Hoanib
The Hoanib is one of the 12 ephemeral seasonal rivers in the west of Namibia, where it used to be the border between northern Damaraland and Kaokoland. Its length is. With the low population density in the area, the oasis character of the river valley and the relatively high wildlife population of the Hoanib, like in the case of the Hoarusib, its valley is one of the last true wilderness areas in Namibia. One of the last settlements of desert elephants, it is characterised by strong wind and water eroded, weathered stone deposits. Inflows of Hoanib are Aap River, Otjitaimo River, Ombonde, Ganamub, Mudorib and Tsuxub.
Hydrology
The Hoanib's catchment area is estimated to be between 15760 and. It extends from the west coast to Ojiovasando and the Black Peaks of the interior. It also includes the resource-rich region Sesfontein, Warmquelle and the Khowarib Gorge. The highest point of the watershed is at. The rainfall in the catchment area is sporadic and varies from zero in the west to per year in the northeast. The proportion of area with less than per year is 71 percent. In only 12 percent of the catchment area is the annual rainfall over per year. The Hoanib flows only every few years from heavy rainfall in the hinterland of the catchment area, but then the flood wave can be several meters high and may last for several days. Not always, but more often in recent years, the water reaches the mouth in the Atlantic. A large part of the water seeps into and contributes to a large dense subsurface aquifer from the exits at various points in the river bed, so that even in dry years there is groundwater. Surrounding groundwater forms efflorescence used by many antelope as salt licks. During dry periods the Hoanib desert elephant dig deep holes to reach the near-surface groundwater.Flora and vegetation
The vegetation of the catchment comprises mainly Mopane savanna and the northern Namib, at 13%. Some larger collections of Ana trees, Leadwood, Mopane, Camel Thorn, Salvadora and Euclea are found in the gallery forests. Often several meters high, sour grasses and reeds grow in the wetlands.With its gallery forests and the larger wetlands in the Khowarib gorge, in a flood area east of Sesfontein and the lower reaches and mouth area, the Hoanib is a linear oasis in the otherwise arid surroundings, providing livelihood for a rich wildlife. In addition to larger populations of many species of antelope found in the lower reaches of the Hoanib, are also a large number of desert elephants, rhinos, giraffes, as well as several lion prides, and smaller predators.