Drought impact detection on crops in the Sahel:a case study for the 2009 campaign.

Late in the ,,70s, as a consequence of recurrent droughts occurred in West and East Africa, the famine struck millions of people imposing to national authorities and to the international community to coordinate efforts and to develop Early Warning Systems to limit the dramatic impact on the affected population. Between 1980 and 2007 the EWS concepts evolved passing from a stand-alone famine oriented analysis tool to a component either of a comprehensive food security information system or of a disaster prevention system. To early detect areas where drought could affect crop production and food security the "ZAR - Zones at Risk" agrometeorological software, based on Meteosat Second Generation rainfall estimation and Global Forecast System rainfall forecast images, has been developed. ZAR is presently exploited by the National Meteorological Services in various Sahelian countries and by Agrhymet Regional Center for regional assessments. The integration of ZAR impact maps (crop onset, soil water availability, crop conditions and phenological phases in a settled time) with the surveys data has improved National Meteorological Services capability in predicting and identifying areas where drought conditions would jeopardize crop production and consequentially quantify the population involved. The ZAR products are validated with the ground data collected in several agricultural campaigns. The analysis of the cropping season 2009 and the impact of localized droughts in terms of area and groups at risk for food security are presented. In particular, the dimension of crop production reduction and its geographical areas distribution over the Sahel have been assessed with the identification of the most vulnerable productions systems.