Development of a spatial projection map of glacial retreat based on vulnerability maps in the Central Cordillera, Peru

Abstract

Increase in average global temperature over the last few decades has caused an accelerated retreat of tropical glaciers. Andean populations live in strict dependence on the water services provided by mountains and glaciers. The present study aims to generate a glacier melt projection map in the Peruvian Central Cordillera based on vulnerability maps over the 1990–2021 period. Seven satellite images were selected to determine the changes in glacier coverage based on normalized indexes. Subsequently, seven parametric maps consisting of terrain and climate characteristics were assimilated into a vulnerability analysis based on the frequency index and the Shannon entropy index model, allowing one to identify areas most susceptible to glacial retreat. The results show that the most important criteria for the southern and northern glacial study areas are surface temperature, elevation, precipitation, aspect, orientation, and slope. The validation results revealed the most accurate set of parameters from the vulnerability map in terms of projecting melting areas and were used to produce a spatial projection map for the period 2021–2055. From 2021, a glacier loss in the range 84–98% would be reached by the 2050s. HIGHLIGHTS A versatile method is proposed to study vulnerabilities in complex terrains and climatic uncertainty such as glacial context.; Updated glacier retreat maps over a long time period from 1990 to 2021 based on remote sensing in Central Andes have been used in this study.; A methodology to project glacier retreat in a context of scarce or limited information is used in this study.;

Keywords

• frequency index (fr)
• glacier retreat
• shannon entropy
• spatial projection
• vulnerability