Using CLUES to find suitable areas for perennial crops
A 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.