เปรียบเทียบวิธี

	ดัชนีปริมาณน้ำฝนมาตรฐาน	ดัชนีการระเหยคายน้ำจากปริมาณน้ำฝนแบบมาตรฐาน
สาขาวิชา	ธรณีฟิสิกส์	ธรณีฟิสิกส์
ตระกูล	Process / pipeline	Process / pipeline
ปีกำเนิด	1993	2010
ผู้ริเริ่ม	Thomas McKee, Neil Doesken, and John Kleist	Vicente-Serrano, Beguería, and López-Moreno
ประเภท	Probabilistic drought indicator	Probability-based water deficit indicator
แหล่งต้นตำรับ	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.
ชื่อเรียกอื่น	SPI	SPEI
ที่เกี่ยวข้อง	3	3
สรุป	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.