Improved 30-m Impervious Surface Data for China, 2020 and 2022, with Enhanced Spatial Detail through fusing 2-m and 30-m resolution data

We present the China Impervious Surface Cover dataset for 2020 and 2022 (CISC2020, CISC2022) at 30-meter spatial resolution. The dataset covers mainland China and adjacent regions where input 2-meter satellite imagery was available. Generation involved a regionally adaptive deep learning strategy integrating high-resolution (2m) imagery, Landsat annual composites, and SRTM elevation data. High-quality training and validation samples were produced using entropy-guided stratified sampling and subsequent expert visual interpretation. The dataset is provided as Cloud Optimized GeoTIFFs (COG) using an Albers projection. Accuracy assessment using independent, expert-interpreted validation points confirms high overall accuracy (Spatially Averaged F1-score > 0.93 for the impervious surface class). This dataset offers reliable, spatially explicit impervious surface information for China, suitable for applications including urban dynamics analysis, environmental monitoring, and regional planning.

The impervious surface products are named cisc_2020.tif and cisc_2022.tif. In addition to impervious surfaces, the model's outputs for the other three classes (water bodies, vegetation, and bare land/other) are provided for user reference. However, the reliability of these auxiliary classes is not guaranteed. Pixel values represent the following classes: 0 = bare land/other), 1 = impervious surface, 2 = vegetation, and 3 = water body.

The impervious surface products cover the mainland area of China. Areas outside of China, or areas within China lacking sufficient 2-meter imagery coverage, are regarded as invalid pixels and assigned value 0. To maximize information content, the data were not clipped to coastlines or administrative boundaries. We also provide masks indicating the valid data extent for each year (2020 and 2022). These files are named valid_mask_2020.tif and valid_mask_2022.tif.

To facilitate better use of the product, we also provide a shapefile indicating the acquisition date of the 2m source data used for each location (see source_date_dissovle.zip)