## 5 Conclusions  
First, A-DInSAR processing and analysis of the cliffs of the Central Coast of Asturias (N Spain) have been presented, using a dataset of 113 descending IW-SLC SAR images of Sentinel-1 A/B from January 2018 to February 2020. For the A-DInSAR processing, professional software (PSIG chain) and free unsupervised service (GEP platform) were applied. The principal aim of this work has been to detect and monitor coastal instabilities, differentiating and quantifying deformations related to slope instabilities from other ground movements or noise and atmospheric artifacts. Firstly, the ground motion analysis was conducted at regional scale. Afterwards, the deformations detected were analyzed at a local scale. The BAPA database has served as a key for the selection of the different local areas. The main contribution of this work is to demonstrate that A-DInSAR techniques can be used to support the management of the coastal cliff areas at the regional scale. The BAPA database has served as a key for the selection of different areas at a local scale. These deformations can be directly related to coastal instabilities and effects on port infrastructures due to marine activity and infrastructure subsidence. The LOS mean deformation velocity maps (mm year\({}^{-1}\)) by means of PSIG and GEP show rates of \(-\)17.1-37.4 and \(-\)23.0-38.3 mm year\({}^{-1}\), respectively. According to the deformation time series (mm), the minimum and maximum accumulated displacements are \(-\)68.5-78.8 and \(-\)48.8-77.0 mm \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Sector**} & \multirow{2}{*}{
\begin{tabular}{c} **Maximum** \\ **Coastal Retreat Rate** \\ **(m Year\({}^{-1}\))** \\ \end{tabular} } & \multicolumn{2}{c}{**LOS Velocity**} & \multicolumn{2}{c}{**LOS Displacement**} \\  & & **(mm Year\({}^{-1}\))** & & **(mm)** & \\ \cline{2-6}  & **PSIG** & **GEP** & **PSIG** & **GEP** \\ \hline Podes Peninsula & 0.71 & No data & \(-\)6.8–12.9 & No data & \(-\)13.7–28.9 \\ Luanco town & 1.22 & \(-\)2–3.7 & \(-\)9.1–7.5 & \(-\)15.8–26.6 & \(-\)12.9–16.3 \\ Cand\(\acute{a}\)s town & 0.78 & \(-\)1.7–1.2 & \(-\)5.6–7.5 & \(-\)3.9–10.1 & \(-\)8.9–10.4 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Maximum coastal retreat rate (2006-2017) [45], LOS mean velocity and maximum LOS accumulated displacements (2018-2020) for some local sectors. by means of PSIG and GEP, respectively. These deformation movements could be related to coastal incidence and retreat. Other deformations that were found are due to anthropic activities and uncorrected atmospheric component. This study considerably improves the previous knowledge of coastal instabilities and other ground motions along the Central cliff coast of Asturias. The factors that limit the application of A-DInSAR in the study area are: (i) the geometry and characteristics of the cliffs of the Asturian coast in relation to satellite trajectories and (ii) the nature of the landslides (rockfalls, flows and undetermined events) occurring over the study area. Future research will involve improving the interpretation of the A-DInSAR dataset, by means of re-processing in ascending trajectories, the application of the ADA methodology and the estimation of the VSLOPE from VLOS measurements obtained in this work. These techniques will contribute to improving the future management of the Asturian Coast. Conceptualization, J.C.-M., M.J.D.-C. and F.M.R. ; methodology, J.C.-M.; software, J.C.-M., A.B. and O.M. ; validation, [PERSON]-M.; formal analysis, [PERSON]-M.; investigation, [PERSON]-M.; resources, [PERSON]-M., M.J.D.-C., P.V., A.B. and O.M. ; data curation, J.C.-M., M.J.D.-C., P.V., A.B. and O.M. ; writing--original draft preparation, [PERSON]-M.; writing--review and editing, [PERSON]-M., M.J.D.-C., F.M.R., A.B., O.M., P.V. and M.J.-S.; visualization, [PERSON]-M.; supervision, [PERSON]-M., M.J.D.-C.; project administration, M.J.D.-C., F.M.R.