Chamoli Disaster Pre-event 2-m DEM Composite from September 2015

38 stereo DEMs from Maxar WorldView satellite images acquired between August and October 2015 were processed to create a 2-meter resolution digital elevation model. Shashank Bhushan of the University Washington produced this composite using the NASA Ames Stereo Pipeline, focusing on the region affected by the February 2021 Chamoli disaster. The dataset includes weighted mean and median elevation composites, plus per-pixel count and accuracy deviation maps.

Use Cases

• Analyzing pre-disaster terrain morphology for the 2021 Chamoli event based on the 2-meter DEM composites.
• Assessing relative elevation accuracy in mountainous regions based on the provided per-pixel normalized median absolute deviation (NMAD) maps.
• Identifying areas with potential data artifacts or cloud cover based on the per-pixel count and NMAD values mentioned in the description.
• Creating shaded relief visualizations for geological studies using the included hillshade files.

Strengths

• High 2-meter spatial resolution derived from 38 cross-track stereo DEMs.
• Includes multiple composite products (weighted mean, median, count, NMAD) for different analytical purposes.
• Co-registered to an external 8-meter DEM mosaic for improved spatial alignment.
• Processing details are explicitly documented, including specific stereo algorithm and correlation kernel settings.

Limitations

• Contains data gaps and residual artifacts due to cloud cover over mountain peaks in the source imagery.
• Row count and total file size are unknown, which may limit suitability assessment.
• Column-level documentation is absent; field semantics must be inferred after download.

Provenance

Source

Maxar/DigitalGlobe WorldView-1 and WorldView-2 satellite imagery.

Collection Method

Processed using NASA Ames Stereo Pipeline v2.6.2 and a modified Shean et al. methodology.

Time Range

August 28, 2015 to October 5, 2015

Geography

Region of interest for the February 7, 2021 Chamoli event, likely in the Indian Himalayas, UTM zone 44N.