Omo River
Encyclopedia
The Omo River is an important river of southern Ethiopia
. Its course is entirely contained within the boundaries of Ethiopia, and empties into Lake Turkana
on the border with Kenya
. It is the principal stream of an endorheic
drainage basin
; the part that the Omo drains includes part of the western Oromia Region
and the middle of the Southern Nations, Nationalities, and People's Region
.
During his second expedition (1895–1897), Vittorio Bottego
was the first European explorer to follow the course of the lower Omo River to its confluence with Lake Turkana.
This river rises in the Shewa
n highlands and is a perennial river. Its course is generally to the south, however with a major bend to the west at about 7° N 37° 30' E to about 36° E where it turns south until 5° 30' N where it makes a large S- bend then resumes its southerly course to Lake Turkana.
According to materials published by the Ethiopian Central Statistical Agency
, the Omo River is 760 kilometers long.
In its course the Omo has a total fall of about 6000 ft (2,000 m), from an elevation of 7600 ft at its source to 1600 ft at lake-level, and is consequently a very rapid stream, being broken by the Kokobi and other falls, and navigable only for a short distance above where it empties into Lake Turkana, one of the lakes of the Great Rift Valley
. The Spectrum Guide to Ethiopia describes it as a popular site for white-water rafting in September and October, when the river is still high from the rainy season. Its most important tributary is the Gibe River
; smaller tributaries include the Wabi, Denchya
, Gojeb
, Mui
and Usno
rivers.
The Omo River formed the eastern boundaries for the former kingdoms of Janjero
, and Garo. The Omo also flows past the Mago
and Omo National Park
s, which are known for their wildlife. Many animals live near and on the river, including hippopotamus
es, crocodile
s and Bitis arietans
.
of Olduwan
hominids from the early Pleistocene
era and up to the Pliocene
era. An important finding is Australopithecus
man, now extinct.
, Nyangatom
, Dizi
and Me'en
, are studied for their diversity
.
Jules Borelli was the first European explorer to thoroughly explore the upper and middle reaches of the Omo in the 1880s. Italian explorer Vittorio Bottego
reached the Omo river on 29 June 1896 during his second African expedition (1895–97), dying during this expedition on 17 March 1897. Herbert Henry Austin and his men reached the Omo delta on 12 September 1898, and found that an Ethiopian expedition, led by Ras Wolda Giyorgis, had previously planted Ethiopian flags on the northern shore of Lake Turkana on 7 April, as well as having plundered the locals and reduced them to poverty. Lieutenant Alexander Bulatovich
led a second Ethiopian expedition which reached the lake August 21, 1899, and was equally destructive. Despite this, the Frenchmen in the party accurately mapped for the first time many of the meanders of the Omo River delta. This rendition of the Omo River remained in use until the 1930s.
The entire Omo river basin is also important geologically and archaeologically. Several hominid fossils and archaeological localities, dating to the Pliocene
and Pleistocene
, have been excavated by French and American teams. Fossils belonging to the genera Australopithecine
and Homo
have been found at several archaeological sites, as well as tools made from quartzite
, the oldest of which date back to about 2.4 million years ago. Because of this, the site was designated a UNESCO
World Heritage Site
in 1980.
When they were discovered it was thought that the tools may have been part of a so-called pre-Oldowan industry, even more primitive than what was found in the Olduvai Gorge
. Later research has shown that the crude looks of the tools were in fact caused by very poor raw materials, and that the techniques used and the shapes permit their inclusion in the Oldowan.
dam with an associated hydropower plant under construction on the Omo river
in Ethiopia
. Once completed it would be the largest hydropower plant in Africa.
A group of international campaigners launched an online petition against Ethiopia's dam project over human rights concerns.
spokeswoman Paulette Jones said. "It takes less intensity of rainfall ... to make a river in any particular part of the country overflow." The seasonal flooding of the Omo River is vital to the indigenous groups that live along it. The flood brings fertile silt and inundates the banks with water, making river bank cultivation possible. The diverse peoples along the lower Omo—which include the Turkana, Dassanach, Hamer, Nyangatom, Karo, Kwegu, Mursi, Bodi, and Me'en—derive a great portion of their food supply from flood retreat cultivation.
