Satellite-Informed Transformer Model for Enhanced Coastal Water Quality Modelling
摘要
Coastal water quality (CWQ) modelling is essential for sustainable management under increasing anthropogenic and climatic pressures. This study proposed an attention-based deep learning model, TabNet, integrated with the Quokka Swarm Optimisation (QSO) algorithm to enhance predictive accuracy, stability, and interpretability. Long-term in-situ CWQ data from Deep Bay, Hong Kong, were synchronised with AlphaEarth satellite-derived features to capture spatial-temporal variability of ammonia nitrogen (NH3-N). Data preprocessing involved temporal alignment, interpolation, and chronological splitting to maintain the integrity of the time series. The baseline model achieved a coefficient of determination (R2 = 0.83), whereas the QSO-optimised model improved predictive accuracy to (R2 = 0.91). Explainable Artificial Intelligence (XAI) approaches, including Local Interpretable Model Agnostic Explanations and Partial Dependence Plots, identified signified AlphaEarth features (e.g., A42, A53, and A61) as strong positive contributors to NH3-N variability, while features such as A25 and A34 showed negative influence, highlighting the nonlinear role of satellite-derived predictors in coastal nutrient dynamics. Geographic Information System (GIS) based spatial validation confirmed the consistency of model outputs, demonstrating the reliability and scalability of the proposed AI-driven model for sustainable CWQ assessment and management.