Glacial changes and cryosphere risks in Villa O'Higgins, Chilean Patagonia, using Remote Sensing and the Analytic Hierarchy Process

Abstract

The region of Villa O'Higgins, Chilean Patagonia, is influenced by the dynamics of glacier melting and suffers from floods from the Mosco River that affect the local population. The aim of this research was to investigate areas susceptible to flooding in the community and relate them to land use and land cover characteristics, verifying changes in glacial and lake cover between 1985 and 2021, using remote sensing. Information on flood events was gathered from digital news reports. Land use and coverage classes have been obtained using 2011 data and 2021 PlanetScope imagery. Geospatial data on drainage, elevation, slope, geology and land use and coverage were considered when applying the Analytic Hierarchy Process (AHP) to identify areas susceptible to flooding. Reports from residents in electronic media indicated that there has been an increase in the supply of water to the Mosco River in recent years from the melting of snow and glaciers upstream, in addition to an increase in heavy rainfall events. Glacial coverage lost 40.83% of its area and lacustrine coverage increased by 422,22% between 1985 and 2021. Areas with high and very high susceptibility to flooding correspond to 4.11% of the sub-basin area and are associated with rural classes and urbanized areas. The identification of areas susceptible to flooding in the community will help in understanding these future events and in studies of socio-environmental vulnerability to the climate crisis and its impacts.