# UAV-Based Evaluation of Rockfall Hazard in the Cultural Heritage Area of Kipinas Monastery, Greece
## 3 Stability Analyses
### Rockfall Susceptibility Analysis
Then, from the attribute table, the 3D coordinates of every point, that consisted of each  
Figure 19: Volume distribution for both the fallen (blue) and the potentially unstable (red) blocks for the whole slope. polyline (X-Y-Z), were converted to 2D (X-Y). The 2D information could then be imported to RocFall software v.8.0.12 (RocScience Inc., Toronto, ON, Canada) in order to achieve the most precise visual interpretation of each slope's profile. In this particular case, for sub-region U1 three (3) main rockfall release points were identified across the slope's profile. The result of the simulation indicates that the failure from two (2) of them (point a and point b) cannot threaten the monastery, and, consequently, the rockfall risk can be neglected. The third identified release point can be harmful for the monastery and the maximum total kinetic energy of the rockfall at the location of impact with the monastery was estimated as 69 kJ. In sub-region U2, there were identified two (2) main rockfall release points that could both, potentially, produce threatening events for the road below the slope. The maximum total kinetic energy of the rockfall at the location of impact with the road was estimated to be 429 kJ for the first release point (point a) and 747 kJ for the second (point b). In the third sub-region (U3), two (2) main detachment points for rockfalls were identified as potentially harmful (point a and point b), and one (1) cannot threaten the road below (point c). The maximum total kinetic energy of the rockfall at the location of impact with the road was estimated as 3621 kJ for the first release point (point a) and 1386 kJ for the second (point b). These were the highest values for any of the investigated slopes. At last, in sub-region U4, two (2) main rockfall release points were identified. Both of them could potentially threaten the road below the slope. The maximum total kinetic energy of the rockfall at the location of impact with the road was estimated as 290 kJ for the first release point (point a) and 102 kJ for the second (point b). The detailed results from this analysis, per sub-region, are demonstrated in Table 5, while a visual interpretation of the rock blocks trajectories is presented in Figure 14:0 \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Sub-Region**} & **Release Point** & **Release Height** & **Rock Block** & **Total Kinetic Energy of the Rockfall (kJ)** \\  & **Location** & **(m)** & **Volume (m3)** & **Rockfall (kJ)** \\ \hline \multirow{3}{*}{U1} & point a & 46 & 0.9 & – \\  & point b & 24 & 1.1 & – \\  & point c & 11 & 0.5 & 69 \\ \hline \multirow{3}{*}{U2} & point a & 41 & 0.7 & 429 \\  & point b & 34 & 1.2 & 747 \\ \hline \multirow{3}{*}{U3} & point a & 47 & 4.4 & 3621 \\  & point b & 38 & 1.4 & 1386 \\ \cline{1-1}  & point c & 30 & 1.8 & – \\ \hline \multirow{3}{*}{U4} & point a & 41 & 0.4 & 290 \\  & point b & 13 & 1.0 & 102 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: The exports from the trajectometry simulations, executed by RocFall software.