Spatial mapping of socio-ecological vulnerability to environmental change in Southern Africa

Aggregate measures that capture multiple aspects of socio-ecological vulnerability in a single or small number of vulnerability indices can be used to produce vulnerability maps that act as powerful visual tools to identify those areas most susceptible to future environmental changes. Such indices are easily communicable and offer valuable guidance to policymakers and investors, providing insights as to where more targeted research or policy interventions can address current challenges and reduce future risks. However, such aggregation inevitably reduces the richness of information provided by the suites of individual vulnerability indicators on which the maps are based. This trade-off between information richness and information communicability is a constant challenge in the quantification and communication of complex phenomena such as socio-ecological vulnerability. This paper presents an exploratory analysis using Principal Component Analysis (PCA) techniques as a means of creating and comparing spatially-explicit aggregate indices of socio-ecological vulnerability. Vulnerability indices are produced for the Southern Africa Development Community region based on published biophysical and socio-economic data and mapped at a 10 arc minute resolution. The resulting vulnerability maps are particularly informative as they indicate the regional spatial variability of four statistically independent components of socio-ecological vulnerability. Such informationrich vulnerability indices represent a potentially useful policy tool for identifying areas of greatest concern in terms of both the relative level, and the underlying causes and impacts of, socio-ecological vulnerability to environmental changes across broad spatial scales.