AUGMENTATION DE LA PLUVIOMÉTRIE ET VULNÉRABILITÉ DES MARAICHERS DE LA CUVETTE DE GUIDIMOUNI (ZINDER, NIGER)

Increased rainfall and market gardeners’ vulnerability in the Guidimouni Basin (Zinder, Niger). The increase in rainfall observed in the Central Sahel since the 1990s has triggered a hydro-sedimentary dynamic which affects the agricultural development of the oasis basins of eastern Niger. This paper aims at analyzing the consequences of this increase in the income of market gardeners in the Guidimouni Basin. The methodological approach of the study draws on the following three activities: i) the collection and analysis of rainfall data; ii) the in situ and cartographic monitoring of hydro-sedimentary processes; and iii) the analysis of agricultural practices and income using a questionnaire administered to 71 farmers and a semi-directive interview guide submitted to the managers of the technical governmental services, local authorities, and key informants. The results showed that the increase in rainfall caused a densification of the hydrographic network and a multiplication of sources of outcropping of the water table. Due to the mixed input, a huge quantity of water flows into the basin, causing the permanent flooding of nearly 75 ha of the exploited plots, in less than a decade. As a result, the proportion of those who hold more than 20 plots has fallen sharply, from 44.4% in 2012 to 1.4% in 2022. The extension and permanence of floods are at the origin of the establishment of a new order preferably in which the outlying plots are the most coveted. Furthermore, exposed plots are frequently buried, to a thickness of 20–40 cm, by sand which is poor in organic matter and nutrients; as a consequence, there is the superficial impoverishment of the soil and the increase in production costs. For these reasons, producers no longer see the improvement in rainfall as an opportunity. The planning and development of adapted crops, such as rice, seem suitable for facing the aforementioned constraints and challenges.