Impacto del retroceso de los glaciares del cerro Perito Moreno sobre el abastecimiento del agua de riego de Mallín Ahogado

Abstract

Freshwater is a valuable, scarce, and vulnerable resource that can be found in solid form in glaciers, perennial bodies of ice formed by the accumulation, compaction, and recrystallization of snow. Glaciers are capable of regulating flows and providing water during the warmest seasons of the year, functions that are jeopardized by their retreat. This final integrative Environmental Engineering project evaluates the impact of the retreat of the North and South Cerro Perito Moreno glaciers on the flow of the Pedregoso stream and on the water supply to the Mallín Ahogado irrigation system, Río Negro, Patagonia, Argentina. Available information, consisting primarily of annual surveys by the DPA (National Park of Patagonia) for the period 2012–present, was compiled and analyzed. The glaciers are in the process of retreating and decreasing their thickness. According to available measurements, they show an average retreat rate of 5.4 m/year and a cumulative retreat of 53.6 m. Historical hydrometeorological data, field surveys, and gauging were analyzed. The ecological flow of the Pedregoso Stream was determined for February at 0.315 m3/s and March at 0.246 m3/s. A series of average daily glacier discharge rates was obtained by correlating them with temperature. These range from 0 m3/s to 0.167 m3/s, with a mean value of 0.047 m3/s. The available water flow for use in the Luden Canal was obtained under a current and future scenario in which the glaciers have disappeared. Adaptation measures to the water deficit and their economic cost were proposed, based on decentralized reservoirs, efficient water distribution systems, field irrigation methods, and the need for access to drinking water for the population. Environmental education, technical advice, and the strengthening of IWRM are presented as essential tools.