The three overall objectives of this thesis are to assess 1) to what degree have soil and vegetation resources
deteriorated, if at all, 2) how do perceptions of environmental change held by local stakeholders correspond to
scientific assessments of present and past environmental conditions in the Ombuga grassland and surrounding
mopane savanna, an important grazing area in central northern Namibia, and 3) how do these relate to national
level assessments? Analysis of the process of developing national level indicators for monitoring of land degradation
in Namibia concluded that specific indicators should be developed on national level, and in some instances
even on regional and local level, instead of the often proposed development of a global set of indicators to be
used everywhere. Reasons for this are: 1) there are no universal causes and effects of land degradation. 2) the participatory
approach, involving stakeholders on both local and national levels gave them ownership of the process
and the resulting indicators, and led to an increased understanding of the concepts of environmental monitoring.
3) the participatory process of developing national indicators taken in Namibia created a common platform for
representatives from various sectors, leading to increased interaction among sectors, an important aspect in most
developing countries, where sectoral approaches predominate. Assessment of local perceptions of environmental
change in and around Ombuga grassland showed that farmers there claimed that overgrazing and low rainfall since
the beginning of the 1990s cause negative environmental changes in the area, confirming findings from national
monitoring. However, results from interviews give a more complex picture of causes and effects of environmental
change, suggesting that 1) decreasing availability of grazing outside the study area, 2) improved access to the area,
3) provision of permanent water supply, and 4) fencing of large areas of the commons, are major factors contributing
to environmental changes in the area. The results suggest that introduction of permanent water supply was the
single most important factor, allowing more people and livestock into the area. Results suggest that assessments
of local knowledge in a relatively small area can provide valuable contributions to development and assessment
of national monitoring initiatives. Investigation of the influence of permanent water points on grazing resources in
Ombuga grassland and surrounding mopane savanna showed that significant grazing induced changes, manifested
by palatable perennial grasses being replaced by less palatable annual grasses, were identified around water points
along a water pipeline as far as 6 km from water points. However, no significant grazing induced changes in grass
composition were observed around privately owned hand dug wells. Private ownership leading to stronger control
of access to traditional wells compared to open access water points along the pipeline seems to be a key factor
preventing over-utilization of grazing resources around the former. Assessment of the usefulness of satellite remote
sensing in detecting observed environmental changes in and around Ombuga grassland shows that the Landsat
TM sensor is capable of identifying bare ground, saltpans and grassland with a fair accuracy. However, there are
apparent difficulties in separating woodland from shrubland, and also shrubland from grassland, using supervised
classification. The results suggest that the use of the soil adjusted vegetation index (SAVI) provides valuable information
about variations of green biomass over time in semi-arid environments. However, because of the strong
influence of underlying soil related to the relatively sparse ground cover in semi-arid environments, it is suggested
that any investigation based on satellite remote sensing in dry environments be supported by a thorough ground
based assessment, taking into account the high spatial and temporal variability of rainfall in these environments.