School of Geography - Theses
Permanent URI for this collection
Search Results
1 - 2 of 2
-
ItemThe geomorphology of Mallacoota Inlet, East Gippsland( 1977)Mallacoota Inlet is an estuary located 537 kilometres by road east of Melbourne (Fig. 1.1). The estuary occupies a drowned river valley cut by the Genoa and Wallagaraugh Rivers at lower sea levels during the Pleistocene era. Mallacoota Inlet has a total shoreline length of 85 kilometres, a surface area of 25 x 106 square metres and a volume at low water of approximately 73 x 10 cubic metres, and is consequently the largest estuary or estuarine lagoon occurring east of the Gippsland Lakes. Two major hydrographic provinces may be differentiated within the Mallacoota system: (1) the basins, and (2) the linear channels. Three major basins comprise Mallacoota Inlet; the Upper Lake, the Lower Lake, and the North East Arm. A further, smaller basinal area is Double Creek Arm (Fig. 1.2). These basins differ in depth and sediment characteristics, and both these characteristics are related to the proximity to, and the source of, sediment within the Mallacoota system. The Upper Lake is a broad, shallow (less than three metres), and relatively flat bottomed basin with margins which are for the most part relatively gently sloping (Figs. 1.3 and 1.4). This basin, being closest to the point of river discharge, receives the greatest amount of fluvial sediment. On the other hand, the North East Arm is a relatively deep (up to six metres) flat bottomed basin with steeply sloping margins
-
ItemThe physiography of Anderson's Inlet, Victoria, with special reference to early stages in the establishment of Spartina( 1971)In recent years, extensive intertidal flats towards the head of Anderson's Inlet, Victoria, have been colonised by Scartina townsendii (sensu lato) an erect, perennial and exotic grass. S. townsendii (s.l.) was first recorded in 1870 in Southampton Water, England, where it is presumed to have evolved by hybridisation between two Scartina species, the local S. maritima and the American S. alternlflora. The new plant spread quickly to other estuaries along the south coast of England, and in 1899 appeared in Poole Harbour, where neither of its parent species had been present. The spread of S. townsendii (s.l.) is accompanied by rapid sediment accretion, and as a result there has been modification of the physiography and ecology of estuaries in which it is found. Such modification occurred in Poole Harbour, which has recently become the centre of much scientific interest. The attention of the author was first drawn to the presence of Scartina in Anderson's Inlet by Dr. B. C. P. Bird, a participant in research at Poole Harbour, who noted the apparent physiographic similarities of the two estuarine systems, and pointed out that recent attempts to establish the features of Scartina colonisation in Poole Harbour have been hampered by an absence of detailed information on the early stages of Scartina spread. Because of the youth of its Scartina marsh, there is at Anderson's Inlet an opportunity to study the initial phases of Spartina invasion and establishment, and the resulting effects on physiography and sedimentation, in an estuarine system which is likely to be changed profoundly by SpartIna introduction. For this purpose, the present research was undertaken.