The observatory 05 Otjiamongombe (commonly named Erichsfelde) is situated approx. 45 km north of Okahandja in the region Otjozontjupa. During the summer months (Sept.-April) there is approx. 360 mm of rainfall which is very variable in space and time.
The topography of the area is almost flat to gently undulated with a mean height of 1500 m above see level. The only hill is the ombutuzo in the western part of the farm with a height of approx. 1900 m above see level. Geolocially the region lies in a transition zone between the western Kalahari margins and the escarpment in the west. Drainage system is heading towards the north, the margins of the Omatako catchment. The watershed to the Atlantic heading to the Swakop catchment is only a few km south.
The observatory itself is situated in the northeastern part of the farm. The topography is flat with a mean height of 1512 m and a slight inclination towards the north. The western part is dissected by a small river (Omuramba) in south-north direction. The unconsolidated subtrates consist of loamy textures with different colours from greyish brown in the western part and reddish in the mid and eastern part of the observatory, partly underlied by calcrete.
The potential natural vegetation is an open thornbush savanna with Acacia species as main woody components and grasses like the Stipagrostis uniplumis, Aristida and Eragrostis species in the herb layer. Trees can reach heights of up to 15 m. In some spots bush encroachment can be observed, this is when the shrub Acacia mellifera occurs as dense thicket. Depending on the habitat and the intensity of disturbance by grazing and trampling animals, annuals can dominate over perennial climax grasses in the herb layer.
Extensive cattle and game farming are the dominant land use system in the area and on the farm as well. One of the research questions on this Observatory and on the whole farm is to compare the actual vegetation with historical vegetation data (from the 1950´s) in the context of land use and climatic change. The disciplines that are working with high intensity on the Observatory are remote sensing, soil science and botany