The water contribution of the glacier and the dynamics of glaciological-hydrological processes in the basin. Yanamarey, Cordillera Blanca, Perú case

The watershed with glacier presence in the Tropical Andes presents continuous melting, as an effect of climate change, which influencing runoff generation and hydrological processes. The study was conducted between 2013 and 2020 in the Yanamarey micro-watershed (Cordillera Blanca, Peru), using satellite images and hydro-glaciological modeling, applying the semi-distributed models GSM and SOCONT, to estimate glaciological and hydrological processes distributed by altitude bands. During this period, an average of 0.27 km² of surface area and 1.65 hm³ of volume were determined in the glacier; the average water contribution in the micro-basin is 93 l/s, distributed as follows: 8 % ice, 15 % snow, 27 % groundwater and 50 % precipitation (direct). In addition, the ice and snow flows show a negative annual trend of 0.5 and 0.7 l/year, respectively. Producing at the end of seven years in: a) glaciological process, ice melt of 14 m below the altitude of 4 800 masl, snow accumulation of 12.7 m above the altitude of 5 000 masl; b) hydrological process (non-glacial zone), in clean soil, accumulated water infiltrates of 118 m (0.19 cm/h) and accumulated surface water 34 m (0.06 cm/h). The estimated values of the water contribution and the variation of annual availability of the glacier mass by altitude give us an idea of the water processes that occur at the headwaters of the basin and the importance of their effects on the lifespan of the glaciers.