Hoarusib

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Hoarusib
Data
location Namibia
River system Hoarusib
muzzle in the Atlantic Coordinates: 19 ° 4 ′ 30 ″  S , 12 ° 33 ′ 20 ″  E 19 ° 4 ′ 30 ″  S , 12 ° 33 ′ 20 ″  E

length 300 km
Catchment area 15,237.459 km²

The Hoarusib is one of the 12 ephemeral dry rivers in western Namibia . It is 300 km long and, with its wetlands in the lower reaches of the Hoanib and Uniab, is one of the most important river oases in the northern Namib , which is characterized by a high and largely untouched wildlife population.

Hydrology

The Hoarusib dewatered in the central Kaokoveld a mountainous and very remote catchment area of 15,237.459 square kilometers, stretching from the Atlantic to the steep edge of mountains in the north to Opuwo in the east and Kaoko Otavi extends to the south and the Tonnies mountains and giraffes mountains includes. The highest point of the catchment area is at 1960 m. Precipitation in the catchment area falls irregularly and varies from 0 mm / a in the estuary to 325 mm / a in the east near Opuwo. 40% of the catchment area receives less than 100 mm / a, only 8% have an annual rainfall of over 300 mm. The Hoarusib comes off regularly and reaches the Atlantic almost every year with frequent and strong floods. In the lower reaches west of Purros there are larger, year-round wetlands . Here the groundwater flow of the Hoarusib meets a hardness threshold , so that groundwater emerges from the surface. In the further course, sources or groundwater appear again and again.

Vegetation and fauna

The majority of the catchment area with 94% consists of Mopane savannah . Only 6% are in the northern Namib area. Along the Horarusib there are gallery forests with tamarisk ( Tamarix ), palm trees (e.g. Hyphaene spec. ), Leadwood ( Combretum imberbe ), anabaum ( Faidherbia albida ), mopane ( Colophospermum mopane ), camel thorn ( Acacia erioloba ) and euclea . In the more humid areas in the lower reaches there are also larger populations of grasses, cyperus and phragmites .

Just like the Hoanib or Uniab , the large wetlands and gallery forests of the Hoarusib in the otherwise dry Kaokoveld provide the basis for significant wildlife. In addition to antelope species, there are also elephants , black rhinos , giraffes as well as lions , hyenas and other predators. The Hoarusib is one of the traditional migration routes of the desert elephants .

Use and settlement

98% of the catchment area is communal land and under tribal administration, the remaining two percent in the lower reaches are part of the Skeleton Coast Park , private farms do not exist. The population is 14,000, of which about two thirds live in Opuwo , the capital of the Kunene region . A large part of the population belongs to the Ovahimba or Ovaherero ethnic groups . The land use is almost exclusively migratory grazing, but tourism is also increasingly playing a role.

In particular, the growing population of Opuwo and increasing tourism, but also plans to expand Möwe Bay as a port, are leading to an increasing threat to the fragile ecosystem of the Hoarusib, on the one hand due to the increasing traffic density, but above all due to the enormous increase in water demand that the The limited resources of the Hoarusib are already under extreme strain.

literature

  • Mary Seely, Kathryn M. Jacobson, Peter J. Jacobson: Ephemeral Rivers and Their Catchments - Sustaining People and Development in Western Namibia . Desert Research Foundation of Namibia, 1995, ISBN 978-99916-709-4-2 .
  • Klaus Hüser, Helga Besler, Wolf Dieter Blümel, Klaus Heine, Hartmut Leser, Uwe Rust : Namibia - A Landscape Studies in Pictures . Klaus Hess, Göttingen / Windhoek 2001, ISBN 978-3-933117-14-4 .
  • Julian Thomas Fennessy: The ecology of desert-dwelling giraffe (Giraffa camelopardalis angolensis) in northwestern Namibia . Diss., Sydney 2004.

Individual evidence

  1. ↑ Mapping the Major Cathments of Namibia. Ben Ben J. Strohbach, National Botanical Research Institute, pp. 5-6.