Assessment of land use change in the dryland agricultural region of Córdoba, Argentina, between 2000 and 2020 based on NDVI data

Abstract

The dryland region of Córdoba province experienced a strong increase in agricultural land-use in the 21st century. Between years 2000 and 2020 the temporal variation of land-use measures derived from the seasonal variation curve of the Normalized Difference Vegetation Index (NDVI) was analyzed. In eleven departments of the region, the following NDVI measurements wereobtained for each crop cycle from September to April: minimum value (NDVIn), maximum value (NDVIx), amplitude (NDVIa=NDVIx-NDVIn) and mean value (NDVIm). The sowing percentage per department was analyzed spatially and temporally, as well as the land use indicators. Both NDVIn and NDVIx are related to the sowing area per department, determining a negative correlation (-0.36) for NDVIn and a positive one (0.596) for NDVIx. The positive correlation with NDVIa (0.569) is considered directly linked to the agricultural land use. The seasonal variation of the NDVI showed changes over time, which werecompatible with the increase in agricultural activity in the region. Although the increase in agricultural land use was noticeable through both the decrease in NDVIn and the increase in NDVIx, along with a general trend towards rising NDVIa values, the variation was more apparent in those departments where agricultural activity increased to a greater proportion.