Spatial distribution and controls of snowmelt runoff in a sublimation-dominated environment in the semiarid Andes of Chile
Abstract. Sublimation is the main ablation component of snow and ice in the upper areas of the semiarid Andes (~26–32° S and ~69–71° W). This region reaches up to 6000 m, is characterized by scarce precipitation, high solar radiation receipt, and low air humidity, and has been affected since 2010 by a severe drought. In this study, we suggest that most of the snowmelt runoff originates from specific areas with topographic and meteorological features that permit large snow accumulation and sufficient energy for snowmelt. We quantify the spatial distribution of snowmelt runoff and sublimation in a catchment of the semiarid Andes using a process-based snow model that is forced and validated with field data, satellite-derived indices of snow presence and an independent SWE reconstruction product. Results from model simulations over a two-year period reproduce point-scale records of snow depth and SWE and are also in good agreement with distributed patterns obtained from satellite-derived products, such as snow cover area and indices of snow absence and persistence. We estimate that 50 % of snowmelt runoff is produced by 18–28 % of the catchment area, which we define as “snowmelt hotspots”. Snowmelt hotspots are located at elevations between 4200 and 4800 m, have easterly aspects, low slope angles, and high snow accumulation and persistence. We suggest that snowmelt hotspots play a key hydrological role when connecting with other features of dry mountain regions, such as areas of groundwater recharge, rock glaciers and mountain peatlands, and recommend more detailed snow and hydrological monitoring of these sites, especially in the current and projected scenarios of scarce precipitation.
Álvaro Ayala et al.
Status: open (until 28 Mar 2023)
- RC1: 'Comment on hess-2023-23', Anonymous Referee #1, 07 Mar 2023 reply
- RC2: 'Comment on hess-2023-23', Anonymous Referee #2, 15 Mar 2023 reply
Álvaro Ayala et al.
Álvaro Ayala et al.
Viewed (geographical distribution)
Review of: “Spatial distribution and controls of snowmelt runoff in a sublimation-dominated environment in the semiarid Andes of Chile” by Álvaro Ayala, Simone Schauwdecker and Shelley MacDonell.
This paper presents an interesting case study of a catchment in the Andes, which is a snowmelt-dependent region in which sublimation plays a significant role on the snow cover and water balance. The paper builds on previous studies focussing on modelling performance and underlying snow processes. The authors perform an elaborate analysis on the hydrological importance of the processes occurring in the Corrales catchment, Chile. In general, this is a well-written manuscript. However, parts of the manuscript require some additional attention, so that the overall quality of the manuscript improves. As such, I advise the paper to be revised before publication. Below I have stated more general and specific comments, which I hope the authors consider to be constructive.
The results contain a lot of information and figures, all of which are important. However, it is sometimes hard to make the connection to the other results for me as reader. Each figure is treated separately, and not always clearly connected to previous results. To illustrate, almost each paragraph starts with “In figure x, we compare…” or “Figure x shows …”.
I would advise the authors to focus on the point you are trying to make and try to make in-text connections between the separate figures based on the general story. This results in a storyline in which the figures are a helpful tool instead of treating the results as a point-by-point discussion of the figures. Another option would be to merge the results in the discussion, however that is also not sufficiently done currently.
All the figures used in the manuscript are important, and significantly contribute to the manuscript. However, multiple figures are rather unconventional. For example, some figures miss an x-axis and/or y-axis label or contain a strange diagonal line through the colorbar. Also, it seems that part of the figures consist of multiple loose figures, which are not all aligned. I encourage the authors to re-do part of their figures, so that these look more professional. (See the specific comments for examples).
Data and code:
I am happy to see that the data used in this manuscript can be found online. However, I highly encourage the authors to also publish their code used for the data analysis. This would make the research more align with the FAIR principles and also accessible for interested readers.