The following are sections from Ugu Lwethu - Our Coast (Goble et al., 2014). Contributions are from a range of authors all of whom are credited per section.
The coast is largely defined by its physical characteristics which together create the environmental template that provides rich natural, social and economic resources. Our KZN coast is shaped by its geological, climatic and oceanographic characteristics, which makes it a complex and unique environment.
Two major sea currents surround the subcontinent of southern Africa, namely the cold Benguela and the warm Agulhas Current. The Agulhas Current, which flows southwards along the eastern and southern coasts, is fed by water from the tropics. The current’ s warm water is a major influencing factor contributing to the climate of the KZN coastal region, giving it its humid subtropical character. The climate is more formally described as mild-temperate with summer rain and an indistinct dry season.
Photo: Kirsty Bowles
Photo: Jennifer Olbers
Geology and Geomorphology
In terms of the geology of KZN, the coast can be readily divided into two zones, separated by the Thukela River. The southern section is made up of bedrock, with a thin cover of soft sediments. This part of the coast consists of a series of rocky headlands with intervening sandy beaches, often across the mouths of estuaries. The rocky hinterland of the southern coast rises steeply to the Drakensberg escarpment, allowing
dozens of rivers to flow to the sea. North of the Thukela River, the coast is composed of soft sediments that were deposited during the past million years; hard rock is virtually absent. Consequently, the northern part of the KZN coast has beaches that extend for kilometres, occasionally broken by tidal inlets and headlands of cemented beach and dune sand.
KZN has a relatively straight, northeast trending coastline, divided into gentle bays by short, low headlands or rocky outcrops. The coast is bathed by the warm waters of the Indian Ocean, with the strong Agulhas Current flowing in a south-westerly direction,
transporting warm water polewards.
The Physical and Coastal Environment PDF