The process of calibrating hydraulic models for water distribution
systems (WDS) is crucial during the model-building process, particularly
when determining the roughness coefficients of pipes. However, using a
single roughness coefficient based solely on pipe material can lead to
significant variations in frictional head losses. To address this issue
and enhance computational efficiency, this study proposes a
single-objective procedure that utilizes Genetic Algorithm (GA) for
optimizing roughness coefficients in the EPANET hydraulic model.
EPANET-GA incorporates an automated calibration process and a User
Graphic Interface (GUI) to analyze the water head pressures of WDS
nodes. Notably, the proposed method not only optimizes roughness
coefficients based on pipe material but also spatial characteristics of
pipes. To demonstrate the effectiveness of this method, the study builds
a hydraulic analysis model for the Zhonghe and Yonghe district of the
Taipei Water Department, integrating graph theory’s connectivity and the
GIS database. The model was optimized with 34,783 node items, 30,940
pipes, and 140 field measurements. Results show that the optimized
roughness coefficient produces a high correlation coefficient (0.9) with
the measured data in a certain time slot. Furthermore, a low standard
error (8.93%) was acheived compared to 24-hour monitoring data. The
proposed method was further compared to WaterGEMs, and the study
concludes that the proposed model provides a reliable reference for the
design and routing scenario of WDS.