<p>Gubici vode nanose veliku štetu vodovodnom sistemu, i ugrožavaju njegovo ispravno funkcionisanje. Cilj istraživanja je unapređenje sistema upravljanja gubicima vode, odnosno istraživanje mogućnosti smanjenja gubitaka u njima. Istraživanje se vrši na bazi međunarodno definisanih standarda i preporuka za smanjenje nefakturisane vode, a primenjuje se na javne sisteme vodosnabdevanja u Srbiji.</p> / <p>Water losses cause big harm to water supply system, and threaten its correct functioning. The aim of the investigation is improvement of water loss management systems in water supply processes, or the investigation of possibilities for reduction of water losses in them. Investigation is made based on international standards and guidelines for non revenue water reduction, and is implemented on public water supply systems in Serbia.</p>

<p>In this study, five real-life problem situations were used to explore the challenges of developing and implementing decision support tools for management of an urban water utility in Uganda. The study sought to explore how the degree of adoption of formal decision support tools in practice, generally perceived to be low, could be improved. In the study, an Action Research (AR) approach was used. AR is an inquiry process that involves partnership between researchers and practitioners for the purpose of addressing a real-life problem issue, while simultaneously gener-ating scientific knowledge. Unlike other research methods where the researcher seeks to study organizational phenomena but not to change them, the action researcher attempts to create or-ganizational change and simultaneously to study the process. It is recognized that AR methods provide a potential avenue to improve the practical relevance of Information Systems (IS) re-search.</p><p>The five cases that were considered in the study involved participatory problem structuring to address water distribution bottlenecks; identification of Non-Revenue Water (NRW) reduction strategies; facilitation of decentralized management of customer accounts; monitoring and con-trol of procurements and expenditure; and geospatial investigation of declining water sales. Dur-ing the study, participation in problem identification was achieved through discussions and brain-storming sessions bringing together top and middle managers within the organization. A number of prototype decision support tools were developed and implemented. Maps and other geovisu-alization tools were also used to inform and enhance the processes of collective problem identifi-cation and structuring.</p><p>Results of the study emphasized the need for proper problem structuring prior to the formula-tion of actions; the challenge of moving from planning to action; the importance of user in-volvement in the development of tools; and the need to manage IS implementation as part of a holistic, organization-wide change process. The challenges of embedding formal decision support within existing work systems in organizations were highlighted, and recommendations were made on how best to achieve this. The AR approach was found to be useful in bridging the gap be-tween academic research and technological practice, thus supporting the development of IS with immediate and practical benefits to organizations.</p>

Water systems in the Sultanate of Oman are inevitably exposed to varied threats and hazards due to both natural and man-made hazards. Natural disasters, especially tropical cyclone Gonu in 2007, cause immense damage to water supply systems in Oman. At the same time water loss from leaks is a major operational problem. This research developed an integrated approach to identify and rank the risks to the water sources, transmission pipelines and distribution networks in Oman and suggests appropriate mitigation measures. The system resilience was evaluated and an emergency response plan for the water supplies developed. The methodology involved mining the data held by the water supply utility for risk and resilience determination and operational data to support calculations of non-revenue water. Risk factors were identified, ranked and scored at a stakeholder workshop and the operational information required was principally gathered from interviews. Finally, an emergency response plan was developed by evaluating the risk and resilience factors. The risk analysis and assessment used a Coarse Risk Analysis (CRA) approach and risk scores were generated using a simple risk matrix based on WHO recommendations. The likelihoods and consequences of a wide range of hazardous events were identified through a key workshop and subsequent questionnaires. The thesis proposes a method of translating the detailed risk evaluations into resilience scores through a methodology used in transportation networks. A water audit indicated that the percentage of NRW in Oman is greater than 35% which is similar to other Gulf countries but high internationally. The principal strategy for managing NRW used in the research was the AWWA water audit method which includes free to use software and was found to be easy to apply in Oman. The research showed that risks to the main desalination processes can be controlled but the risk due to feed water quality might remain high even after implementing mitigation measures because the intake is close to an oil port with a significant risk of oil contamination and algal blooms. The most severe risks to transmission mains were found to be associated with pipe rather than pump failure. The systems in Oman were found to be moderately resilient, the resilience of desalination plants reasonably high but the transmission mains and pumping stations are very vulnerable. The integrated strategy developed in this study has a wide applicability, particularly in the Gulf area, which may have risks from exceptional events and will be experiencing NRW. Other developing countries may also experience such risks but with different magnitudes and the risk evaluation tables could provide a useful format for further work.