The large and destructive flood of 2006 is the only one that has occurred within the past fifty years. Recent drop in the level of Lake Turkana, which is generally recognized to receive about ninety percent of its waters from the Omo River's inflow, has already caused a rise in salinity level. The increased size of the delta, now about 500 square miles (1,295 km²) in extent, has provided lands for recessional cultivation and pasture for cattle and other domestic livestock of the pastoralists and agro-pastoralists indigenous to the lower Omo basin.
Ethiopia
Ethiopia , officially known as the Federal Democratic Republic of Ethiopia, is a country located in the Horn of Africa. It is the second-most populous nation in Africa, with over 82 million inhabitants, and the tenth-largest by area, occupying 1,100,000 km2...
. Its course is entirely contained within the boundaries of Ethiopia, and empties into Lake Turkana
Lake Turkana
Lake Turkana , formerly known as Lake Rudolf, is a lake in the Great Rift Valley in Kenya, with its far northern end crossing into Ethiopia. It is the world's largest permanent desert lake and the world's largest alkaline lake...
on the border with Kenya
Kenya
Kenya , officially known as the Republic of Kenya, is a country in East Africa that lies on the equator, with the Indian Ocean to its south-east...
. It is the principal stream of an endorheic
Endorheic
An endorheic basin is a closed drainage basin that retains water and allows no outflow to other bodies of water such as rivers or oceans...
drainage basin
Drainage basin
A drainage basin is an extent or an area of land where surface water from rain and melting snow or ice converges to a single point, usually the exit of the basin, where the waters join another waterbody, such as a river, lake, reservoir, estuary, wetland, sea, or ocean...
; the part that the Omo drains includes part of the western Oromia Region
Oromia Region
Oromia is one of the nine ethnic divisions of Ethiopia...
and the middle of the Southern Nations, Nationalities, and People's Region
Southern Nations, Nationalities, and People's Region
Southern Nations, Nationalities, and People's Region is one of the nine ethnic divisions of Ethiopia. It was formed from the merger of the former Regions 7-11 following the 1994 elections...
.
During his second expedition (1895–1897), Vittorio Bottego
Vittorio Bottego
Vittorio Bottego was an Italian army officer and one of the first Western explorers of Jubaland in the Horn of Africa , where he led two expeditions. Bottego was born in Parma....
was the first European explorer to follow the course of the lower Omo River to its confluence with Lake Turkana.
Geography
Shewa
Shewa is a historical region of Ethiopia, formerly an autonomous kingdom within the Ethiopian Empire...
n highlands and is a perennial river. Its course is generally to the south, however with a major bend to the west at about 7° N 37° 30' E to about 36° E where it turns south until 5° 30' N where it makes a large S- bend then resumes its southerly course to Lake Turkana.
According to materials published by the Ethiopian Central Statistical Agency
Central Statistical Agency (Ethiopia)
The Central Statistical Agency is an agency of the government of Ethiopia designated to provide all surveys and censuses for that country used to monitor economic and social growth, as well as to act as an official training center in that field. It is part of the Ethiopian Ministry of Finance and...
, the Omo River is 760 kilometers long.
In its course the Omo has a total fall of about 6000 ft (2,000 m), from an elevation of 7600 ft at its source to 1600 ft at lake-level, and is consequently a very rapid stream, being broken by the Kokobi and other falls, and navigable only for a short distance above where it empties into Lake Turkana, one of the lakes of the Great Rift Valley
Great Rift Valley
The Great Rift Valley is a name given in the late 19th century by British explorer John Walter Gregory to the continuous geographic trench, approximately in length, that runs from northern Syria in Southwest Asia to central Mozambique in South East Africa...
