Annual 1 km Precipitation Concentration Index Dataset for China, 1951–2025

Monthly precipitation inputs were obtained from the “China 1 km Monthly Total Precipitation Dataset (1951–2025)”; the underlying precipitation records were derived from meteorological-station observations and spatially interpolated to produce continuous monthly grids at a 1 km spatial resolution.

Following the PCI method proposed by Oliver (1980), PCI was calculated for each grid cell and year as 100 times the ratio of the sum of squared monthly precipitation amounts to the square of annual precipitation. Higher PCI values indicate that annual precipitation is concentrated in fewer months, whereas lower values indicate a more even monthly distribution. The dataset uses the WGS 84 Albers equal-area projection, was spatially clipped to the national boundary of China, and is stored as single-band GeoTIFF files.