Now showing 1 - 3 of 3
- ItemTowards a multi-instrument analysis of atmospheric composition in fire driven ecosystems(2013) Smith, Nadia; De Klerk, Helen Margaret; Schloms, Bennie H. A.; Weisz, Elisabeth; Huang, AllenMuch research has gone into mapping the onset and spatial extent of fires using imager data from space. In addition, much progress has been made in the ability to characterize and trace biomass burning plumes with hyperspectral sounders. In this paper we investigate the feasibility of combining satellite measurements from different instruments to promote an improved and comprehensive understanding of pollution events.
- ItemUsing CLUES to find suitable areas for perennial crops(Cape Land Use Expert System (CLUES), 2009-09) Van Niekerk, AdriaanA web-based spatial decision support system (SDSS), called the Cape Land Use Expert System (CLUES), was developed to demonstrate how the Internet can be used to perform land suitability analysis in the Western Cape. CLUES consists of five components: a land unit database (LUD), knowledge base, inference engine, web map service (WMS) and graphical user interface (GUI). The LUD consists of polygons (land units) and attributes (land properties), while the knowledge base stores each user’s land use requirement rules. These rules are used by the inference engine to rate the suitability of each land unit in the LUD. The result is then mapped by the WMS and presented to the users as suitability maps. Users can direct the entire analysis through a userfriendly GUI. The capabilities CLUES is demonstrated in this paper by applying it to perennial crops. Several factors relating to topography, climate, soil and existing land use is combined by the system to produce a map showing areas of various levels of suitability for producing perennial crops. Similarly, the system can be used to map suitable areas for other crops. It can also be used to support decisions about conservation management and urban planning. Although CLUES was specifically developed to perform land suitability analysis in the Western Cape, the technology can also be applied to other regions and modified for other applications.
- ItemAvian endemism in northeastern tropical Africa(Det Kongelige Danske Videnskabernes Selskab, 2001) Fjeldsa, Jon; De Klerk, Helen MargaretThe avian endemism of Ethiopia and the Horn of Africa was analyzed using a database where all bird distributions in Africa south of the Sahara are recorded in a one-degree grid. Applying a hierarchical classification algorithm, the tropical northeastern Subregion of Africa stands out clearly and can be subdivided in all Ethiopian Highlands Province and the Somalia-Masai. Tana-Jubba and Turkana districts and a Danakil Province. The Horn of Africa Province is associated with the Northern Arid (Sahara) Subregion in this hierarchical classification, although this reflects the replacement of savanna with desert birds more than shared endemism. Although most of the Ethiopian Highland endemics are distributed all over the highland, a more complex pattern of local endemics can also be defined, using a complementarity algorithm. Local endemism is very pronounced among the larks, Alaudidae. The majority of endemics belongs to recently radiated groups, and is mainly related to the fauna of East Africa; however, the fauna of the Sidamo district contains relict elements, two of these of a significant evolutionary age. The pattern of endemism in the birds of northeastern tropical Africa has a number of features in common with patterns found in plants.