השוואת שיטות

	NDVI	מדד ההתאדות-משקעים הסטנדרטי
תחום	גאופיזיקה	גאופיזיקה
משפחה	Process / pipeline	Process / pipeline
שנת המקור	1973	2010
הוגה השיטה	Rouse, Haas, Schell, and Deering	Vicente-Serrano, Beguería, and López-Moreno
סוג	Spectral index for vegetation assessment	Probability-based water deficit indicator
מקור מכונן	Rouse, J. W., Haas, R. H., Schell, J. A., & Deering, D. W. (1973). Monitoring vegetation systems in the Great Plains with ERTS. Third Earth Resources Technology Satellite Symposium Proceedings, 1, 309-317.	Vicente-Serrano, S. M., Beguería, S., & López-Moreno, J. I. (2010). A multiscalar drought index sensitive to global warming: the Standardized Precipitation Evapotranspiration Index. Journal of Climate, 23(7), 1696-1718.
כינויים	NDVI	SPEI
קשורות	3	3
תקציר	The Normalized Difference Vegetation Index (NDVI) is a spectral index computed from satellite or aerial multispectral imagery that quantifies vegetation greenness and vigor. Introduced by Rouse and colleagues in 1973 using Landsat data, NDVI has become the most widely used remote sensing metric for vegetation monitoring, drought assessment, crop productivity forecasting, and land cover change detection.	The Standardized Precipitation Evapotranspiration Index (SPEI) is a climate index that combines precipitation and temperature (via reference evapotranspiration) to characterize water deficits and droughts. Developed by Vicente-Serrano and colleagues in 2010, SPEI extends the SPI framework to account for the combined effect of precipitation deficiency and increased evaporative demand from warming, providing a more physically-based drought metric than precipitation-only indices.