Optimizing intermittent water supply in urban pipe distribution networks

In many urban areas of the developing world, piped water is supplied only intermittently, as valves direct water to different parts of the water distribution system at different times. The flow is transient, and may transition between free-surface and pressurized, resulting in complex dynamical features with important consequences for water suppliers and users. Here, we develop a computational model of transition, transient pipe flow in a network, accounting for a wide variety of realistic boundary conditions. We validate the model against several published data sets, and demonstrate its use on a real pipe network. The model is extended to consider several optimization problems motivated by realistic scenarios. We demonstrate how to infer water flow in a small pipe network from a single pressure sensor, and show how to control water inflow to minimize damaging pressure gradients

Editorial: Efficient water systems management

This special issue of Journal of Hydroinformatics presents a collection of papers initially presented at the 2nd EWaS International Conference 'Efficient & Sustainable Water Systems toward Worth Living Development'. The conference was held on June 1–4, 2016, in Platanias/Chania, Crete, Greece (http://www.ewas2.tuc.gr/). The conference was co-organized by the University of Thessaly/Civil Engineering Department and the Technical University of Crete/School of Environmental Engineering (Co-chairmen: V. Kanakoudis – University of Thessaly, G. Karatzas – Technical University of Crete, vice chairman: E. Keramaris – University of Thessaly). The EWaS series of conferences started in 2013, when the 1st EWaS Conference was held in Thessaloniki. The 2nd EWaS International Conference highlighted the need to improve the efficiency and sustainability of water systems in a changing and fragile environment, especially under the frustrating economic conditions encountered today. Water scarcity and climate change are both considered today as the main causes of water-related problems. Moreover, it is estimated that 20–40% of Europe's available drinking water is being wasted through real (physical) losses occurring along the supply systems. This results in inefficient use of water and energy resources as well as negative economic, technical, social and environmental impacts. Efficient and sustainable management of water distribution systems asks for advanced tools and strategies for their analysis, monitoring, planning and operation. In this context, the integration with ICT innovations in the water sector offers new opportunities for water distribution systems management in urban areas, while exploiting the smart water networks paradigm. The current special issue of Journal of Hydroinformatics was guest-edited by Associate Professor Vasilis Kanakoudis (University of Thessaly, Volos, Greece) and Professor Marco Franchini (University of Ferrara, Italy). The papers included in this special issue are based on the initial presentations at the conference. However, they have been extended (by at least 50%) and revised, having gone through

Advances in Modeling and Management of Urban Water Networks

The Special Issue on Advances in Modeling and Management of Urban Water Networks (UWNs) explores four important topics of research in the context of UWNs: asset management, modeling of demand and hydraulics, energy recovery, and pipe burst identification and leakage reduction. In the first topic, the multi-objective optimization of interventions on the network is presented to find trade-off solutions between costs and efficiency. In the second topic, methodologies are presented to simulate and predict demand and to simulate network behavior in emergency scenarios. In the third topic, a methodology is presented for the multi-objective optimization of pump-as-turbine (PAT) installation sites in transmission mains. In the fourth topic, methodologies for pipe burst identification and leakage reduction are presented. As for the urban drainage systems (UDSs), the two explored topics are asset management, with a system upgrade to reduce flooding, and modeling of flow and water quality, with analyses on the transition from surface to pressurized flow, impact of water use reduction on the operation of UDSs, and sediment transport in pressurized pipes. The Special Issue also includes one paper dealing with the hydraulic modeling of an urban river with a complex cross-section

Technical Performance Indicators for Small-sized Water Supply Networks - Case Study in Dong Van City, Vietnam

