Renovation and Upgrading of the Urban Water Distribution Systems by Multi-Objective Optimization Approach (Case Study: Part of Zahedan Distribution Network)

Document Type : Case study

Authors

1 Former Graduated Student, Dept. of Civil Engineering, Shahid Nikbakht Faculty of Engineering, University of Sistan and Baluchestan, Zahedan, Iran

2 Assoc. Prof., Dept. of Civil Engineering, Shahid Nikbakht Faculty of Engineering, University of Sistan and Baluchestan, Zahedan, Iran

3 PhD. Student, Dept. of Civil Engineering, Shahid Nikbakht Faculty of Engineering, University of Sistan and Baluchestan, Zahedan, Iran

Abstract

Pipe wear in urban water supply networks is one of the most important challenges faced by water authorities. Older pipes must be replaced by new ones once they reach the end of their service life or are no longer useful due to a rise in demand and changes in surface roughness. Budget limits are one of the most common reasons for the failure of renovation and upgrade plans in water supply networks. In the traditional approach, the whole renovation is done in one phase and does not take into account the growth and development of the system. Therefore, uncertainties due to unforeseen changes are not considered. The present study addresses the renovation and upgrade of a part of the water supply network in Zahedan city via a novel approach. This approach involves dividing the plan into phases and redesigning some of the pipes during 5-year phases based on budget partitioning. To improve the hydraulic performance of the network, a multi-objective simulation-optimization model was developed with the pipe replacement cost and the water supply network reliability as the objective functions that must be minimized and maximized, respectively. For this purpose, the EPANET simulator model was combined with the Gray Wolf Optimization (GWO) algorithm in MATLAB software. The model execution results in each Phase were presented in the form of a Pareto front between the objective functions. This allows the company to renovate the water supply network based on the budget in each phase. After optimization in phase 1, the results were presented as a Pareto front between the network reliability coefficient and the reconstruction cost. One of the optimal answers on the chart was selected as the final design. In this optimal design, 22 pipes at a cost of 276 million Tomans and a reliability coefficient of 48.2% were replaced. After applying changes in the diameter of the pipes according to the design, the first phase was optimized as the basic model of the second phase. In phase 2, 32 pipes were selected and renovated. Similarly, after the end of Phase 4, it was found that the network reliability has increased significantly (150%) and the pressure of all network nodes was within the allowable range. The results indicate that the used approach can considerably increase the reliability of the network in addition to appropriately managing the renovation budget.

