Modeling the impact of climate change on the hydrology of Andasa watershed

Negusu Tarekegn,Yihun Dile,Alemayehu Muluneh,Brook Abate

doi:10.1007/s40808-020-01063-7

Abstract

This paper was aimed to study the impact of climate change on the hydrology of Andasa watershed for the period 2013–2099. The soil and water assessment tool (SWAT) was calibrated and validated, and thereby used to study the impact of climate change on the water balance. The future climate change scenarios were developed using future climate outputs from the Hadley Center Climate Model version 3 (HadCM3) A2 (high) and B2 (low) emission scenarios and Canadian Earth System Model version 2 (CanESM2) Representative concentration pathways (RCP) 4.5 and 8.5 scenarios. The large-scale maximum/minimum temperature and rainfall data were downscaled to fine-scale resolution using the Statistical Downscaling Model (SDSM). The mean monthly temperature projection of the four scenarios indicated an increase by a range of 0.4–8.5 °C while the mean monthly rainfall showed both a decrease of up to 97% and an increase of up to 109%. The long-term mean of all the scenarios indicated an increasing temperature and decreasing rainfall trends. Simulations showed that climate change may cause substantial impacts in the hydrology of the watershed by increasing the potential evapotranspiration (PET) by 4.4–17.3% and decreasing streamflow and soil water by 48.8–95.6% and 12.7–76.8%, respectively. The findings suggested that climate change may cause moisture-constrained environments in the watershed, which may impact agricultural activities in the watershed. Appropriate agricultural water management interventions should be implemented to mitigate and adapt to the plausible impacts of climate change by conserving soil moisture and reducing evapotranspiration.

Highlights

Water resources systems are described by the interactions of various interlinked components that yields numerous economic, environmental, ecological, and social Impacts (Loucks et al 2005). Praskievicz and Chang (2009) reviewed land use/cover as one factor affecting the extent of climate change impact on hydrologic processes
The decrease in mean monthly rainfall ranges between 9.2% and 97.1% in which the highest decrease was predicted by the Canadian Earth System Model version 2 (CanESM2) model in the Representative concentration pathways (RCP) 8.5 scenario in the middle of the century
The future climate of the Andasa watershed was studied by downscaling Global Climate Models (GCMs) outputs using the Statistical Downscaling Model (SDSM version 4.2)

Summary

Introduction

Water resources systems are described by the interactions of various interlinked components that yields numerous economic, environmental, ecological, and social Impacts (Loucks et al 2005). Praskievicz and Chang (2009) reviewed land use/cover as one factor affecting the extent of climate change impact on hydrologic processes. Water resources systems are described by the interactions of various interlinked components that yields numerous economic, environmental, ecological, and social Impacts (Loucks et al 2005). Praskievicz and Chang (2009) reviewed land use/cover as one factor affecting the extent of climate change impact on hydrologic processes. The climate change effects on society and natural resources rest on the response of the hydrological cycle and further to warming (Marvel and Bonfil 2013). According to Trenberth et al (2000), doubling of C O2 emission globally may expedite the hydrological cycle by 10% through changes in the evaporation and rainfall regime. Studies predict that the rainfall could decline by 10% by the mid-century in the south of the Sahara, which will cause water scarcity (Nyong 2005). Evidenced by historical data and climate projections, freshwater resources become vulnerable and highly affected due to climate change (Bates et al 2008)

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