Date of Award

1-1-2019

Publication Type

Master Thesis

Degree Name

M.A.Sc.

Department

Civil and Environmental Engineering

Keywords

Climate Change Impacts, Hydrology, Kruger National Park, Regional Climate Model, South Africa, SWAT

Supervisor

Tirupati Bolisetti

Rights

info:eu-repo/semantics/openAccess

Abstract

Olifants River watershed one of the largest river basins in South Africa, which is home for one of the most important natural parks in the world, Kruger National Park (KNP). The activities in this watershed generate 6% of the Gross Domestic Product. It requires a minimum amount of water termed as ecological reserve for sustaining the ecohydrology which is often jeopardized due to the water scarcity. The objective of this study is to assess the impact of climate change on the hydrologic regime in the Olifants River watershed.A hydrological model is developed using Soil and Water Assessment Tool (SWAT). The model was calibrated using multisite data (2003-2008) and validated (2009-2012) by comparing the simulated results with the observed streamflow data. The Nash Sutcliffe Efficiency (NSE), Kling Gupta Efficiency (KGE) and Percent Bias (PBIAS) for the Mamba (B7H015) flow station are found to be 0.60, 0.80, -2.21% and 0.56, 0.63, -0.47% for the calibration and validation period, respectively. The same are 0.52, 0.65 19.26% and 0.74, 0.81, 8.82% for the calibration and validation periods for Blyde (B6H005) station.The calibrated model is forced with the bias corrected future climate data extracted from Coordinated Regional Climate Downscaling Experiment (CORDEX) for nine climate ensembles under moderate (rcp4.5) and high (rcp8.5) emission scenarios for mid-century (2041-2070) and end-century (2071-2100) periods. The results indicate that the annual average temperature is projected to increase by 1.7°C to 4.6°C by the end century compared to the base period (1985-2005). The mean annual precipitation is projected to decrease in the future by 12-29%. The minimum flow (0.5 m3/s) availability at B7H015 for the ecological reserve of KNP would decrease 2-12% in the future.

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