Keywords


Alperovits, E. & Shamir, U. 1977. Design of optimal water distribution systems. Water Resources Research, 13(6), 885-900.
Farmani, R., Savic, D. A. & Walters, G. A. 2004. The simultaneous multi-objective optimization of any town pipe rehabilitation, tank sizing, tank siting, and pump operation schedules. World Water and Environmental Resources Congress. Salt Lake City, Utah, United States.
Fujiwara, O. & Khang, D. B. 1990. A two‐phase decomposition method for optimal design of looped water distribution networks. Water Resources Research, 26(4), 539-549.
Ghorbani Dastgerdi, V. 2015. Multiobjective optimization of water distribution networks (WDNs) with mixed reliability index using classic and fuzzy violation function. M.Sc. Thesis, Department of Civil Engineering, Isfahan University of Technology. Isfahan, Iran. (In Persian)
Goulter, I. C. & Morgan, D. R. 1985. An integrated approach to the layout and design of water distribution networks. Civil Engineering Systems, 2(2), 104-113.
Hoseyni, A. S. Givehchi, M. & Jafari-Asl, J. 2019. Geometric optimization of labyrinth spillways and improvement of hydraulic performance using gray wolf algorithm. Iranian Journal of Irrigation and Drainage, 13(6), 1589-1600. (In Persian)
Karimi Darmian, M. 2014. Pressure calibration and its management in Zahedan urban water distribution network using WATER GEMS model. MSc. Thesis, University of Sistan and Baluchestan. Zahedan, Iran. (In Persian)
Kadu, M. S., Gupta, R. & Bhave, P. R., 2008. Optimal design of water networks using a modified genetic algorithm with reduction in search space. Journal of Water Resources Planning and Management, 134(2), 147-160.
Mansouri, R. Mohammadizadeh, M., 2019. Applied of central force algorithm (CFO) in optimization of irrigation water distribution network. Iranian Journal of Irrigation and Drainage. 31(1), 101-114. (In Persian)
Masoumi, M., Kashkooli, B. S., Monem, M. J. & Montaseri, H. 2016. Multi-objective optimal design of on-demand pressurized irrigation networks. Water Resources Management, 30(14), 5051-5063.
Mazaherizadeh, M. Faridhosseini, A. & Davari, K. 2019. Multi objective design of water distribution system using todini’s resilience index and improving the strength pareto evolutionary algorithm. Journal of Water and Wastewater, 30(6), 18-34. (In Persian)
Minaei, A. 2016. Renewing the water distribution network using the multi-objective decision making. MSc. Thesis, Shahid Chamran University, Ahvaz, Iran. (In Persian)
Minaei, A., Haghighi, A. & Ghafouri, H. R. 2019. Computer-aided decision-making model for multiphase upgrading of aged water distribution mains. Journal of Water Resources Planning and Management, 145(5), p.04019008.
Mirjalili, S., Mirjalili, S. M. & Lewis, A. 2014. Grey wolf optimizer. Advances in Engineering Software, 69,
46-61.
Monem, M. J. & Kashkooli, B. S. 2017. New discrete particle swarm optimization applied to the design of pressurized irrigation networks. Journal of Irrigation and Drainage Engineering, 143(1), p.04016071.
Muro, C., Escobedo, R., Spector, L. & Coppinger, R. P. 2011. Wolf-pack (canis iupus) hunting strategies emerge from simple rules in computational simulations. Behavioural Processes, 88(3), 192-197.
Savic, D. A. & Walters, G. A. 1997. Genetic algorithms for least-cost design of water distribution networks. Journal of Water Resources Planning and Management, 123(2), 67-77.
Shekofteh, M. R. & Jalili Ghazizadeh, M. R. 2020. The optimized implementation of the district metered areas in the water distribution networks using graph theory. Journal of Water and Wastewater, 31(1), 12-24. (In Persian)
Simpson, A. R., Murphy, L. J. & Dandy, G. C. 1993. Pipe network optimization using genetic algorithms. Water Resources Planning and Management Division Specialty Conference, Seatel, Washington, USA.
 Tabesh, M. & Soltani, J. 2005. Evaluation of mechanical reliability of urban water distribution networks using artificial neural networks for optimal operation management. 2nd Conference on Water Resources Management, Isfahan University of Technology. Iran. (In Persian)
Taheri Hosseinabadi, S. 2015. Providing a composite index of reliability in order to assess the sustainability of urban water distribution networks. M.Sc. Thesis, Department of Civil Engineering, Isfahan University of Technology. Iran. (In Persian)
Tanyimboh, T. T. 2017. Informational entropy: a failure tolerance and reliability surrogate for water distribution networks. Water Resources Management, 31(10), 3189-3204.
Todini, E. 2000. Looped water distribution networks design using a resilience index
based heuristic approach. Urban Water, 2(2), 115-122.
Tolson, B. A., Maier, H. R., Simpson, A. R. & Lence, B. J. 2004. Genetic algorithms for reliability-based optimization of water distribution systems. Journal of Water Resources Planning and Management, 130(1), 63-72.
Zecchin, A. C., Maier, H. R., Simpson, A. R., Leonard, M. & Nixon, J. B., 2007. Ant colony optimization applied to water distribution system design: comparative study of five algorithms. Journal of Water Resources Planning and Management, 133(1), 87-92.