. The Spectrum Guide to Ethiopia describes it as a popular site for white-water rafting in September and October, when the river is still high from the rainy season. Its most important tributary is the Gibe River
Gibe River
The Gibe River is a tributary of the Omo River. Located in southwest Ethiopia, it is not navigable, like almost all rivers in the country.-Overview:...
; smaller tributaries include the Wabi, Denchya
Denchya River
The Denchya River is a river of southern Ethiopia. It is a south-flowing tributary of the Omo River, entering it on the right bank at ....
, Gojeb
Gojeb River
The Gojeb River is eastward-flowing tributary of the Omo River in Ethiopia. It rises in the mountains of Guma, flowing in almost a direct line its confluence with the Omo at....
, Mui
Mui River
The Mui is a river of southern Ethiopia. Located inside Omo National Park, it is a tributary of the Omo River on the right side, merging with the larger stream at ....
and Usno
Usno River
The Usno River is a tributary of the Omo in Ethiopia. Formed by the confluence of the Magi and the Neri, it flows south past the Nyalibong Hills before it enters the Omo at . Almost all of its course is inside the boundaries of the Mago National Park....
rivers.
The Omo River formed the eastern boundaries for the former kingdoms of Janjero
Kingdom of Janjero
The Kingdom of Janjero was a tiny kingdom located in what is now Ethiopia. It lay in the angle formed by the Omo and the Jimma Gibe Rivers; to the west lay the Kingdom of Jimma and to the south the Kingdom of Garo...
, and Garo. The Omo also flows past the Mago
Mago National Park
Mago National Park is one of the National Parks of Ethiopia. Located in the Southern Nations, Nationalities, and Peoples Region about 782 kilometers south of Addis Ababa and north of a large 90° bend in the Omo River, the 2162 square kilometers of this park are divided by the Mago River, a...
and Omo National Park
Omo National Park
Omo National Park is one of the National Parks of Ethiopia. Located in the Southern Nations, Nationalities, and Peoples Region on the west bank of the Omo River, the park covers approximately 4,068 square kilometers, about 870 kilometers southwest of Addis Ababa; across the Omo is the Mago National...
s, which are known for their wildlife. Many animals live near and on the river, including hippopotamus
Hippopotamus
The hippopotamus , or hippo, from the ancient Greek for "river horse" , is a large, mostly herbivorous mammal in sub-Saharan Africa, and one of only two extant species in the family Hippopotamidae After the elephant and rhinoceros, the hippopotamus is the third largest land mammal and the heaviest...
es, crocodile
Crocodile
A crocodile is any species belonging to the family Crocodylidae . The term can also be used more loosely to include all extant members of the order Crocodilia: i.e...
s and Bitis arietans
Bitis arietans
Bitis arietans is a venomous viper species found in savannah and grasslands from Morocco and western Arabia throughout Africa except for the Sahara and rain forest regions. It is responsible for causing the most fatalities in Africa owing to various factors, such as its wide distribution and...
.
Early findings
On the banks of the Omo River archeologists have found fossil fragmentsOmo remains
The Omo remains are a collection of hominid bones discovered between 1967 and 1974 at the Kibish sites near the Omo River, Omo National Park in south-western Ethiopia. The bones were recovered by a scientific team from the Kenya National Museums directed by Richard Leakey and others...
of Olduwan
Olduwan
The Oldowan, often spelled Olduwan or Oldawan, is the archaeological term used to refer to the stone tool industry that was used by Hominines during the Lower Paleolithic period...
hominids from the early Pleistocene
Pleistocene
The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....
era and up to the Pliocene
Pliocene
The Pliocene Epoch is the period in the geologic timescale that extends from 5.332 million to 2.588 million years before present. It is the second and youngest epoch of the Neogene Period in the Cenozoic Era. The Pliocene follows the Miocene Epoch and is followed by the Pleistocene Epoch...
era. An important finding is Australopithecus
Australopithecus
Australopithecus is a genus of hominids that is now extinct. From the evidence gathered by palaeontologists and archaeologists, it appears that the Australopithecus genus evolved in eastern Africa around 4 million years ago before spreading throughout the continent and eventually becoming extinct...
man, now extinct.
