User:Dzlinker/Lake

Fetzara
Fetzara
Location	Annaba
Coordinates	36°47′30″N 7°33′30″E / 36.79167°N 7.55833°E
Basin countries	Algeria
Surface area	20.68 hectares (51.1 acres)
Surface elevation	25.35 metres (83.2 ft)

Lake Fetzara lengthens about 17 kilometers southwest of Annaba at the extreme east of the Algeria and 13 kilometers in the widest part. The lake dried up for many years and thereby lost its qualities of including the most important nesting site for 12 species of Waterflows.

Localization

The Lake Fetzara is located 17 Km southwest of the capital of the Wilaya of Annaba and 14 Km from the Mediterranean Sea. It elongates in the East-West direction on 17 Km long and 13 Km in its greater width. It is limited to the North by the massif of the Edough by Ain there hills south and dune located to the East and West. The road national 44 (RN 44) leading to the city of Constantine pass north of the site, while to the West and South, passes the path list N ° 13 (CW 13) and, to the West, the province N ° 108 path (CW 108). Note also that the way of railway, Algiers-Annaba, passes between the RN 44 and the Lake. The Lake Fetzara is situated in the wilaya of Annaba, Daira and municipality of Berrahal. At the periphery of the Lake are several areas: to the North, the Chief place of Berrahal commune, to the South the territories of the municipalities of El Eulma (Oued El Hout) and Cheurfa and, to the East, the small villages of El Gantra and Oued Zied.

Characteristics

An old book illustration of the lake (19th century)

Geology

The low lands constituting the majority of the wetland formed during the Halocène. Alluvium formed West to the coast of Skikda and, to the East, to the coastal region of Annaba plain. The mountains, North of the zone, are composed of igneous and metamorphic Triassic rocks. These rocks are crystalline schists and granites. The hills, to the South of the Lake, formed in the Miocene, consist of flisch and sandstone, and shale mixed with alluvium sometimes. Outcrops of rocks formed in the mountains located north of the site, cleavable, physical disintegration is important, this is the source of the sandy nature terraces.

Geomorphology

The topography of the site is divided into 4 distinct sets: the mountains surrounding reaching 40 metres above, the terrace formed in the centre of the Lake reaching an altitude between 2 to 40 metres, the plain of Annaba with an altitude between 11 and 20 metres and finally the low land whose elevation is less than 11 metres. There are also 4 types of soils, little advanced non-climate-related due to erosion, the colluvium and alluvium, vertisols, expansive alluvial rich clay drought comes easily to crack; hydromorphic soils and soils with high salinity helomorphes.

Hydrology

A space view of the lake (on the right)

The waters of Lake Fetzara come from the surrounding mountains, outside the many châabates (creeks) from the surrounding massifs, there are three main wadis: Oued El Hout in the South, Wadi Mellah West and Oued Zied Northeast. The three are channelled, their waters are normally evacuated by the Medjouba Wadi which flows at the level of the Wadi Seybousa, which leads into the Mediterranean Sea, a little more to the East of the site. This is the result of the failed attempt of drying by the colonizers as part of a program that affected the majority of the large wetlands of the country. These "amenities", whose effects persist today even, are that the Lake regularly dries in summer, the waters of the Oued El Hout continuing only to the site. The deepest part of the Lake is formed by sedimentation at an altitude of about 10 metres. During the rainy season, the water goes back to the coast about 12 metres or 2 metres from the level of the centre of the Lake. This temporary aspect, the succession of periods of drying and water makes particularly interesting the Lake in the light of the mineralization renewed each season, which creates a highly favorable environment for wintering birds feed and including surface waterfowl and coots.

Watershed

The area of the watershed of the Lake, de compris the wadis and the châabets (creeks) is 515 km2, vast and undulating with a slight slope in the direction of the Lake. To the North, the divide line is at a height of about 100 metres with a steep slope, apart from the slopes of the Oued Zied consisting of mountains whose height rises to more than 100 metres. The sharing of the waters of the Western parties line and is between 20 and 3 metres, the flow rate is estimated at 210 mm per day on average.

Climate

Mediterranean-type, temperate and characterized by a soft wet season and a dry, hot summer the average temperature is 11 ° c in winter and 25 ° c in summer. The rainfall is between 600 and 700 mm per year, of which 80% are concentrated in the rainy season between the months of October to March. Monthly average humidity is 68% to 75%. The annual total evaporation is 1.376 mm, monthly evaporation exceeds the monthly rainfall during the months of March and October. The winds in winter, are North - East and North-West, while in the summer, they are generally Northeast. The Sirocco blows about 18 days per year.

Hydrological values

The waters of Lake Fetzara are collected from El Hout, El Mellah and Zied wadis and flowing peripheral slopes. The area submerged in winter is of the order of 5,800 hectares. During the season dry, rainfall being near zero, little water arrives at the Lake. The drainage of the site takes place throughout the year through the main channel which water evacuation into the Oued Medjouba, then, in the Oued Seybousa that leads to the sea. During the summer season, the Lake is completely dry, this is mainly due to the deterioration of the lock of the main channel of escape El Gantra, located to the East of the Lake. Hydrological characteristics of the Lake are flood retention control