Gilgel Abay (ግልገል አባይ, Gǝlgäl Abbay), or Lesser Abay, is a river of central

Ethiopia Ethiopia, , om, Itiyoophiyaa, so, Itoobiya, ti, ኢትዮጵያ, Ítiyop'iya, aa, Itiyoppiya officially the Federal Democratic Republic of Ethiopia, is a landlocked country in the Horn of Africa. It shares borders with Eritrea to the ...

. Rising in the mountains of

Gojjam Gojjam ( ''gōjjām'', originally ጐዛም ''gʷazzam'', later ጐዣም ''gʷažžām'', ጎዣም ''gōžžām'') is a historical province in northwestern Ethiopia, with its capital city at Debre Marqos. Gojjam's earliest western boundary ex ...

, it flows northward to empty into south-western

Lake Tana Lake Tana ( am, ጣና ሐይቅ, T’ana ḥāyik’i; previously Tsana) is the largest lake in Ethiopia and the source of the Blue Nile. Located in Amhara Region in the north-western Ethiopian Highlands, the lake is approximately long and wid ...

at . Tributaries of the Gilgel Abbay include the Ashar, Jamma, Kelti and the Koger. It was regarded as the true source of the

Nile The Nile, , Bohairic , lg, Kiira , Nobiin language, Nobiin: Áman Dawū is a major north-flowing river in northeastern Africa. It flows into the Mediterranean Sea. The Nile is the longest river in Africa and has historically been considered ...

for a long time and the Jesuit priest Pedro Paez visited it in 1618. The name Gilgel Abbay means Lesser Nile, as Abbay is the name for the

Blue Nile The Blue Nile (; ) is a river originating at Lake Tana in Ethiopia. It travels for approximately through Ethiopia and Sudan. Along with the White Nile, it is one of the two major tributaries of the Nile and supplies about 85.6% of the water ...

Characteristics

It is a

meander A meander is one of a series of regular sinuous curves in the channel of a river or other watercourse. It is produced as a watercourse erodes the sediments of an outer, concave bank ( cut bank) and deposits sediments on an inner, convex bank ...

ing river, with a catchment area of 3887 km³. Near its mouth it is 71 meter wide, with a slope gradient of 0.7 metre per kilometre. The average diameter of the bed material is 0.37 mm (

sand Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer to a textural class of s ...

Sediment transport

The river transports carries annually 22,185 tonnes of

bedload The term bed load or bedload describes particles in a flowing fluid (usually water) that are transported along the stream bed. Bed load is complementary to suspended load and wash load. Bed load moves by rolling, sliding, and/or saltating (hopp ...

and 7.6 million tonnes of

suspended sediment The suspended load of a flow of fluid, such as a river, is the portion of its sediment uplifted by the fluid's flow in the process of sediment transportation. It is kept suspended by the fluid's turbulence. The suspended load generally consists of ...

Characteristics

Sediment transport

See also

References

Further reading