Evaluation of aparent loss components in water distribution systems with multiple criteria decision making for sustainable water management

Preventing water losses plays a critical role in the efficient use of water resources. Effective management of administrative losses, including losses caused by subscriber meter errors and illegal uses, makes a significant contribution to ensuring water and financial efficiency. Excessive water use occurs in systems with high administrative losses. In addition, direct revenue losses of administrations increase due to the increase in the administrative loss rate. This study aims to prioritize the management components of administrative losses and unbilled legal uses in urban water supply and distribution systems and to provide a framework for the effective and sustainable management of these components. Within the scope of the study, criteria were first determined in economic, administrative/management, socio-economic, environmental and social categories in order to evaluate the components that need to be improved. Analytical Hierarchy Process (AHP) and Analytical Network Process (ANP) methods were applied separately in determining the importance levels of the components on the decision criteria. Then, TOPSIS (Technique for Order Preference by Similarity to Ideal Solution) method was applied to the decision matrices weighted with AHP and ANP and the ranking of the components according to their effects on water losses was obtained. In addition, probabilistic analyses of the components on administrative losses were performed using Bayesian networks. In the last stage, risk classification was carried out by calculating the risk potentials of the components in terms of cost, water-energy-income loss, and social impact with the Fuzzy Logic Theory. These analyses provided important data to minimize administrative losses in water supply distribution systems, to ensure water and financial efficiency, and to minimize the factors causing income loss. The results of the criteria weighting method show that administrative loss components have a great impact on the criteria of water protection, efficiency, operating cost, solvency and income increase. When the effects of administrative water loss components in terms of cost, water-energy-income loss and social impact are examined with probabilistic analysis and risk assessments, it is determined that data measurement and management and meter management are of high importance in the main components, and irregular or incorrect measurement of system inlet flow and high average meter age are of high importance in the sub-components. In the probability-based risk assessment model, the components are examined in the categories of probability of occurrence (P), investment, operating, maintenance and rehabilitation costs (C), water, energy and income loss (L) and social impact (S), and the aim is to systematically evaluate the risks and estimate their effects. The results indicated that the main heading of data measurement and management affected the probability of administrative loss at a level of 89.78, and that the components of the inadequacy of the accrual and billing system, the high level of losses due to illegal use, and the high level of unmeasured uses that were not legally billed had a high level of impact. The results of the study will contribute to the development of applicable strategies for apparent loss management in urban water management and will guide decision-makers in the field of water management.