*2.4. Modeling of the E*ff*ects of Pluvial Floods on Several Urban Services*

Projections of rainfall and sea level rise were used to feed the 1D/2D coupled USM to analyze the hydraulic behavior of the underground sewer system and the overland flood-prone areas in the case of pluvial floods for current and future rainfall conditions.

Concerning the assessment of multiple hazards and risks, the proposed methodology is based on the development of coupled models and tools ("loosely or integrated models"); thus, the outputs of certain models are used as inputs in others according to the scheme presented in Figure 6 [27].

*Sustainability* **2020**, *12*, 5638

**Figure 6.** Scheme of loosely coupled model approach used for the multi-hazards assessment [27].

The aim of the developed loosely coupled models was the assessment of multi-hazards and multi-risks (including direct and indirect impacts) produced by urban pluvial floods and the cascading effects on other urban services (electrical system, waste collection system and surface traffic system). Table 1 summarizes the analyzed services affected by pluvial floods in Barcelona, the behavior of which was based on the developed loosely coupled models [27]. Figure 7 shows the analyzed interrelationships to assess the resilience of some main city services in the case of urban flooding episodes [28].

**Table 1.** Loosely coupled models developed and used for the flood resilience analysis in Barcelona.


**Figure 7.** Diagram of the impact analyses carried out within this paper and the potential cascading effects.
