In modern conditions of significant deterioration of water supply networks, rising costs of water resources, and increasing energy consumption, the issue of water losses particularly hidden leaks has become critically important for ensuring sustainable water supply. According to global practices, hidden leaks account for 10% to 50% of total losses in water supply systems, depending on the age and technical condition of the pipelines. In Ukraine, the problem of hidden leaks is particularly acute due to the aging of urban infrastructure, limited financial resources for network modernization, and insufficient implementation of modern leak detection technologies. The developed method allows high-accuracy localization of the leak location using a minimal number of pressure and flow measurements, which is confirmed by numerical simulations and field experiments. To theoretically substantiate the statistical-hydraulic method of hidden leak localization, numerical modeling of localization error based on system input parameters was conducted, such as pipeline diameter, excess pressure in the network, leak orifice area, dimensionless leak flow rate, and relative leak location. A key feature of the study is the consideration of the probability of multiple simultaneous leaks in network sections. The Poisson model of independent events was used to assess this probability. Based on the assumptions of stationarity, ordinariness, and independence of accidents, analytical expressions were obtained to estimate the risk of multiple leaks depending on specific failure rates, pipeline length, and the time required for leak elimination. The development of the statistical-hydraulic leak localization method was based on analyzing the influence of input hydraulic parameters on the leak location and the resulting localization error. In general, the leak point coordinate X is a function of 11 dimensional input parameters: X = F (z₁, z₂, p₁, p₂, γ, L, D, Δe, Q₁, Q₂,ν).Using Buckingham’s π-theorem, the relative coordinate X/L can be represented as a function of eight dimensionless complexes: X/L =f (I, Δe/D, ΔQ/Q, Re₁, Re₂, Eu, ω₀/ωтр). Theoretical studies were conducted using a numerical simulation model to determine systematic relative errors of the statistical-hydraulic method depending on five main input parameters: dimensionless leak flow rate, pipe diameter, orifice area, excess pressure, and relative leak coordinate. The resulting trend lines can be used to adjust the expected leak location. For each parameter, separate graphs of average error and standard deviation were constructed to enable corrections based on specific site conditions. The proposed statistical-hydraulic leak localization method has several practical advantages. Using statistical processing of measurement point packets, high accuracy in determining the leak coordinate is achieved. This eliminates the need for additional excavations to install sensors along the pipeline. The method was implemented in Microsoft Excel using macros to automate calculations. The method significantly reduces the time needed for leak localization and repair, improving the overall reliability of water supply systems. To enhance the reliability forecasting of water networks, a Poisson-based model for multiple leak risk assessment was developed. An optimization function Fopt was introduced, representing the ratio of relative localization error to the probability of leak detection after the first auxiliary pipeline excavation. This allowed for an analytical justification of the efficiency of the statistical-hydraulic method compared to the traditional hydraulic gradient method. Considering the significant effect of hydraulic friction factor accuracy on localization errors, a comparative analysis of friction factor formulas was performed. Thus, the dissertation addresses a vital scientific and practical problem of improving hidden leak localization methods in pressurized water supply systems through the development of a statistical-hydraulic approach that incorporates key hydraulic parameters and statistical leak characteristics. The findings contribute to enhancing the efficiency of water supply networks and promoting sustainable development of centralized water supply systems in Ukraine.
