*2.1. Historical Data of Metro Systems' Flood Events in Barcelona*

Table 1 summarizes a two-decade historical data of Metro system flood events. Only those events that caused service disruption have been considered. The table was obtained linking Barcelona Metro system records from system administrator TMB, with internet media. Service disruption information is available for request to TMB, due to its confidential nature.


**Table 1.** Barcelona Metro service disruptions due to flooding events in the last 20 years.

Table 1 suggests Barcelona Metro flooding events frequency has increased over the last two years, indicating that these events could maintain or increase their frequency or intensity, due to climate change influence on rainfall variations [16]. Barcelona rainfall events frequency and intensity increases, doubling frequency downpours and peak rainfall rates up to 20% higher [41], rainfall intensities rise due to climate change impacts [42].
