IANIGLA   20881
INSTITUTO ARGENTINO DE NIVOLOGIA, GLACIOLOGIA Y CIENCIAS AMBIENTALES
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Comprehensive water management under future climate change and glacier retreat scenarios
Autor/es:
FLOR JARA; ELIZABETH B. NARANJO TAMAYO; HÉCTOR MAURERI; VÍCTOR SALINAS
Reunión:
Otro; First (CR)2 Online Summer School: Integrative Assessment of Climate Change. Water Scarcity; 2021
Institución organizadora:
Center for Climate and Resilience Research (CR2)
Resumen:
Historically, glaciers have been the mainstay of agricultural activities and therefore thus, of life in communities and towns, both towards the coast and in the Andes; due to meltwater increasing river flows especially in the times of higher temperatures, when rainfall in the middle and lower areas of the valleys becomes scarce. However, in recent decades, the increase in the average temperature, the reduction of rains and the elevation of the isotherm 0, as a result of climate change, have accelerated the melting of Andean glaciers, reducing their volume and aggravating the narrowness and water vulnerability that causes global warming in the Andean countries of the Southern Cone (Paz, 2011).The authors of paper Two decades of glacier mass loss along the Andes in Nature geoscience (Dussaillant, et al.,2019) verified that the volume change of glaciers varies spatially and temporally. For example, that the loss of mass in glaciers located in the tropics and in southern Patagonia was maintained at a high and constant rate in the last twenty years. But in the Arid Andes and the North of Patagonia, from Salta to the south of Chubut, between 2009 and 2018 the glaciers lost mass at a higher rate than between 2000 and 2009, which indicates that there was a change in the climate regime.Studies on future glaciers Andes change projections so far predicted that by the end of this century, under the most optimistic scenarios, the lost volume of glaciers would be 30 percent of the current volume. While in the most pessimistic scenarios, if carbon dioxide emissions to the environment remained as they have been before, the loss of glacial volume would be double: 60 percent of the current volume would disappear (Web CCT Mendoza, 2019).Tropical glaciers in the Peruvian Andes are very sensitive to climate change and rapidly respond to varying climate settings (e.g. Kaser and Osmaston, 2002; Rabatel et al., 2013, Juřicová and Simona, 2018). The region is part of the outer tropics, which have a tropical character during the humid season and a subtropical character during the dry season (Kaser, 2001). The humid season, which is influenced by the Intertropical Convergence Zone (ITCZ), occurs during the austral summer, October-April, during which 90% of the annual amount of precipitation is concentrated (Juřicová and Simona, 2018). Long-term measurements suggest that warming in the tropical Andes could likely explain the retreat observed over the last few decades (Juřicová and Simona, 2018).The Quillcay sub-basin in Peru is one of the regions that has been affected by the increase in temperature, the effect of climate change. The latter has accelerated the glacial retreat and the increased risk of avalanches and floods in this sub-basin. In this sense, since 2011, the sub-basin that has been declared in a state of emergency due to the potential danger posed by the Palcacocha lagoon, which increased its volume from 524,800m³ in 1972 to 17,325,206 m³ in April 2009 (Web Ministerio de medio Ambiente Perú, 2020). Beyond at present the population of the sub-basin is affected by alluvium and avalanches. In a investigation (Muñoz, R., 2018), on the Quillcay basin, the authors found in the historical simulation in the period 1983 - 1998 that there is no significant trend in temperature and precipitation. While a loss of mass of the glacier of around 20% and a loss of volume of 2% per year. Regarding future scenarios (2021-2050), they found a positive trend towards an increase in temperature, with an increase of 1.5ºC in RCP 8.5 and 1ºC in RCP 6. While in precipitation they found a reduction in precipitation and no changes seasonal.They conclude that the Quillcay river basin will go from being a system highly dependent on glacial contributions to depending on the precipitation system (with a soil cover with greater importance in water regulation).