This study aims to track and analyze changes in cropping intensity across the Philippines to understand spatial and temporal patterns of agricultural practice. This analysis uses MODIS Terra surface reflectance data from 2001 to 2024 to derive a nationwide NDVI time series. The data were grouped into 3-year periods (e.g. 2001-2003, 2002-2004) to model dominant crop cycle patterns using Harmonic analysis, and a moving maximum filter was applied to enhance the detection of vegetation peaks. The first derivative of the filtered temporal signal was computed, and sequences of zero slope segments were extracted to represent valid crop cycles. Cropping Intensity (CI) was calculated averaging the detected crop cycles per year, resulting in values of 1, 2, or 3 cycles per year. Results show that 63.7% of land remained stable in its cropping intensity (CI), with double cropping (CI2) accounting for nearly half of stable areas. This dominance reflects the country’s two main cropping seasons, anchored by rice–maize production systems. Intensification (12.6% of transitions) and de- intensification (12.1%) occurred at nearly equal rates, mainly between CI2 and CI3, while 11.7% of transitions involved exchanges with non-cropland, particularly grassland and wetland. Area-based trends highlight further structural shifts. Single cropping declined by nearly 50% over the 24 years, while double cropping, though reduced by 25% since its early-2000s peak, remained the dominant practice, covering ~70% of total crop area. Triple cropping expanded modestly by ~6%, reflecting gradual intensification in select regions. Comparisons with official data show that satellite-derived crop areas (~5.1 Mha) are consistently lower than reported statistics (~7 Mha), reflecting methodological differences between earth observation and survey-based approaches. The results support the use of remote sensing-derived cropping intensity monitoring as a supplementary tool for assessing agricultural dynamics in the country and its potential in guiding sustainable agricultural planning.

This study is part of the 46th Asian Conference on Remote Sensing (ACRS) on 27-31 October 2025 in Makassar, Indonesia.

More information here.