Operation Of Water Distribution Systems Research Articles

Novel approach for burst detection in water distribution systems based on graph neural networks

Sustainable management of water resources is a key challenge for the well-being and security of current and future society worldwide. In this regard, water utilities have to ensure fresh water for all users in a demand scenario stressed by climate change along with the increase in the size of cities. Dealing with anomalies, such as leakages and pipe bursts, represents one of the major issues for efficient water distribution system (WDS) operation and management. To this end, it is crucial to count on suitable methods and technologies to provide a quick, reliable, and accurate detection of such anomalies and supply disruption events. Therefore, this work proposes a novel WDS management framework based on the development of graph convolutional neural networks (GCN) models for bursts detection in WDSs. These methods rely on a WDS graph representation for a set of pressure and flow rates measures. Such a graph is used to design two GCN-based models to identify bursts. In addition, two conventional multi-layer perceptron models are used as the benchmarks to compare the graph-based methodologies. Finally, the proposed methodology is tested on a water utility network, showing the high potential of graph convolutional networks for anomaly detection on WDSs.

Comparison of the Performance of a Surrogate Based Gaussian Process, NSGA2 and PSO Multi-objective Optimization of the Operation and Fuzzy Structural Reliability of Water Distribution System: Case Study for the City of Asmara, Eritrea

Comparison of the Performance of a Surrogate Based Gaussian Process, NSGA2 and PSO Multi-objective Optimization of the Operation and Fuzzy Structural Reliability of Water Distribution System: Case Study for the City of Asmara, Eritrea

Optimal water distribution model of canals considering the workload of managers

AbstractThe optimal operation of water distribution systems is an important research area for the modernization of irrigation schemes. In this paper, an improved 0–1 programming model is developed. This model has three objectives: minimum time of water distribution, minimum spacing of tertiary canals in a group, and the minimum difference of water distribution duration among tertiary canals in the group. The study results show that with the conventional model, 0–1 programming model and improved 0–1 programming model, the durations for the three models are 159.09, 140.50 and 141.07 h, respectively. The working distances are 44.8, 185.5 and 60.6 km. Compared with the conventional model, the lower canals of the improved 0–1 model are all large flow rate operations, while the conventional model inevitably has small flow rate operations, and the improved 0–1 model greatly reduces the duration of water distribution. Compared with the 0–1 model, the improved 0–1 model divides the adjacent canals into a group as much as possible, and the canals between groups start and end operations at the same time as much as possible, so the improved 0–1 model shortens the working distance of the staff and makes it easy for canal managers to operate canals.

Energy Consumption by DHW System with a Circulation Loop as an Energy Efficiency Component, Based on an Example of a Residential Building

In the EU countries, almost 50% of the produced energy is used in residential buildings. More than 25% of this energy is used to produce domestic hot water, of which almost 80% is used to heat water in domestic hot water circulation systems. This is due to high expectations on the part of residents based on their comfort, in particular regarding the supply of heat for heating and domestic hot water. In the course of their long-term research conducted on real systems, the authors confirmed that the operation of domestic hot water distribution systems causes significant costs, mainly due to heat losses. Therefore, typical variants of energy optimization of such systems were analyzed. Tests have shown that selected solutions, such as the use of control automation, are not sufficient, and recommended additional thermal insulation may not be applicable due to technical reasons. With an aim of finding a solution to the problem, the publication analyzes operational data from an existing heat source and domestic hot water circulation system in a residential building. On the basis of these analyses, a solution was proposed to reduce energy consumption within the installation by means of its hydraulic optimization. The reduction of heat losses in domestic hot water installation by means of a method presented by the authors is estimated at approximately 20%.

