Author(s)

Batablinlè Lamboni¹, Lawin Agnidé Emmanuel², Celestin Manirakiza¹, Zakari Moussa Djibib³

¹Institute of Mathematics and Physical Sciences, University of Abomey-Calavi, Abomey-Calavi, Benin.
²Applied Hydrology Laboratory, University of Abomey-Calavi, Abomey-Calavi, Benin.
³Faculty of Sciences, Department of Mathematic, University of Lomé, Lomé, Togo.

This study assessed the rainfall trends and changes over Mono river basin under the highest greenhouse gas emission scenario RCP8.5. Simulations of eight regional climate models (RCMs) provided by Africa-CORDEX program were considered. To analyze the performance of a set of regional climate models, the MBE (mean bias error), the RMSE (root mean square error), the volume bias (VB), correlation coefficient (R²) and the t-Test statistics were calculated. The precipitation concentration index (PCI), Mann-Kendall trend test, Theil-Sen’s slope estimator (β), and relative percentage change methods were also adopted for data analysis. Changes from the baseline period 1981-2010 were computed for far future (2061-2090 and 2071-2100). As results, the analysis herein highlighted the multi-models’ mean ability to simulate the Mono river basin rainfall adequately. Two distinct patterns emerged from the calculated PCI indicating that stations in southern basin will have moderate, irregular, and strongly irregular rainfall concentrations, whereas stations in northern basin will have irregular and strongly irregular rainfall concentrations. Significant declining in the rainfall was detected in most stations for the future period. The evolution of the monthly average rainfall amounts will be broadly characterized by a decrease and increase between 32.4 and 12% with late rainy seasons. It is understood that future changes in rainfall distribution and trends will affect the availability of water for crops, which should affect the productivity of rain fed agriculture.

Future Rainfall, Variability, Trend, Change, Mono Basin

Lamboni, B. , Emmanuel, L. , Manirakiza, C. and Djibib, Z. (2019) Variability of Future Rainfall over the Mono River Basin of West-Africa. American Journal of Climate Change, 8, 137-155. doi: 10.4236/ajcc.2019.81008.