South African National Land-Cover Change Map

Fritz Schoeman, Terence Newby, Mark Thompson, Elzie Catharina Van den Berg

Abstract


Globally, countries face a changing environment due to population growth, increase in agricultural production, increasing demand on natural resources, climate change and resultant degradation of the natural environment. One means of monitoring this changing scenario is through land-cover change mapping. Modern Earth Observation (EO) technologies, especially those EO datasets comprising a multi-year data archive, lend themselves to land-cover change studies. This project used a practical and cost-effective approach for monitoring land-cover change at a national scale over time using EO data. The primary objective of this study was to determine the extent of transformed landscape change within South Africa over a 10-year period between 1994 and 2005. The project used three generalised land-cover datasets (for 1994, 2000 and 2005) and quantified the change between these assessment years. The land-cover change was based on five classes: Urban, Mining, Forestry, Cultivation and Other. The standardised five class land-cover datasets representing the three assessment years were compared within a uniform national grid, based on 500 m x 500 m cells. The land-cover allocated to each cell in each year represented the spatially dominant land-cover within that cell, as determined from the original land-cover datasets. Various spatial modelling procedures were used to ensure compilation of comparable and standardised land-cover class allocations to each cell for each year, prior to any year-on-year change analyses. The results indicate that at a national level there has been a total increase of 1.2% in transformed land specifically associated with Urban, Cultivation, Plantation Forestry and Mining. This represents an increase from 14.5% transformed land in 1994 to 15.7% in 2005 across South Africa.


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