Moghra Oasis واحة القارة | |
|---|---|
Water source | |
  Moghra Oasis Location in Egypt | |
| Coordinates:30°15′18″N28°55′52″E / 30.255°N 28.931°E /30.255; 28.931 | |
| Country | Egypt |
| Governorate | Matrouh |
| Population | |
• Total | 0 |
| Time zone | UTC+2 (EST) |
TheMoghra Oasis is an uninhabited oasis in the northeastern part of theQattara Depression in theWestern Desert of Egypt. It has a 4 km2 (1.5 sq mi) lake containing brackish water, salt marshes and a swamp withreeds.
The Qattara Depression is about 133 metres (436 ft) below sea level and is shaped like a teardrop, with Moghra Oasis in its northeastern corner. The floor of the Depression consists ofsalt marshes anddry lake beds that flood occasionally and there are also large areas of windblown sand.[1] Moghra Oasis consists of a 4 km2 (1.5 sq mi) lake containing brackish water some 38 metres (125 ft) below sea level. Adjoining it aresalt marshes and somePhragmites swamps. To the south and west there are sand dunes near the lake and extensive sheets of sand beyond.[2]
The water rises to the surface from anaquifer in theNubian sandstone, but its precise source is unclear as theNubian Sandstone Aquifer System is at great depths in this area.[3] Just to the north of the oasis is a cliff which gives its name to theMoghra Formation, a thick layer ofclastic sedimentary rocks with some minor carbonate interbeds. This formation containsfossils ofvertebrates and plants; large mammals found here includehyaenodontsMegistotherium andHyaenaelurus.[4] Thesefluvial deposits are likely to have come from a river system which opened into the Nile Delta at the Moghra Oasis.[5]
To the south of the lake, the saltmarsh gradually merges into saline flats largely devoid of vegetation. There are three main species in this plant community, each dominating its own concentric zone;Zygophyllum album,Nitraria retusa andTamarix nilotica.[6] The most important variables affecting the distribution and structure of the communities are the moisture content of the soil and the salinity.[7]
In the outer zone, where the salinity is low and the surface is friable, small scattered plants ofZygophyllum album occur. In the innermost part of this zone the plants are larger and more crowded and they sometimes form hummocks. Here they are associated withT. nilotica,Alhagi maurorum andN. retusa. The next zone is dominated byN. retusa which shows a wide range of tolerances to moisture and salinity conditions. Among sand dunes it forms hummocks and plays an important role in stabilising dunes. In the outer fringes of the zone it is associated withZ. album andT. nilotica while on the inner fringes, where the water table is high but the soil has a low salinity level, the community includesPhragmites australis,Juncus rigidus,Sporobolus spicatus andZ. album. TheT. nilotica dominated area forms a scrub community on the outer fringes of the dune zone surrounding the salt flats, where it is associated withA. maurorum,Cressa cretica,N. retusa andZ album.[6] There are a few abandoned groves ofdate palms in the sandy areas.[2]
