Cascading rock–ice avalanche and downstream flooding in the Nepal Himalaya

This repository contains the derived datasets, GIS products, figure-source data, and analysis code supporting the study “Cascading rock–ice avalanche and downstream flooding in the Nepal Himalaya,” which reconstructs the 26 August 2026 Langtang Lirung event in central Nepal. The archived products document: (1) mapping and topographic characterization of the 0.716-km² failure source; (2) repeat-DEM analysis of source-area elevation change and the estimated 110.80 Mm³ gross topographic loss; (3) immediate pre-event Sentinel-2 surface classification and model-constrained glacier-ice partitioning; (4) atmospheric moisture-transport and precipitation analyses; (5) multi-decadal ERA5-Land temperature reconstruction and permafrost-relevant thermal metrics; (6) the validated 36.515-km source-connected downstream pathway and associated geomorphic evidence; and (7) scripts and tabulated source data used to generate the principal and supplementary figures. Raw third-party satellite, reanalysis, precipitation, glacier, and elevation datasets are not redistributed where redistribution is unnecessary or subject to provider-specific terms. Instead, the repository provides derived products and reproducible analysis materials together with information identifying the original data sources. Numerical mass-flow simulations that have not yet passed source-valley routing and flux-conservation validation are not presented as observational estimates of event velocity, travel time, or discharge. Relevant diagnostic material, where included, is explicitly identified as model diagnostic output. See the accompanying README and manuscript Supplementary Materials for dataset descriptions, processing methods, coordinate reference systems, units, uncertainty treatment, and provenance.