scholarly journals Technical note: Problem-specific variators in a genetic algorithm for the optimization of drinking water networks

2018 ◽  
Vol 11 (2) ◽  
pp. 101-105
Author(s):  
Karel van Laarhoven ◽  
Ina Vertommen ◽  
Peter van Thienen

Abstract. Genetic algorithms can be a powerful tool for the automated design of optimal drinking water distribution networks. Fast convergence of such algorithms is a crucial factor for successful practical implementation at the drinking water utility level. In this technical note, we therefore investigate the performance of a suite of genetic variators that was tailored to the optimization of a least-cost network design. Different combinations of the variators are tested in terms of convergence rate and the robustness of the results during optimization of the real-world drinking water distribution network of Sittard, the Netherlands. The variator configurations that reproducibly reach the furthest convergence after 105 function evaluations are reported. In the future these may aid in dealing with the computational challenges of optimizing real-world networks.

2018 ◽  
Author(s):  
Karel van Laarhoven ◽  
Ina Vertommen ◽  
Peter van Thienen

Abstract. Genetic algorithms can be a powerful tool for the automated design of optimal drinking water distribution networks. Fast convergence of such algorithms is a crucial factor for successful practical implementation at the drinking water utility level. In this technical note, we therefore investigate the performance of a suite of genetic variators that was tailored to the optimisation of a least-cost network design. Different combinations of the variators are tested in terms of convergence rate and the robustness of the results during optimisation of the real world drinking water distribution network of Sittard, the Netherlands. The variator configurations that reproducibly reach the furthest convergence after 105 function evaluations are reported. In the future these may aid in dealing with the computational challenges of optimizing real world networks.


2022 ◽  
Author(s):  
Marius Møller Rokstad ◽  
Karel Antonie van Laarhoven

Abstract. Drinking water distribution networks form an essential part of modern-day critical infrastructure. Sectorizing a network into district metered areas is a key technique for pressure management and water loss reduction. Sectorizing an existing network from scratch is, however, an exceedingly complex design task that designs in a well-studied general mathematical problem. Numerical optimization techniques such as evolutionary algorithms can be used to search for near-optimal solutions to such problems, but doing so within a reasonable timeframe remains an ongoing challenge. In this work, we introduce two heuristic tricks that use information of the network structure and information of the operational requirements of the drinking water distribution network to modify the basic evolutionary algorithm used to solve the general problem. These techniques not only reduce the time required to find good solutions, but also ensure that these solutions better match the requirements of drinking water practice. Both techniques were demonstrated by applying them in the sectorization of the actual distribution network of a large city.


2020 ◽  
Vol 13 (2) ◽  
pp. 29-41
Author(s):  
Faycal Taghlabi ◽  
Laila Sour ◽  
Ali Agoumi

Abstract. The role of a drinking water distribution network (DWDN) is to supply high-quality water at the necessary pressure at various times of the day for several consumption scenarios. Locating and identifying water leakage areas has become a major concern for managers of the water supply, to optimize and improve constancy of supply. In this paper, we present the results of field research conducted to detect and to locate leaks in the DWDN focusing on the resolution of the Fixed And Variable Area Discharge (FAVAD) equation by use of the prediction algorithms in conjunction with hydraulic modeling and the Geographical Information System (GIS). The leak localization method is applied in the oldest part of Casablanca. We have used, in this research, two methodologies in different leak episodes: (i) the first episode is based on a simulation of artificial leaks on the MATLAB platform using the EPANET code to establish a database of pressures that describes the network's behavior in the presence of leaks. The data thus established have been fed into a machine learning algorithm called random forest, which will forecast the leakage rate and its location in the network; (ii) the second was field-testing a real simulation of artificial leaks by opening and closing of hydrants, on different locations with a leak size of 6 and 17 L s−1. The two methods converged to comparable results. The leak position is spotted within a 100 m radius of the actual leaks.


2018 ◽  
Vol 13 (2) ◽  
pp. 328-334 ◽  
Author(s):  
P. van Thienen ◽  
B. de Graaf ◽  
J. Hoogterp ◽  
J. van Summeren ◽  
A. Vogelaar

Abstract Traditional approaches to optimal water quality sensor placement in drinking water distribution networks can be limiting, because they are oriented towards obtaining information and mitigating effects. Approaches optimizing the utility's response to contamination merit wider study and application. The performance of these different approaches is studied and discussed in this paper. It is also shown that practical considerations can impose significant limitations on the performance that can be achieved by a water quality sensor network. These aspects should be taken into account when optimizing sensor placement in a real drinking water distribution network.


2008 ◽  
Vol 8 (4) ◽  
pp. 421-426
Author(s):  
J. Menaia ◽  
M. Benoliel ◽  
A. Lopes ◽  
C. Neto ◽  
E. Ferreira ◽  
...  

