Mechanism Saturation Index for uncertainty quantification

Develop and report a Mechanism Saturation Index that formalizes SHAP-disorder escalation for uncertainty quantification and early warning under extreme precipitation.

Background

The paper uses increasing within-class SHAP standard deviation as an empirical indicator of progressive mechanistic saturation at extreme precipitation intensities. It proposes converting this diagnostic into a dedicated index that can quantify uncertainty and provide early warning when correction reliability is degrading.

The index has not yet been presented or evaluated in the paper; its development and separate reporting are explicitly deferred.