Projected Changes in the Rainfall Annual Cycle over the Senegal River Basin Using CMIP5 bias-Corrected Simulations

Moussa Diakhaté^{1, 2,} , Mamadou Lamine Mbaye³, Ibrahima Camara² and Mamadou Baïlo Barry^{1, 4}

¹Ecole Supérieure des Sciences et Techniques de l’Ingénieur (ESTI), Université Amadou Mahtar Mbow (UAM), Dakar, Senegal

²Laboratoire de Physique de l’Atmosphère et de l’Océan – Siméon Fongang (LPAO-SF), Ecole Supérieure Polytechnique (ESP), Université Cheikh Anta Diop (UCAD), Dakar-Fann, Senegal

³Laboratoire d’Océanographie, des Sciences de l’Environnement et du Climat (LOSEC), UFR Sciences et Technologies, Université Assane Seck de Ziguinchor (UASZ), Ziguinchor, Senegal

⁴Institut Supérieur des Sciences de l’Éducation de Guinée (ISSEG), Conakry, Guinea

Cite this paper:
Moussa Diakhaté, Mamadou Lamine Mbaye, Ibrahima Camara and Mamadou Baïlo Barry. Projected Changes in the Rainfall Annual Cycle over the Senegal River Basin Using CMIP5 bias-Corrected Simulations. American Journal of Environmental Protection. 2022; 10(1):41-46. doi: 10.12691/env-10-1-5

Abstract

This study provides a synthetic analysis of the current state and the future changes in the rainfall annual cycle over the Senegal river basin (SRB) using observed data from the SIEREM (Système d’Informations Environnementales sur les Ressources en Eau et leur Modélisation) database, and 29 CMIP5 (Climate Model Intercomparison Project 5) simulations. The output of the models are bias-corrected using the observational data as a reference. This process revealed the added value of the bias correction that has reduced considerably the biases in the amplitude of the rainfall annual cycle. With the corrected simulations, future changes (by 2050 and 2100) in the seasonal variation of rainfall are analyzed under two scenarios (RCP4.5 and RCP8.5), and over each of the 7 sub-basins (SB) of the SRB. A decrease of about 20% in rainfall amount over the first phase of the monsoon season (May-August) is expected under the scenario RCP8.5, leading to a displacement of the monsoon peak from August to September. This change is shown to affect the least humid SBs (SB 3-7).

Keywords:
Senegal River Basin rainfall seasonal cycle climate models bias correction future projections

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