WetSpass-M Modern
Spatially distributed monthly water balance model for QGIS. Estimates groundwater recharge, evapotranspiration, surface runoff, and interception using GeoTIFF inputs. Adds a dynamic soil-water bucket to the original Wetspass-M 2016 physics, with automatic spin-up convergence detection.
WetSpass-M Modern is a modernized version of the original Wetspass-M 2016 model (Abdollahi, Bashir & Batelaan, Vrije Universiteit Brussel). It estimates diffuse and focused groundwater recharge, evapotranspiration, surface runoff, and interception at monthly, seasonal, and annual time steps.
The modernization preserves the original physics but adds:
- A dynamic soil-water bucket (soil moisture carried forward between months) replacing the original quasi-steady-state assumption. Essential for seasonally-concentrated rainfall regimes such as monsoonal, Mediterranean, and semi-arid climates.
- An ET cap at (P - runoff) instead of P, ensuring the catchment-scale mass balance closes exactly.
- Groundwater-fed ET reported separately as Cell_gw_discharge, outside the precipitation balance.
- Nodata-preserving aggregation so annual rasters share the same valid-cell mask.
- Automatic spin-up with convergence detection (mean |dS| compared to max(1 mm, 0.5% of mean annual P)).
- Automatic checkpointing after every completed month, so a power loss or drive disconnection resumes where it stopped.
- A dedicated Water Balance tab with explicit dS and an acceptability verdict.
- A Wetspass-M 2016 compatibility mode for validation against legacy results.
- A Focused Recharge module for streambed infiltration along ephemeral stream networks.
Inputs: 12 monthly climate rasters (rainfall, PET, temperature, wind, groundwater depth), a DEM, land use, soil, and optional slope. Outputs: monthly, seasonal, and annual GeoTIFFs of every flux, plus a per-month summary table.
Original authors (Wetspass-M 2016):
K. Abdollahi, I. Bashir, O. Batelaan - Vrije Universiteit Brussel
Modernization:
M. G. Gurmu
Email: [email protected]