Brief communication: A framework to classify glaciers for water resource evaluation and management in the Southern Andes

Abstract

Abstract. Over the last 2 decades the importance of Andean glaciers, particularly as water resources, has been recognized in both scientific literature and the public sphere. This has led to the inclusion of glaciers in the environmental impact assessment and the development of glacier protection laws in both Chile and Argentina. However, these laws are limited in their ability to protect, manage, and monitor water resources as they do not differentiate between glacier types. We propose three glacier categories that aim to group glaciers based on their sensitivity to environmental changes as a framework that could be adopted to match the level of protection to the current and future needs of society, be region-specific, and evolve through time. Finally, we review both national inventories with respect to this classification to facilitate the evaluation and/or management of water resources.

Internal structure and water routing of an ice-debris landform assemblage using multiple geophysical methods in the semiarid Andes

“…In addition, outputs from runoff contribution models in the Southern Andes show that most of these glaciers have already reached, or will soon, their peak water with a decrease in runoff thereafter (Huss and Hock, 2018;Burger et al, 2019;Ayala et al, 2020). Hence, as seasonal water availability decreases, ice-debris landforms will contribute a larger component of baseflow to rivers and streams (Janke et al, 2015;Schaffer and MacDonell, 2022).…”

“…In a warming climate, it is expected that in arid mountain regions debris-free glaciers and debris-covered glaciers may evolve towards rock glaciers (Janke et al, 2017;Anderson et al, 2018;Kellerer-Pirklbauer and Kaufmann, 2018;Schaffer and MacDonell, 2022;Navarro et al, 2023), thereby affecting water storage, production and transfer. The results of this study show that the debris-covered glacier has a different capacity to store and transfer water flow than the rock glacier.…”

“…This is related to a high storage capacity and low possibility to infiltrate flows to subglacial areas for the former, and a higher capacity to transmit vertical and horizontal flows of the latter. Ice volumes will diminish in deglaciating mountain environments (Wagner et al, 2021b), but over time remaining ice may become more insulated by sediment (Schaffer and MacDonell, 2022). In parallel, there may be a potential enhancement of water being infiltrated to greater depths due to the fragmented or absence of impermeable bodies of the evolved landforms, causing higher groundwater flow and longer residence times since flows are more likely to deepen and transfer through the subsurface compartment.…”

“…Mountain and valley glaciers are crucial hydrological units in semiarid regions of Chile as they provide an important water contribution during the ablation season (e.g., Favier et al, 2009;Ayala et al, 2016;Ayala et al, 2020), when precipitation is scarce and water demand is at its maximum (Navarro et al, 2023). In total, more ice is stored in debris-free glaciers than in debris-covered and rock glaciers (Barcaza et al, 2017), and as they are more sensitive to recent climate changes (Schaffer and MacDonell, 2022) they currently provide higher volumes of water to rivers (Ayala et al, 2016;Burger et al, 2019). However, in some catchments, debriscovered glaciers provide a notable contribution to streamflow (Ayala et al, 2016), and insulation provided by the debris-cover (Nicholson et al, 2018) enables ice to be stored at lower elevations than what might be possible for exposed ice (Ayala et al, 2016).…”

“…Transitions from one type to another likely impact meltwater generation quantity and timing as well as storage and routing dynamics. Additionally, the inherent features that define each glacier type, particularly their debris cover properties, mean that they would respond to climatic changes with varying degree of sensitivity (Schaffer and MacDonell, 2022). Hence, the evolution to periglacial landforms, as warming and drier climate impacts its ice content, may change runoff timing and hydrological connectivity.…”