# GIS-Based Identification of Locations in Water Distribution Networks Vulnerable to Leakage
## 3 Materials and Methods
### Parameters Used in Vulnerability Analysis of the WDN
Figure 2: Flows (m\({}^{3}\)) and pressures (bar) per day in DMA 1, the straight line represents the average. Degradation or drops in chlorine concentration might be associated with water loss and leakage. Leakage in the WDN can adversely affect the flow and pressure in the pipelines and have a detrimental effect on water quality. The chlorine level is usually higher near the source (desalination plants) in the WDN because the chlorine dosage is injected at this phase and then reduces in the later distribution stages. Several studies have used changes in water quality parameters and chlorine concentrations to detect leakages in the WDN [41; 42]; thus, drops in chlorine are used in this study. Table 2 summarizes the drops in chlorine for the 13 DMA. Physical parameters refer to the pipe properties, such as pipe length, pipe material, pipe diameter, and the number of fittings in the WDN. These parameters are almost fixed and rarely change in the WDN. Generally, continuous (long) pipes perform better against hazards and are more durable than short pipes. Therefore, long pipes are less prone to leakage [23]. Pipe length can be used as a measure for representing water leakage, as recommended by the IWA. In this case, leakage can be expressed as the number of leaks per km per year [43]. In this study, pipe length (in m) per junction was used as a condition factor for leakage, as proposed in Equation (3) and Table 3.  
The number of fittings is another important parameter, where the higher the number of joints and fittings, the greater the potential for leakages and losses in the WDNs. Usually, \begin{table}
\begin{tabular}{c c c c c} \hline
**DMA** & **Area Name** & **Average CL** & **Max CL** & **Min CL** \\ \hline
1 & Rahmaniya 1 & 0.258 & 0.263 & 0.247 \\
2 & Rahmaniya 3 & 0.249 & 0.260 & 0.246 \\
3 & Ind. Area 4 & 0.223 & 0.255 & 0.153 \\
4 & Barashi & 0.256 & 0.279 & 0.242 \\
5 & Maysaloon & 0.259 & 0.296 & 0.226 \\
6 & Al Faya & 0.228 & 0.228 & 0.227 \\
7 & Al Guwair & 0.283 & 0.354 & 0.264 \\
8 & Butina & 0.279 & 0.324 & 0.246 \\
9 & Al Sabkha & 0.15 & 0.176 & 0.079 \\
10 & Al Ghafia & 0.187 & 0.227 & 0.150 \\
11 & Al Nasserya & 0.211 & 0.255 & 0.162 \\
12 & Al Qadisiya & 0.172 & 0.196 & 0.141 \\
13 & Ind. Area 6 & 0.238 & 0.356 & 0.118 \\ \hline \end{tabular}
\end{table} 
Table 2: Drops in chlorine (CL) in ppm. \begin{table}
\begin{tabular}{c c c c c} \hline
**DMA** & **Area Name** & **Length (m)** & **Junctions** & **L/Junction** \\ \hline
1 & Rahmaniya 1 & 22,492 & 247 & 91.061 \\
2 & Rahmaniya 3 & 23,501 & 277 & 84.842 \\
3 & Ind. Area 4 & 30,701 & 518 & 59.268 \\
4 & Barashi & 57,819 & 515 & 112.27 \\
5 & Maysaloon & 13,651 & 233 & 58.586 \\
6 & Al Faya & 16,800 & 95 & 176.84 \\
7 & Al Guwair & 11,002 & 411 & 26.768 \\
8 & Butina & 17,585 & 646 & 27.221 \\
9 & Al Sabkha & 33,467 & 399 & 83.876 \\
10 & Al Ghafia & 35,667 & 994 & 35.882 \\
11 & Al Nasserya & 17,786 & 278 & 63.979 \\
12 & Al Qadisiya & 25,041 & 476 & 52.607 \\
13 & Ind. Area 6 & 29,720 & 398 & 74.674 \\ \hline \end{tabular}
\end{table} 
Table 3: Pipe length and junctions. damage and leakage in WDNs occur in segments with fittings, such as tees, bends, and customer connections. Fitting locations are considered weak points in the WDN and are susceptible to leakage [23]. Table 4 presents information computed using Equation (4) in the 13 areas used in this study. This parameter represents the total number of fittings and customer connections per length, and these values, calculated by Equation (4), are shown in the last column of Table 4.  
\[\frac{\Sigma\mathrm{N_{F}}+\mathrm{N_{cc}}}{\Sigma\mathrm{L_{pipe}}} \tag{4}\]  
Pipelines in any WDN typically consist of different pipe diameters and corresponding pipe material. Pipe material usually varies, especially in old networks with segments in the network that have been upgraded or been through rehabilitation for different reasons. A study found that diverse pipe materials running under the same conditions perform differently regarding water leakage.