Title:

Characteristics of local groundwater recharge cycles in South African semi-arid hard rock terrains: Rainfall–groundwater interaction

Publication Year:
2012
Abstract:

The semi-arid and arid regions occupy almost two-thirds of South Africa and fall in the winter and summer rainfall zones of the sub-continent. The annual rainfall patterns can be regarded as intermittent with a significant spatial variability due to the unique winter/summer synoptic systems manifesting over Southern Africa. Summer rainfall events indicate that episodic wet periods, consisting of up to 8 consecutive days, may contain falls that contribute to almost 45% to 60% of the total annual rainfall of an area; associated with relatively higher rain rates (1.5 to 10 mm·h-1). Hyetograph-hydrograph time-series data sets, however, indicate that episodic rainfall events are responsible for rapid, but sustainable groundwater recharge events. The recurrence rate of these events in the semi-arid and arid regions is still low and aquifer storage-recharge is therefore not an annual event. Keywords: semi-arid and arid regions, unique rainfall patterns, episodic wet periods, hydrogeological profile, fractured hard rock terrain, direct recharge mound, aquifer storage recharge, recharge recurrence rate.

Publication Title:

Water S.A.

Volume:
38
Issue:
5
Pages:
747-754
Item Type:
Journal Article
Language:
en