Wasser ist die Basis des Lebens sowie der Existenz und der Schlüssel zur nachhaltigen Entwicklung. Die Generalversammlung der Vereinten Nationen hat das Menschenrecht auf Wasser und sanitäre Einrichtungen anerkannt und bestätigt, dass sauberes Trinkwasser und sanitäre Einrichtungen für die Verwirklichung aller Menschenrechte unerlässlich sind. Tatsächlich verwenden jedoch immer noch 663 Millionen Menschen auf der ganzen Welt nicht verbesserte Trinkwasserquellen wie ungeschützte Brunnen, Quellen und Oberflächenwasser verwenden. Nahezu alle diese Menschen leben in Entwicklungsländern wie Asien oder Afrika. Paradoxerweise weisen diese Länder auch die weltweit höchste Wasserverschwendungsrate auf. Die Weltbank schätzt, dass rund 30% des Wassers, das in Wasserversorgungssystemen verteilt wird, was 45 Millionen Kubikmetern Wasser entspricht, täglich durch Leckagen in Wasserverteilungsnetzen verloren geht. Diese Wassermenge würde ausreichen, um etwa 200 Millionen Menschen zu versorgen. Außerdem werden fast 30 Millionen Kubikmeter Wasser täglich an Kunden ausgeliefert, aber aufgrund von Ungenauigkeiten bei der Messung, Diebstahl, Rechnungsfehler und Korruption nicht in Rechnung gestellt. In den asiatischen Ländern schätzt die Asian Development Bank, dass die nicht Einnahmen generierende Wassermenge (Non-revenue Water) etwa 29 Mrd. m³/Jahr beträgt, was 9 Mrd. USD pro Jahr entspricht. Wenn das Wasservolumen der physischen Verluste auf die Hälfte des derzeitigen Niveaus reduziert wird, reicht dieses Volumen aus, um 150 Millionen Menschen zu versorgen. Es gibt viele Gründe für dieses Problem in Entwicklungsländern, aber die Ineffizienz des Managements von Wasserversorgungssystemen (WSS) ist einer der Hauptgründe. WSS fehlen in diesen Ländern häufig Methoden und Werkzeuge zur Bewertung der Leistung des Betriebs und der Verwaltung sowie zur Verbesserung. Verschiedene Agenturen und Organisationen weltweit haben detaillierte Leistungsbewertungsrahmen aus verschiedenen Indikatoren entwickelt, um alle Aspekte des WSS umfassend abzudecken. Diese Systeme scheinen jedoch nur für WSS in Industrieländern geeignet zu sein, da viele Faktoren bezüglich der Wasserversorgungsbedingungen in Entwicklungsländern nicht erwähnt wurden. In Entwicklungsländern beispielsweise liefern WSS aufgrund begrenzter verfügbarer Bedingungen (z. B. Wasserknappheit und / oder Infrastrukturbeschränkungen) häufig einige Stunden pro Tag Wasser, abhängig von verfügbaren Quellen und der Nachfrage der Kunden, was zu privaten Speichertanks und Schwimmerventilen in den Häusern der Kunden führt, um Wasser während des Zeitraums ohne Wasserzufuhr zu speichern. Der nicht kontinuierliche Betrieb verursacht auch viele unerwünschte Folgen, wie z. B. eine Verringerung der Wasserqualität und schädliche Auswirkungen auf die Anlagen. Darüber hinaus ändert das Vorhandensein von privaten Tanks (möglicherweise mit Schwimmerventilen) nicht nur das Verhalten der Hydraulik im Wasserverteilungssystem, sondern hat auch einen negativen Einfluss auf die Wasserqualität und den fehlerhaften Betrieb der Zähler der Kunden. Trotzdem erwähnen fast alle verfügbaren Evaluierungssysteme nicht diese Beziehungen und Wechselwirkungen in ihren Systemen. Vietnam ist ein typisches Beispiel für Entwicklungsländer in Bezug auf schlechtes Management von WSS. Obwohl Vietnam ein wasserreiches Land mit einem durchschnittlichen jährlichen Wasservolumen von fast 9560 m3 pro Einwohner ist, leidet es immer noch an wirtschaftlicher Wasserknappheit. Gemäß den nationalen Zielen der vietnamesischen Regierung wird im Jahr 2025 die städtische Bevölkerung zu 100% mit Trinkwasser aus zentralen Wasserversorgungssystemen versorgt, während die Abdeckung der Wasserversorgung 2009 noch 73% betrug. Insbesondere in kleinen Städten (Bevölkerung zwischen 4000 und unter 50000) erreichte die Abdeckung nur 50%. Laut Dekret Nr. 42/2009/NĐ-CP der vietnamesischen Regierung beträgt die Anzahl der Kleinstädte 633 in insgesamt 805 Städten Vietnams (etwa 80%). Daher wird die Steigerung der Effizienz beim Betrieb und die Verbesserung der WSS in Kleinstädten einer der Schlüsselfaktoren sein, um die nachhaltige Entwicklung des Wasserversorgungssektors zu gewährleisten, insbesondere bei begrenzten oder knappen Wasserversorgungsressourcen. Kleinere WSS (S-WSS), abgesehen von den oben genannten Herausforderungen, haben weitaus größere Schwierigkeiten als mittlere und große Städte wie beispielsweise niedrige Kapital- und Betriebskosten, geringe physische Vermögenswerte, fehlende Kontroll- und Messgeräte sowie fehlende Daten. Dies führt zu erheblichen Schwierigkeiten bei der Verwaltung und dem Betrieb von S-WSS. Viele spezifische Forschungen erwähnten die Probleme der diskontinuierlichen Versorgung. Es gibt jedoch keine Untersuchungen, die sich umfassend mit den Problemen in S-WSS befassen. In Bezug auf das Management von S-WSS in Entwicklungsländern wird diese Studie ein wichtiges Leistungsbewertungssystem und entsprechende Benchmarks für das Management und den Betrieb von S-WSS in Entwicklungsländern entwickeln. Darüber hinaus schlägt die Studie geeignete Methoden vor, um Daten unter den limitierenden Randbedingungen von S-WSS zu sammeln. Die Studie wird in der Dong Van Stadt, Vietnam, als Fallstudie durchgeführt

