Forest Disturbance in China from 1986 to 2020: 30 m disturbance attributes and 1 km annual density products

Abstract: This repository hosts a comprehensive forest disturbance dataset for China, spanning the period from 1986 to 2020. The dataset was generated using the Continuous Change Detection and Classification (CCDC) algorithm on the Google Earth Engine (GEE) platform, utilizing all available Landsat time-series imagery from 1985 to 2021. This dataset provides a dual-scale perspective on forest dynamics, offering both fine-scale disturbance attributes (30 m resolution) and aggregated disturbance density (1 km resolution) to support diverse ecological and climatic applications. The dataset consists of two major components: 1. 30 m Resolution Forest Disturbance Attributes: These raster files record the specific characteristics of detected forest disturbance events at a 30 m spatial resolution. (1) CFD_year.tif: Records the year of the forest disturbance event. The pixel values are stored as indices relative to the base year 1985. Value Range: 1 represents 1986, 2 represents 1987, ..., and 35 represents 2020. Nodata value: -128 (indicating no disturbance or non-forest areas). (2) CFD_mag.tif: This dataset records the maximum disturbance magnitude (abbreviated as "mag"), representing the maximum spectral change detected within a specific time segment and spectral band. It is quantified by the difference between the end-point of the pre-disturbance segment and the start-point of the post-disturbance segment, where a larger value indicates a more severe disturbance. To facilitate interpretation, the raw magnitude values were reclassified into five discrete classes using the Jenks Natural Breaks method. The final pixel values correspond to the following ranges: Class 1 (0 < mag ≤ 0.09), Class 2 (0.09 <mag ≤ 0.19), Class 3 (0.19 < mag ≤ 0.30), Class 4 (0.30 <mag ≤ 0.45), and Class 5 (mag > 0.45). (3) CFD_num.tif: Records the total number of disturbance events detected within the pixel during the study period. 2. 1 km Resolution Annual Forest Disturbance Density (CFDD): Derived from the 30 m disturbance year data, this product quantifies the spatiotemporal density of disturbances. CFDD[Year].tif (e.g., CFDD2000.tif): Represents the annual forest disturbance density. Unit: The pixel value indicates the ratio of disturbed forest area within each 1 km × 1 km grid cell (Unit: % or dimensionless fraction).