مقایسهٔ روش‌ها

	شاخص استاندارد بارش	شاخص استانداردشده بارش-تبخیر و تعرق
حوزه	ژئوفیزیک	ژئوفیزیک
خانواده	Process / pipeline	Process / pipeline
سال پیدایش	1993	2010
پدیدآور	Thomas McKee, Neil Doesken, and John Kleist	Vicente-Serrano, Beguería, and López-Moreno
نوع	Probabilistic drought indicator	Probability-based water deficit indicator
منبع بنیادین	McKee, T. B., Doesken, N. J., & Kleist, J. (1993). The relationship of drought frequency and duration to time scales. Proceedings of the Eighth Conference on Applied Climatology, 179-184.	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.
نام‌های دیگر	SPI	SPEI
مرتبط	3	3
خلاصه	The Standardized Precipitation Index (SPI) is a climate index that quantifies precipitation anomalies relative to historical norms, standardized to account for differences in precipitation climatology across regions. Introduced by McKee, Doesken, and Kleist in 1993, SPI has become a primary tool for drought detection and characterization, adopted by meteorological agencies worldwide for operational drought monitoring and early warning systems.	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.