Composite2Change (C2C) on Google Earth Engine: Time-series change detection and metrics characterizing disturbance and recovery

Satellite time series enable the consistent and scalable characterization of land cover changes and vegetation dynamics across extensive areas. The Composite2Change (C2C) protocol applies temporal spectral trend analysis to identify land change events, producing metrics that describe the timing, magnitude, duration, rate, direction, and recovery dynamics of disturbances. These metrics summarize spectral trajectories and support mapping and modelling applications. While the methods have been published and their value demonstrated, their replication across regions and sensors has been limited due to high storage and computational demands, coupled with the lack of available implementation. To address these barriers, we implemented C2C as a reproducible cloud-native framework within Google Earth Engine (C2C-GEE). C2C-GEE enables users to generate change products and metrics that describe the spectral and temporal signatures of land cover change and recovery. The framework supports the transparent and systematic generation of standardized change metrics for large-area mapping and modelling applications worldwide.