This post converts the selected engineering video into a quick written workflow so the user can understand the process before opening the full video. It is designed as a time-saving overview for students, engineers, and website visitors.

Source video: How to merge raster DEM using QGIS and clip the merged DEM using mask layer
Step-by-step workflow summary for Merge and Clip DEM in QGIS: Clean Terrain Preparation
Visual overview of the main steps covered by the video.

Step-by-step workflow

  1. Place all DEM tiles in one folder and confirm they use the same CRS and unit.
  2. Load the tiles and visually check coverage of the project area.
  3. Use Merge/Mosaic to create a single continuous raster.
  4. Prepare the project boundary or buffer polygon for clipping.
  5. Clip the merged DEM by mask layer and set no-data value correctly.
  6. Save the clipped DEM with a clear filename and use it for analysis.

Best use case

Use this before catchment delineation, slope analysis, contour extraction, and terrain model transfer to engineering software.

Quality check

Check for seam lines after merge and inspect edge gaps after clipping. Missing DEM strips can create wrong drainage paths.

Recommended output

By the end of this workflow, the user should have a clean engineering output such as a map, terrain product, hydraulic model setup, water-level result, or project concept figure that can be used in reports and presentations.

Time-saving note

Read this page first for the workflow logic. Then open the video only for the detailed screen clicks, software interface steps, and practical demonstration.