Calibration of Water Distribution Network Models and Comparison between (DDA) and (PDA)

In this study, we present a calibration methodology for drinking water distribution network models using two hydraulic simulation approaches: Demand Driven Analysis (DDA) and Pressure Driven Analysis (PDA), implemented in EPANET 2.2. The calibration process focuses on determining two critical parameters the discharge coefficient and the pressure exponent which govern flow behavior under pressure-dependent conditions. Unlike DDA, which assumes fixed consumption at nodes regardless of pressure, PDA accounts for variable flow rates based on available pressure, offering a more realistic representation of network performance during low-pressure scenarios. These coefficients were derived from national plumbing standards applicable to different consumer categories in Algeria and Romania, and integrated into the numerical models to enhance simulation accuracy. A detailed comparison between DDA and PDA is provided, highlighting the strengths and limitations of each approach. Importantly, this type of numerical model is especially valuable during the design phase of water distribution systems, when physical measurements are unavailable and planning decisions must rely on regulatory data and theoretical assumptions.