###### Abstract
In the same sector, the researchers [7] model the response of the SAR backscattered signal based on the development of saline crust and detect that the control in the backscattered signal is due to the development of saline crust where the moisture given by brines exerts secondary control depending on the evaporation rate [8]. On the other hand, and in parallel, several experimental studies show the relation between the complex dielectric constant and salt content in the soil [9; 10]. Using the RADARSAT-2 satellite over the Chott El Djerid [3] to monitor a spatiotemporal evaporitic process combining scatterometers and SAR for the monitoring of sedimentation processes. A complete wet-to-dry cycle and observed the temporal evolution of the copolarized phase difference is presented in [11]. Responses in the C-band and L-band radar signal (AIRSAR, PALSAR) are used simultaneously to study the salinity effects of evaporitic geological materials from Death Valley, USA (\(-\)86 m.a.s.l) on complex permittivity in magnitude of the backscatter coefficient [12] and subsequently, using SIR-C / X-SAR [13], proposes a backscattering coefficient of copolarization and phase difference for soil indicator affected by salinity and humidity. Research by L-band in the Nop Nur Lake basin (780 m.a.s.l), in China [14] uses RADARSAT-2 and ALOS-PALSAR images to interpret the surface and coastline of the lacustrine tank using single band and polarimetry. Furthermore, the detection of subsurface deposits are analyzed to understand the evolution of the lake, establishing an empirical relation between the results of polarimetric decomposition and surface salinity [15]. Subsequently, comparing terrain information with polarimetry results for two ALOS PALSAR images [16], they managed to determine two layers, each with different dispersion, roughness, humidity, and salinity. Then [17] demonstrated the penetration capacity of the L band of the ALOS PALSAR sensor in saline soil, by detecting the presence of a subsurface brine layer using polarimetric decomposition. Finally, types of salt crusts are differentiated using the surface roughness parameters [18], extracted thanks to the polarimetry in ALOS PALSAR images. Notwithstanding, the research using L-band SAR in the study of salars is mainly focused on backscattering mechanisms rather than spatiotemporal monitoring. Although previous investigations are exhaustive, it remains unexplored how the backscattered signal in C- and L-bands behaves over the salars placed in the Andes Highlands where geographical and climatic conditions are distinctive. The main goal of this paper is to determine the seasonality in the response of the SAR backscattered power over the salar, through a four-year multitemporal analysis (2014-2018) with Sentinel 1 (C-band) and ALOS-2/PALSAR-2 (L-band) in order to qualitatively estimate the salar dynamics related to either climatic, annual or eventual weather influences. Here we reveal that the salt pans do not appear to be stable over the time analyzed. Likewise, the backscattering coefficient seasonality also showed that surface properties could qualitatively determine the surface roughness under certain climate conditions. Based on the hypotheses of the salar surface evolution and the drying-up cycles, the dynamic processes of the Salar de Aguas Calientes Sur is being discussed.