Human impact
The lower valley of the Omo is currently believed by some to have been a crossroads for thousands of years as various cultures and ethnic groups migrated around the region. To this day, the people of the Lower Valley of the Omo, including the Mursi, SuriSurma people
Surma is a panethnicity residing in South Sudan and southwestern Ethiopia. It includes the Nilo-Saharan-speaking Suri, Mursi and Me'en.-Overview:...
, Nyangatom
Nyangatom people
The Nyangatom are a Nilotic ethnic group inhabiting southwestern Ethiopia and southeastern South Sudan...
, Dizi
Dizi people
Dizi is the name of an ethnic group living in southern Ethiopia. They share a number of somatic similarities with certain culturally related peoples of south-western Ethiopia, which include the Sheko and Nao, the Gimira , the Tsara, the Dime, the Aari and certain sub-groups of the Basketo people....
and Me'en
Surma people
Surma is a panethnicity residing in South Sudan and southwestern Ethiopia. It includes the Nilo-Saharan-speaking Suri, Mursi and Me'en.-Overview:...
, are studied for their diversity
Multiculturalism
Multiculturalism is the appreciation, acceptance or promotion of multiple cultures, applied to the demographic make-up of a specific place, usually at the organizational level, e.g...
.
Jules Borelli was the first European explorer to thoroughly explore the upper and middle reaches of the Omo in the 1880s. Italian explorer Vittorio Bottego
Vittorio Bottego
Vittorio Bottego was an Italian army officer and one of the first Western explorers of Jubaland in the Horn of Africa , where he led two expeditions. Bottego was born in Parma....
reached the Omo river on 29 June 1896 during his second African expedition (1895–97), dying during this expedition on 17 March 1897. Herbert Henry Austin and his men reached the Omo delta on 12 September 1898, and found that an Ethiopian expedition, led by Ras Wolda Giyorgis, had previously planted Ethiopian flags on the northern shore of Lake Turkana on 7 April, as well as having plundered the locals and reduced them to poverty. Lieutenant Alexander Bulatovich
Alexander Bulatovich
Alexander Ksaverievich Bulatovich tonsured Father Antony was a Russian military officer, explorer of Africa, writer, hieromonk and the leader of imiaslavie movement in Eastern Orthodox Christianity.-Biography:...
led a second Ethiopian expedition which reached the lake August 21, 1899, and was equally destructive. Despite this, the Frenchmen in the party accurately mapped for the first time many of the meanders of the Omo River delta. This rendition of the Omo River remained in use until the 1930s.
The entire Omo river basin is also important geologically and archaeologically. Several hominid fossils and archaeological localities, dating to the Pliocene
Pliocene
The Pliocene Epoch is the period in the geologic timescale that extends from 5.332 million to 2.588 million years before present. It is the second and youngest epoch of the Neogene Period in the Cenozoic Era. The Pliocene follows the Miocene Epoch and is followed by the Pleistocene Epoch...
and Pleistocene
Pleistocene
The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....
, have been excavated by French and American teams. Fossils belonging to the genera Australopithecine
Australopithecine
The term australopithecine refers generally to any species in the related genera Australopithecus or Paranthropus. These species occurred in the Plio-Pleistocene era, and were bipedal and dentally similar to humans, but with a brain size not much larger than modern apes, lacking the...
and Homo
Homo (genus)
Homo is the genus that includes modern humans and species closely related to them. The genus is estimated to be about 2.3 to 2.4 million years old, evolving from australopithecine ancestors with the appearance of Homo habilis....
have been found at several archaeological sites, as well as tools made from quartzite
Quartzite
Quartzite is a hard metamorphic rock which was originally sandstone. Sandstone is converted into quartzite through heating and pressure usually related to tectonic compression within orogenic belts. Pure quartzite is usually white to gray, though quartzites often occur in various shades of pink...
