Variability of Future Rainfall over the Mono River Basin of West-Africa

Abstract

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 (R 2) 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.

Analysis of Local Rainfall Characteristics as a Mitigation Strategy for Hydrometeorology Disaster in Rain-fed Reservoirs Area

“…Rainfall volatility analysis is based on calculating the coefficient of variation (CV), the standardized precipitation anomaly index (SPAI), and the precipitation concentration index (PCI) [17], while the trend is analyzed by using Mann-Kendall (MK) test [2,[18][19][20][21]. SPAI was used to display quantitative analysis related to changes in rainfall and identify potential floods or droughts [8,22], where rainfall is seasonal and periodic in a monsoon-dominated climate context [23], like the climate in Indonesia.…”

“…Table 4 present the annual PCI values based on monthly rainfall data each year. The classification criteria using the criteria introduced by Oliver in 1980 [21] are presented in Table.5. The average PCI in the 2007-2018 periods was 19.67, which was classified as a high concentration of rainfall.…”

Extreme Rainfall and Temperature Changes Assessment on late-twenty-first-century over the Mono River Basin, Togo (West-Africa)

“…The analysis of the maximum duration of wet sequences shows a sharp decline in the Mono basin (Batablinlè et al, 2018). Ly et al (2013) showed a gradual decrease in the maximum duration of the number of wet sequences in West Africa since 1960. Our work shows that such an evolution diagnosed on the present climate is likely to persist in the future.…”

“…This study area has already been described by certain authors (Batablinlè et al, 2018;Lamboni et al, 2019b).…”

Validation of Three Satellite Precipitation Products in Two South-Western African Watersheds: Bandama (Ivory Coast) and Mono (Togo)

“…The lowest rainfall is about 300 mm/year recorded in Sahel area and the highest value is obtained at mountainous area with total precipitation amount about 2400 mm/year. The climate system over Mono and Bandama river basin are presented by Lamboni et al [16] and Soro et al [17], respectively. The northern part presents unimodal rainfall regime while the central and southern part show bimodal.…”