On-line version ISSN 1816-7950
Print version ISSN 0378-4738
Water SA vol.34 n.1 Pretoria Jan. 2008
JS BeckI; GR BassonII
IDepartment of Civil Engineering, University of Stellenbosch, Stellenbosch, South Africa (Presently at: MWH Ltd NZ, PO Box 12941, Auckland 1642, New Zealand)
IIDepartment of Civil Engineering, University of Stellenbosch, Private Bag X1, Matieland, Stellenbosch 7602, South Africa
2D numerical modelling of the breaching process of the Klein River Estuary in South Africa was carried out. The model was calibrated on field data and performs reasonably well, and is able to simulate the ebb and flood channels that form upstream of the mouth. The focus of the simulations was to determine the effectiveness of flushing of sediments during breaching, by investigating the breaching process at different water levels in the estuary, as well as at two different areas along the berm. Breaching at higher water levels increases the effectiveness of flushing as the discharge through the mouth increases significantly at higher water levels. Flushing towards the middle or south-east side of the berm is much more effective than towards the north-west side.
Key words: estuary, breaching, Klein River, sediment flushing, numerical modelling
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BECK JS, THERON AT, KEMP A, HUIZINGA P and BASSON GR (2004) Hydraulics of Estuarine Sediment Dynamics in South Africa - Implications for Estuarine Reserve Determination and the Development of Management Guidelines. WRC Report No 1257/1/04. Water Research Commission, Pretoria, South Africa. [ Links ]
BOURMAN RP and BARNETT EJ (1995) Impacts of river regulation on the terminal lakes and the mouth of the River Murray. Australian Geographical Studies 33 101-115. [ Links ]
CSIR (1999) Klein River Estuary - The Effects of Mouth Breachings in 1998. CSIR Report No. ENV/S-C 99014. Stellenbosch. [ Links ]
CSIR (2000) Great Brak Estuary Management Programme - Report on the Monitoring Results for the Period November 1999 to November 2000. CSIR Report No ENV-S-C 2000-131. Stellenbosch. [ Links ]
CSIR (2003) Great Brak Estuary Management Programme, Review Report. CSIR Report ENV-S-C-2003-092. Stellenbosch. [ Links ]
ENGELUND F and FREDS0E J (1976) A sediment transport model for straight alluvial channels. Nordic Hydrol. 7 293-306. [ Links ]
HARVEY N (1996) The significance of coastal processes for the management of the River Murray Estuary. Australian Geographical Studies 34 45-57. [ Links ]
GOODWIN P and CUFFE CK (1993) Russian River Estuary Study 1992 - 1993. Department of Planning, Sonoma County, United States. HUIZINGA P (1994) Estuaries: From Midgley's involvement in St Lucia to the present and challenges for the future. In: 50 Years of Water Engineering in South Africa. (14-15 July 1994) A Tribute to Prof Des Midgley. Water Engineering Division, South African Institution of Civil Engineers. South Africa. [ Links ]
MATINI-LAMB J, CHURCH J, COOK D, MANNING D and FULLER J (2006) Russian River Estuary Sandbar Breaching - 2005 Monitoring Report. Sonoma County Water Agency, United States. [ Links ]
SCHUMANN EH (ed.) (2003) Towards the Management of Marine Sedimentation in South African Estuaries with Special Reference to the Eastern Cape. WRC Report No. 1109/1/03. Water Research Commission, Pretoria, South Africa. [ Links ]
VAN NIEKERK L, VAN DER MERWE JH and HUIzINGA P (2005) The hydrodynamics of the Bot River Estuary revisited. Water SA 31 (1) 73-85. [ Links ]
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Received 16 May 2006;
Accepted in revised form 30 October 2007.