DEMs

Purpose

This page will outline digital elevation models as terrain data sources for hydrology, topography, exposure, and contextual geospatial analysis.

Outline

• What DEMs represent and how elevation differs from derived terrain products.
• Common strengths across global, national, and local elevation datasets.
• Limitations around resolution, vertical accuracy, voids, artifacts, and datum differences.
• How slope, aspect, hillshade, flow direction, and watershed layers support workflows.
• Workflow relevance for flood screening, habitat modeling, infrastructure planning, and normalization.
• Engineering implications for reprojection, resampling, edge effects, and derivative computation.
• Access patterns through Earth Engine collections, national agencies, STAC catalogs, and cloud archives.

Later Examples

• Terrain derivative workflow sketch.
• Elevation-aware masking or stratification outline.
• Comparing coarse global DEMs with local high-resolution products.