The influence of the Benguela Current, combined with predominantly southerly winds, is largely responsible for the cool climate at the coast and the prevalence of fog during the nights and in the morning. (Ref1)
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HOLGAT RIVER ESTUARY: Hydrodynamics and mouth dynamics |
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Hydrodynamics | ||||
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The Namaqualand coastline is under influence
of the northflowing Benguela Current with characteristic upwelling of
cold nutrient-rich water. Upwelling is enhanced during summer, by
the prevalence of southerly to south-easterly winds, which tend to
move inshore surface water away from the coast, thereby making room for
the deeper-lying cooler water (Heydorn and Tinley 1980).
The influence of the Benguela Current, combined with predominantly southerly winds, is largely responsible for the cool climate at the coast and the prevalence of fog during the nights and in the morning. (Ref1) |
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Prevailing swells approach the coast predominantly from a sout-westerly or south south-westerly direction. They reach a height oof over 1,6m for 50 percent of the time in the nearshore area, as measured at Oranjemund, 56 km to the north of the Holgat (J. Rossouw pers.comm). | ||||
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Wave frequency at Buchu Bay, 29km to the north of the Holgat, is 10-15 seconds for 95 percent of the waves (Ashby, Harper and Van Schaik 1973). | ||||
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The wave and swell patterns of the West Coast play a major role in the longshore distribution of marine sediments, erosion and deposition phenomena and hence also in beach and dune formation (Tankard and Rogers 1978). (Ref 1) | ||||
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Mouth dynamics | ||||
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The mouth of the Holgat is situated approximately 56 km south-east of the Orange River mouth and 35 km north of Port Nolloth.(Ref 1) | ||||
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Useful links | |||||