The Jamma River (Amharic: ጃማ) is a river in 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 ...

and a tributary to the Abay (or

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 to ...

). It drains parts of the Semien Shewa Zones of the Amhara and Oromia Regions. The Upper Jamma flows through steep, deep canyons cut first through volcanic rock and then through the

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...

sandstone and shaly sandstone, with

Jurassic The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The J ...

limestone at the bottom."Local History in Ethiopia"
(pdf) The Nordic Africa Institute website (accessed 29 January 2008) It has a drainage area of about 15,782 square kilometers in size. Tributaries include the Wanchet. The earliest mention of this river is in the ''Gadla'' of

Tekle Haymanot Abune Tekle Haymanot ( Ge'ez: አቡነ ተክለ ሃይማኖት; known in the Coptic Church as Saint Takla Haymanot of Ethiopia; 1215 – 1313) was an Ethiopian saint and monk mostly venerated as a hermit. He was the Abuna of Ethiopia who f ...

, which was written in the fourteenth century. One of the earliest European mentions is by the missionary

Pedro Páez Pedro Páez Jaramillo, S.J. ( pt, Pêro Pais; 1564 – 20 May 1622) was a Spanish Jesuit missionary in Ethiopia. Páez is considered by many experts on Ethiopia to be the most effective Catholic missionary in Ethiopia. He is believed to be the ...

, who was the first European to see and describe the origin of the Abay. According to Johann Ludwig Krapf, in the 1840s the Jamma defined the boundary between

Marra Biete Marra Biete (Amharic: መራ ቤቴ) is a former province of Ethiopia, located inside the boundaries of the modern Semien Shewa Zone of the Amhara Region, north of Shewa Meda. According to Johann Ludwig Krapf, Marra Biete lay in the northwest pa ...

and Moret, two districts of the former province or

Sultanate This article includes a list of successive Islamic states and Muslim dynasties beginning with the time of the Islamic prophet Muhammad (570–632 CE) and the early Muslim conquests that spread Islam outside of the Arabian Peninsula, and continui ...

Shewa Shewa ( am, ሸዋ; , om, Shawaa), formerly romanized as Shua, Shoa, Showa, Shuwa (''Scioà'' in Italian language, Italian), is a historical region of Ethiopia which was formerly an autonomous monarchy, kingdom within the Ethiopian Empire. The ...

.''Journals of the Rev. Messrs. Isenberg and Krapf, Missionaries of the Church Missionary Society, Detailing their proceedings in the kingdom of Shoa, and journeys in other parts of Abyssinia, in the years 1839, 1840, 1841 and 1842''
(London, 1843), p. 290

Notes

External links

Ethiopia Disaster Prevention and Preparedness Agency: Administrative atlas: Oromiya region

Ethiopia Disaster Prevention and Preparedness Agency: Flood Vulnerable Areas as of August 24, 2006
Tributaries of the Blue Nile Important Bird Areas of Ethiopia {{Ethiopia-river-stub