Spatiotemporal Dynamics of Soil Erosion and Its Interactive Mechanisms with NDVI in the Yellow River Basin, China

Land Use/Land Cover (LUCC) Data
Annual land use/cover maps for 1995, 2000, 2005, 2010, 2015, and 2020 were obtained from the Resource and Environment Data Cloud Platform (https://www.resdc.cn/
) developed by the Chinese Academy of Sciences. These maps were derived from Landsat TM/ETM+/OLI imagery with an overall accuracy exceeding 90%. Considering the relatively small interannual variation, the land use data for 1995, 2000, 2005, 2010, 2015, and 2020 were used to represent adjacent years for SE estimation.

Vegetation Index (NDVI) Data
The MODIS NDVI product (MOD13A3, 1 km, monthly, 2001–2022) was acquired from the NASA Earthdata portal (https://earthdata.nasa.gov/
). Monthly data were composited to annual mean NDVI to analyze vegetation cover dynamics. The Sen’s slope estimator and Mann–Kendall test were applied to detect long-term trends and change points in vegetation recovery.

Digital Elevation Model (DEM)
Elevation data with a 30-m resolution were sourced from the Shuttle Radar Topography Mission (SRTM) provided by the United States Geological Survey (USGS, https://earthexplorer.usgs.gov/
). Slope and flow direction were derived from the DEM to support soil erosion modeling in the InVEST SDR module.

Meteorological Data
Daily precipitation and temperature data (1995–2022) were obtained from the China Meteorological Data Service Center (CMDC, https://data.cma.cn/
). Annual mean precipitation was interpolated using the Inverse Distance Weighting (IDW) method to match the spatial resolution of other datasets.

Soil Data
Soil texture and organic matter content were derived from the Harmonized World Soil Database (HWSD v1.2), complemented by data from the National Second Soil Survey of China. These parameters were used to calculate soil erodibility factors required by the InVEST SDR model.