Strategy to Enhance Emergency Interconnected Operation of Water Distribution System

This study identified the causes of insufficient emergency interconnected operation (EIO) performance, such as pressure-related problems and connection problems caused by elevation differences between blocks, the characteristics and locations of emergency interconnection pipes (EIPs), and pumps. Then, it tested four strategies to improve the EIO performance, including increasing the EIP diameter or installing additional EIPs, pressure reducing valves (PRVs), or pumps. The advanced pressure-driven analysis model was applied to quantify the EIO performance improvement achieved using these strategies. Further, these strategies were tested in a real water distribution system. To solve the low-pressure problem, the EIP diameter was increased and an additional pump was installed; the former did not significantly improve, whereas the latter improved supply by 20–30%. To solve the high-pressure problem, PRVs were installed to maintain the EIO performance effectively. To solve connection problems, new EIPs were installed. Although this improved the supply performance, the installation of pumps was recommended to overcome elevation differences. The proposed strategies should contribute to the allocation of facilities such as EIPs, pumps, and PRVs for realizing effective EIO.

Management and health risk assessment of chemical contamination events in water distribution systems using PSO.

An accidental or intentional contamination event can raise health and sociopolitical concerns, erode public trust, and affect the operation of water distribution systems. In this regard, emergency management plans are required to describe the necessary measures in order to deal with a threat. This study was carried out to investigate the best ways to manage intrusion in a water distribution network. In this research, the optimal management approach to deal with chemical contamination in a water distribution network was examined under three scenarios using the particle swarm optimization method. In each scenario, three management solutions were used to manage the contamination, including closing the pipe, opening the fire hydrant, and using a combination of pipe closure and fire hydrant opening. Contamination risk impact on consumers' health was assessed in the network's emergency status and after implementation of the best pollution management scenarios. The results showed that in the benchmark network, pipe closure was slightly more successful than opening of the fire hydrant valve. In pollution management of a real network, pipe closure was less effective than the hydrant opening in all scenarios. Generally, all applied scenarios were successful in reducing the contamination risk among the exposed people, so that carcinogenic and non-carcinogenic risks reduced by 100% in all scenarios compared to the non-management state.

Development of optimal water distribution system design and operation approach considering hydraulic and water quality criteria in many-objective optimization framework

Abstract Water distribution systems (WDSs) are major infrastructure, and it needs to consider economic, hydraulic stability, and water quality safety to optimal design and operation of WDSs. However, the previous studies related to WDS design and operation were focused on each field (i.e. design: optimal pipe diameter, pump sizing, and valve location; operation: optimal pump scheduling, etc.) even though the WDS design and operation have a correlation. Therefore, to achieve economic feasibility, hydraulic stability, and water quality safety under WDS design and operation process, this study develops an optimal WDS design and operation approach considering hydraulic and water quality criteria in the many-objective optimization framework. To consider design and operation, this study applies three objective functions to minimize the total design and operation cost (i.e. the pipe cost, pump construction, and pump operation cost), maximize system robustness, and minimize the amount of chlorine requisition simultaneously under the hydraulic and quality constraints. The proposed optimal WDS design and operation model was applied to the two-stage optimization procedures. The first process determined the optimal pipe diameter set. The second process determined the optimal pump construction and scheduling considering three objective functions such as the total pump cost, the system robustness, and the quantity of the required residual chlorine for determining optimally the available number of pumps, capacity, and scheduling. For the optimization, the self-adaptive multi-objective harmony search is used and a famous benchmark network for the optimal design and pump operation of WDSs is applied to verify the proposed approach. This study can provide a new perspective on WDS design and operation technique considering the essential design factors to the water utility.

A systematic approach for estimating water losses in irrigation canals

In order to determine water losses in irrigation canals, a systematic approach was developed, consisting of two main components: a seepage simulation model and a hydraulic simulation model. The SEEP/W module of the Geo-Studio software was used to simulate the seepage rate, and the Hydrologic Engineering Center-River Analysis System (HEC-RAS) hydrodynamic model was used for hydraulic simulation. Different operation scenarios were designed to investigate all possible situations in daily operation of water distribution and delivery systems. The seepage simulation results show that the seepage losses were higher at the bottom and corners of the canal, because the hydraulic gradient was affected by the hydraulic load. The hydraulic simulation results show that due to physical and management infrastructure (using non-automated and operator-based regulation structures), operational losses accounted for a significant volume of losses compared to seepage losses. In most operation scenarios, the maximum seepage loss was 10%, and the remaining 90% was related to operational losses. It is concluded that any factor (decrease or increase of inflow to the canal) that causes an increase or decrease of operational losses is ultimately a determining factor in reducing or increasing total losses. Therefore, management approaches should be adopted to improve performance of the system and reduce losses, especially operational losses, by improving the operation methods of water level regulation and off-take structures.

