3rd HyMeX workshop 1-4 June 2009 Heraklion (Gournes), Crete-Greece
Contribution to the study of space distribution fluctuations of precipitations in AlgeriaKhéloufi Benabdeli (Faculty of Science of nature and life/(LRSBG), University of Mascara); Djamila Harrache
The distribution of annual averages of precipitations gives one distorts, very vague and unusable image of the rainfall. Precipitations are distributed in space according to a geographical and orographical organization. It's the slopes North and North-West and their altitudes which receive the strongest precipitations. The average height of annual precipitations varies significantly from east to west and especially from north to south as shown the following table:
| Areas | 1915-1940 | 1975-2000 | Difference |
| West littoral | 450 | 375 | -75 mm |
| Center littoral | 670 | 620 | -50 mm |
| East littoral | 850 | 690 | -160 mm |
| West Tell | 410 | 350 | -60 mm |
| Center Tell | 620 | 580 | -40 mm |
| East Tell | 860 | 770 | -110 mm |
The fluctuation of precipitations remains very important and differs from one year to another with a tendency for a reduction.
Unfortunately these precipitations are characterized since 1980 by fluctuations dominated by a downward trend as confirms it some data recapitulated in the table which follows by geographical area of Algeria.
| Areas | autumn | winter | Spring | Summer | Total |
| West | -17 mm | -39 mm | + 21 mm | + 9 mm | -68 mm |
| Center | + 2 mm | -34 mm | + 13 mm | + 7 mm | -38 mm |
| East | -56 mm | -43 mm | -20 mm | + 2 mm | -117 mm |
| Saharian | + 2 mm | + 5 mm | + 6 mm | + 3 mm | +16 mm |
| Atlas | | | | | |
During the last decades, the precipitations had a tendency to decrease and the average data from a few stations representing the four geographical regions of Algeria confirm that. The annual average deficit recorded is estimated at:
- 68 mm for the west region
- 38 mm for the central region
- 117 mm for the east region
