Tendencia del área nevada en las subcuencas de los ríos Grande y Barrancas, Argentina

The study of interannual variability of snow accumulation in mountainous environments allows for an understanding of the hydric dynamics in basins that depend almost exclusively on meltwater. This paper presents an analysis of the hydro-snow dynamics of the upper Colorado River basin (Argentina), in the context of the vulnerability of Andean basins to the effects of climate change. A multitemporal series of MOD10A1 and MOD10A2 satellite products was used to estimate total snow cover during the period 2000-2022, as well as streamflow measurements from the Buta Ranquil station (Nqn). The results show a negative trend in maximum toal snow cover during the study period. In recent years, there has been a delay in the occurrence of snow precipitation, greater variability, an advancement in the annual cycle peak, and a negative trend in maximum snow-covered area, particularly in areas above 2,500 meters above sea level. The seasonal trend analisys indicated significant negative trends in the amplitude of the annual snow cover cycle and a negative trend in the phase for 66.9% of the analyzed area, indicating that snowfalls occurred around mid-winter in the later years of the analyzed period.