Análisis de la dinámica costera en la región de las Grutas, provincia de Río Negro

Abstract

In this manuscript, the geological and geomorphological study of the resort town of Las Grutas is carried out, in order to understand the evolution of the local coastal dynamics and how this is related to the retreat of the cliffs exposed there. From surveys carried out with UAV, based on the digital elevation models (DEM) obtained in 2021 and 2022, it was possible to quantify the variation in the volume of beach deposits, as well as topographic profiles of the area. Furthermore, using the orthomosaics generated from the flights, in comparison with historical aerial photographs, it was possible to estimate a speed of retreat of the cliff between the years 1969 and 2021, obtaining an average value of 3 meters of retreat in the least affected sectors and up to approximately 6 meters in the most affected sectors. Processes and factors that condition the coastal zone were identified, including marine erosion processes, which result in basal cavities and caves present in the cliffs, channels and grooves on the abrasion platform, and subaerial processes, which in certain sectors result in resulting in areas with landslides. Also, conditioning factors of the stability of the cliff were identified, related to its lithology, structures and slopes. Monitoring with UAVs is proposed as a continuous coastal monitoring method, since its centimter spatial resolution provides the possibility of quantifying processes that occur with a high level of detail.