*3.7.4.9 Validation and calibration*

Models are often calibrated and validated using real-world data to ensure accuracy. This involves adjusting model parameters to match observed conditions and using historical data to test the model's predictive capabilities.

#### *3.7.4.10 Policy and decision support*

Mathematical models provide a scientific basis for making informed decisions about phosphorus management. They help evaluate the potential impact of different policies and management actions.
