Precipitation chemical composition and atmospheric nitrogen deposition in the lake Victoria catchment (East Africa)


In the framework of the CASAQUE and INMS projects, measurements of the precipitation chemical composition were initiated in 2017 over a two-year period in Mbita (Kenya). This work emphasized that the nitrogenous contribution is predominant and represent about half of the total precipitation chemical content. The annual nitrogen wet deposition flux is about 6 to 8 kgN.ha-1 .yr-1 . This study constitutes a unique database for the INMS demonstration region of East Africa documenting for the first time the nitrogen deposition in the lake Victoria basin.

In Africa it is expected that Nitrogen (N) deposition to ecosystems will increase by 50% by 2100, especially through wet deposition, due to changes in climate, land uses and atmospheric concentrations. Currently, experimental studies conducted in the African continent remain scarce and scattered. Furthermore, the impact of nitrogen management and nitrogen deposition in Africa has become a major societal challenge related to food security, global change and biodiversity loss.