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Unesco-ihe Phd Trifunovic Thesis (1)

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  • PATTERN RECOGNITION

    nemanja trifunovic

    FOR RELIABILITY ASSESSMENT OF WATER DISTRIBUTION NETWORKS

  • PATTERN RECOGNITION FOR RELIABILITY ASSESSMENT OF WATER DISTRIBUTION NETWORKS

  • Cover photo: Network repair work in Ulaanbaatar, Mongolia

  • PATTERN RECOGNITION FOR RELIABILITY ASSESSMENT OF

    WATER DISTRIBUTION NETWORKS

    DISSERTATION

    Submitted in fulfilment of the requirements of the Board for Doctorates of Delft University of Technology

    and of the Academic Board of the UNESCO-IHE Institute for Water Education

    for the Degree of DOCTOR to be defended in public,

    on Monday, February 13, 2012, at 10:00 o'clock in Delft, The Netherlands

    by

    Nemanja TRIFUNOVI

    Master of Science in Civil Engineering, University of Belgrade, Yugoslavia born in Zagreb, Yugoslavia

  • iv

    This dissertation has been approved by the supervisor: Prof. dr. K. Vairavamoorthy Composition of Doctoral Committee: Chairman Rector Magnificus Delft University of Technology Vice-Chairman Rector UNESCO-IHE Prof. dr. K. Vairavamoorthy, UNESCO-IHE/Delft University of Technology, supervisor Prof. dr. ir. L. Rietveld, Delft University of Technology Prof. dr. D. Solomatine, UNESCO-IHE/Delft University of Technology Prof. dr. D. Savi, University of Exeter, UK Prof. dr. M. Iveti, University of Belgrade, Serbia Prof. dr. M. Kennedy, UNESCO-IHE/Delft University of Technology, reserve CRC Press/Balkema is an imprint of the Taylor & Francis Group, an informa business

    2012, Nemanja Trifunovi

    All rights reserved. No part of this publication or the information contained herein may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, by photocopying, recording or otherwise, without written prior permission from the publishers.

    Although all care is taken to ensure the integrity and quality of this publication and the information herein, no responsibility is assumed by the publishers nor the author for any damage to the property or persons as a result of operation or use of this publication and/or the information contained herein.

    Published by: CRC Press/Balkema PO Box 447, 2300 AK Leiden, the Netherlands e-mail: [email protected] www.crcpress.com - www.taylorandfrancis.co.uk - www.ba.balkema.nl

    ISBN 978-0-415-62116-8 (Taylor & Francis Group)

  • v

    This research is about water distribution network resilience. Resilience was crucial to bring it to the end. My gratitude goes to my supervisor, Prof. Kala Vairavamoorthy, who has been persistently emphasising the relevance of this step in my career. His constant encouragements were necessary boosts for the sacrifice I was to go through besides my regular work and private life, both being very demanding in the last five years. Furthermore, I would like to thank Dr. Assela Pathirana for his intellectual support in the programming side of my work and critical evaluation of my concepts. I was always of opinion that one learns more from those who oppose his/her ideas that from those who share them. Coincidentally, both Kala and Assela have roots in Sri Lanka, the country until recently torn by ethnic conflicts. I mention this because I am originating from Yugoslavia, the country that did not survive such a conflict. As a consequence, I was building my life in The Netherlands during the most obvious period for doing a PhD. Only later, working closely with these two very sharp brains, I realised that the pointless drama of civil wars may have brought us together in spite of cultural differences caused by our origin. Next, my thanks go to Mr. Jan-Herman Koster who understood that a PhD can hardly be completed working exclusively outside office hours. The support he gave as my department head in the last two years of the study, and specifically since September 2010, was essential to bring it to the end. Special thanks also go to those departmental colleagues who were picking bits of my regular work in order to open more space for the research. Being part of such a nice and diverse group of people has grossly enriched my life and is still bringing lots of pleasure in my work, in general. And finally: to my dear Gordana, Stefan and Jana. They have always been my paramount focus and inspiration. Without them, this work would have possibly been finished earlier but the life would have little meaning.

  • Making persistent effort without any result can be frustrating. Losing belief and patience can be devastating. On a dead-end road, the only way is the way back. After the point of no return, the only way is towards the end.

