NPP Dataset of Afforestation Areas in the "Two Rivers and Four Tributaries" Basin (2015 and 2022)

The NPP Dataset of Afforestation Areas in the "Two Rivers and Four Tributaries" (Liangjiang Sihe) Basin (2015 and 2022) covers the afforestation areas within the "Two Rivers and Four Tributaries" watershed in the Tibet Autonomous Region, containing two snapshots of Net Primary Productivity (NPP) spatial distribution data for 2015 and 2022, which serve as a basis for dynamically assessing the ecological benefits of the afforestation project.This dataset was produced from the MODIS annual NPP product (MOD17A3HGF V6) accessed through the Google Earth Engine platform.

The original raster was clipped and overlaid using the watershed vector boundary together with afforestation spatial distribution data to extract NPP pixel values within the afforestation areas, then unified in projection and stored in GeoTIFF format. Results show that NPP in the afforestation areas ranged from 27.97 to 662.67 gC/m²·a in 2015 and from 26.25 to 770.12 gC/m²·a in 2022. Spatially, vegetation productivity was higher in the southeastern valley areas and lower in the northwestern high-altitude regions and around lakes; compared with 2015, the extent of high-value zones in the southeast expanded noticeably in 2022.