Future changes in precipitation, evapotranspiration and streamflows in the Mono Basin of West Africa

Lamboni Batablinlè,Kodja Domiho Japhet,Amoussou Ernest,Lawin E Agnidé,Vissin Expédit

doi:10.5194/piahs-384-283-2021

Abstract

Abstract. The impact of climate change on precipitation and water availability is of major concern for policy makers in the Mono Basin of West Africa, whose economy mainly depends on rainfed agriculture and hydropower generation. The objective of this study is to project rainfall, flows and evapotranspiration (ET) in the future period and understand their changes across Mono River Basin. Observed data were considered for the historical period 1980–2010, and a Multi-model ensemble for future projections data of eight selected Regional Climate Models under RCP 4.5 and RCP 8.5 over the periods 2011–2100 was used. The GR4J model was used to simulate daily flows of the Mono watershed. The ensemble mean shows a decrease and increase streamflows between −54 % and 42 %, −58 % and 31 % under the RCP4.5, RCP8.5 scenario, respectively. The greatest decreases of high flows is projected to occur in the near term under RCP8.5, whereas the greatest decrease of low flows is projected to occur in the long term under the same RCP. For the rainfall and ET, the both scenarios (RCP4.5 and RCP8.5) predict an increase of ET while the rainfall will decrease. The results of this study of would be very useful in the choice of management and adaptation policies for water resources management.

Highlights

The future projection of climate change reported by the 5th Intergovernmental Panel on Climate Change (IPCC) assessment indicated that the global mean temperature will continue to rise for the rest of 21th century, and the amplitude for 2081–2100, relative to 1986–2005 ranges from 0.3 to 4.8 ◦C, under four Representative Concentration Pathways (RCP) scenarios (IPCC, 2007)
The impact of climate change on precipitation and water availability is of major concern for policy makers in the Mono Basin of West Africa
3.1 Results 3.1.1 Projected changes in ET and the rainfall The changes relating to the evapotranspiration (ET) and rainfall between the future and the historical period are shown in Proc

Summary

Introduction

The future projection of climate change reported by the 5th Intergovernmental Panel on Climate Change (IPCC) assessment indicated that the global mean temperature will continue to rise for the rest of 21th century, and the amplitude for 2081–2100, relative to 1986–2005 ranges from 0.3 to 4.8 ◦C, under four Representative Concentration Pathways (RCP) scenarios (IPCC, 2007). An increase in temperature results in a higher evapotranspiration (ET) demand and will, in combination with a decrease in precipitation, severely stress the water resources in the region. Climate change and increasing climate variability might add to these trends and further degrade the availability and quality of water and arable land (Giertz and Diekkrüger, 2003). The impact of climate change on precipitation and water availability is of major concern for policy makers in the Mono Basin of West Africa. In order to proffer solutions to the problems associated with water resources management within the Mono, there is a need to understand the relationship between these variables at the basin’s scale

Objectives

Results

Conclusion