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The protection and the sustainable management of soil resources in Africa are of paramount importance, particularly in the context of the uncertain impact of climate change and the increasing pressures of human activities. From the perspective of a policy-maker interested in topics such as food security and land degradation in Africa, this situation requires up-to-date and relevant soil information at regional and continental scales. To provide timely and reliable information on soils at synoptic scales, moderate and coarse spatial resolution satellite data offer many possibilities. The paper reviews how a range of multispectral, thermal infrared, passive microwave and active microwave spaceborne sensors can be used in the delineation of soil units, as well as in the assessment of some of their key properties and threats to soil functions from pressures such as water and wind erosion, landslides and salinization. The paper shows that remotely sensed data can be used for mapping soils in Africa but often need to be combined with ancillary data and field observations in order to be effective. Remote sensing is shown to be a key component of the emerging discipline of digital soil mapping. [ABSTRACT FROM PUBLISHER]

Dambos are shallow, seasonally waterlogged, tropical and subtropical African wetlands. Their importance, through their role in agriculture and water supply to downstream river networks, has been widely acknowledged. As a result, much research has been conducted on the hydrological functions of dambos and their hydrogeological structures, in an attempt to better understand, utilize and manage this regionally ubiquitous landform. However, these studies have resulted in little consensus regarding the geomorphology of dambos, their hydrological regimes and the hydrogeological model that drives those regimes. This review paper, focusing on dambo hydrology, hydrogeology and their primary determinants, highlights the key issues of the debate and draws some overriding conclusions from the divergent literature. Five hypotheses are proposed based on these conclusions, in an attempt to focus future dambo research efforts. [ABSTRACT FROM AUTHOR]

The article discusses the pollen analysis conducted in East and Southern Africa which is associated with the vegetation and climatic changes in several localities in the area. It focuses on theoretical concerns as to how the tropics and subtropics had responded to the expansions and contractions of ice sheets in the Northern Hemisphere. It is stated that the work defines the very essence of Quaternary palaeoenvironmental reconstruction and demonstrates how fieldwork supported by meticulous and painstaking laboratory and statistical analysis can reveal a scientifically robust and insightful history of the physical environment. The study was considered crucial to the resolution of a fascinating complex of tropical and subtropical environmental changes in the African continent.