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

Assessment of public water distribution using geographic information system in Yola, Nigeria

Public water supply is capital intensive and requires a significant investment, effective management and public participation. The task is most challenging in developing countries with lower income, where less attention is given to provision of infrastructure and inefficient management of the system is ever present. However, the issue of inadequacy of water supply and ineffective distribution system in most of the cities in developing countries has been compounded by rapid increase in population. This research focuses on assessment of public water distribution in Yola, Nigeria using geographic information system (GIS). It is aimed at analyzing water distribution system in Yola with a view to optimize the distribution. The study considers elevation, population density and availability of space as well as centrality within the densely populated areas as criteria for the analysis. Five different datasets were used for the study; street data, existing pipeline network, parcels (open spaces), elevation and population data. Yola geodatabase is the source of spatial data generated using ArcGIS 10.2.1. The existing water distribution network was digitized on the street map to define the areas covered by the network; digital elevation model (DEM) was also generated using ArcGIS 10.2.1 to visualize the topography of the study area. A suitability model with elevations, available spaces and population density as inputs, was developed to determine suitable locations for reservoirs in order to ensure smooth flow from the reservoirs to consumers under gravity. Shortfall in water supply for Yola was also determined by computing water supply deficiency for each administrative ward within the study area. Findings from the study provided three alternatives and the first alternative with three reservoirs is considered the most suitable. Reservoir locations in the first alternative were determined based on the top most level of the set criteria, to ensure total coverage of the study area. This study concluded that suitability analysis using spatial analyst extension provides suitable location for reservoirs to ensure optimal water distribution system

Master Plan of Water Distribution System for Srinagar and Hanumanth Nagar Wards - using EPANET

Every metropolitan city requires a master plan which provides a conceptual layout to guide future growth and development of the city. One of the reasons for water crisis in developing countries is due to inefficient and wasteful water management systems. In this research paper EPANET is used to build the water network model, optimize it, compute head-loss, velocity of flow in each node and flow in each pipe in the water distribution. It can be used to consider and understand the growth of the demand of city with the design period of 30 years. The above knowledge is used to identify the risks related to the growth and to suggest measures to overcome these risks. The design of new model will make the respective authorities aware of the new challenges arising from changing demands

District heating and cooling optimization and enhancement – towards integration of renewables, storage and smart grid

District heating and cooling (DHC) systems are attracting increased interest for their low carbon potential. However, most DHC systems are not operating at the expected performance level. Optimization and Enhancement of DHC networks to reduce (a) fossil fuel consumption, CO2 emission, and heat losses across the network, while (b) increasing return on investment, form key challenges faced by decision makers in the fast developing energy landscape. While the academic literature is abundant of research based on field experiments, simulations, optimization strategies and algorithms etc., there is a lack of a comprehensive review that addresses the multi-faceted dimensions of the optimization and enhancement of DHC systems with a view to promote integration of smart grids, energy storage and increased share of renewable energy. The paper focuses on four areas: energy generation, energy distribution, heat substations, and terminal users, identifying state-of-the-art methods and solutions, while paving the way for future research