Potentiel d'adaptation des modèles de fonte de glaciers tempérés aux spécificités des glaciers tropicaux

Abstract

In Peru, fresh water supply of over 200 million people is bounded to the melting of tropical glaciers. Those glaciers have shown a great sensitivity to climate change in the past few years, losing 30% in surface in 30 years. Existing models are designed for temperate glaciers and are, most certainly, not suitable for an accurate surveillance of tropical glaciers bounded to climatic specificities such as the temporal stability and the power of incoming solar radiations. The absence of a dedicated model for the evaluation of this retreat may generate severe consequences on water resources projections of watersheds supplied by tropical glaciers. The goal of this study is to improve a « traditional » physically based hydrologic model by alternately integrating three modules adapted to tropical glaciers’ specificities: a shadow module of the surroundings of the glacier, a multilayer ice temperature module and a sublimation module that will take into account the competition between melting and sublimation. The study has been done on the Peruvian glacier of Cuchillacocha located at 20 km of Huaraz (Ancash) on the cordillera Blanca on datasets collected in 2013 and 2014. All the modules presented in this study have reduced the melting volume simulated in comparison of the traditional model. Results also show that ice temperature and shadow modules have a comparable and moderate effect on the estimation of melting volumes whereas the sublimation module has a pronounced and variable effect on the two years of simulation. This study shows that each module embodies a potential improvement for hydrologic modelling of watersheds supplied by tropical glaciers. Nonetheless those modules need further improvement and assessment in order to contribute to the creation of a model suitable for a better vigilance of tropical glaciers.

Date	19 Jun 2015
Original language	French
Awarding Institution	École de technologie supérieure
Supervisor	Michel Baraër (Supervisor)