Rainfall Context Case Study¶
This study re-runs the main workflow's five catchments
with monthly SILO rainfall attached as context (run_hydroseason's rainfall
path). The window and extent inputs are the same (2005-01-01 to 2025-12-01,
252 months); rainfall is monthly SILO (silo-open-data), pre-fetched and
trimmed to that range.
Rainfall is strictly additive¶
Rainfall is resolved after the water-only analyze_catchment call and
cannot change regime, route, or hydrological-year boundaries. Every
water-only column of this study's summary (regime, route, route_reason,
timing statistics, n_hydro_years, n_events, longest_low_spell_months,
...) is identical to the main workflow's. Only the rainfall-comparison
columns are new: rainfall_regime, rainfall_amplitude_snr,
rainfall_peak_timing_concentration, rainfall_trough_timing_concentration,
rainfall_divergence, and rainfall_peak_lag_months.
Results¶
| Catchment | Water Regime | Rainfall Regime | Water Peak R | Rainfall Peak R | Divergence | Peak Lag (months) |
|---|---|---|---|---|---|---|
| Daly River (NT) | seasonal | seasonal | 0.878 | 0.874 | agree | 2 |
| Fitzroy River (WA) | seasonal | seasonal | 0.900 | 0.908 | agree | 1 |
| Gilbert River (QLD) | seasonal | seasonal | 0.934 | 0.914 | agree | 1 |
| Lachlan River (NSW) | aseasonal | aseasonal | 0.393 | 0.416 | agree | N/A |
| Moonie River (QLD/NSW) | aseasonal | seasonal | 0.444 | 0.594 | extent_damped | N/A |
rainfall_divergence compares the rainfall-only regime with the water
regime: agree means both give the same regime; extent_damped means
rainfall shows a seasonal signal that surface-water extent does not.
Findings¶
- Seasonal catchments agree. Daly, Fitzroy, and Gilbert are seasonal in both series, with similar peak timing concentration (R within 0.03).
- Extent lags rainfall by one to two months. Fitzroy and Gilbert peak 1 month after rainfall, Daly 2 months.
- Lachlan is aseasonal in both series. Neither rainfall nor water shows a recurring annual cycle.
- Moonie shows
extent_damped. Its rainfall is seasonal, but its surface water is not: peak water timing does not recur (p = 0.232), so no hydrological year is defined. Rainfall does not override that: rainfall is ancillary by design. - None of this changes routing. The water-only columns are identical to the main workflow whatever rainfall shows.
Reproduction¶
python scripts/_build_study_case_rainfall.py --check
See case_studies/README.md for data provenance and licensing.