Supplementary Data for "Evolving resource potential of glacial lakes with ongoing deglaciation"

This respository contains the source data for the study for Evolving resource potential of glacial lakes with ongoing deglaciation

by Georg Veh and co-authors.

We quantified the volume and theoretical lifetime of each glacier lake worldwide. We used a global dataset of glacier lake outlines that were mapped from satellite imagery taken in 1990 and 2020 by Zhang et al. (2024, Nat. Comm.). Lake volumes were estimated using a Bayesian hierarchical area–volume regression model, drawing on a compilation of >300 bathymetrically surveyed lakes. To constrain the potential volume and Timing of sediment infill, we combined lake catchments (derived from digital elevation models) with reported data of catchment-wide erosion rates (Wilner et al., 2024). Lake lifetimes were then approximated by modelling the timespan when expected sediment delivery equals the the current (2020) lake volume. Social implications of changing lake volumes were inferred from the estimated number of people living in the upstream contributing catchments, as well as in the first 50 km downstream of lakes, using four gridded datasets of population Counts.

The accompanying code can be found on Github: https://github.com/geveh/LakeVolumes

On Github, we list all third-party sources that are necessary to download before repeating our analysis and re-plottig the figures in the Main text and Extended data of our manuscript.   

Our analysis follows a 7-step procedure, so we provide seven zipped folders containing both input and Output data from our analysis. We provide only the input that we produced on our own or that we modified to the extent that they become new independent data. Similarly, we only provide output data such as R-objects that are key to our analysis and that are not shown as a figure in the paper. Please see the Github repository for additional input files for, or output files generated from, our analysis.

01_Lake_types.zip

Input/output data to assign a dam type to each lake in the glacial lake inventory of Zhang et al. (2024) as of 1990 and 2020.

• "RGI2000-v7.0-o2regions_modified_densified.gpkg" (Modified outlines of the O2 regions in the RGI V7.0)
• "all_lakes_including_dam_type.rds" (R-object of all glacial lakes with an assigned dam type)
• "Lakes19902020_damtype.RDS" (R-object of all glacial lakes in 1990 and 2020 with a dam type assigned)

02_VA_model.zip

Input/output data to fit a Bayesian hierarchical linear regression model of lake area A versus volume V distinguished by dam type.

• "va.txt" (Text file of bathymetrically surveyed lakes including their volume V and area A (converted from the Excel Sheet)) 
• "VA_model.RDS" (R-object with linear regression model of V versus A distinguished by dam type)
• "VA_data.RDS" (R-object of all non-repetitively surveyed glacial lakes)

03_global_lake_volume.zip

Input/output data to estimate the local, regional, and global volume of glacial lakes.

• "VA_model.RDS" (R-object with linear regression model of V versus A distinguished by dam type)
• "VA_data.RDS" (R-object of all non-repetitively surveyed glacial lakes)
•  "Lakes19902020_damtype.RDS" (R-object of glacial lakes mapped by Zhang et al. (2024) in 1990 and 2020 with a posterior median and 68% HDI estimate of their volume)
• "all_lakes_with_volumes.RDS" (R-object with posterior median and 68% volume estimate for each lake in 1990 and 2020)
• "volume_regional_lakes.RDS" (R-object with a posterior estimate of regional glacial lake volumes, including the median and 68% HDI of lake volumes)

04_Catchment_statistics.zip

Input/output data to download the Copernicus GLO30 DEM and land cover maps. The script then derives the catchment of each lake, and summarises catchment-wide statistics including glacial cover, land cover, and relief.

• "RGI2000-v7.0-o2regions_modified_densified.gpkg" (Modified outlines of the O2 regions in the RGI V7.0)
• "Lakes19902020_damtype.RDS" (R-object of glacial lakes mapped by Zhang et al. (2024) in 1990 and 2020 with a posterior median and 68% HDI estimate of their volume)
• "lakes_with_catchment_and_landcover.rds" (R-object of all glacial lakes as of 2020 including statistics on relief, as well as glacier and land cover)

05_Lake_volumes_glaciers_elev_dist.zip

Input/output data to estimate trends of glacier volume (change) with glacial lake volume (change), and to assess flow path distances from glacial lakes to the coast.

• "Millan_glacier_volumes.xlsx" (Excel-file of regional glacier volumes, extracted from Millan et al. (2022): https://www.nature.com/articles/s41561-021-00885-z
• "Hugonnet_glacier_loss.txt" (Text-file glacier with mass loss data from Hugonnet et al. (2021), available at https://doi.org/10.6096/13)
• "all_lakes_with_volumes.RDS" (R-object with posterior median and 68% volume estimate for each lake in 1990 and 2020)
• "lakes_with_catchment_and_landcover.rds" (R-object with catchment-wide statistics on relief, glacier and land cover for all lakes in 2020)
• "flowpaths_detailed.txt" (Irregular txt file provided by Wolfgang Schwanghart. The file is organised by lines, with every lake is identified by 5 lines: its ID, and the X, Y, distance, and Z coordinate from the source towards the coast. Every fifth line, a new flow path starts from a new lake starts.)

06_Lifetime.zip

Input/output data to approximate the local, regional, and global lifetime (longevity) of glacial lakes.

• "lakes_with_catchment_and_landcover.rds" (R-object with catchment-wide statistics on relief, glacier and land cover for all lakes in 2020)
• "all_lakes_with_volumes.RDS" (R-object with posterior median and 68% volume estimate for each lake in 1990 and 2020)
• "simulated_infill_times.RDS" (R-object with simulated lifetimes of each glacial lake under fluvial and glacial erosion rates, and a scenario weighted by glacial cover in a given catchment)

07_population_estimates.zip

Input/output data to extract population in the catchment feeding glacial lakes, and within the first 50 km downstream of glacial lakes

• "all_catchments_dissolved_no_holes.gpkg" (Geopackage with all catchments feeding glacial lakes, dissolved, derived from COP30 DEM data)
• "all_lakes_with_volumes.RDS" (R-object with posterior median and 68% volume estimate for each lake in 1990 and 2020)
• "flowpaths_detailed.txt" (Flowpaths from all lakes as of 2020 from the lake to the coast/ endorheic basin)
• "volume_regional_lakes.RDS" (R-object with a posterior estimate of regional glacial lake volumes, including the median and 68% HDI of lake volumes)
• "diff.gpkg" (Geopackage that contains the difference between catchments and a dissolved 1-km buffer around flowpaths originating from glacial lakes)
• "flowpath_buffers.gpkg" (1km buffer along the first 50-km flow paths downstream of glacial lakes)
• "all_catchments.gpkg" / "all_catchments.gpkg" (Geopackage / R-object containing all catchments feeding glacial lakes worldwide in 2020)
• "population_upstream_downstream.pdf" (PDF figure showing little barplots of the regional population living in the upstream catchment and along a 1-km wide, 50-km long buffer downstream of lakes)