Diagnostic analysis of Baroda branch canal of Som Kamla Amba irrigation project, Rajasthan, India

Irrigation projects are of paramount importance in meeting the water demand of agriculture sector. Therefore, evaluating the performance of irrigation systems makes it possible to improve agricultural water management and consequently enhances irrigation efficiency. In this perspective, the present study focuses on diagnostic analysis of the Baroda branch canal of the Som Kamla Amba irrigation project, Rajasthan, India. This study attempts to identify constraints attributed to poor irrigation efficiency and remedial strategies to improve irrigation management. Results revealed that poor maintenance and lacking immediate action of damaged water distribution network were culprits resulting in silting and vegetation infestation. Poor structures viz., tempered pipe outlets and gates, blockage of minors, unauthorized pumping, and poor operations of water distribution systems resulted in poor performance of Baroda branch canal. The performance of Baroda branch canal system can be improved by adoption of appropriate strategies.

Определение приоритетных направлений по обеспечению надежной и эффективной работы существующих систем подачи и распределения воды

This paper addresses a method for determining priority areas for ensuring and maintaining the suffi-cient reliability and efficiency of existing water supply and distribution systems, based on previously obtained mathematical models of water sampling (cross-section method) and flow distribution. The main task of the organisations, operating water supply and distribution systems, involves a high-quality water supply to consumers. Regardless of the wear of water supply and distribution systems, as well as changes in their structural state, the water having suitable parameters must be supplied to the con-sumer in the required quantity. Given the variety of regimes, modelling the operation of water supply and distribution systems indicates a wide range of their possible behaviour, for example, poor quality of supply to consumers during trouble-free operation or no impact of shutdowns of some sections on the quality of supply. It is necessary to analyse the systems and model their operation regimes using a mathematical tool. Here, probabilistic nodal reliability indices of water supply to consumers were used in mathematical models. They include Kj and Pj, decomposed into components characterising the wear of elements (sections) in the system and the reliability of supply to consumers in each of its structural states. The need to adjust the system parameters to ensure the required level of reliability of its opera-tion was assessed, with various solutions being outlined. The technical and economical comparison of possible measures allows an optimum option to be determined, prioritising the replacement of outdated elements and the construction of additional elements (sections) of the system. All stages of the sug-gested method, which can be widely used by organisations, maintaining water supply and distribution systems, are shown in the example of a system.

Comparison of Imputation Methods for End-User Demands in Water Distribution Systems

AbstractThis study examines the impact of advanced metering infrastructure (AMI) end-user demand metering failure on water distribution system (WDS) operation and management. To address this issue,...

Using a digital twin to explore water infrastructure impacts during the COVID-19 pandemic.

During the coronavirus disease 2019 (COVID-19) pandemic, the daily pattern of activities changed dramatically for people across the globe, as they socially distanced and worked remotely. Changes in daily routines created changes in water consumption patterns. Significant changes in water demands can affect the operation of water distribution systems, resulting in new patterns of flow, with implications for water age, pressure, and energy consumption. This research develops a digital twin to couple Advanced Metering Infrastructure (AMI) data with a hydraulic model to assess impacts on infrastructure due to changes in water demands associated with the COVID-19 pandemic for a case study. Using 2019 and COVID-19 modeling scenarios, the hydraulic model was executed to evaluate changes to water quality based on water age, pressure across nodes in the network, and the energy required by the system to distribute potable water. A water supply interruption event was modeled as a water main break to assess network resiliency for 2019 and COVID-19 demands. A digital twin provides the capabilities to explore and visualize emerging consumption patterns and their effects on the functioning of water systems, providing valuable analyses for water utility managers and insight for optimizing infrastructure operations and planning for long-term impacts.

