Satellite view of the Sahel

In spite of the urgent need for improved resource management in the Sahel and the considerable amount of money spent on remote sensing since the early 1970s, there are few operational programmes using remotely sensed data. Against this background CTA has helped to finance a publication entitled Remote sensing of the Sahelian environment: a review of the current status and future prospects, the purpose of which is to provide the basis for decision making on how to allocate resources for research and development for the application of remote sensing. The transfer of technology from research to operation involves multidisciplinary investigation by a team consisting of users as well as scientists. Satellite data applications that are ready for this transition are discussed and illustrated with Landsat and other satellite, colour-enhanced images. Such applications include rainfall estimation, range land production monitoring, food security and early warning systems, savanna fire monitoring, groundwater survey and cartography. Other applications which are included, but which require further substantial research, include crop production monitoring and modeling, evapotranspiration estimation, hydrological catchment modeling, fuelwood estimation and erosion monitoring and prediction. The authors argue that conventional approaches to technology transfer such as training courses and short term, in-country demonstration projects will not, on their own, result in effective and permanent integration of remotely sensed techniques into operational programmes. Long term monitoring of the Sahel is essential if the extent and severity of degradation is to be assessed, but the contribution of remote sensing data needs to be more clearly understood at senior levels of government. Close links need to be established between users of remote sensing technology and research institutes in the Sahel, and the publication of research results needs to be improved. Too many projects end with reports that are not effectively published or widely circulated and are lost within a very short time. The authors suggest that a centralised archive of satellite data should be developed for the Sahel, and that the cost of data to noncommercial activities should take account of the resources to which they have access. This would reduce the current problem of prohibitive data costs. Databases of information derived from processing and analysis of satelitte data should also be established since these also can be of direct use for management and planning in the region. Remote sensing of the Sahelian environment, 128pp, jointly published by The Commision of the European Communities (DG VIII) and CTA ISBN 92 9081 072 6 available from CTARemote sensing of the Sahelian environment, 128pp, jointly published by The Commision of the European Communities (DG VIII) and CTA ISBN 92 9081 072 6 available from CT