3.1.1. Barcelona Road Hazards

Figure 12 shows the percentage of road sections that were affected by flood-depths at various return periods for the Baseline (a) and Climate Change (b) scenarios using the rules as described in Table 5. As the severity of the events increases, the number of deep-flooded roads continues to grow whereas the percentage of shallow flooded roads affected begins to level out around 12%. This "levelling out" of the number of shallow flooded sections is due to the transition of road hazard classifications whereby as the severity of the event increases, previously shallow ponding areas upon the surface continue to accumulate flood waters thus moving their flood depths from below 30 cm to 30 cm+ thus transitioning to deep-flooded road status.

**Figure 12.** Affected road sections in Barcelona case study area for (**a**) Baseline Scenarios, (**b**) Climate Change Scenarios.

#### 3.1.2. Bristol Road Hazards

Figure 13 shows percentage of affected lane sections for the Bristol case study with respect to the severity of the pluvial flooding events for Baseline (a) and Climate Change (b) scenarios. Within the Bristol case study, an additional criteria specifying the minimum length of a flooded road was included to reduce the number of "flood zones" in the traffic model. This reduction of flood zones was implemented in order improve model performance. In this instance, the minimum length for a flooded road was set to 10 m; therefore, if the length of the section of road that is flooded is less than 10 m, the road will be regarded as not flooded, thereby bringing the overall percentages down. Like that of the Barcelona case study, there is a positive correlation between the severity of the event and the percentage of affected links. For both the Baseline and Climate Change scenarios, we see climbing numbers of affected links and again the transition of shallow flooded areas to deep flooded as the severity of rainfall events increase.

**Figure 13.** Affected road sections in the Bristol case study area for (**a**) Baseline Scenarios, (**b**) Climate Change Scenarios.

#### *3.2. Impact Assessment*