Optimization of Water Distribution System Operation with Multiple Tanks and Pumps: Application for Asmara, Eritrea’s Water Supply System

Pump energy consumption is the major operational cost of water distribution systems (WDS). Defining better pump operation policies can reduce the cost and the enhance service provided. The nonlinear hydraulic behavior of WDS makes the pump scheduling problem complex, especially in large WDS in which several tanks and pumping stations coexist. The nonlinear hydraulic behavior of WDS is captured using numerical simulation. However, the required energy calculations were computed from the flow rate and head increase after the pumping stations. There are many optimization algorithms for the reduction of the operational cost. The majority of these algorithms are applied to hypothetical case studies with reduced feasible solution spaces. When the search space becomes large and many alternatives (pumps combinations) are possible, most of the proposed algorithms fail. Thus, the application of these algorithms in real case studies is very limited, and water utility managers still rely on human expertise to schedule pump operation rather than on automatic scheduling. This paper proposes the use of a genetic algorithm for large WDS with a many tanks and pumps. Offline hydraulic simulations allow the definition of water level bounds in the tanks. The combination of the pumps is determined a priori and the optimization algorithm is run in a reduced search space. These preparations allow the genetic algorithm to identify quickly the optimal policy and reduce the cost of energy consumption. The proposed framework was applied to the WDS of the city of Asmara, Eritrea, with 12 tanks and 9 pumping stations. The results showed that the tanks controlled by pumps worked perfectly and the water level was kept within the defined ranges. However, the constraints were not fulfilled for uncontrolled tanks. This application showed the limitations of methodologies proposed in the literature, and it is suggested that further techniques be found to schedule the pump working policies of large WDS while reducing the violations of constraints.

Технико-экономическое обоснование стоимости транспортировки сточных вод для ирригационных целей в административном округе Кербела (Ирак)

Introduction. The study presents an assessment of the economic feasibility of different pipe materials used to transport treated wastewater. The choice was made between pipes made of ductile iron, glass-fiber reinforced polyester (GRP), concrete, and plastic. Hydraulic calculations of operation of an irrigation water supply and distribution system were made using WaterCAD V8i software. Two options of the system operation, that entail different flow rates and diameters, are considered: if the flow rate is equal to 1.16 m3/s and pipe diameters vary from 800 mm to 1,200 mm, and if the flow rate is equal to 4.63 m3/s, and pipe diameters vary from 1,600 to 2,000 mm. Materials and methods. The article analyzes the legal and regulatory documentation on design and construction, urban planning solutions for residential areas, architectural and structural solutions for apartment buildings, statistical and analytical reports on housing construction in Russia, presented on the Internet. Results. Irrigation water represents treated wastewater fed by the wastewater treatment facilities in the city of Karbala, Iraq. Two hydraulic models were designed with account for the above-mentioned costs. Head losses were estimated for each model with regard for all studied materials and pipe diameters using the WaterCAD V8i software and a mathematical model for the purpose of selecting the optimal pipe diameter. Conclusions. A mathematical model was developed to calculate the cost of transporting wastewater in pipes having different diameters and made of four different materials. The ratio of costs to the diameter of pipes, made of four different materials, was identified by developing an empirical equation. The co-authors used the Darcy – Weisbach technique and the Hazen – Williams method to calculate the operating costs with regard for variable diameters, flow rates for the two models, head losses due to friction, annual operation time, annual cost of electric energy, and the energy efficiency of the unit. Thus, a mathematical model was obtained, that can be applied to select the most optimal pipe diameter.

