Characterization of components of water supply systems from GPR images and tools of intelligent data analysis

[EN] Over time, due to multiple operational and maintenance activities, the networks of water supply systems (WSSs) undergo interventions, modifications or even are closed. In many cases, these activities are not properly registered. Knowledge of the paths and characteristics (status and age, etc.) of the WSS pipes is obviously necessary for efficient and dynamic management of such systems. This problem is greatly augmented by considering the detection and control of leaks. Access to reliable leakage information is a complex task. In many cases, leaks are detected when the damage is already considerable, which brings high social and economic costs. In this sense, non-destructive methods (e.g., ground penetrating radar - GPR) may be a constructive response to these problems, since they allow, as evidenced in this thesis, to ascertain paths of pipes, identify component characteristics, and detect primordial water leaks. Selection of GPR in this work is justified by its characteristics as non-destructive technique that allows studying both metallic and non-metallic objects. Although the capture of information with GPR is usually successful, such aspects as the capture settings, the large volume of generated information, and the use and interpretation of such information require high level of skill and experience. This dissertation may be seen as a step forward towards the development of tools able to tackle the problem of lack of knowledge on the WSS buried assets. The main objective of this doctoral work is thus to generate tools and assess their feasibility of application to the characterization of components of WSSs from GPR images. In this work we have carried out laboratory tests specifically designed to propose, develop and evaluate methods for the characterization of the WSS buried components. Additionally, we have conducted field tests, which have enabled us to determine the feasibility of implementing such methodologies under uncontrolled conditions. The methodologies developed are based on techniques of intelligent data analysis. The basic principle of this work has involved the processing of data obtained through the GPR to look for useful information about WSS components, with special emphasis on the pipes. After performing numerous activities, one can conclude that, using GPR images, it is feasible to obtain more information than the typical identification of hyperbolae currently performed. In addition, this information can be observed directly, e.g. more simply, using the methodologies proposed in this doctoral work. These methodologies also prove that it is feasible to identify patterns (especially with the preprocessing algorithm termed Agent race) that provide fairly good approximation of the location of leaks in WSSs. Also, in the case of pipes, one can obtain such other characteristics as diameter and material. The main outcomes of this thesis consist in a series of tools we have developed to locate, identify and visualize WSS components from GPR images. Most interestingly, the data are synthesized and reduced so that the characteristics of the different components of the images recorded in GPR are preserved. The ultimate goal is that the developed tools facilitate decision-making in the technical management of WSSs, and that such tools can even be operated by personnel with limited experience in handling non-destructive methodologies, specifically GPR.[ES] Con el paso del tiempo, y debido a múltiples actividades operacionales y de mantenimiento, las redes de los sistemas de abastecimiento de agua (SAAs) sufren intervenciones, modificaciones o incluso, son clausuradas, sin que, en muchos casos, estas actividades sean correctamente registradas. El conocimiento de los trazados y características (estado y edad, entre otros) de las tuberías en los SAAs es obviamente necesario para una gestión eficiente y dinámica de tales sistemas. A esta problemática se suma la detección y el control de las fugas de agua. El acceso a información fiable sobre las fugas es una tarea compleja. En muchos casos, las fugas son detectadas cuando los daños en la red son ya considerables, lo que trae consigo altos costes sociales y económicos. En este sentido, los métodos no destructivos (por ejemplo, ground penetrating radar - GPR), pueden ser una respuesta a estas problemáticas, ya que permiten, como se pone de manifiesto en esta tesis, localizar los trazados de las tuberías, identificar características de los componentes y detectar las fugas de agua cuando aún no son significativas. La selección del GPR, en este trabajo se justifica por sus características como técnica no destructiva, que permite estudiar tanto objetos metálicos como no metálicos. Aunque la captura de información con GPR suele ser exitosa, la configuración de la captura, el gran volumen de información, y el uso y la interpretación de la información requieren de alto nivel de habilidad y experiencia por parte del personal. Esta tesis doctoral se plantea como un avance hacia el desarrollo de herramientas que permitan responder a la problemática del desconocimiento de los activos enterrados de los SAAs. El objetivo principal de este trabajo doctoral es, pues, generar herramientas y evaluar la viabilidad de su aplicación en la caracterización de componentes de un SAA, a partir de imágenes GPR. En este trabajo hemos realizado ensayos de laboratorio específicamente diseñados para plantear, elaborar y evaluar metodologías para la caracterización de los componentes enterrados de los SAAs. Adicionalmente, hemos realizado ensayos de campo, que han permitido determinar la viabilidad de aplicación