Multiobjecitve Sampling Design for Calibration of Water Distribution Network Model Using Genetic Algorithm and Neural Network

Document Type : Research Paper

Authors

1 PhD Candidate of Hydraulic Engineering, Department of Civil and Environmental Engineering, Amir Kabir University of Technology

2 Assistant Professor, Department of Civil & Environmental Engineering, Amir Kabir University of Technology

Abstract

In this paper, a novel multiobjective optimization model is presented for selecting optimal locations in the water distribution network (WDN) with the aim of installing pressure loggers. The pressure data collected at optimal locations will be used later on in the calibration of the proposed WDN model. Objective functions consist of maximization of calibrated model prediction accuracy and minimization of the total cost for sampling design. In order to decrease the model run time, an optimization model has been developed using multiobjective genetic algorithm and adaptive neural network (MOGA-ANN). Neural networks (NNs) are initially trained after a number of initial GA generations and periodically retrained and updated after generation of a specified number of full model-analyzed solutions. Trained NNs are replaced with the fitness evaluation of some chromosomes within the GA progress. Using cache prevents objective function evaluation of repetitive chromosomes within GA. Optimal solutions are obtained through pareto-optimal front with respect to the two objective functions. Results show that jointing NNs in MOGA for approximating portions of chromosomes’ fitness in each generation leads to considerable savings in model run time and can be promising for reducing run-time in optimization models with significant computational effort.

Keywords


1- De Schaetzen, W. (2000). ‘‘Optimal calibration and sampling design for hydraulic network models.’’ PhD. thesis, School of Engineering and Computer Science, Univ. of Exeter, Exeter, U.K.
2- Kapelan, Z. S. (2002). ‘‘Calibration of WDS hydraulic models.’’ PhD. thesis, School of Engineering and Computer Science, Univ. of Exeter, Exeter, U.K.
3-Kapelan, Z. S., Savic, D. A., and Walters, G. A. (2003). “Multi-objective sampling design for water distribution model calibration.” Journal of Water Resources Planning and Management, 129(6), 466-479.
4- Bush, C. A., and Uber, J. G. (1998). “Sampling design methods for water distribution model calibration.” Journal of Water Resources Planning and Management, 124(6), 334-344.
5- Lansey, K. E., El-Shorbagy, W., Ahmed, I., Araujo, J., and Haan, C. T. (2001). ‘‘Calibration assessment and data collection for water distribution networks.’’ J. Hydraul. Eng., 127(4), 270–279.
6- Broad, D. R., Dandy, G. C., and Maier, H. R. (2005), “Water distribution system optimization using metamodels.” Journal of Water Resources Planning and Management, 131(3), 172-180.
7- Yan, S., and Minsker, B. (2006). ‘‘Optimal groundwater remediation design using an adaptive neural network genetic algorithm.’’ Water Resour. Res., 42(5).
8- Kapelan, Z. S., Savic, D. A., and Walters, G. A. (2005). “Optimal sampling design methodologies for water distribution model calibration.” Journal of Hydraulic Engineering, 131(3), 190-200.
9- Wu, J. C., Zheng, C. C., and Zheng, L. C. (2006). “A comprative study of Monte Carlo simple genetic algorithm and noisy genetic algorithm for cost-effective sampling network design under uncertainty.” Advance in Water Resources, 29(1), 899-911.
10- Gopalakrishnan, G., Minsker, B. S., and Goldberg, D. (2001). “Optimal sampling in a noisy genetic algorithm for risk-based remediation design.” Phelps, D., and Sehlke, G., eds., Bridging the gap: meeting the world's water and environmental resources challenges. Proc. World Water and Environmental Resources Congress, Washington, D.C.
11- Deb, K., Pratap, A., Agarwal, S., and Meyarivan, T. (2002). “A fast and elitist multiobjective genetic algorithm: NSGA-II.” IEEE Trans. Evol. Comput., 6(4), 182–197.
12- Ferreri, G. B., Napoli, E., and Tumbiolo, A. (1994). “Calibration of roughness in water distribution networks.” Proc. 2nd International Conference on Water Pipeline Systems, Edinburgh, UK, D. S. Miller, ed., vol. 1, 379-396.
13- Ormsbee, L. E. (1989). “Implicit network calibration.” Journal of Water Resources Planning and Management, 115(2), 243-257.
14- MATLAB 7.2 (2006). The Math works Inc.
15- Lingireddy, S., and Ormsbee, L. E. (1998). “Neural networks in optimal calibration of water distribution systems.” Artificial Neural Networks for Civil Engineers: Advanced Features and Applications, I. Flood and N. Kartam, eds., ASCE, Reston, VA., 53–76.