**3. Conclusions**

This study assessed of climate change impacts on the seasonal river discharge in two rivers in West Africa, including the Niger, and the Hadejia-Jama'are Komadugu-Yobe Basin (HJKYB). For this analysis, we set up and validated the PCR-GLOBWB model at the selected gauging stations of each river basin. Climate change impacts on river discharge seasonality were examined with five bias-corrected GCMs, collected from the "ISIMIP" project framework. The PCR-GLOBWB model validation performance was satisfactory in its performance for all statistics at each of the basins (**Table 5**). The five bias-corrected GCMs were then used to force PCR-GLOBWB in the reference and far-future period. Based on our results, Climate change will influence the seasonal regime of discharge of the selected rivers, i.e., the timing and the magnitude of flows. The findings of this study reveal that there are little differences in SI between the present and the far-future. However, climate change will affect the temporal seasonality pattern. At the gauges of the Niger, Yobe, and Jamaare rivers, decreasing discharge volumes when the high-flow period begins

*Future Climate Change Impacts on River Discharge Seasonality for Selected West African River… DOI: http://dx.doi.org/10.5772/intechopen.99426*

(typically May–July) is expected in the far future. This is explained by the delayed start of the raining season. All four rivers steadily project increasing river discharge at the end of the high-flow season (typically August–November) during the peakflow period. In this basins, increased precipitation amounts result in a projected increase in discharge volumes.

Adequate storage has to be made for the increased high-flow season; otherwise, water scarcity may disturb agricultural production regardless of the overall increases in annual water availability. Even though increased discharge volumes can be considered advantageous to agricultural productivity, this can only be achievable when there are provisions to store excess flow for later use. When there are no/sufficient existent storage structures, much of the additional flow is lost. Increased high flow may destroy croplands through flooding. Increased discharge volumes could lead to floods and destroy crops over a vast expanse of land. Excess water could reduce plant development, delay farm operations, make the soil soggy and unworkable. The projected increased discharge for the HJRB could help revive the currently shrinking Lake Chad basin. The findings of this study show that climate change will significantly impact the hydrological regimes of the two basins examined, with significant consequences for water resource planning and management. Finally, the methods used in this study may prove helpful for future research examining the effects of climate change on the hydrology of different regions.
