Shoreline processes and coastal compartments of Golden Bay, South Island, New Zealand.
Degree GrantorUniversity of Canterbury
Degree NameMaster of Science
Golden Bay is a broad, shallow, roughly circular embayment over 30 km across. Depths within the bay do not exceed 40 m and the shoreline is formed by a narrow strip of prograded beach ridges, fronted by predominantly sandy beaches and extensive intertidal sand- flats. The coastline is dissected by a number of river mouths and shallow inlets.
Wave energies within Golden Bay are low compared with exposed open-ocean shores elsewhere in New Zealand but the incidence of storm surges coupled with the large tidal range, greater than 4. 0 m, means that considerable potential for both foreshore erosion and long shore transport of sand exist.
Beach sediments are predominantly medium to fine sands that are well to very well sorted. Local deviations from this trend exist due to local sediment sources and hydraulic factors. The protected northern beaches show less volumetric beach change (20-40 m³/m) than the more exposed southern beaches (40-80 m³ /m). The relatively large amounts of short term volumetric beach change can be accounted for by the large short term sea level variations, associated with tidal variations and storm surges, and the accompanying changing wave conditions.
The major length of the Golden Bay shoreline is stable to pro grading; only 9.0 km of coastline are subject to continual or episodic erosion. However these areas are of prime concern to coastal management as these sections are extensively developed for housing and recreation.
There exists within Golden Bay nine coastal compartments which display distinct variations in terms of either marine processes, beach sediments and morphodynamics or shoreline change. Within three of these larger compartments there exist a number of less exclusive cells which display one common characteristic but may very with respect to these criteria.