In this study, five real-life problem situations were used to explore the challenges of developing and implementing decision support tools for management of an urban water utility in Uganda. The study sought to explore how the degree of adoption of formal decision support tools in practice, generally perceived to be low, could be improved. In the study, an Action Research (AR) approach was used. AR is an inquiry process that involves partnership between researchers and practitioners for the purpose of addressing a real-life problem issue, while simultaneously gener-ating scientific knowledge. Unlike other research methods where the researcher seeks to study organizational phenomena but not to change them, the action researcher attempts to create or-ganizational change and simultaneously to study the process. It is recognized that AR methods provide a potential avenue to improve the practical relevance of Information Systems (IS) re-search. The five cases that were considered in the study involved participatory problem structuring to address water distribution bottlenecks; identification of Non-Revenue Water (NRW) reduction strategies; facilitation of decentralized management of customer accounts; monitoring and con-trol of procurements and expenditure; and geospatial investigation of declining water sales. Dur-ing the study, participation in problem identification was achieved through discussions and brain-storming sessions bringing together top and middle managers within the organization. A number of prototype decision support tools were developed and implemented. Maps and other geovisu-alization tools were also used to inform and enhance the processes of collective problem identifi-cation and structuring. Results of the study emphasized the need for proper problem structuring prior to the formula-tion of actions; the challenge of moving from planning to action; the importance of user in-volvement in the development of tools; and the need to manage IS implementation as part of a holistic, organization-wide change process. The challenges of embedding formal decision support within existing work systems in organizations were highlighted, and recommendations were made on how best to achieve this. The AR approach was found to be useful in bridging the gap be-tween academic research and technological practice, thus supporting the development of IS with immediate and practical benefits to organizations. / QC 20101115

The American Water Works Association (AWWA) and the International Water Association (IWA) have designated the volume of water not registered by water meters as a form of "apparent loss" in a distribution system. The term apparent is given because this volume is not technically a water loss, as is the case of wasted water from real leaks in the distribution system. Large volumes of apparent losses hurt the revenue of utilities that rely on water metering to bill their customers. This is critical to utilities given that billed consumption is often the main source of income to provide adequate service. This form of apparent losses is a challenge to water management, particularly, in the case of significant drought because of the uncertainty about the real volume of water consumed. Although the impact of apparent losses from a single residential service connection is not as significant compared to an industrial meter with low accuracy, the cumulative effect of apparent losses across residential users can be very significant. Until the early 2000's water utilities in the U.S. relied on mechanical water meters to measure residential water use. Since then, electronic meters with higher accuracy at low flow rates have been developed. Data collection from meters has also evolved as well, from the manual reading by an operator, to drive-by systems and most recently to remote readings using a network of transmitters/receivers (i.e., advanced metering infrastructure or AMI). An expectation of this dissertation is that it will help water utilities to have a better idea of the volume of apparent losses due to metering inaccuracy (i.e., registration error) and provide insights into the effects of installing AMI systems to residential metered water (MW). To achieve this goal, two main objectives are fulfilled 1) to expand on the knowledge of registration error (RE) in mechanical nutating-disc (ND) meters used to monitor residential consumption, and 2) to evaluate the impact of metering infrastructure upgrades on the volume of metered water (MW) from residential service connections. This dissertation follows the manuscript format with