We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Computation of Drought Index SPI with Alternative Distribution Functions.
- Authors
Angelidis, Panagiotis; Maris, Fotios; Kotsovinos, Nikos; Hrissanthou, Vlassios
- Abstract
The Standardized Precipitation Index (SPI) is widely used as drought meteorological index, to identify the duration and/or severity of a drought. The SPI is usually computed by fitting the gamma probability distribution to the observed precipitation data. In this work, the possibility to calculate SPI by fitting to the precipitation data the normal and the log-normal probability distributions was studied. For this purpose, 19 time series of monthly precipitation of 76 years were used, and the assumption that the gamma probability distribution would provide better representation of the precipitation data than log-normal and normal distributions, at various time scales (1, 3, 6, 12 and 24 months) was tested. It is concluded that for SPI of 12 or 24 months, the log-normal or the normal probability distribution can be used for simplicity, instead of gamma, producing almost the same results.
- Subjects
DROUGHTS; METEOROLOGICAL observations; METEOROLOGICAL precipitation; PROBABILITY theory; WATER supply; NATURAL disasters
- Publication
Water Resources Management, 2012, Vol 26, Issue 9, p2453
- ISSN
0920-4741
- Publication type
Article
- DOI
10.1007/s11269-012-0026-0