Rivers

Draa River

April 11, 2013, 3:15 pm
Content Cover Image

Scene in the middle Draa Valley from an historic kasbah. @ C.Michael Hogan

The Draa River of Morocco rised in the High Atlas Mountains and flows to the Atlantic Ocean. Even though the Draa Basin is sparsely populated compared to world standards, the human population exacts an overdrafting of the river and its associated groundwater by historic standards, leading to an undersupply of the river's waters for humans as well as the indigenous riparian biota. In fact land use patterns along the Draa Valley have led to human settlements that are solely centered on the Draa River, with intense extraction for agricultural and domestic use, as the virtually sole water source for this arid region.

The Draa Valley is noted for its rich heritage of petroglyphs and rock paintings, left by an era of humans when the landscape was more lush and hospitable to agriculture. Furthermore, the Draa is one of the earliest noted rivers in recorded history on the African Atlantic shores, when Hanno the Navigator chronicled sighting the Draa mouth circa 500 BC.

Hydrology

The Draa Basin is relatively arid, incurring only about 25 centimeters of precipitation annually, except for higher reach parts of the catchment in the High Atlas. The Draa generally drains southern slopes of the High Atlas Mountains and Anti-Atlas Mountains, prior to eventual discharge to the Atlantic near Tan Tan. Historically the Draa has been considered a permanent river, but over-extraction in modern times makes its flow throughout all reaches as problematic. In any case south of the Draa Valley, there is no more southerly perennial river (or standing lake) in North Africa on the Atlantic shores.

Water quality

Water quality is a matter of concern in the vicinity of and downriver from human settlements along the oasis chains; impacts stem from agricultural return flows that are ion rich and from discharge of typically untreated or partially treated domestic sewage. Even though the human population densities are not considered high by world perspectives, the human densities and extraction/water use rates are high by historic standards, and with regard to river flow rates. Correspondingly the percolation rates of extracted and used water are high in the relatively porous soils of the generally level areas of the plains. Therefore, it is not surprising that in the vicinity of oases there are high sulfate levels in groundwater (generally above 400 milligrams per litre); moreover, nitrate levels in groundwater are around 27 milligrams per litre, and reflect the fact that most domestic sewage from the oasis settlements are discharged untreated to reach the groundwater.

Aquatic biota

There are a number of endemic cyprinidae fish species endemic to the High Atlas reaches of the Draa catchment as well as drainages of the north slopes of the High Atlas; unfortunately, not enough research has gone into the fish species of this region to provide accurate mapping. Barbus lepineyi is an example endemic fish to the Draa River Basin.

Terrestrial ecoregions

1. Northern Sahara steppe and woodlands

2. Mediterranean acacia-argania woodlands and succulent thickets

3. Mediterranean woodlands and forests

4. Mediterranean dry woodlands and steppe

5. Mediterranean High Atlas juniper steppe

Map source: World Wildlife Fund

The highest elevation reaches of the Draa catchment are covered by the Mediterranean High Atlas juniper steppe ecoregion. This ecoregion covers the uppermost ridgeline of the Draa drainages and also stores snowpack for vital late season runoff in the Draa Basin as well as the key urban areas in the watersheds to the north serving Fes, Marrakech and Meknes.

Next highest elevation easternmost reaches of the Draa Basin are covered by Mediterranean woodlands and forests. This ecoregion hosts an important avian assemblage, with over 120 species, including an endemic subspecies of great spotted woodpecker, Dendrocopos major numidus, an endemic subspecies of grey shrike, Lanus meridionalis algeriensis, the endangered Algerian nuthatch (Sitta ledanti), and raptors such as golden eagle (Aquila chrysaetos), black-shouldered kite (Elanus caeruleus), short-toed eagle (Circaetus gallicus), booted eagle (Hieratus pennatus), and the vulnerable lesser kestrel (Falco naumanni). Reptiles are also well represented in these forest ecosystems, including the spurred tortoise (Testudo graeca VU), common chameleon (Chamaeleo chamaeleon), North African ocellated lizard (Lacerta pater), Atlas mountain viper (Macrovipera mauritanica), Olivier’s desert-racer (Mesalina olivieri), Eumeces algeriensis, Chalcides mauretanicus, Lataste’s viper (Vipera latasti), Acanthodactylus maculatus, A. savigni, A. lineomaculatus.

