Regionalization of drought in Northern Algeria using the standardized precipitation index

21 Pages·2011·9.04 MB·English

IV international workshop on hydrological extremes
From prediction to prevention of hydrological risk
in Mediterranean countries
University of Calabria, Soil Protection Dept.,
Cosenza (Italy), Sept. 15–17, 2011
Sabrina TAIBI
National High School of Hydraulic (ENSH)
Blida, Algeria

Annual water surface potential
in Northern Algeria:
(cid:190) Late 70’s: 13,5 Billion m3
(cid:190) 1980-1990: 12,4 Billion m3
(cid:190) Currently : 10 Billion m3

Study area
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653
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433
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393
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mm
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102 rainfall gauging stations
Standardized Rotated Principal
precipitation index Component Analysis
: Standardized precipitation index of the year (i)
:Rainfall precipitated during the year (i)
: Average inter-annual rainfall during
SPI values Category
the period of study (1936-2010) ≥ 2 Extremely wet
: Standard-deviation of average 1,5 ≤ SPI < 2 Very wet
1 ≤ SPI < 1,5 Moderatly wet
Inter-annual rainfall
(-) 1 < SPI < 1 Near normal
(-) 1,5 < SPI ≤ (-) 1 dry
(-) 2< SPI ≤ (-) 1,5 severly dry
SPI ≤ (-) 2 Extremely dry