Author: Rahimov, Ashraf Rasul o‘g‘li; Murodullayev, Javoxir Raxmatillo o‘g‘li

Annotation: The paper proposes a six-stage methodology for calibrating the hydraulic model of an urban water distribution network from field measurements, and tests it on the Karshi city network under conditions of incomplete input data. The methodology combines three interrelated measurement types: seven-day continuous pressure logging at eight points, minimum night flow (MNF) measurement in an isolated zone, and a night-time stepped pressure test. Measurements were carried out on 5-12 October 2025. The network-average pressure was 41.5 m and the maximum pressure in the low zone 57.7 m; the daily fluctuation was about 5 m at the outlets of the head pumping stations and 14-17 m in the low zones. The minimum night flow was 27.1 m³/h, from which a physical loss of 25.1 m³/h, or 20.9 litres per connection per hour, was separated. Regression in logarithmic coordinates yielded a pressure-leakage exponent N₁ = 1.205 ± 0.037 (R² > 0.998). After calibration the root-mean-square error fell from 7.49 m to 0.56 m, with all residuals inside a ±1 m band.

Keywords: hydraulic model, calibration, field measurements, pressure logger, minimum night flow, FAVAD, N₁ exponent, RMSE, EPANET, Karshi city.

Pages in journal: 320 - 329