A Head Formulation for the Steady-State Analysis of Water Distribution Systems Using an Explicit and Exact Expression of the Colebrook–White Equation

Steady-state demand-driven water distribution system (WDS) solution is the bedrock for much research conducted in the field related to WDSs. WDSs are modeled using the Darcy–Weisbach equation with the Swamee–Jain equation. However, the Swamee–Jain equation approximates the Colebrook–White equation, errors of which are within 1% for ϵ/D∈[10−6,10−2] and Re∈[5000,108]. A formulation is presented for the solution of WDSs using the Colebrook–White equation. The correctness and efficacy of the head formulation have been demonstrated by applying it to six WDSs with the number of pipes ranges from 454 to 157,044 and the number of nodes ranges from 443 to 150,630. The addition of a physically and fundamentally more accurate WDS solution method can improve the quality of the results achieved in both academic research and industrial application, such as contamination source identification, water hammer analysis, WDS network calibration, sensor placement, and least-cost design and operation of WDSs.

The faster the better: On the shortest paths role for near real-time decision making of water utilities

Near real-time monitoring and control of critical infrastructure is essential for the operation and management of cities in a world that is, today, more complex and interconnected than ever. Such an infrastructure can be represented as complex networks an some of their related indices and statistics, many of them based on the shortest paths, play a pivotal role in the decision making for public services such as internet, energy or water. Particularly, the literature has shown that shortest paths are key for resilience and criticality assessment in a water distribution systems (WDS). This paper proposes a procedure to speed-up the computation of shortest paths in a WDS, as it can straightforwardly benefit any critical infrastructure. The proposal is based on a reduced dimension of a complex network representing any critical infrastructure. Despite the consequent decrease in the number of all possible paths in the network, the main advantage and novelty of this proposal is to continue finding the exact solution for the shortest paths. Experimental results show that the procedure brings a computational-time reduction consistently over 50% and up to 90% in some cases. In addition, the paper reveals how the use of shortest paths benefits WDS operation and management, as well as playing a key role in near real-time contamination detection and leakage control.

Multi-objective optimization of water distribution system: a hybrid evolutionary algorithm

The optimal operation of water distribution systems is complicated due to multiple objectives that are in conflict, such as water quality versus cost. This work proposes to combine Strength Pareto Evolutionary Algorithm (SPEAII) with Multi-Objective Particle Swarm Optimization (MOPSO) algorithm, called MOPSO-SPEAII, to establish a multi-objective model which handles water quality, costs and storage-reliable requirement. The main idea is that genetic operators are combined with particle swarm operators such that the fitness of SPEAII results is evaluated using MOPSO. An optimization-simulation model is prepared by linking the hybrid algorithm with EPANET software, and it is employed for a typical case study from the literature. The model outcomes verify that the MOPSO-SPEAII is more stable compared to SPEAII in terms of closeness to global minimum and can be used as a robust decision tool. However, the model application for a real sized system increases the computational intensity of the model.

Approach for Water Distribution System Model Calibration Based on Iterative Sherman–Morrison Formula

AbstractReal-time modeling of water distribution systems (WDSs) has received much attention in WDS operation and management. As the model input, nodal water demand must be calibrated in a timely ma...

Analytical Optimization Approach for Simultaneous Design and Operation of Water Distribution–Systems Optimization

AbstractThis paper presents an analytical algorithm for simultaneous least-cost design and operation of looped water distribution systems (WDSs). This method could be used to replace evolutionary m...

Minimizing Pumping Energy Cost in Real-Time Operations of Water Distribution Systems Using Economic Model Predictive Control

Optimizing pump operations is a challenging task for real-time management of water distribution systems (WDSs). With suitable pump scheduling, pumping costs can be significantly reduced. In this research, a novel economic model predictive control (EMPC) framework for real-time management of WDSs is proposed. Optimal pump operations are selected based on predicted system behavior over a receding time horizon with the aim to minimize the total pumping energy cost. Time-varying electricity tariffs are considered while all the required water demands are satisfied. The novelty of this framework is to choose the number of pumps to operate in each pump station as decision variables in order to optimize the total pumping energy costs. By using integer programming, the proposed EMPC is applied to a benchmark case study, the Richmond Pruned network. The simulation with an EPANET hydraulic simulator is implemented. Moreover, a comparison of the results obtained using the proposed EMPC with those obtained using trigger-level control demonstrates significant economic benefits of the proposed EMPC.