## 3 Results from the Application of the Decision-Support Tool
Having defined the spatial distribution of both the standard (i.e., seismic faulting, slope instability, and soil liquefaction) and more complex (secondary seismic faulting) earthquake-related geohazards, four scenarios have been identified and examined for the CI routing analysis. It is noted that these scenarios do not include any other design criteria, as in the more holistic and realistic scenario that will be presented in the sequence. Accordingly, they consider three rather extreme cases and one intermediate case:  
* Scenario 1: Both primary and secondary seismic fault zones are much more important than slope inclination and potentially liquefiable areas. * Scenario 2: Potentially liquefiable areas are much more important than the slope inclination and seismic fault zones. * Scenario 3: Slope inclination is much more important than potentially liquefiable areas and seismic fault zones. * Scenario 4: An intermediate scenario in which the slope inclination, potentially liquefiable areas, and seismic fault zones are equally important. Table 1 indicates the CI design criteria and sub-criteria that have been adopted, along with their respective weight factors (i.e., influence), as obtained from the implementation of AHP. Low values of influence indicate that a criterion or sub-criterion has a marginal impact on the CI routing analysis; thus, the resulting CI route could potentially cross this geohazardous zone. In contrast, a high influence value implies that a geohazardous zone must not be crossed when performing CI routing analysis. The criterion of slope inclination has been distinguished into five classes (sub-criteria) representing zones of slope inclination ranging from 0\({}^{\circ}\) to 50\({}^{\circ}\), and the preference is given to pipeline passage via (almost) flat areas, i.e., all higher inclination zones are assigned a much higher weight factor. Additionally, three sub-scenarios have been examined regarding the geo  
Figure 6: Second-order geodata of the examined area for the application of the decision-support tool: (**a**) secondary seismic fault zones and (**b**) potentially liquefiable areas. hazard of seismic faulting by assigning the specific weight factors to the main, the 1 st secondary, and the 2 nd secondary faults, aiming to their avoidance in the 1 st, 2 nd, and 3 rd sub-scenarios, respectively. After assigning weight factors to the selected design criteria and sub-criteria, the LCPA technique has been implemented to derive several cost- and length-minimized CI routing alternatives. Figure 7a-d presents the obtained CI routes corresponding to scenarios 1, 2, 3, and 4, respectively. The yellow points denote the starting and ending points of the proposed routings. In particular, in all scenarios, three optimal routes have been derived depending on which fault zone is considered more critical and has to be avoided. According to the weight factors in the right column of Table 1 in all subplots of Figure 7, Route I, Route II, and Route III refer to sub-scenario 1 (81.8% for the primary seismic fault zone), 2 (81.8% for the 1 st secondary fault zone), and 3 (81.8% for the 2 nd secondary fault zone), respectively. A more holistic and realistic scenario (i.e., scenario 5) has also been defined and examined. In addition to the aforementioned earthquake-related geohazards, geospatial data pertaining to the existing road network, urban areas, and NATURA 2000 areas has been collected from the OpenStreetMap exports on Humanitarian Data eXchange (HDX) [66], Geodata.gov.gr [62], and the datahub of the European Environment Agency [67], respectively, and has been used as additional design criteria. The collected geodata is depicted in Figure 8, and Table 2 provides further insight into the qualitative prioritization of the selected criteria. It is noted that similar prioritization tables have been used to obtain the weight factors in Table 1 according to the standard process of AHP. In the sequence, Table 3 summarizes the influence of the considered geodata as obtained after the implementation of AHP.