Science et changements planétaires / Sécheresse


Remote sensing assessment and monitoring of surface water levels in Loumbila basin (Burkina Faso) Volume 12, issue 1, Mars 2001


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Département de géographie, Faculté des lettres et des sciences humaines, Université de Niamey, Niger.
  • Page(s) : 31-6
  • Published in: 2001

In Sahelian countries, including Burkina Faso, drinking water supplies for rural and urban populations are a major concern. Burkina Faso has decided to build several dams to contain runoff as a means to meet its drinking water needs. A geographical information system (GIS) has been set up to assess surface water areas in Loumbila basin on the basis of diachronic satellite images. The results indicate that the problem of meeting the water requirements of large urban centres such as Ouagadougou could be explained by competition between small and large dams. There is also a problem of insufficient updated data, which limits decision making on surface water resource management. The technique involves image classification based on the assumption that tracts of water have different spectral behaviour than other surfaces. Bodies of water can be extracted from remote sensing images and are subsequently used as a framework fot the GIS on surface water areas. The results of this study highlight that water areas have a special spectral signature expressed clearly in the near and medium infrared zone, which means that they can be classified into separate categories from other sufaces. Supervised classification provide the most controlled results. This technique facilitates monitoring of the number and area of tracts of water.