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EVOLUTION OF IRRIGATION AND IMPACT ON THE COMMUNITIES OF TAFILALET OASIS (ERRACHIDIA, SOUTH EASTERN MOROCCO) International Conference WASAMED BARI, ITALIE, FEV. 2007 L.KABIRI*, P. MINOIA**, M. CAMUFFO**ET R. BORGHI**
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LOCALISATION OF THE CASE STUDY
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Domaine anti Atlasique et.. Domaine atlasique et mesetien Domaine rifain Study area Structural frame of Morocco and localisation of the case study
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Detail of the regional geological features
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Localisation of the water basins
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SITUATION AND DELIMITATION OF THE BASINS 60.000 Km ² (9 % of national space ) 0.81 millions inhabitants (2.7% of Maroc) Overlapping 3 economical regions 4 provinces 70 rural communes 9 municipalities 22 ONEP centres 1395 localities
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CLIMATE Climate: arid becoming Saharian towards South caracterised by inter and intra-annual irregularity. The extreme temperatures vary between winter freezing within the basins upstreams and a maximal average in july of 41 °C. The yearly average temperature is 20 °C with variations between 16 ° ande 23°C. Average evaporation varies between 2678 mm upstream (Rheris) and 5342 mm to the South (Taouz, Ziz) with an average over the totality of the watersheds of 3460 mm. Average pluviometry in the basin : 200 mm in the High Atlas reaching 50 mm in the Southern zone (Anti-Atlas and Tafilalet)
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Freshwater resources Water amounts are in average 581 millions Mm3 (3.4% of the national amounts). Great inter-annual variability caracterised by considerable differences between the law and the aluvional water periods. The natural perennial flow are weak sometimes non-existing.
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Section along the oued Ziz Section along the Tarda oued Section along the oued Ferkla Groundwater (Ziz, Tarda et Ferkla)
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Haut Guir(Jurassique and quaternaire) extracted : 11 Mm3 Haut Ziz-Rheris(Jurassique and quaternaire) extracted: 63.1 Mm3 Moyen et Bas Guir (Crétacé et Quaternaire) Extracted : 16.8 Mm3 Moyen Rheris (Infrac and quaternaire) extracted : 13.5 Mm3 Moyen Ziz (Crétacé and quaternaire) extracted : 48.4 Mm3 Bas Ziz (Quaternaire and Primaire) extracted: 23.4 Mm3 Bas Rheris (Quaternaire and Primaire) extracted : 21.5 Mm3 Maider (Quaternaire and Primaire) extracted : 22.6 Mm3 -Number of water tables: 16 -Exploitable resources: 313 Mm3/per year, 8 % of national resources -current exploited volumes estimated at 220 Mm3/year Resources and extractions
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The whole urban pollution contaminates the water corses downstream the centres 22 % of measured points overpass the rules required for NH4 + State of freshwater quality
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14Mm3 0 Mm3 14 Mm3 558Mm3 206 Mm3 352 Mm3 Water consumptions
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AEP: * rendement : 60% * perte d’eau = 5.6 Mm3/an Retard d’équipement des périmètres dominés par les barrages : 2639 ha Efficience relativement faible du réseau et du système d’irrigattion (75 %) : manque à gagner :51 Mm3/an Efficience des adducteurs :70 % à 80 %, soit une perte de 146.8 Mm3/an(moyenne) Soit une perte totale de 179 Mm3/an sur 558 Mm3/an régularisé pour l’irrigation (32 %) Main issues: weak efficiency
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Traditional systems for water management in oasis Some examples
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Tanast (water watch)
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Oughrour
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Khettarats Khettarat
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Collective pumping stations at Ferkla (1952-1954)
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Extension of irrigation areas in Ferkla oasis in the decade 1988/89-1998/99
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Regression of date palm numbers at Ferkla
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Main issue: decreasing and overexploited water resources TINEJDAD water table DAYET MAIDER water table Conséquences Intrusion of saline waters in groundwater tables Degradation of sources Difficult relations between AEP-rural and irrigation services (PMH) Increase of pumping costs
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Water amounts at the Hassan Addakhil dam 1939-1971 : 199 Mm3 1939-2005 : 146 Mm3 (-24%) 1971-2005 : 103 Mm3 (-87%) Meski
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State of date Palms
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State of olive trees
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Civil society reaction: active associations Recently introduced solutions in Jorf geo-membrane basins from khettarat to collect waters for oasis agriculture (cooperation IFAD-ORMVAT-local NGO)
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Jorf: Drip irrigation
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Merci pour votre attention
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