Fig. 2. Outbreaks of locusts, drought, and famine against the background of historical trends for population and rainfall in Niger in the twentieth century. Data sources for rainfall, from rain gauge stations across West Africa (L’Hôte et al. 200, Table 1). The “Sahelian annual rainfall index” reflects differences from the mean annual rainfall measured over the long term (1896 to 2000). Sources: Lahmeyer 2006 (population, Y-axis left side), Raynaut 1997 (drought and famine), and MacDonald 1986 (locust outbreaks data). Note: rainfall data aggregated to regional levels do not reflect more local and patchy patterns of rainfall, water scarcity, and famine.