de tales metodologías bajo condiciones no controladas. Las metodologías elaboradas están basadas en técnicas de análisis inteligentes de datos. El principio básico de este trabajo ha consistido en el tratamiento adecuado de los datos obtenidos mediante el GPR, a fin de buscar información de utilidad para los SAAs respecto a sus componentes, con especial énfasis en las tuberías. Tras la realización de múltiples actividades, se puede concluir que es viable obtener más información de las imágenes de GPR que la que actualmente se obtiene con la típica identificación de hipérbolas. Esta información, además, puede ser observada directamente, de manera más sencilla, mediante las metodologías planteadas en este trabajo doctoral. Con estas metodologías se ha probado que también es viable la identificación de patrones (especialmente el pre-procesado con el algoritmo Agent race) que proporcionan aproximación bastante acertada de la localización de las fugas de agua en los SAAs. También, en el caso de las tuberías, se puede obtener otro tipo de características tales como el diámetro y el material. Como resultado de esta tesis se han desarrollado una serie de herramientas que permiten visualizar, identificar y localizar componentes de los SAAs a partir de imágenes de GPR. El resultado más interesante es que los resultados obtenidos son sintetizados y reducidos de manera que preservan las características de los diferentes componentes registrados en las imágenes de GPR. El objetivo último es que las herramientas desarrolladas faciliten la toma de decisiones en la gestión técnica de los SAAs y que tales herramientas puedan ser operadas incluso por personal con una experiencia limitada en el manejo[CA] Amb el temps, a causa de les múltiples activitats d'operació i manteniment, les xarxes de sistemes d'abastament d'aigua (SAAs) se sotmeten a intervencions, modificacions o fins i tot estan tancades. En molts casos, aquestes activitats no estan degudament registrats. El coneixement dels camins i característiques (estat i edat, etc.) de les canonades d'aigua i sanejament fa evident la necessitat d'una gestió eficient i dinàmica d'aquests sistemes. Aquest problema es veu augmentat en gran mesura tenint en compte la detecció i control de fuites. L'accés a informació fiable sobre les fuites és una tasca complexa. En molts casos, les fugues es detecten quan el dany ja és considerable, el que porta costos socials i econòmics. En aquest sentit, els mètodes no destructius (per exemple, ground penetrating radar - GPR) poden ser una resposta constructiva a aquests problemes, ja que permeten, com s'evidencia en aquesta tesi, per determinar rutes de canonades, identificar les característiques dels components, i detectar les fuites d'aigua quan encara no són significatives. La selecció del GPR en aquest treball es justifica per les seves característiques com a tècnica no destructiva que permet estudiar tant objectes metàl·lics i no metàl·lics. Tot i que la captura d'informació amb GPR sol ser reeixida, aspectes com ara la configuració de captura, el gran volum d'informació que es genera, i l'ús i la interpretació d'aquesta informació requereix alt nivell d'habilitat i experiència. Aquesta tesi pot ser vista com un pas endavant cap al desenvolupament d'eines capaces d'abordar el problema de la manca de coneixement sobre els actius d'aigua i sanejament enterrat. L'objectiu principal d'aquest treball doctoral és, doncs, generar eines i avaluar la seva factibilitat d'aplicació a la caracterització dels components de los SAAs, a partir d'imatges GPR. En aquest treball s'han dut a terme proves de laboratori específicament dissenyats per proposar, desenvolupar i avaluar mètodes per a la caracterització dels components d'aigua i sanejament soterrat. A més, hem dut a terme proves de camp, que ens han permès determinar la viabilitat de la implementació d'aquestes metodologies en condicions no controlades. Les metodologies desenvolupades es basen en tècniques d'anàlisi intel·ligent de dades. El principi bàsic d'aquest treball ha consistit en el tractament de dades obtingudes a través del GPR per buscar informació útil sobre els components d'SAA, amb especial èmfasi en la canonades. Després de realitzar nombroses activitats, es pot concloure que, amb l'ús d'imatges de GPR, és factible obtenir més informació que la identificació típica d'hipèrboles realitzat actualment. A més, aquesta informació pot ser observada directament, per exemple, més simplement, utilitzant les metodologies proposades en aquest treball doctoral. Aquestes metodologies també demostren que és factible per identificar patrons (especialment el pre-processat amb l'algoritme Agent race) que proporcionen bastant bona aproximació de la localització de fuites en SAAs. També, en el cas de tubs, es pot obtenir altres característiques com ara el diàmetre i el material. Els principals resultats d'aquesta tesi consisteixen en una sèrie d'eines que hem desenvolupat per localitzar, identificar i visualitzar els components dels SAAS a partir d'imatges GPR. El resultat més interessant és que els resultats obtinguts són sintetitzats i reduïts de manera que preserven les característiques dels diferents components registrats en les imatges de GPR. L'objectiu final és que les eines desenvolupades faciliten la presa de decisions en la gestió tècnica de SAA, i que tals eines poden fins i tot ser operades per personal amb poca experiència en el maneig de metodologies no destructives, específicament GPR.Ayala Cabrera, D. (2015). Characterization of components of water supply systems from GPR images and tools of intelligent data analysis [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/59235TESISPremios Extraordinarios de tesis doctorale

