# Qualification of Hydraulic Analysis Models for Optimal Design of Water Distribution Systems
## 3 Application and Results
### Hydraulic Comparison of Abnormal System Conditions for WDSs
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**Label**} & \multirow{2}{*}{**Elevation (m)**} & \multirow{2}{*}{**Base Demand (CMH)**} & \multicolumn{3}{c}{**Demand-Driven Analysis (DDA)**} & \multicolumn{3}{c}{**Pressure-Driven Analysis (PDA)**} \\ \cline{3-8}  & & & **Demand** & **Hydraulic** & **Pressure (m)** & **Demand** & **Hydraulic** & **Head (m)** & **Pressure (m)** \\ \hline
2 & 150 & 100 & 100.00 & 181.42 & 31.42 & 100.00 & 194.66 & 44.60 \\
3 & 160 & 100 & 100.00 & 176.05 & 16.05 & 100.00 & 188.40 & 28.40 \\
4 & 155 & 120 & 120.00 & 171.55 & 16.55 & 120.00 & 179.44 & 24.40 \\
5 & 150 & 270 & 270.00 & 171.41 & 21.41 & 270.00 & 179.91 & 29.90 \\
6 & 165 & 2430 & 2430.00 & 164.54 & \(-\)0.46 & 1021.30 & 166.77 & 1.80 \\
7 & 160 & 200 & 200.00 & 167.35 & 7.35 & 133.87 & 164.48 & 4.50 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Scenario 1 for the two-loop network. Figure 3: Abnormal system conditions for two-loop network: (**a**) Scenario 1 and (**b**) Scenario 2. In the case of the Hanoi network, the fire flow was simulated by increasing the demand on node 31, while in the case of pipe break, pipes 24 and 33 were closed. Figure 6 shows the layout of the network for both scenarios. Due to the high number of nodes for the Hanoi and Balerma networks, the tables of final nodal pressures are not presented in this paper; instead, a comparative graph is presented for both scenarios. If an abnormal situation occurs as in Scenarios 1 and 2 (Figure 6) in the Hanoi network, with a total demand of 21,440 m\({}^{3}\)/h, the difference in pressure and supply flow for each scenario is shown in Figures 7 and 8, where the difference between the two approaches can be clearly appreciated. Figure 4: Hydraulic pressure in each node for DDA and PDA in the two-loop network (Scenario 1). \begin{table}
\begin{tabular}{l c c c c c c c c} \hline \hline \multirow{2}{*}{**Label**} & \multirow{2}{*}{**Elevation (m)**} & \multirow{2}{*}{**Base Demand (CMH)**} & \multicolumn{4}{c}{**Demand-Driven Analysis (DDA)**} & \multicolumn{4}{c}{**Pressure-Driven Analysis (PDA)**} \\ \cline{3-10}  & & & **Demand** & **Hydraulic** & **Pressure (m)** & **Demand** & **Hydraulic** & **Pressure (m)** \\ \hline
2 & 150 & 100 & 100.00 & 181.42 & 31.42 & 100.00 & 199.02 & 49.00 \\
3 & 160 & 100 & 100.00 & 149.44 & \(-\)10.56 & 0.00 & 160.00 & 0.00 \\
4 & 155 & 120 & 120.00 & 154.47 & \(-\)0.53 & 120.00 & 181.94 & 26.90 \\
5 & 150 & 270 & 270.00 & 149.49 & \(-\)0.51 & 1.29 & 150.00 & 0.00 \\
6 & 165 & 2430 & 2430.00 & 145.26 & \(-\)19.74 & 1234.74 & 167.58 & 2.60 \\
7 & 160 & 200 & 200.00 & 146.88 & \(-\)13.12 & 0.00 & 160.00 & 0.00 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Scenario 2 for the two-loop network. Figure 5: Hydraulic pressure in each node for DDA and PDA in the two-loop network (Scenario 2). In the case of Scenario 1, when node 31 increases the extreme demand for fire flow, the total supplied discharge using PDA is reduced to 97.4%, and in each nodal demand aspect, the demand in the vicinity of the fire area decreases significantly to 73.8-87.5%. For the pressure difference, the nodal pressure that is not directly affected by the fire area presents  
Figure 8: Hydraulic pressure in each node for DDA and PDA in the Hanoi network (Scenario 2). Figure 6: Abnormal system conditions for Hanoi network: (**a**) Scenario 1 and (**b**) Scenario 2. Figure 7: Hydraulic pressure in each node for DDA and PDA in the Hanoi network (Scenario 1). for DDA. However, in the PDA condition, some nodes that showed negative pressure did not serve the water demand; therefore, the pressure values were zero.