, the oldest of which date back to about 2.4 million years ago. Because of this, the site was designated a UNESCO
UNESCO
The United Nations Educational, Scientific and Cultural Organization is a specialized agency of the United Nations...
World Heritage Site
World Heritage Site
A UNESCO World Heritage Site is a place that is listed by the UNESCO as of special cultural or physical significance...
in 1980.
When they were discovered it was thought that the tools may have been part of a so-called pre-Oldowan industry, even more primitive than what was found in the Olduvai Gorge
Olduvai Gorge
The Olduvai Gorge is a steep-sided ravine in the Great Rift Valley that stretches through eastern Africa. It is in the eastern Serengeti Plains in northern Tanzania and is about long. It is located 45 km from the Laetoli archaeological site...
. Later research has shown that the crude looks of the tools were in fact caused by very poor raw materials, and that the techniques used and the shapes permit their inclusion in the Oldowan.
Gibe III proposed dam
The Gibe III Hydroelectric dam is a 243 m high roller-compacted concreteRoller-compacted concrete
Roller-compacted concrete or rolled concrete is a special blend of concrete that has essentially the same ingredients as conventional concrete but in different ratios, and increasingly with partial substitution of fly ash for Portland cement. RCC is a mix of cement/fly ash, water, sand, aggregate...
dam with an associated hydropower plant under construction on the Omo river
Omo River
The Omo River is an important river of southern Ethiopia. Its course is entirely contained within the boundaries of Ethiopia, and empties into Lake Turkana on the border with Kenya...
in Ethiopia
Ethiopia
Ethiopia , officially known as the Federal Democratic Republic of Ethiopia, is a country located in the Horn of Africa. It is the second-most populous nation in Africa, with over 82 million inhabitants, and the tenth-largest by area, occupying 1,100,000 km2...
. Once completed it would be the largest hydropower plant in Africa.
A group of international campaigners launched an online petition against Ethiopia's dam project over human rights concerns.
2006 floods
Heavy rains in 2006 caused the Omo to flood its lower course, drowning at least 456 people and stranding over 20,000 people over the space of five days ending 16 August. While seasonal heavy rains are normal for this part of the country, overgrazing and deforestation are blamed for this tragedy. "The rivers in Ethiopia have less capacity to hold as much water as they did years before, because they are being filled up with silt," World Food ProgrammeWorld Food Programme
The World Food Programme is the food aid branch of the United Nations, and the world's largest humanitarian organization addressing hunger worldwide. WFP provides food, on average, to 90 million people per year, 58 million of whom are children...
spokeswoman Paulette Jones said. "It takes less intensity of rainfall ... to make a river in any particular part of the country overflow." The seasonal flooding of the Omo River is vital to the indigenous groups that live along it. The flood brings fertile silt and inundates the banks with water, making river bank cultivation possible. The diverse peoples along the lower Omo—which include the Turkana, Dassanach, Hamer, Nyangatom, Karo, Kwegu, Mursi, Bodi, and Me'en—derive a great portion of their food supply from flood retreat cultivation.
The large and destructive flood of 2006 is the only one that has occurred within the past fifty years. Recent drop in the level of Lake Turkana, which is generally recognized to receive about ninety percent of its waters from the Omo River's inflow, has already caused a rise in salinity level. The increased size of the delta, now about 500 square miles (1,295 km²) in extent, has provided lands for recessional cultivation and pasture for cattle and other domestic livestock of the pastoralists and agro-pastoralists indigenous to the lower Omo basin.
See also
- List of Ethiopian rivers
- List of fossil sites (with link directory)
- Omo RemainsOmo remainsThe Omo remains are a collection of hominid bones discovered between 1967 and 1974 at the Kibish sites near the Omo River, Omo National Park in south-western Ethiopia. The bones were recovered by a scientific team from the Kenya National Museums directed by Richard Leakey and others...