Rainfall and runoff
Change rainfall, surface cover and soil wetness; compare a simplified water budget.
Predict the effect before changing a value. Keep other values fixed, then compare the result and explain the relationship.
Explain and challenge the result
Compare with discussion guidance
More paved cover or wetter soil increases the chosen fast-runoff fraction. Check that rainfall input equals runoff plus the other pathways. The model omits spatial differences, soil properties, channel routing and a real storm time series.