3D model evolution of a leak based on GPR image interpretations

This paper presents some aspects of the time propagation of underground water leakage in controlled laboratory conditions using a drilled polyvinyl chloride (PVC) pipe and interpreting ground penetrating radar (GPR) images. GPR pre-processed images are interpreted for easy identification and extraction of surfaces and volumes of water leakage. Finally, the temporal evolution of a water leak is shown using 3D models based on interpretation of GPR images. Water volumes obtained using this approach can be easily observed by personnel who lack highly specialized training in the analysis of raw data. The results of this study are promising and can help develop techniques to validate non-destructive models for the identification, distribution, and prediction of water leaks in water supply systems using GPR.Part of this work has been developed under the support of an FPI (Formacion de Personal Investigador)-UPV (Universitat Politecnica de Valencia) scholarship granted to the second author by the Programa de Ayudas de Investigacion y Desarrollo (PAID) of the Universitat Politecnica de Valencia, and the support of Fundacion Carolina PhD, within its short stances scholarship program for the first author. The use of English in this paper has been revised by John Rawlins.Ocana-Levario, S.; Ayala Cabrera, D.; Izquierdo Sebastián, J.; Pérez García, R. (2015). 3D model evolution of a leak based on GPR image interpretations. Water Science and Technology: Water Supply. 15(6):1312-1319. doi:10.2166/ws.2015.093S1312131915

Caracterización de tuberías enterradas para redes de abastecimiento en servicio mediante el análisis de imágenes obtenidas con radar de subsuelo (Ground Penetrating Radar - GPR)

En este trabajo se evalúa la viabilidad del método propuesto de análisis de radargramas para la caracterización de los componentes del sistema de abastecimiento en servicio, con la realización de ensayos de laboratorio, empleando tuberías de diferentes características materiales en un entorno controlado.Ayala Cabrera, D. (2009). Caracterización de tuberías enterradas para redes de abastecimiento en servicio mediante el análisis de imágenes obtenidas con radar de subsuelo (Ground Penetrating Radar - GPR). http://hdl.handle.net/10251/1443

Analysis of online pressure for resilience phase characterisation of leakages/burst events

[EN] While operating a water distribution network (WDN), it is essential to prepare the system to face with intentional (e.g., cyber-physical attack) or unintentional (e.g., pipe leakage/burst) adverse events or other drivers such as the effects of climate change. Increasing the network’s preparedness to deal with anomalous events is an effective manner to improve the system’s resilience, reducing the negative impacts of events. In this paper, leakage/burst events, and ordinary network operation, are captured by both sensors and expert knowledge in a WDN in Spain. Event-driven and data-driven approaches are used to characterise the system behaviour, in particular when it is operating under the effects of an anomalous event, based on the resilience phases (i.e., absorptive, adaptive, restorative) for the collected dataset. The relationship of clustering pressure head time series based on their potential state in a particular resilience phase, in three random cases of short-term leakage events, was explored. This paper focuses on capturing the behaviour of the system, through the exploration of the hydraulic parameters of WDNs (in particular the pressure head) before, during, and after a leakage event, by means of a spatial-temporal analysis. It was observed that the network behaviour could be categorised into 1) ordinary operation and 2) during the event, which would allow to characterise the system behaviour when influenced by leakage/burst event and also explore its adaptability to resilience phases. The results show that it is possible to extract relevant patterns (i.e., feature maps) and generate an anomaly indicator from the pressure head heatmaps that facilitate the characterisation of anomalous events for WDNs.Hoseini Ghafari, S.; Francés-Chust, J.; Piller, O.; Ayala-Cabrera, D. (2024). Analysis of online pressure for resilience phase characterisation of leakages/burst events. Editorial Universitat Politècnica de València. 1-14. https://doi.org/10.4995/WDSA-CCWI2022.2022.1408211

