Spatial monitoring of natural resource condition in Southern Africa
South Africa’s natural vegetation and soils, which are essential resources for agricultural practices, are becoming degraded. Natural resource disturbances can also cause extensive harm to local communities and their economies. To allow successful natural resource monitoring, there is an urgent need for integrated GIS spatial data and development of remotely sensed indicators of key ecosystems processes. Satellite remote sensing provides the most cost-effective and reliable tool for generating these spatial data. The main objective of the study is, therefore, to develop and evaluate methodologies for assessing, mapping and monitoring the condition of natural resources in southern Africa with the aid of remote sensing and GIS. The resulting integrated spatial framework represents methodologies for, firstly, identifying and accessing vegetation and soil parameters on a gradient from pristine to degraded condition; secondly, identifying, assessing, processing and modelling GIS and remotesensing spatial data to derived degradation maps, which identify rangeland condition and woody cover classes and, thirdly, comparing two satellite remote-sensing sensors (LANDSAT ETM and MODIS) and making statements of degradation. This approach could make an integrated spatial framework comprehensive in its considerations of provincial degradation mapping and robust enough to be used for monitoring on a national scale. By acquiring spatial and non-spatial data in a quantitative logically robust but accurate manner, integrated spatial frameworks provides the structure for combining specialized information as well as for analysis in an effective management programme. This could guide rangeland managers in assessing, mapping and monitoring of natural resources in a scientifically acceptable way. All of these factors emphasise the need for the development of a national rangeland monitoring strategy and monitoring system.