Beschreibung:
<jats:title>Abstract</jats:title>
<jats:p>The expansion of irrigated croplands throughout the 20th century boosted global agricultural productivity, yet limited improvement occurred in sub-Saharan Africa where many irrigation schemes and policies under-delivered. We mapped the distribution of croplands under active irrigation between 1986 and 2020 for one of Africa’s largest and most important transboundary river basins—the Senegal River Valley; using Landsat imagery with a random forest classifier and hidden Markov Model. We document two distinct epochs of irrigation development. Initially, a period of stagnation where less than 900 ha yr<jats:sup>−1</jats:sup> was added, lasting until 2008. Followed by a boom phase of rapidly expanding intensively irrigated production with ∼9,000 ha yr<jats:sup>−1</jats:sup> added for the last 12 years. These epochs overlap with national agricultural policy frameworks: the 1980s laissez-faire policies limited state involvement in agriculture and promoted Asian imports; followed by a more interventionist period focused on promoting domestic production following the food price crisis of 2008.</jats:p>