Digitalization of Water Distribution Systems in Small Cities, a Tool for Verification and Hydraulic Analysis: A Case Study of Pamplona, Colombia

[EN] Digitalization in water networks is essential for the future planning of urban development processes in cities and is one of the great challenges faced by small cities regarding water management and the advancement of their infrastructures towards sustainable systems. The main objective of this study is to propose a methodology that allows water utilities with limited budgets to start the path toward the digitalization and construction of the hydraulic model of their water distribution networks. The small city of Pamplona in Colombia was used as a case study. The work explains in detail the challenges faced and the solutions proposed during the digitalization process. The methodology is developed in six phases: an analysis of the cadastre and existing information, the creation and conceptualization of the base hydraulic model, the development of the topography using drones with a limited budget, an analysis of water demand, the development of a digital hydraulic model, and a hydraulic analysis of the system. The product generated is a tool to assess the overall performance of the network and contributes to the advancement of SDG-6, SDG-9, and SDG-11. Finally, this document can be replicated by other cities and companies with similar characteristics (e.g., limited size and budget) and offers an intermediate position on the road to digitalization and the first steps towards the implementation of a digital twin.Bonilla, C.; Brentan, B.; Montalvo, I.; Ayala-Cabrera, D.; Izquierdo Sebastián, J. (2023). Digitalization of Water Distribution Systems in Small Cities, a Tool for Verification and Hydraulic Analysis: A Case Study of Pamplona, Colombia. Water. 15(21):1-20. https://doi.org/10.3390/w15213824120152

Hybrid optimization proposal for the design of collective on-rotation operating irrigation networks

[EN] Hybrid models have been used in many engineering applications in order to find better solutions and to reduce project costs. In this paper a methodology for the optimal design of collective working shift irrigation systems is proposed. The proposal is based on a hybrid model of optimization, which includes Linear Programming (LP) and Genetic Algorithms (GA). The method is applied to an irrigation network to check its effectiveness to minimize the total investment costs for pipelines. The results are compared to another hybrid model for optimization, which is based on Nonlinear Programming (NLP) and GA. The advantage of the developed method is a more cost effective design using discrete pipeline diameters. (C) 2016 Published by Elsevier Ltd.Thanks to the Technical University of Loja/Ecuador for funding the research, the Gestar group of investigation of the University of Zaragoza, Spain and to Dr. Andreas Fries.Lapo Pauta, CM.; Pérez García, R.; Izquierdo Sebastián, J.; Ayala Cabrera, D. (2017). Hybrid optimization proposal for the design of collective on-rotation operating irrigation networks. Procedia Engineering. 186:530-536. doi:10.1016/j.proeng.2017.03.266S53053618

Water distribution network disruptive events. Generation and exploration of an incident hub to increase the network preparedness

[EN] This paper seeks to develop increased knowledge about disruptive events in a water distribution network (WDN) through the experience acquired by previous anomalous events in the system. This work explores the various relationships between several parameters in an incident hub (specifically water loss events) in a Spanish real, small WDN. The incident hub consists of basic elements recorded during an incident (e.g. breakdown, maintenance activity, among others) and the corresponding causes that generated the incident (e.g. breakage due to excess pressure, breakage due to tree roots, etc.), as well as the management times of the incident (e.g. awareness time, isolation, and repair time). The utility collected and stored these data, which were completed with direct interviews with the system operator. Measurements were performed at pressure and flow sensors, which allowed evaluating the effects of both the incident itself and the actions taken to solve it. The records of the incidents are categorised depending on the nature of the data they contain to facilitate mapping their causes and effects. To characterise the disruptive events, a feature extraction process has been proposed using a temporal-spatial approach combined with a migration proposed that describes parameters’ behaviour in the spatial dimension for a certain period of time. The characteristics obtained in the previous lessons of the incidents contained in the incident hub are compared with potential causes obtained with different control parameters. The objective is to determine the potential causal relationship of the incident that allows its characterisation. The results of this characterisation are presented and analysed in this contribution. The outcomes are promising in the sense of a clear ability to provide WDNs with key parameters that foster prediction and classification processes.Ayala-Cabrera, D.; Francés-Chust, J.; Hoseini-Ghafari, S.; Stanton, G.; Izquierdo, J. (2024). Water distribution network disruptive events. Generation and exploration of an incident hub to increase the network preparedness. Editorial Universitat Politècnica de València. https://doi.org/10.4995/WDSA-CCWI2022.2022.1483

GPR image analysis to locate water leaks from buried pipes by applying variance filters