The westernmost terrestrial ecoregion through which the Draa River flows is the Mediterranean acacia-argania woodlands and thickets. The major plant species which develop with Argania are: Periploca laevigata, Senecio anthephorbium, Launaea arborescens, Warionia saharae, Acacia gummifera, Rhus trpartitum, Withania frutescens, Euphorbia officinarum, Cytisus albidus, Ephedra altissima, and Tetraclinis articulata. The boundaries of the ecoregion correspond to those of the boundaries of the Argania forest. Acacia gummifera grows in shrubs and is a common companion species to the argan tree. Other acacia species such as Acacia ehrebengiana are more common in inland, and are widely distributed through out the Sahara Desert. Balanites aegyptiaca and Maerua crassifolia commonly grow among Acacia-Argania woodlands in the eastern part of the ecoregion.

Important Bird Areas

caption The marbled duck is a winter migrant to the Draa Valley. EOL

The nearly-perennial rivers and coastal wetlands of Morocco are a key flyway for migrant palearctic species coming south from Europe to rest or overwinter. The following two Important Bird Areas are associated with the Draa catchment.

The Barrage al Monsour Ad-Dhabi is an unprotected reservoir formed near the confluences of the Dades River and Ourzatate River by construction of a hydroelectric plant in 1972; this reservoir is near the town of Ourzatate. Along portions of the shallow perimeter of the lake are dense vegetative stands of Cynodon dactylon, Phragmites australis and Tamarix canariensis. Known to breed here are the bird species marbled duck (Marmaronetta angustirostris) and ruddy shelduck (Tadorna ferruginea).

caption Upper and middle reaches of the Draa River.

The Msseyed is an unprotected area about 70 kilometres east of Tan Tan between the Draa Valley and . The extreme northwest of the Msseyed holds dense stands of Argania spinosa and Euphorbia echinus; however, in the more arid southeastern part of the Msseyed are the densest known stands in Morocco of Acacia raddiana, as well as vigourous growth ol Limoniastrum ifniense and Nitraria retusa. Key avian species found here are the M. angustirostris and T. ferruginea.

Prehistory and ancient history

caption Petroglyph from Ait Waazik/ Tazarine near Zagora, Draa Valley. A controversial figurine was recovered in the lower Draa Valley near Tan Tan; although the quartzite object resembles a female human form and has been dated to 500,000 to 300,000 years before present, its authenticity as a hominid produced art object is unclear. The object is known in archaeological circles as the Venus of Tan Tan, but analysis and discussion is proceeding to interpret this find; if authenticated as of hominid origin, it would be the oldest art object known, and produced by a near ancestor of Homo sapiens.

In any case the Draa River Valley is rich in prehistoric art, including numerous extant petroglyphsA petroglyph is a prehistorical rock carving by humans.. Some of the more important archaeological sites for rock etching and rock painting in the Draa Basin are: Aït Ouaazik ( Asguine Tarna, Tazzarine), Tiouririne e Tisguinine (Zagora) and Foum Chenna (Tinzouline).

Hanno the Navigator of Carthage is the first to note the Draa in written history when he recorded his passage by the mouth, as part of his epic voyage through the Straits of Gibraltar circa 500 BC.

References

  • Robert G. Bednarik. 2003. A figurine from the African Acheulian. Current Anthropology 44(3): 405-13.
  • J.D.Fage,  Anthony Oliver Roland and A.D.Roberts, eds. 1979. The Cambridge History of Africa. Cambridge University Press.  ISBN 978-0-521-21592-3.
  • A.Hammoudi. 1985. Substance and Relation: Water Rights and Water Distribution in the Dra Valley. In: Mayer, A.E. (Ed.), Property, Social Structure, and law in the Modern Middle East. New York: pp. 27–57
  • C.Michael Hogan. 2007. Volubilis. Megalithic Portal, ed. A. Burnham
  • IUCN. 2011. The Status and Distribution of Freshwater Biodiversity in Northern Africa. Internation Union for Conservation of Nature
  • Stephan Klose and Klaus Haaken. Groundwater quality in Ouled Yauob. Impetus Atlas Morocco.
  • D.Jacques-Meunié. 1982. Le Maroc Saharien, des origines à 1670. Thèse d'État. 2 tomes, Librairie Klincksieck, Paris
Glossary

Citation

Hogan, C. (2013). Draa River. Retrieved from http://www.eoearth.org/view/article/175783