## 2 Materials and Methods
### Elaboration of GIS Indicators
#### 2.3.2 GIS Indicators of Anthropization  
The phenomenon of anthropization is spatially evaluated using GIS indicators of territorial transformation. This spatial transformation generates subphenomena such as the \"dam effect\" and \"soil sealing\" or alterations in the orography of the land which, according to the bibliography consulted, may have important implications on the risk of flooding of a territory. By using historic GIS cartography, the evolution of various dimensionless indicators associated with these subphenomena is evaluated numerically over time. The indicators selected to evaluate the patterns of territorial transformation in the study area are detailed below:  
* Linear infrastructure density (_LID_) index: Linear communication infrastructures are largely associated with the generation of \"dam effects\" during episodes of torrential rain that generate floods [33; 34]. This index is calculated over time to show the importance of the impact produced by these infrastructures within the whole of the phenomenon of the anthropization of a territory. This dimensionless index evaluates \begin{table}
\begin{tabular}{c c c c} \hline \hline  & **Minor Damage** & **Relevant Damage** & **Catastrophic Damage** \\ \hline
**Impact on communications** & Temporary path blocks & Temporary roadblocks & Block on highways or critical \\  & & & road infrastructure \\ \hline
**Damage to buildings and material goods** & Flooding of garages in buildings & Flood inside homes and main areas of buildings & Structural destruction or complete loss of the value of material goods \\ \hline
**Agriculture and livestock** & Partial crop damage & Complete loss of the crop & Tree uprooting or drowning \\  & & & of animals \\ \hline
**Operation of public services** & Malfunction of nonessential services (e.g., streetlamps) & Temporary outages of essential supply (water, electricity) & Permanent or prolonged \\ \hline
**Environmental damage** & Damage to unprotected areas with no environmental, historical, or cultural value & Recoverable damage to protected areas (e.g., loss of the beach line) & Irreversible damage in protected areas \\ \hline \hline \end{tabular}
\end{table} 
Table 1: \(I_{\text{EDS}}\) criteria for the level of significance of the damage. Figure 6: Detail of spatial distribution of the georeferenced database generated for damage. Source of data: Own elaboration from several emergency services of various municipalities, regional and state emergency service [31; 32]. the spatial presence of these infrastructures in each analysis spatial cell by taking the size and relevance of the linear infrastructure into consideration. \[LID=\frac{\sum h_{i}L_{i}^{2}}{S_{tr}} \tag{1}\]  
\(L_{i}\) = length of existing linear infrastructures (m)  
\(h_{i}\) = weighting coefficient (highway = 1, normal road = 0.75, country road = 0.5)  
\(S_{tr}\) = territorial surface in reference (m\({}^{2}\))
* Index of soil artificialization (\(SA\)): The urbanization of the territory is, together with erosion, the main cause of the \"sealing effect\" of the soil [35; 36]. This phenomenon notably reduces the soil's ability to absorb rainwater. To analyze this phenomenon, the artificial transformation process of the territory is evaluated over the last decades by applying the CORINE Land Cover criteria [37]. The indicator differentiates areas of low permeability (such as urban areas without green areas) from artificial areas with absorption capacity (such as golf resorts). This dimensionless index evaluates land artificial transformation in each analysis cell by taking the size of the linear infrastructure into consideration.