[EN] Nowadays, there is growing interest in controlling and reducing the amount of water lost through leakage in water supply systems (WSSs). Leakage is, in fact, one of the biggest problems faced by the managers of these utilities. This work addresses the problem of leakage in WSSs by using GPR (Ground Penetrating Radar) as a non-destructive method. The main objective is to identify and extract features from GPR images such as leaks and components in a controlled laboratory condition by a methodology based on second order statistical parameters and, using the obtained features, to create 3D models that allows quick visualization of components and leaks in WSSs from GPR image analysis and subsequent interpretation. This methodology has been used before in other fields and provided promising results. The results obtained with the proposed methodology are presented, analyzed, interpreted and compared with the results obtained by using a well-established multi-agent based methodology. These results show that the variance filter is capable of highlighting the characteristics of components and anomalies, in an intuitive manner, which can be identified by non-highly qualified personnel, using the 3D models we develop. This research intends to pave the way towards future intelligent detection systems that enable the automatic detection of leaks in WSSs. (C) 2017 Published by Elsevier B.V.Part of this work has been developed under the support of Fundacion Carolina PhD (2014) and short-term scholarship program for the first author (Doctorado y estancias cortas).Ocaña-Levario, SJ.; Carreño-Alvarado, EP.; Ayala Cabrera, D.; Izquierdo Sebastián, J. (2018). GPR image analysis to locate water leaks from buried pipes by applying variance filters. Journal of Applied Geophysics. 152:236-247. https://doi.org/10.1016/j.jappgeo.2018.03.025S23624715

Water supply system component evaluation from GPR radargrams using a multi-agent approach

This paper uses a multi-agent approach as a quick and easy tool for the interpretation and analysis of the characteristics of Water Supply System (WSS) components when working on a collection of Ground Penetrating Radar (GPR) survey files. The multi-agent algorithm proposed in this paper has been developed in Matlab and is based on Game Theory. The input is the result of the GPR radargram survey and the output consists of the agent scores in the game proposed in this paper. Useful information can be gained by interpreting the columns of the output matrix that describe the agents’ movements, together with the associated racing times. In effect, this analysis enables a simple determination of the electromagnetic properties of the underground system and provides an accurate classification of these properties. The results of this agent racing algorithm are promising, since it groups, and consequently, decreases the number of points that make up the initial radargrams; while at the same time preserving its main properties, and enabling clearer views of pipes and a better identification of the components in WSS.This work has been supported by project IDAWAS, DPI2009-11591, of the Direccion General de Investigacion of the Ministerio de Ciencia e Innovacion of Spain, ACOMP/2011/188 of the Conselleria de Educacion of the Generalitat Valenciana, and the FPI-UPV scholarship granted to the first author by the Programa de Ayudas de Investigacion y Desarrollo (PAID) of the Universitat Politecnica de Valencia.Ayala Cabrera, D.; Izquierdo Sebastián, J.; Montalvo Arango, I.; Pérez García, R. (2013). Water supply system component evaluation from GPR radargrams using a multi-agent approach. Mathematical and Computer Modelling. 57(7-8):1927-1932. https://doi.org/10.1016/j.mcm.2011.12.034S19271932577-

3D Representation of (Buried) Water Supply Elements using Pre-Processed GPR Images

[EN] In this paper, a ground penetrating radar (GPR) is used as a non-destructive method to assess the buried elements of water supply systems (WSSs). The aim is the detection of various pipe materials (such as plastic and metallic, among others), and the identification of other important aspects (e.g. water leakage). This work seeks to use the visualization advantages of the subsoil characteristics provided by pre-processed GPR images. These features, which are represented as anomalies into the images, are extracted and merged to generate 3D models. The 3D representations obtained facilitate elucidation by personnel non-highly skilful in the interpretation of data from non-destructive techniques. The work is performed on GPR images of WSS pipes taken from strategic locations of urban environments. The goal is to promote the use of these technologies in the WSSs intended to generate relevant information that allows the adequate and dynamic technical management of these systems. The results and analyses are presented in this paper.Part of this work has been developed under the support of an FPI-UPV scholarship granted to the first author by the Programa de Ayudas de Investigación y Desarrollo (PAID) of the Universitat Politècnica de València. Additionally, we wish to thank the AQUARUM consortium for their help in field data capturing.Ayala Cabrera, D.; Ocaña Levario, SJ.; Izquierdo Sebastián, J.; Pérez García, R. (2015). 3D Representation of (Buried) Water Supply Elements using Pre-Processed GPR Images. Atiner's Conference Paper Series. WAT2015(1706):3-15. http://hdl.handle.net/10251/74270S315WAT2015170