Assessment of the risk of desertification in the municipality of Tanda (Niger)

The rural municipality of Tanda, with its extended rainy season and crossed by the Niger River, is an attractive area. Interactions with the indigenous population are putting pressure on vegetation regeneration. To assess the risk of desertification, we analyzed daily rainfall data from 1931 to 2007, calculated the differential vegetation indices (NDVI and SAVI) from Landsat images (1973, 1984, 1992, and 2002), and discussed the results. Finally, the Google Earth image is compared with the 1975 aerial photograph. The climate analysis shows interannual variation in precipitation with alternating dry and wet periods. A comparison between the years 1984/1973 and 2002/1992 shows a downward trend in vegetation indices despite a return to wetter conditions in 1992 and 2002. Between 1992/1984 and 2002/1973, the results show an increase in vegetation indices due to rainfall during wet periods (1992 and 2002), reflecting the difficulty of comparing different climatic conditions.