Dataset for manuscript 'Engineered waterways reshaped the long-runout sediment plume from the 2021 Chamoli event'

This dataset contains the geospatial vector data used to reconstruct the downstream pathway of the sediment plume generated by the 2021 Chamoli hazard cascade. It supports the analyses presented in the manuscript “Engineered waterways transformed the sediment plume from the 2021 Chamoli hazard cascade into a downstream water management problem.” The deposited files contain: Chamoli_plume_path_with_main_tributary.gpkg: routed river-network context used to identify the main plume pathway and major tributaries. It contains 52,282 points with elevation, flow distance, drainage area, chi, source and basin identifiers. plume path on river network_EPSG4326_30m.gpkg: the selected river plume pathway represented by 28,046 network points at approximately 30 m spacing in EPSG:4326. plume path on canal.gpkg: 1,784 canal-network segments defining the plume-connected canal pathway used in the analysis. affected_canal_network_ganga_yamuna.gpkg: the wider connected Ganga–Yamuna canal network used to delineate the downstream population-exposure domain. It contains 2,050 canal segments in Uttarakhand and Uttar Pradesh. Dam points in plume path.gpkg: locations of 11 dams, barrages and hydropower structures associated with the analysed propagation pathway. event_shapefile.zip: 12 dated GeoJSON polygons defining the PlanetScope observation areas and scene footprints. These cover nine river observations between 8 and 25 February 2021 and three canal observations on 11, 14 and 16 February 2021. The river network was derived from Copernicus DEM data, a Dynamic World water mask and LSDTopoTools routing. Canal pathways and infrastructure locations were selected or refined in QGIS using the sources described in the manuscript. Licensed PlanetScope imagery is not included. The accompanying extraction and analysis code, scientific parameters and manual observation table are archived separately as SUPERSLUG Plume Tracking: https://doi.org/10.5281/zenodo.21923049.