Glacier retreat in Sibinacocha’s Basin-Multi temporal analysis and social perceptions

This research compares the social perceptions about glacier retreat with temporal analysis of satellite images of the Sibinacocha Glacier Lake (SGL) basin. The study is based on a multitemporal analysis (1992-2020) of Landsat 5 and 8 satellite images, in which, through spectral indices and manual corrections, an average retreat of 30% was estimated in the study basin. In addition, coincidences were identified between periods of retreat/ growth and periods of El Niño/La Niña events. The information related to social perceptions was collected from surveys carried out in November 2020 to 154 people from the town of Phinaya (located at 5 km from the SGL dam); the results reported that all of those surveyed identified a glacier retreat, more than 60 % expressed concern regarding the glacier retreat, while more than 70% identified a more accelerated retreat in recent years compared to the last two decades. The last finding was consistent with the glaciar retreat slopes for the last 5, 20 and 25 years in the SGL basin suggesting that local population manages to perceive the changes in the glacial dynamics.