustainability.

     

Optimal Land-Use Management for Surface Source Water Protection Under Uncertainty: A Case Study of Songhuaba Watershed (Southwestern China)

The water supply to Chinese cities is increasingly degrading from pollution due to watershed activities. Consequently, water source protection requires urgent action using optimal land-use management efforts. An inexact linear programming model for optimal land-use management of surface water source area was developed. The model was proposed to balance the economic benefits of land-use development and water source protection. The maximum net economic benefit (NEB) was chosen as the objective of land-use management. The total environmental capacity (TEC) of rivers and the minimum water supply (MWS) were considered key constraints. Other constraints included forest coverage, government requirements concerning the proportions of various land-use types, soil loss, slope lands, and technical constraints. A case study was conducted for the Songhuaba Watershed, a reservoir supplying water to Kunming City, the third largest city in southwestern China. A 15-year (2006 to 2020) optimal model for land-use management was developed to better protect this water source and to gain maximum benefits from development. Ten constraints were involved in the optimal model, and results indicated that NEB ranged between 893 and 1,459 million US$. The proposed model will allow local authorities to better understand and address complex land-use systems and to develop optimal land-use management strategies for balancing source water protection and local economic development.     

Optimization of Irrigation with Photovoltaic Pumping System

The usual methods for optimal sizing of photovoltaic (PV) irrigation water pumping systems, which separately considered the demand for hydraulic energy and possibilities of its production from available solar energy with the PV pumping system, are not optimal. However, by systematic approach to the problem, taking into account all relevant elements, from the PV water pumping system, water intake, local climate, soil, crops to method of irrigation, it is possible to optimize the determination of nominal power of the PV generator and obtain quality solutions. This paper presents one such method for optimal sizing. For the purpose of testing the proposed model for optimal sizing, in order to show to what extent it describes the system and to obtain corresponding research results, two areas were selected, in typical climate regions of Osijek and Split, as patterns of continental and coastal Croatia. By variation of certain values in the system, their effects on calculation of the optimal electric power of PV generator were observed.     

引汉济渭调水工程受水区水资源优化配置研究

陕西省引汉济渭调水工程是解决关中地区严重缺水的跨流域调水工程,在充分考虑受水区的经济、社会和生态环境等因素以及水资源供需平衡分析基础上,基于系统分析方法建立了大系统分解协调模型,以供水区综合效益最大、缺水量最小为全局最优解,得到了2020年和2030年调水工程所调水量的优化配置方案。     

Intermittent Water Supply under Water Scarcity Situations

Abstract

This paper describes the recently developed ‘Guidelines for the design and control of intermittent water distribution systems’. These guidelines outline a new approach to the design of urban water distribution systems for developing countries in order to maintain adequate and equitable supplies under the common conditions of water resource shortage. The guidelines are novel in that they recognise the reality of intermittent supply and hence provide new methods of analysis and design, appropriate for such systems. Design objectives specifically tailored to intermittent systems are developed and drive the design process. These objectives are expressed in terms of equity in supply, adequate pressure at water connections and duration or time of supply that are convenient to the consumers. The modifications required to model such systems have been incorporated into a new network analysis simulation tool coupled with an optimal design tool.     

潮汐变化对长江沿江大型泵站变频变速优化运行方式影响探讨

针对长江沿江大型泵站变频变速优化运行受潮汐影响的问题,提出了以泵站单机组耗电费用最少为目标函数的优化运行数学模型,考虑水量与机组功率约束,采用动态规划的方法,以江都四站为例进行计算,确定不同水量约束、不同日均扬程、不同日均潮差变幅条件下单纯长江潮汐变化对泵站单机组变频变速优化运行结果的影响。结果表明:随着日均扬程的降低、日均潮差的增大,沿江泵站变频变速优化运行效果愈加明显。     

邯郸市南水北调供水区多水源联合调度研究

为了增加供水区水资源的承载能力,促进社会、经济、环境可持续发展,通过对邯郸市南水北调供水区的供水系统的分析,建立了供水系统优化调度的动态规划模型,经过调试计算,制定了外调水与当地水不同来水组合情况下的调度方式,为其他地市多水源联合调度提供借鉴。     

Energy efficiency in a water supply system:Energy consumption and CO2 emission

This paper presents important fundamentals associated with water and energy efficiency and highlights the importance of using renewable energy sources.A model of multi-criteria optimization for energy efficiency based on water and environmental management policies,including the preservation of water resources and the control of water pressure and energy consumption through a hybrid energy solution,was developed and applied to a water supply system.The methodology developed includes three solutions:(1)the use of a water turbine in pipe systems where pressures are higher than necessary and pressure-reducing valves are installed,(2)the optimization of pumping operation according to the electricity tariff and water demand,and(3)the use of other renewable energy sources,including a wind turbine,to supply energy to the pumping station,with the remaining energy being sold to the national electric grid.The use of an integrated solution(water and energy)proves to be a valuable input for creating benefits from available hydro energy in the water supply system in order to produce clean power,and the use of a wind source allows for the reduction of energy consumption in pumping stations,as well as of the CO2 emission to the atmosphere.