## 2 Methodology
### Research Questions  
The main goal of this SLR was to provide answers to the research questions listed in Table 2. In this section, each study question is explained briefly.  
RQ1 discovers the spatial scales of pilot zones in previous studies that could be divided into three different categories; community, urban and regional. This distinction is clarified in Section 3.2. This question also has the purpose of identifying the countries that have been investigated in this field to pinpoint an area that may require future investigation.  
RQ2 aims to identify the type of floods that occurred in the networks that are mainly categorized into three types; pluvial (or surface water), fluvial (or river flood), and coastal (or sea level rise). In parallel, RQ3 examines the models that are applied to different types of floods. This may identify a gap in addition to the most used model for each flood type.  
RQ4 aims to find ways of applying the flood model results to the traffic model and determine the techniques used to integrate flood and traffic models. It is crucial to recognize  
\begin{table}
\begin{tabular}{c c} \hline
**NO.** & **Question** \\ \hline \(1\) & What spatial scales and geographical areas are analyzed in assessing the indirect impacts of floods on transportation? \\ \hline \(2\) & What types of floods in transportation networks were modeled? \\ \hline \(3\) & What models were applied for modeling the flood in the network? \\ \hline \(4\) & How are the flood impacts seen in the traffic networks? \\ \hline \(5\) & What transportation modes are evaluated in the indirect impact analysis of floods? \\ \hline \(6\) & What aspects or variables of traffic are modeled? \\ \hline \(7\) & What types of models were used for modeling the traffic situation in flooding? \\ \hline \(8\) & What types and sources of data were used to parametrize the models? \\ \hline \end{tabular}
\end{table}
Table 2: Research questions.  
Figure 2: The instruction of the applied methodology in the current SLR.  
the most efficient way of integrating the flood and traffic models between the existing methods, namely dynamic and static, in different situations. Geographic Information System (GIS) is the most common connector of the flood and traffic models, while dynamic integration programming software, such as Python, can accelerate the analysis by updating the flood situation and its impact on the traffic.  
RQ5, by considering the mode of transportation that is analyzed in case of flooding, sets the boundaries of the analysis itself. Rail, road, and waterways are the three motorized modes of transportation that are examined in flood situations. On the other hand, multimodal transport networks have attracted researchers' attention due to their increasing usage in recent years. Therefore, their situation in case of flooding is a vital issue that needs to be examined.  
RQ6 aims to identify which aspects of the flooded network modeling are the focus of used models and may reveal a research gap for future models. Models that aim to analyze flooded networks could consider several factors, such as the increased time and distance required for travel, as well as the additional emissions generated, which can be quantified in monetary terms.  
The goal of RQ7 is to explore the various traffic flow models that have developed over time, with the aim of providing a comprehensive understanding of how vehicles interact with the network during flooding scenarios. Macroscopic, microscopic, and mesoscopic are three common traffic models which determine the simulated details in a traffic network. In some cases, a combination of these traffic models could be used as well. Exploring the application and efficiency of each model in different flooded transportation modes lights up the way for further studies and research in this field.  
RQ8 provides a comprehensive list of the data types and sources utilized to parameterize existing models. It also could be used as a reference for data collection for future research.