Hydraulic Analysis, Calibration, and Validation of Developed QGIS–EPANET Model

Abstract

Hydraulic model calibration and validation are essential components of water distribution system analysis, providing a quantitative basis for evaluating model reliability and its ability to reproduce real-world hydraulic behaviour. This study presents the calibration and validation of a QGIS–EPANET model developed for Enugu Metropolis, integrating spatial data with hydraulic simulation to improve prediction accuracy. Field measurements from  ENSWC operational records were utilized to adjust pipe roughness, nodal demand, and minor loss coefficients until the simulated pressures and flows aligned with observed data. Calibration yielded an average pressure deviation of 0.88 m, while computed statistical indices—RMSE (1.12 m), MAPE (3.87%), and R² (0.93)—indicated excellent agreement between observed and simulated values. Validation using independent datasets further confirmed model robustness, with RMSE = 0.95 m, MAPE = 2.64%, and R² = 0.92. The results demonstrate that the QGIS–EPANET framework offers high predictive reliability and provides a dependable decision-support tool for optimizing water distribution in Enugu Metropolis.