Concerns arise from the possible occurrence of pathogens in drinking water pipe biofilms and storage tank sediments. In these studies, biofilm samples from pipes and sediments from storage tanks of the Lisbon drinking water distribution system were analyzed. Protein determinations and heterotrophic counts on pipe biofilm samples were used to assess the Lisbon network sessile colonization intensity and distribution. Indicator and pathogenic microorganisms were analyzed in pipe biofilm samples, as well as in storage tanks biofilm and sediments, by using cultural methods and PCR, to assess risks. Results have shown that the Lisbon network sessile colonization is relatively weak in intensity. In addition, no meaningful hazards were apparent for both the network biofilm and the storage tanks biofilm and sediments.


2021 ◽  
Author(s):  
Jon Kristian Rakstang ◽  
Michael B. Waak ◽  
Marius M. Rokstad ◽  
Cynthia Hallé

<p>Municipal drinking water distribution networks are complex and dynamic systems often spanning many hundreds of kilometers and serving thousands of consumers. Degradation of water quality within a distribution network can be associated to water age (i.e., time elapsed after treatment). Norwegian distribution networks often consist of an intricate combination of pressure zones, in which the transport path(s) between source and consumer is not easily ascertained. Water age is therefore poorly understood in many Norwegian distribution networks. In this study, simulations obtained from a water network model were used to estimate water age in a Norwegian municipal distribution network. A full-scale tracer study using sodium chloride salt was conducted to assess simulation accuracy. Water conductivity provided empirical estimates of salt arrival time at five monitoring stations. These estimates were consistently higher than simulated peak arrival times. Nevertheless, empirical and simulated water age correlated well, indicating that additional network model calibration will improve accuracy. Subsequently, simulated mean water age also correlated strongly with heterotrophic plate count (HPC) monitoring data from the distribution network (Pearson’s R= 0.78, P= 0.00046), indicating biomass accumulation during distribution—perhaps due to bacterial growth or biofilm interactions—and illustrating the importance of water age for water quality. This study demonstrates that Norwegian network models can be calibrated with simple and cost-effective salt tracer studies to improve water age estimates. Improved water age estimation will increase our understanding of water quality dynamics in distribution networks. This can, through digital tools, be used to monitor and control water age, and its impact on biogrowth in the network.</p>


2019 ◽  
Vol 2 (1) ◽  
pp. 11 ◽  
Author(s):  
Arif Susanto ◽  
Purwanto Purwanto ◽  
Agus Hadiyarto

Abstract:. The requirement of consumed drinking water so that it does not create disturbance to public health is that it needs a quality monitoring. Water fluoridation in Tembagapura City aims to reach its concentration level toward certain safe level, and it can provide maximum benefits for dental health. Analysis and simulation methods using EPAnet software. The results of hydrolic simulation and water quality for fluoride concentration of each node and link in the drinking water distribution network system have changed in every time change following the drinking water distribution segment. From hydraulic simulations, especially for head and flow at separate points, it consists of simultaneous solution in flow equivalence for every junction and headloss relationship in every link of network as a result of hydraulic balancing. New segment will be made at the end of each link that receives inflow from a node if the quality of the new node is different from the link in the last segment. Every pipe in network contains singular segment where the water quality is in line with the preliminary quality stated in the preliminary node. With the availability of hydraulic model and water quality for fluoride concentration, a further research can be conducted for chlorine decay, growth of by product i.e. Trihalomethans (THMs) as well as water age simultaneously in drinking water supply systems in Tembagapura City.  Keyword: EPAnet, distribution network, fluoride concentration. Abstrak: Persyaratan kualitas air minum yang dikonsumsi masyarakat agar tidak menimbulkan gangguan kesehatan, maka penyelenggara air minum perlu melakukan pemantauan kualitasnya. Fluoridasi air di Kota Tembagapura ditujukan untuk mencapai tingkat konsentrasi fluoride pada level tertentu yang aman dan dapat memberikan manfaat maksimal bagi kesehatan gigi. Metode analisis dan simulasi menggunakan perangkat lunak EPAnet. Hasil simulasi hidrolis dan kualitas air untuk konsentrasi fluoride pada setiap node dan link pada sistem jaringan distribusi air minum berubah pada setiap perubahan waktu mengikuti segmen distribusi air minum tersebut. Dari simulasi hidrolis, khusus untuk head dan aliran pada titik yang terpisah meliputi penyelesaian secara simultan dalam persamaan aliran untuk tiap sambungan (junction), dan hubungan headloss pada setiap link pada jaringan sebagai akibat dari hydrolic balancing. Segmen baru terbentuk pada akhir dari setiap link yang menerima inflow dari sebuah node, jika kualitas node baru berbeda dari link pada segmen terakhir. Setiap pipa dalam jaringan mengandung segmen tunggal, di mana kualitas air sebanding dengan kualitas awal yang ditetapkan di node awal. Dengan tersedianya model hidrolis dan kualitas air untuk konsentrasi fluoride, maka dapat dilakukan penelitian lanjutan untuk peluruhan klorin, pertumbuhan by product yaitu trihalomethans (THMs) serta usia air secara simultan pada sistem penyediaan air minum di Kota Tembagapura.Kata Kunci: EPAnet, jaringan distribusi, konsentrasi fluoride.


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