WEST KIMBERLEY PLACE REPORT - Department of Sustainability ...

Western Australia, the Eyre Peninsula–Kangaroo Island coastal stretch, western
Victoria and south-western Tasmania, but these are all much shorter in total length
and all include significantly higher proportions of sandy beaches than the Kimberley
coast.
Other long dominantly-rocky coast sections include the Zuytdorp Cliffs of Western
Australia and the Bunda and Baxter Cliffs of the Great Australian Bight; however
these are much shorter coastal stretches than the Kimberley (Short and Woodroffe
2009). They also take a very different plan form, being straight or at most gently
curvilinear, with internally draining limestone hinterland areas resulting in a lack of
fluvial system controls on coastal forms (DEWHA 2009c; Sharples et al. 2009;
Sharples 2009; White 2009).
Comparably well-expressed and extensive ria coasts in Australia include:
- Arnhem Land coast: intricate fold and joint-controlled rocky quartzite coasts
of at least partly ria character, including the Wessell Islands. The Arnhem Land coast
is similar in some respects to the Kimberley but is much less extensive (Sharples et al.
2009; Sharples 2009).
- The east coast of Australia (New South Wales) contains many very wellexpressed
rias, for example, the drowned river valleys of Sydney Harbour and the
Hawkesbury River, but these are mostly individual flooded river valleys separated by
long stretches of sandy, swell-aligned coasts. They do not form a long integral
dominantly-ria rocky coast as does the Kimberley (DEWHA 2009c; Sharples et al.
2009; Sharples 2009.
- Southern Tasmania demonstrates a well developed complex ria coast, but is
much less extensive than the Kimberley coast, with a much higher proportion of
sandy embayments. Its wave-dominated environment is not comparable to the
Kimberley in terms of tidal processes. Many of its narrow inlets are extensional
faulted graben structures formerly occupied by rivers but are different in structural
origin to the Kimberley coast. This reflects a different set of processes and results in
different bathymetry and expression from the Kimberley (DEWHA 2009c; Maher and
Copp 2009; Sharples 2009).
Comparable tide-dominated Australian coasts:
The Kimberley coast has the highest tidal ranges of the Australian coast (Short and
Woodroffe 2009). Similarly high tidal ranges occur south-west of the Kimberley
(Eighty Mile Beach region) and in the eastern Bonaparte Gulf region, however these
coasts are of very different character to the Kimberley rocky coast, comprising mainly
sandy beaches and tidal mudflats. Without the complex rocky coastal plan forms
constraining coastal response to tides, these regions do not exhibit the dramatic tidal
current phenomena of the Kimberley. Comparably intricate rocky coasts elsewhere
(e.g., Arnhem Land, south-east Tasmania) have much lower tidal ranges with
consequently much less pronounced tidal current processes (DEWHA 2009c;
Sharples 2009; Sharples et al. 2009; Chris Sharples pers. comm. 2009).
Comparable coasts with reduced high-density coastal infrastructure:
There are no comparably long stretches of the Australian coast with equivalently lowdensity
near coastal infrastructure (including roads) or physical disturbance. The two
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