remtools

Basin‑Wide REM Protocol

This repository implements a basin‑wide River Elevation Model (REM) protocol for the GRMW Atlas metric update project. The workflow generates an REM over a full basin using three DEM inputs:

1. USGS 10 m DEM
2. Water Surface Elevation (WSE) DEM
3. Bathymetric DEM

All processing is performed with Python scripts that read from and write to GeoPackage files.

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Workflow Overview

1. Stream Network Delineation

   • Script: scripts/0_get_streams.py
   • Uses WhiteboxTools to hydrologically condition the USGS 10 m LiDAR DEM.
   • Thresholds flow‑accumulation to create a vectorized stream network.

2. Transect Generation

   • Script: scripts/1_get_transects.py
   • Generates perpendicular lines (500 m length) at a user‑defined spacing (default: 10 m) along the stream network.

3. Elevation Extraction Along Transects

   • Script: scripts/2_get_elevations_along_transect.py
   • For each transect, extracts the minimum elevation from the WSE DEM.
   • Creates three points per transect:
     • Point at minimum elevation
     • Two endpoints of the transect

4. Water Surface Interpolation

   • Script: scripts/3_interpolate_water_surface.py
   • Applies Inverse Distance Weighting (IDW) to the WSE points.
   • Uses a maximum interpolation radius equal to the valley’s maximum width.
   • Outputs an interpolated WSE raster.

5. REM Calculation

   • REM = Bathymetric DEM − Interpolated WSE raster

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