Assessment of the possible relationships and influence of climate variability and water flow on water quality in major rivers of the Kruger National Park

Abstract

Water is a vital resource required by all living organisms for their continued survival, however current trends indicate that water resources, especially in semi-arid regions such as South Africa, are becoming more stressed alongside the prevalence of climate change. The Kruger National Park (KNP), a prime conservation area in the east of South Africa is no exception to these challenges and has, for several decades, been subject to persistent water quality and flow issues, putting vulnerable ecosystems at risk. This research undertook to establish the historic trends and current state of water quality of the seven major rivers that flow through the park, as well as to determine the influence of regional climate variability upon these water resources. Mann-Kendall (MK) Time Series Trend Analyses were compiled to determine temporal water quality trends for the rivers and revealed that approximately 75% of all water quality observations - indicated by eleven parameters - exhibited a deteriorating trend over time. Of particular significance were the ions responsible for salinisation and wastewaters responsible for microbial pollution. Acidification was a secondary concern for many of the water quality monitoring sites. Spearman’s Rank Correlation Analyses were compiled to establish the relationships between various climate, water quality and water flow parameters. The results indicated that variations in water quality were most strongly associated with climate variability at monitoring sites further south (e.g.: Crocodile and Sabie Rivers) due to a higher average annual rainfall impacting water flow, and therefore the dilution capacity of the rivers. Subsequently, various solutions were recommended, involving a combination of political, environmental and management strategies and activities to address these water quality issues and ensure good quality water for the KNP well into the future.