Enhancement of rainfall and runoff upstream from irrigation location in a climate model of West Africa

https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1002/2014WR015592This study investigates the impact of potential medium-scale irrigation (about 60,000 km2) on the climate of West Africa using the MIT Regional Climate Model. We find that irrigation at this scale induces an atmospheric response similar to that of large-scale irrigation (about 400,000km2) which was considered in our previous theoretical study. While the volume of water needed for large-scale irrigation is about

230–270 km3, the medium-scale irrigation requires about 50 km3, and the annual flow of the Niger river in the relevant section is about 70 km3. The remote response of rainfall distribution to local irrigation exhibits a signifi- cant sensitivity to the latitudinal location of irrigation. The nature of this response is such that irrigation from the Niger River around latitude 18