Thesis (MSc (Geography and Environmental Studies))--University of Stellenbosch, 2005. / 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.

A sustainable society is a society that satisfies its resource requirements without endangering the sustainability of these resources. The mineral endowment on the African continent is estimated to be the first or second largest of world reserves. Therefore, it is recognised that the African continent still heavily depends on mineral exports as a key contributor to the gross domestic product (GDP) of various countries. These mining activities, however, do introduce primary and secondary environmental degradation factors. They attract communities to these mining areas, light and heavy industrial establishments occur, giving rise to artisanal activities. This study focussed on satellite RS products as an aid to a mine’s operations and the monitoring of its environment. Effective operational mine management and control ensures a more sustainable and profitable lifecycle for mines. Satellite based RS holds the potential to observe the mine and its surrounding areas at high temporal intervals, different spectral wavelengths and spatial resolutions. The combination of SAR and optical information creates a spatial platform to observe and measure the mine’s operations and the behaviour of specific land cover and land use classes over time and contributes to a better understanding of the mining activities and their influence on the environment within a specific geographical area. This study will introduce an integrated methodology to collect, process and analyse spatial information over a specific targeted mine. This methodology utilises a medium resolution land cover base map, derived from Landsat 8, to understand the predominant land cover types of the surrounding area. Using very high resolution mono- and stereoscopic satellite imagery provides a finer scale analysis and identifies changes in features at a smaller scale. Combining these technologies with the synthetic aperture radar (SAR) applications for precise measurement of surface subsidence or upliftment becomes a spatial toolbox for mine management. This study examines a combination of satellite remote sensing products guided by a systematic workflow methodology to integrate spatial results as an aid for mining operations and environmental monitoring. Some of the results that can be highlighted is the successful land cover classification using the Landsat 8 satellite. The land cover that dominated the Kolomela mine area was the “SHRUBLAND/GRASS” class with a 94% coverage and “MINE” class of 2.6%. Sishen mine had a similar dominated land cover characteristic with a “SHRUBLAND/GRASS” class of 90% and “MINE” class of 4.8%. The Pléiades time-series classification analysis was done using three scenes each acquired at a different time interval. The Sishen and Kolomela mine showed especially changes from the bare soil class to the asphalt or mine class. The Pléiades stereoscopic analysis provided volumetric change detection over small, medium, large and recessed areas. Both the Sishen and Kolomela mines demonstrated height profile changes in each selected category. The last category of results focused on the SAR technology to measure within millimetre accuracy the subsidence and upliftment behaviour of surface areas over time. The Royal Bafokeng Platinum tailings pond area was measured using 74 TerraSAR-X scenes. The tailings wall area was confirmed as stable with natural subsidence that occurred in its surrounding area due to seasonal changes of the soil during rainy and dry periods. The Chuquicamata mine as a large open pit copper mine area was analysed using 52 TerraSAR-X scenes. The analysis demonstrated significant vertical surface movement over some of the dumping sites. It is the wish of the researcher that this dissertation and future research scholars will continue to contribute in this scientific field. These contributions can only assist the mining sector to continuously improve its mining operations as well as its monitoring of the primary as well as the secondary environmental impacts to ensure improved sustainability for the next generation. / Environmental Sciences / M. Sc. (Environmental Science)