  • ix

    Contents Summary/Samenvatting List of Figures List of Tables Abbreviations

    1 INTRODUCTION 1 1.1 Water Distribution Models 2 1.2 Limits and Risks 3 1.3 Reliability 4 1.4 Aim of the Study 5 1.5 Structure of the Thesis 5 1.6 Acknowledgements 6

    2 THEORETICAL AND CONCEPTUAL FRAMEWORK 7 2.1 Background 8 2.2 Reliability Assessment of Water Distribution Networks 8 2.3 Classification of Methods for Reliability Assessment 12 2.4 Modelling Failures in Water Distribution Systems 14

    2.4.1 Pipe Failures 14 2.4.2 Lifetime Distribution Models 15

    2.5 Simulation Approaches Using Demand-Driven Models 17 2.5.1 Reliability Approach Based on Pressure Drop Analysis 17 2.5.2 Reliability Approach Based on Demand Reduction Analysis 20

    2.6 Main Gaps in Networks Reliability Analyses 24 2.6.1 Definitions (A) 24 2.6.2 Methods (B) 26 2.6.3 Tools (C) 27

    2.7 Research Objectives and Scope 29 2.7.1 Key Research Questions 29 2.7.2 Research Hypotheses 30

    2.8 Research Methodology 30 References 32

    3 EMITTER BASED ALGORITHM FOR PRESSURE-DRIVEN DEMAND CALCULATIONS OF WATER DISTRIBUTION NETWORKS 35

    3.1 Introduction 36 3.2 Pressure-Driven Demand Concept 36 3.3 Emitter Performance under Extreme Topographic Conditions 40 3.4 Emitter Based PDD Algorithm 45 3.5 Test Case 46 3.6 Calculation of Available Demand 52 3.7 Networks of Combined Configuration 56 3.8 Conclusions 63

    References 64

  • x

    4 SPATIAL NETWORK GENERATION TOOL FOR PERFORMANCE ANALYSIS OF WATER DISTRIBUTION NETWORKS 65

    4.1 Introduction 66 4.2 Graph Theory Terminology and Application 68 4.3 Generation Theory Concepts Used in Network Generation Algorithm 72 4.4 Generation Process 74

    4.4.1 Non-random Generation 75 4.4.2 Random Generation 77

    4.5 Algorithm of Network Generation Tool 77 4.5.1 Screening of Sub-graphs 80 4.5.2 Assigning of Network Parameters 82

    4.6 Network Generation Tool in Use 83 4.6.1 Random Generation 84 4.6.2 Non-random Generation 86

    4.7 Test Cases 87 4.8 Conclusions 96

    References 98

    5 HYDRAULIC RELIABILITY DIAGRAM AND NETWORK BUFFER INDEX AS INDICATORS OF WATER DISTRIBUTION NETWORK RESILIENCE 99

    5.1 Introduction 100 5.2 Hydraulic Reliability Diagram 100 5.3 Relation between Pipe Flow and Loss of Demand 107 5.4 Hydraulics of Looped Networks under Stress Conditions 109

    5.4.1 The Law of Continuity in Each Junction 110 5.4.2 Total Loss of Demand from Failure of Pipe 110 5.4.3 Relation between Nodal Demand and Pressure 110 5.4.4 Balance of Head Losses in Loops 111

    5.5 Network Buffer Index 114 5.6 Comparison of NBI with the Resilience Indices 115 5.7 Test Network from Literature 121 5.8 Case: Water Distribution Network Amsterdam North 123 5.9 Conclusions 126

    References 128

    6 IMPACTS OF NODE CONNECTIVITY ON RELIABILITY OF WATER DISTRIBUTION NETWORKS 129

    6.1 Introduction 130 6.2 Tools for Analysis of Network Connectivity 131 6.3 Geometric Properties as Indicators of Network Reliability 133

    6.3.1 Network Configuration Assessment 133 6.3.2 Measures of Network Connectivity 136 6.3.3 Network Diagnostics Tool 139

    6.4 Analysis of Network Connectivity Based on Graph Theory 140 6.4.1 Node Degree 140 6.4.2 Graph Density 141 6.4.3 Geodesic Distance and Diameter 141 6.4.4 Betweenness Centrality 142

  • xi

    6.4.5 Closeness Centrality 142 6.4.6 Clustering Coefficient 143

    6.5 Simulation Runs, Case 16 Networks 144 6.6 Simulation Runs, Case 30 Networks 146 6.7 Simulation Runs, Case Three Clusters of 10 Networks 153 6.8 Simulation Runs, Case NGT Networks 158 6.9 Statistical Analysis 166 6.10 Conclusions 170

    References 172

    7 DIAGNOSTICS OF REGULAR PERFORMANCE OF WATER DISTRIBUTION NETWORKS AND ITS RELATION TO THE NETWORK RELIABILITY 173

    7.1 Introduction 174 7.2 Hydraulic Properties as Indicators of Network Reliability 175

    7.2.1 Network Power Balance 175 7.2.2 Network Pressure Buffer 176 7.2.3 Network Residence Time 177 7.2.4 Network Diagnostics Tool 178

    7.3 Simulation Runs 178 7.4 Correlation of Reliability Measures with Demand Growth 179 7.5 Correlation of Reliability Measures with Diameter Increase 182 7.6 Network Properties and Their Relation to Demand Loss 186 7.7 Pipe Flows and Volumes as Indicators of Network Reliability 192 7.8 Conclusions 202

    References 204

    8 ECONOMIC ASPECTS OF DECISION MAKING IN RELIABILITY ASSESSME

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