Hydrology & Geospatial Analysis

Whitebox Tool Integration

GriidAi integrates with Whitebox (WBT) to provide advanced geospatial analysis and processing capabilities directly within the GriidAi Workspace. The integration supports terrain analysis, DEM conditioning, hydrology, watershed delineation, raster sampling, interpolation, rasterization, and LiDAR workflows.

The documented runtime inventory snapshot contains 733 tools. Here we have highlighted the main workflow families and priority capabilities used in GriidAi.

1. Terrain Analysis

• Slope
  • Calculates terrain steepness from a Digital Elevation Model (DEM).
  • Supports terrain assessment and identification of flat, moderate, and steep areas.
  • Runs on a safely staged, projected DEM for terrain analysis.
• Aspect
  • Determines the direction of maximum terrain descent.
  • Helps describe terrain orientation and slope-facing direction.
  • Published outputs use cleaned aspect values, with invalid or flat cells handled as nodata.
• Hillshade
  • Creates a shaded-relief visualization from elevation data.
  • Helps reveal ridges, valleys, and other terrain features.
  • Uses projected terrain data as part of the terrain-derivative workflow.

2. DEM Conditioning

• Fill Depressions
  • Removes or fills sinks in a DEM before hydrological routing.
  • Prepares elevation data for downstream flow and drainage analysis.
  • Used when hydrological conditioning is required rather than for terrain-only analysis.
• Breach Depressions (Least Cost)
  • Breaches depressions using a least-cost approach where appropriate.
  • Provides an alternative DEM-conditioning method for improving drainage connectivity.
  • Tool parameters are resolved from the live Whitebox runtime before execution.

3. Flow & Hydrology Analysis

• Flow Direction
  • Creates a routing or pointer raster that represents how flow moves across conditioned terrain.
  • Provides the flow-routing input used by downstream hydrology workflows.
  • The exact routing tool is selected according to the workflow requirements.
• Flow Accumulation
  • Calculates contributing cells or contributing area across the terrain.
  • Highlights locations where upstream flow becomes concentrated.
  • Provides a key input for drainage and stream-extraction workflows.

4. Stream & Watershed Analysis

• Stream Extraction
  • Extracts a stream raster from flow-accumulation results.
  • Uses an explicit threshold to define where the drainage network begins.
  • Runs after the required DEM-conditioning and flow-routing steps.
• Raster Streams to Vector
  • Converts a raster stream network into vector features.
  • Uses the stream raster together with the required flow-direction information.
  • Final vector results are published as GeoParquet after a native intermediate is created.
• Snap Pour Points
  • Adjusts outlet or pour points to appropriate drainage locations.
  • Helps align watershed outlets with the derived drainage network.
  • Outlet points are validated for CRS compatibility and DEM coverage before processing.
• Watershed
  • Delineates the upstream catchment draining to selected outlet points.
  • Uses the prepared flow chain together with validated and, when needed, snapped outlets.
  • Produces a watershed result only after required outlet and raster checks pass.
• Subbasins
  • Divides a drainage system into smaller catchment areas.
  • Supports more detailed analysis of individual drainage units within a larger watershed.
  • Uses compatible hydrology inputs according to live runtime metadata.

5. Raster Sampling

• Extract Raster Values at Points
  • Extracts raster values at point locations.
  • Can attach values such as elevation or other raster-derived measurements to point features.
  • Point geometry is checked and aligned to the raster CRS before sampling.

6. Interpolation

• IDW Interpolation
  • Creates a raster surface from numeric point observations using Inverse Distance Weighting (IDW).
  • Requires a numeric input field, a projected CRS, and an appropriate cell size.
  • The estimated output grid size is checked before processing to avoid unsafe oversized rasters.

7. Vector to Raster Conversion

• Points to Raster
  • Converts point features into raster format.
  • Uses a defined target grid, resolution, and extent.
• Lines to Raster
  • Converts line features into raster format.
  • Maintains alignment with the target raster grid used by the workflow.
• Polygons to Raster
  • Converts polygon features into raster format.
  • Checks geometry, CRS, extent, resolution, and alignment against the target grid.

Processing Requirements

• CRS & Staging
  • Terrain, hydrology, and distance workflows require a projected CRS.
  • Raster inputs are safely staged in the working directory before Whitebox execution.
• Tool & Parameter Discovery
  • The installed runtime inventory and live parameter metadata take priority over assumed tool names or parameter keys.
  • GriidAi resolves exact tool and parameter definitions before execution when metadata may vary.
• Output Validation
  • Outputs are checked for existence, non-zero size, readability, CRS, nodata behavior, and workflow-specific quality criteria.

Output Formats & Publication

• Raster Outputs
  • Validated raster results are published as GeoTIFF outputs.
  • Raster outputs preserve required CRS and nodata semantics and are checked before publication.
• Vector Outputs
  • Whitebox writes a native vector intermediate, such as GPKG, before canonical conversion.
  • The final published vector artifact is GeoParquet rather than the native intermediate.