HiLPD-GEE: high spatial resolution land productivity dynamics calculation tool using Landsat and MODIS data

Land productivity is one of the sub-indicators for measuring SDG 15.3.1. Land Productivity Dynamics (LPD) is the most popular approach for reporting this indicator at the global scale. A major limitation of existing products of LPD is the coarse spatial resolution caused by remote sensing data input, which cannot meet the requirement of fine-scale land degradation assessment. To resolve this problem, this study developed a tool (HiLPD-GEE) to calculate 30 m LPD by fusing Landsat and MODIS data based on Google Earth Engine (GEE). The tool generates high-quality fused Normalized Difference Vegetation Index (NDVI) dataset for LPD calculation through gap filling and Savitzky–Golay filtering (GF-SG) and then uses the method recommended by the European Commission Joint Research Centre (JRC) to calculate LPD. The tool can calculate 30 m LPD in any spatial range within any time window after 2013, supporting global land degradation monitoring. To demonstrate the applicability of this tool, the LPD product was produced for African Great Green Wall (GGW) countries. The analysis proves that the 30 m LPD product generated by HiLPD-GEE could reflect the land productivity change effectively and reflect more spatial details. The results also provide an important insight for the GGW initiative.