Hydrological Sciences

Flow calculation

• r.carve: Takes vector stream data, transforms it to raster and subtracts depth from the output DEM.
• r.drain: Traces a flow through an elevation model on a raster map.
• r.fillnulls: Fills no-data areas in raster maps using v.surf.rst splines interpolation
• r.fill.dir: Filters and generates a depressionless elevation map and a flow direction map from a given elevation layer.
• r.flow: Construction of slope curves (flowlines), flowpath lengths, and flowline densities (upslope areas) from a raster digital elevation model (DEM)
• r.topidx: Creates topographic index [ln(a/tan(beta))] map from elevation map.
• r.terraflow: Flow computation for massive grids.

Groundwater flow

• r.gwflow: Numerical calculation program for transient, confined and unconfined groundwater flow in two dimensions.
• r3.gwflow: Numerical calculation program for transient, confined groundwater flow in three dimensions.

Hydrological models

• r.topmodel: Simulates TOPMODEL which is a physically based hydrologic model.

Sediment modules

• r.sim.sediment: Sediment transport and erosion/deposition simulation using path sampling method (SIMWE)
• r.sim.water: Overland flow hydrologic simulation using path sampling method (SIMWE)

Stream modules

• r.stream.angle:
• r.stream.basins:
• r.stream.del:
• r.stream.distance:
• r.stream.extract:
• r.stream.order:
• r.stream.pos:
• r.stream.stats:

Watershed modules

• r.basin.fill: Generates a raster map layer showing watershed subbasins.
• r.water.outlet: Watershed basin creation program.
• r.watershed: Watershed basin analysis program.

Tutorial: Creating watersheds

References

• Metz et al 2009: Fast Stream Extraction from Large, Radar-Based Elevation Models with Variable Level of Detail (PDF)
• Metz et al 2010: Accurate stream extraction from large, radar-based elevation models (PDF)