Point Roadknight Land System

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Along the coast from Breamlea to Eastern View, coastal dunes occur discontinuously. In some localities a primary and a secondary dune form a thin barrier between the sea and the Tertiary sediments, but in the locality of Point Impossible the dune system is more complex and extensive.

The foredune and secondary dune material is aeolian sand and shell grit. On older dunes, mobilization of calcium carbonate has resulted in the formation of calcarenite, which may outcrop on blowouts or steep slopes. Away from these calcarenite pavements, the soils are freely drained calcareous sands. The exposed calcarenite pavements may support red calcareous gradational soils, but extensive sheet erosion has removed most of this material.

Recreation and access to the foreshore are the main land uses. Some buildings have been sited in these dunes at Breamlea and Fairhaven. Native grasses and shrubs that colonize these dunes are very sensitive to disturbance and, once devoid of vegetative cover, wind erosion is likely to occur. Hand planting of Ammophila arenaria has been necessary to stabilize many areas.

A Study of land in the catchments of the Otway Range and adjacent plains - point roadknight

Sections of coastline in the drier eastern parts of the study area
often have extensive calcareous dune systems. On many of these
dunes the native vegetation has been trampled and destroyed and the
hand planting of Ammophila arenaria has been necessary to restabilize
the dune system.

Area: 8 km²	Component and its proportion of land system
Area: 8 km²	1 20%	2 50%	3 25%	4 2%	5 3%
CLIMATE Rainfall, mm	Annual: 600 – 750, lowest January (30), highest August (75)
Temperature, 0^oC	Annual: 14, lowest July (10), highest February (18)
	Temperature: less than 10^oC (av.) July
	Precipitation: less than potential evapotranspiration mid October - early April
GEOLOGY Age, lithology	Recent aeolian sand and shell grit			Cemented deposits (calcarenite and travertine)
TOPOGRAPHY Landscape	Longitudinal coastal dunes to the east of the Otway Range
Elevation, m	0 – 25
Local relief, m	15
Drainage pattern	Absent
Drainage density, km/km²	-
Land form	Foredune	Shifting dune	Older more stable dunes		Interdune corridor
Land form element	Windward exposed slope	Leeward and windward slopes	Gentler slope	Steeper slope	-
Slope (and range), %	40 (10-65)	30 (5-65)	9 (0-20)	15 (5-10)	3 (0-7)
Slope shape	Irregular	Irregular	Convex	Linear	Concave
NATIVE VEGETATION Structure	Tussock grassland	Open heath	Low woodland	Low woodland	Possibly open heath
Dominant species	Spinifex hirsutus, Tetragonia tetragonioides	Helichrysum paralium, Leucopogon parviflorus	Melaleuca lanceolata, Leptospermum laevigatum, Leucopogon parviflorus	Melaleuca lanceolata, Leucopogon parviflorus, Acacia longifolia	Helichrysum paralium
SOIL Parent material	Coarse sand, shell grit	Coarse sand, shell grit	Coarse sand, shell grit	Calcarenite, coarse sand	Calcarenite, travertine
Description	Yellow calcareous sand soils, uniform texture	Yellow calcareous sand soils, uniform texture	Brown calcareous sand soils, uniform texture	Stony black calcareous sand soils, uniform texture	Red calcareous gradational soils
Surface texture	Coarse sand	Coarse sand	Loamy sand	Loamy sand	Sandy loam
Permeability	Very high	Very high	Very high	Moderate	Very low
Depth, m	>2	>2	>2	>2	0.3
LAND USE	Uncleared areas: Passive and active recreation; foreshore access; nature conservation; sand extraction. Minor cleared areas: Recreational facilities; refuse tip; foreshore access; residential
SOIL DETERIORATION HAZARD Critical land features, processes, forms	Marine erosion and accretion occur seasonally. Native vegetation is sensitive to trampling and disturbance. Weakly structured sands are prone to wind erosion. Low inherent fertility and high permeability lead to nutrient decline.	Native vegetation is sensitive to trampling and disturbance. Weakly structured sands are prone to wind erosion. Low inherent fertility and high permeability lead to nutrient decline.	Weakly structured sands are prone to wind erosion. Low inherent fertility, high alkalinity and high permeability lead to nutrient decline.	Weakly sands with restricted drainage on steep slopes are prone to sheet erosion. Low inherent fertility and high alkalinity lead to nutrient decline.	Low permeability and weak structure lead to sheet erosion, exposing calcarenite pavement.

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