Seasonal Changes in light interception among land use/land cover classes: an analysis based on SAC-C images

PIÑEIRO, G.; PARUELO, J. M.; LORETI, J.

Buenos Aires

Simposio; 29th International Symposium on Remote Sensing of Environment; 2002

Abstract – The “Río de la Plata” Grasslands have suffered important changes in land use and cover since the settlement of Europeans 400 years ago. The objective of our project was to evaluate the impact of land use change (agriculture and afforestation) on  carbon uptake and its surrogate: the amount of radiation intercepted by the vegetation. The MMRS sensor of the recently lunched SAC-C (CONAE) satellite is particularly suitable to this purpose because of its high spatial and temporal resolutions. From bands 3 and 4 of MMRS images, we derived the normalized difference vegetation index (NDVI), a spectral index linearly related with the proportion of photosynthetic active radiation intercepted by green vegetation, and hence to carbon uptake. Our results show that agriculture primarily changes the spatial heterogeneity of light interception, while afforestation increases substantially the total amount of radiation intercepted by green canopies. Our preliminary analysis stresses the suitability of the MMRS sensor on board of SAC-C to detect spatial and temporal ecosystem functional changes associated with the modification of land use and cover.