Iranian Remote Sensing and GIS Society / Shahid Beheshti University Iranian Journal of Remote Sensing and GIS 2008-5966 11 1 2019 04 21 Investigation of the saturation effect of vegetation indices in LAI estimation of crops Investigation of the saturation effect of vegetation indices in LAI estimation of crops 33 48 96696 10.52547/gisj.11.1.33 FA Maedeh Behifar Remote Sensing and GIS department, School of Geography, University of Tehran Mohsen Azadbakht Assistant Professor in Remote Sensing, Remote Sensing and GIS Research Center Farzaneh Hadadi Remote sensing expert, Iranian Space Research Center AliAkbar Matkan Professor in Remote Sensing, Remote Sensing and GIS Research Center 0000-0001-5394-4599 Journal Article 2020 12 22 Vegetation indices are used to estimate vegetation parameters from satellite images. Despite their capabilities, performance of some vegetation indices decreases in high vegetation densities, making them inappropriate for estimation of the desired parameters. Vegetation indices are saturated in alfalfa farms due to the high chlorophyll content and high vegetation density; therefore, monitoring the changes of this plant is hindered. However, all indices do not perform similarly. In this research, the performance of different vegetation indices at different LAI values were investigated. The results showed that the CIgreen, CIrededge and NGRDI indices gained the best performance at high LAI values and they were less saturated. In contrast, the NDVI, NDREI and GNDI indices did not perform well and they were saturated at medium and high levels of LAI. Vegetation indices are used to estimate vegetation parameters from satellite images. Despite their capabilities, performance of some vegetation indices decreases in high vegetation densities, making them inappropriate for estimation of the desired parameters. Vegetation indices are saturated in alfalfa farms due to the high chlorophyll content and high vegetation density; therefore, monitoring the changes of this plant is hindered. However, all indices do not perform similarly. In this research, the performance of different vegetation indices at different LAI values were investigated. The results showed that the CIgreen, CIrededge and NGRDI indices gained the best performance at high LAI values and they were less saturated. In contrast, the NDVI, NDREI and GNDI indices did not perform well and they were saturated at medium and high levels of LAI. https://gisj.sbu.ac.ir/article_96696_6fd32d113ccbaf402c7df48681799d0b.pdf