## 6 Discussion  
### Data Integration and Calculation  
The information obtained in the seismic refraction and passive MASW surveys, together with the interpretation of the VES surveys, has defined a zone of low compaction surface materials with velocities below 1000 m.s\({}^{-1}\) (\(V_{p}\)) and 600 m.s\({}^{-1}\) (\(V_{s}\)), which are correlated with resistivities lower than 1500 Ohm.m. These surface materials would correspond to vegetative and transported soils and colluvial ones with a high percentage of coarse material (pebbles and blocks) embedded in a clay-silt matrix. The geophysical levels below these materials' present characteristics, both in seismic and electrical techniques, of compact to very compact materials, which would correspond to a competent and cemented substrate. From this considered model, the correlation between the fundamental frequencies \(f_{o}\), obtained at the control points in the HVSR tests and the thicknesses of surface materials (sediments) in said areas obtained from the data of the SEV tests, has been proposed and executed at the same points. Therefore, the results of the thickness of the sedimentary materials over the metamorphized rocky substrate are presented in Table 3, together with the values obtained in the  
Figure 7: Results obtained in the interpretation of VES surveys (in Ohm.m). A red rectangle marks the defined sediment layers over the basement, and the blue rectangles show the water saturation levels. tests of the HVSR technique. The depths shown for each of the five VES surveys carried out also correspond to the values of the position of said basement in the refraction and MASW-type tests of the seismic method. This relationship is essential to the whole area to establish the empirical correlation concerning the fundamental frequencies obtained in HVSR surveys, which respond to Equation (1). Figure 8 shows the graphic correlation established between both groups of data in Table 3 and the value of the adjustment of the curve. In this case, said value (R\({}^{2}\)) has been established in 0.932, a result that can be considered a good correlation value, even using the few available data, with which we can consider an estimation error of 10% in subsequent calculations. Therefore, Equation (1) would be transformed according to the following values:  
\[H=31.039\;\;f_{o}\;^{-0.351} \tag{3}\]  
If we consider that \(H\) is the value of the thickness of surface sediments expressed in meters, from that Equation (3), it can be calculated for each point of the HVSR test station measured and based on the value obtained from the fundamental frequency (\(f_{o}\), in hertz), the value of the thickness of the sediments found over the rocky substratum. Table 4 presents the calculations established for each of the measured HVSR station points, including the five corresponding to the control points (in the position of the VES  
Figure 8: Empirical correlation established between VES (sediment thickness) and HVSR (frequencies) surveys. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**VES Number** & \
\begin{tabular}{c} **Rock Depth in VES** \\ **Surveys (m)** \\ \end{tabular} &
\begin{tabular}{c} **Corresponding** \\ **HVSR Survey** \\ \end{tabular} & \(f_{o}\) **(Hz)** \\ \hline
1 & 21.9 & S1 & 3.21 \\
2 & 22.2 & S2 & 2.61 \\
3 & 32.8 & S3 & 0.70 \\
4 & 35.1 & S4 & 0.49 \\
5 & 57.8 & S5 & 0.25 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Relationship between depth values obtained in VES and corresponding HVSR frequencies. tests and indicated with the prefix S), applying the formula of Equation (3). To calculate the \(K_{g}\) value, also shown in Table 4, the results obtained in Table 2 were used and applied Equation (2). As [46] considers, the values over 5 to 10 in \(K_{g}\) value (it depends on area and materials conditions) are prone to show instability or are capable of showing it. In this case, it can be correlated with a susceptibility to the present capability of sliding or a movement downhill, so that they can mark areas of potential movements in a landslide.