ESTIMATION OF DEGLACIATION IN THE SUB-BASIN OF THE QUILLCAY RIVER – PERU, IN THE FACE OF CLIMATE CHANGE

In recent decades, glaciers globally, and mainly tropical glaciers, have experienced an accelerated retreat in snow cover due to climate change. In the tropical glaciers of Peru, it has generated the development of numerous lagoons and an increase in their volume over the years. In this research, a methodology with new improved indices is proposed: Normalized Difference Snow Index without water information (NDSInw) and Normalized Difference Water Index without snow cover (NDWIns). The changes that occurred through a multi-temporal analysis of the snow surface in the Quillcay River sub-basin during 1986 to 2021 are identified using satellite images from the Landsat 5, 8 and 9 collection 2 of the Google Earth Engine data catalog and processing spatial data using the rgee Application Programming Interface (API). The results obtained from the deglaciation of the snow-capped mountains in the 35 years of analysis resulted in a decrease of 27.82% compared to 1986.