three journal articles constituting the main chapters after a general introduction characterizing the issues in Chapter 1. Chapter 2 is an experimental study that evaluates the influence of service time (ST) and volumetric throughput (TP) on the accuracy of ND meters within the recommended flow rates set by the U.S. water industry for meters with an internal diameter of ⅝-in. (15-mm). Over 300 meters removed from service were tested for accuracy. Key findings of this study are 1) ND meters that have been in service over 25 years have a greater likelihood of poor accuracy at the minimum recommended flow rate (Q^min) of 0.25 gallons per minute (gpm) (57 liters per hour (L/h)) and 0.5 gpm (114 L/h) independent of TP, and 2) comparison with data from accelerated laboratory testing showed that simulated use may not necessarily reflect the actual performance of ND meters in service, particularly, at 0.25 and 0.5 gpm. Chapter 3 is an experimental study that investigates REs of ND meters below the minimum recommended flow rate (Q^min = 0.25 gpm), particularly, at ½, ¼ and ⅛ of Q^min. Over 100 meters removed from service were tested in this study. Key findings of this study are 1) confirmed how performance decreases with reducing flow rate below Q^min, 2) of the variables considered, TP was found to be a better indicator of RE at Q_(1/8)^min up to an approximate meter reading of 0.66 MG (2.5 ML) compared to ST for 10 ≤ ST ≤ 24 years, with minimal influence at Q_(1/4)^min and none at Q_(1/2)^min, and 3) a strong linear relationship was found between RE at Q_(1/2)^min and RE at Q^min independent of TP or ST. Chapter 4 is a study that evaluates the extent to which the implementation of a new AMI system combined with a system-wide installation of new ND meters impacted the volume of MW from residential service connections of a 22,000-person municipality in southwest Virginia. Time-series analysis techniques were employed to evaluate changes in the trend of bimonthly MW and median daily MW over a six-year period. Key findings of this study are 1) the AMI system improved the accountability of MW for the utility, 2) despite an ongoing downward annual trend in MW, average bimonthly MW mildly increased after the AMI system was fully operational, and 3) annual MW increased by 2.2% in the 12-month period immediately following the metering infrastructure upgrade. / Doctor of Philosophy / An expectation of this dissertation is that it will help water utilities to have a better idea of the volume of water not being measured by residential water meters in their system (i.e., registration error) and provide insights into the effects of replacing water meters and installing automatic data collections systems (i.e., metering infrastructure upgrades) to improve accounting of water and revenue. To achieve these goals three studies were conducted. In the first two studies, over 400 nutating-disc (ND) water meters, a type of mechanical meter used to measure water, were removed from service and tested to evaluate the percent of water not measured at different ranges of flow (volume per time), and to determine if metering errors changed depending on the service time (ST) of the meter or total volume of water that had gone through (TP) it while in service. The third study consisted in the review of water consumption data from a municipality in southwest Virginia that underwent a metering infrastructure upgrade consisting of replacing all their water meters and installing an advanced metering infrastructure (AMI) system (i.e., automatic meter reading). Key findings discussed in this dissertation are 1) confirmed how performance of ND meters decreases with reducing flow rate below 0.25 gallons per minute (gpm). This is the minimum flow rate (Q^min) recommended by the U.S. water industry for accuracy testing of mechanical meters. 2) ND meters that have been in service over 25 years have a greater likelihood of poor accuracy at Q^min and 0.5 gpm independent of TP. 3) The relative influence of TP and ST on accuracy varied with the test flow rate. 4) Comparison with data from accelerated laboratory testing showed that simulated use may not necessarily reflect the actual performance of ND meters in service, particularly, at 0.25 and 0.5 gpm. 5) The AMI system improved the accountability of water for the utility. 6) Despite an ongoing downward annual trend in metered water (MW), average bimonthly MW mildly increased after the AMI system was fully operational. And 7) annual MW increased by 2.2% in the 12-month period immediately following the metering infrastructure upgrade.

