🤖 AI Summary
Urban functional identification faces challenges in modeling high-order morphological–functional relationships and ensuring model interpretability. Method: We propose an interpretable graph neural network (GNN) framework featuring a morphology–function attribution path decoupling mechanism. A morphology-topology encoder captures structural features—e.g., block density and road-network connectivity—while counterfactual perturbation analysis enables spatially explicit, semantically aligned attribution. A multi-city graph atlas supports cross-regional generalization. Contribution/Results: This work achieves, for the first time, unified structural interpretability and semantic understandability of GNNs for urban functional inference. Evaluated on six major cities, our method attains an F1-score of 0.89 for functional classification and >82% accuracy in attributing critical morphological elements. It further generates a verifiable, transferable morphology–function mapping rule base, advancing both transparency and practical applicability in urban analytics.