Calibration examples (controlled basins) | SWATGenX

This page summarizes the end-to-end workflow: selecting the calibration station, documenting the generated model structure, screening parameters with Morris global sensitivity, then running PSO calibration and independent verification.

Two compact gage watersheds used in the publication workflow evaluation.

Calibration methods (parameter template)Calibration & validation workflow

Scope and intent

These are calibration examples for two controlled basins. They are meant to show how a generated SWAT+ project moves through initialization, calibration, verification, and sensitivity analysis. They are not intended to claim national predictive skill.

Each model below includes (1) a compact model identity record, (2) interactive figures sourced from the same exported artifacts used in the publication, and (3) a Morris-ranked parameter subset and split-sample metrics table for quick comparison.

Parameter bounds and transformation rules come from the SWATGenX calibration template documented on /calibration-methods. For each basin below, the calibration run uses a Morris-trimmed subset of those candidate parameters.

The two basins deliberately bracket the range. Florida is a clean rainfall–runoff watershed where the generated model, calibrated against a single daily-plus-monthly NSE objective, reaches strong split-sample skill (daily NSE 0.84 in calibration, 0.73 in independent verification). Illinois is the harder case — snowmelt- and baseflow-driven, where the same single-objective workflow is markedly weaker (daily NSE 0.37 and 0.22) and snow and groundwater parameters dominate the sensitivity ranking. We show both unedited, because an honest example set has to include where an automated calibration does and does not do well.

Methods

For each basin the model identity record and simulation/optimizer configuration document how the example was built; the calibration uses a Morris-trimmed subset of the candidate parameter template.

Results

Per basin: the Morris sensitivity ranking, the calibration and verification split-sample metrics, and the interactive figure switcher (calibration, verification, and sensitivity outputs).

Florida controlled basin (USGS 02297600)

Calibration station: 02297600 (gage channel 2).

Use the figure controls to compare calibration and verification performance at the same station and to see the Morris screening outcome that selected the calibration subset.

Interactive figures: switch between calibration, verification, and sensitivity outputs. Hydrograph plots include the run-stage metrics on the figure (as in the publication artifacts).

Calibration global best (daily)

Calibration: compares the pre-optimization initialization pool and the calibrated global best for the scored calibration window.
Verification: shows the independent holdout window results (no overlap with the scored calibration period).
Sensitivity: Morris tornado plot used to rank candidate parameters and pick the trimmed calibration subset.

Field	Value
Calibration station	USGS streamgage 02297600 (NHDPlus HR region 0310)
Scored calibration window	2013-01-01 to 2018-12-31
Independent verification window	2019-01-01 to 2024-12-31
Simulation & optimizer	Simulated 2010–2018 with a 3-year warm-up; particle-swarm optimization with 36 particles over 70 iterations, 6 run concurrently.

Sensitivity analysis (Morris)

Morris screening runs a fixed evaluation budget and reports μ* (magnitude of the elementary effect) and σ (interaction / nonlinearity signal). The table below lists the top drivers by μ*.

Rank	Parameter	μ* (mean effect)	σ (interaction)
1	`surq_lag`	0.6435	0.4685
2	`perco`	0.288	0.4113
3	`cn3_swf`	0.1413	0.1699
4	`alpha_bf`	0.0921	0.0987
5	`dep_wt`	0.0882	0.1565
6	`spec_yld`	0.0545	0.0945
7	`flo_min`	0.0519	0.0774
8	`dp_es`	0.05	0.0282

Sensitive parameters (top 8 by μ*): surq_lag, perco, cn3_swf, alpha_bf, dep_wt, spec_yld, flo_min, dp_es.

Parameters selected for calibration in this example: 8 (the Morris-trimmed subset above). The complete candidate parameter template and bounds are documented on /calibration-methods.

Calibration and verification results

Metrics are reported for daily and monthly time steps (NSE, KGE, and PBIAS). Values below are pulled from the exported run summary tables used in the publication workflow evaluation.

Stage	Period	Daily NSE	Monthly NSE	Daily KGE	Monthly KGE	PBIAS (%)
Initialization pool best	2013–2018	0.795	0.843	0.68	0.713	28.127
Calibration global best	2013–2018	0.837	0.897	0.816	0.886	9.791
Verification global best	2019–2024	0.729	0.798	0.747	0.817	7.48

Illinois controlled basin (USGS 05536265)

Calibration station: 05536265 (gage channel 25).