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AbstractThis study focuses on assessing trends and variability in rainfall of Vhembe District South Africa. Mann-Kendall trend analysis and Sen’s slope estimator are used in determining the changes in the rainfall climatology. The interesting observation is that humid zone and semi-arid zones in the district exhibit different behaviour as far as trend analysis is concerned. Due to diverse rainfall zones, this study provides major evidence that rainfall is highly variable within local settings. The direction of rainfall trend was, in general, downward and statically significant across the semi-arid zone. Statistically significant (downward) trends (95% to 99%) were observed in densely populated areas affected by urban sprawl, depleted vegetation cover, or other human development such as large-scale farming and construction. Generally, changes in rainfall characteristics were mostly observed to start in the mid-1990s. Global climate change influence on the changes in rainfall characteristics was not conclusive. However, the local anthropogenic climate change was obviously one of the causes of changes in rainfall.

AbstractThe impact of anthropogenic climate change on potato production in north east South Africa (Limpopo Province) is studied. Decreasing trend in the area rainfall due to altered dynamics and thermodynamics of rainfall forcing caused by climate change, resulted in rivers and streams to dry. Analysing rainfall time series of the past 50 years (1960-2009), shows that north east South Africa has experienced 60 percent less rainfall than normal and high frequency of drought recurrence. Consequently, farm units declined from 1200 units to 300 units as from 1960 to 2006 affecting dry land potato farming and food security in the area. In this study, aforestation and agroforestry are shown as the cheapest mitigation measure that can increase rainfall and has the potential of reducing greenhouse gas emissions. While suggested adaptation measures include; new potato varieties that require less water and fast maturing or breeding short-season varieties are recommended to contain fast water loss.