This research focused on evaluating and comparing the perceptions, water-use behaviour, water conservation awareness and overall water stewardship of participants residing in Hammanskraal and Atteridgeville who have experienced intermittent water supply in their domestic households – due to either water contamination incidents caused by dilapidated infrastructure or water restrictions implemented by the City of Tshwane Metropolitan Municipality during the 2016–2017 drought in the Gauteng Province. The research concluded that the municipality needs to implement proactive water conservation awareness initiatives on an ongoing basis to reduce high water demands and to create a culture of water stewardship, especially in Atteridgeville. Transparent communication is also required from the municipality to instil the necessary trust among the public. It is recommended that the municipality attends to water leaks and ongoing complaints from the public timeously to reduce the current apathy from the public against reporting water-related issues and to ultimately ensure compliance to water restrictions. / Hierdie navorsing fokus op die evaluering en vergelyking van deelnemers wat in Hammanskraal en Atteridgeville woon se persepsies, waterverbruiksgedrag, waterbewaringsbewustheid en algehele waterrentmeesterskap, wat onderbroke watervoorsiening in hulle huishoudings ervaar het – as gevolg van waterbesoedelingsvoorvalle wat deur vervalle infrastruktuur veroorsaak is en waterbeperkings wat deur die Stad Tshwane Metropolitaanse Munisipaliteit gedurende die 2016 tot 2017-droogte in Gauteng ingestel is. Die navorsing het tot die gevolgtrekking gekom dat die munisipaliteit proaktiewe waterbewaringsbewustheidsinisiatiewe op ’n deurlopende grondslag moet implementeer om hoë wateraanvraag te verminder en ’n kultuur van waterrentmeesterskap, veral in Atteridgeville, te skep. Deursigtige kommunikasie word ook van die munisipaliteit vereis om die nodige vertroue by die publiek te kweek. Daar word aanbeveel dat die munisipaliteit betyds aandag aan waterlekkasies en deurlopende klagtes van die publiek sal gee om die huidige onverskilligheid van die publiek by die aanmeld van waterverwante aangeleenthede te verminder en om uiteindelik te verseker dat die publiek die waterbeperkings eerbiedig. / Patlisiso ena e ne e tsepame hodima ho lekola le ho bapisa maikutlo, boitshwaro ba tshebediso ya metsi, tsebo ka poloko ya metsi le tlhokomelo e akaretsang ya metsi ke bankakarolo ba dulang Hammanskraal le Atteridgeville ba bileng le phepelo ya metsi e kgaohang malapeng a bona – e ka ba ka lebaka la diketsahalo tsa tshilafatso ya metsi e bakilweng ke dipeipi tse senyehileng kapa ho kgaolwa ha metsi ho kentsweng tshebetsong ke Masepala wa Motsemoholo wa Metropolitan wa Tshwane nakong ya komello ya 2016–2017 porofenseng ya Gauteng. Patlisiso e fumane hore masepala o hloka ho kenya tshebetsong matsholo a ho atisa tsebo ka poloko ya metsi ka mokgwa o tswellang e le ho fokotsa tlhokeho e phahameng ya metsi le ho theha ditlwaelo tsa tlhokomelo ya metsi, haholo ho la Atteridgeville. Ho boetse ho hlokeha puisano e hlakileng e nang le ponaletso ho tswa ho masepala e le hore setjhaba se be le tshepo ho ona. Ho kgothaletswa hore masepala a sebetsane le diketsahalo tsa ho dutla ha metsi le ditletlebo tse tswellang tse tswang ho setjhaba ka potlako e le ho fokotsa maikutlo a ho tsotelle a tswang ho setjhaba mabapi le ho tlaleha mathata a amanang le metsi le ho netefatsa hore batho ba latela melawana ya phokotso ya metsi. / Geography / M. Sc. (Geography)