The development of a spatial database for research into cryogenic processes and Landforms in Southern Africa

Abstract

The first publication on southern African geocryology in 1944 resulted in a recognition of the potential of cryogenic phenomena in establishing long-term climatic records in the region, leading to a substantial increase in publications and research. Cryogenic studies are concerned with the way frost-induced processes have modified, and continue to modify, the mountain regions of the subcontinent. However, problems exist in interpreting relict forms, while supportive evidence for glacial and periglacial hypotheses are lacking. Insufficient data regarding Quaternary cryogenic activity have resulted in contradicting qualitative interpretations of the palaeoclimate and poor spatial and temporal resolution. It is apparent that there is a need for a more rigorous approach in southern African cryogenic studies as well as a better understanding of relict phenomena and the palaeo-environment. For this purpose a database that acts as a supplementary source and a tool for GIS-based analysis, was compiled. In addition, several glossaries and indices were constructed. The main glossary is a first effort at explaining past terminology usage and providing a terminology basis specifically for current research in southern Africa. Through database manipulation, the spatial distribution of past and present cryogenic phenomena as found in southern Africa, was mapped and it was found that cryogenic features and processes cluster along the Main Escarpment and the Western Cape Mountains. It is not clear if this is the actual situation or whether it represents a bias in the areas investigated. Further, likely regions for glacial ice development and survival and regions for periglacial activity were determined. The extent of relict and contemporary cryogenic activity was also verified. Evaluation of available data indicates that the extent of the cryogenic palaeo-environment did not differ considerably from the current one. An improved understanding of the spatial distribution of both relict and current cryogenic phenomena was achieved. The database represents a contribution towards the reconstruction of the southern African Quaternary environment and supplements current knowledge on the subject. While not necessarily providing solutions to current research problems, the database, combined with the glossaries and indices, will be invaluable in future research and modelling of the Quaternary in southern Africa.