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Geomorphology report on coastal erosion at the Detention River estuary, Hellyer, North-West Tasmania.
Ellison, JC and White, M and Poole, M and Beasy, K and McNab, S and Walford, H (2010) Geomorphology report on coastal erosion at the Detention River estuary, Hellyer, North-West Tasmania. Project Report. University of Tasmania, Hobart. (Unpublished)
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The western bank of the Detention River estuary has in the last few years suffered
erosion owing to the active estuarine channel meandering to the west. The main
estuarine channel was located in the centre of the estuary from 1971 to 1997 at least,
and has moved west after 2004 following increased sand deposition in the mouth.
Human activity in the area is further exacerbating the erosion problem, and fallen
trees also contribute to sediment erosion. Erosion at this site is not primarily caused
by rise in sea-level, though it exemplifies the types of impacts that widespread
coastal areas in Tasmania will experience in coming decades.
Recommendations to mitigate this erosion problem must be agreed by stakeholders
involved, and options include restriction of public access, further removal of large
woody debris at the base of the erosion scarp, increasing the sheer strength of the
erosion bank by control of runoff and revegetation, and boat wake restriction in the
estuary. These actions would all decrease erosive forces at the site. Subject to EIA
approval and supervision by a hydraulic engineer this geomorphologists’ report can
also support the option of reconstruction of the central estuary main channel at its
position around 1988 to 1997, to relieve flow at the erosion site. This might include
the option of subsequent beach replenishment of the erosion site, though involving
no hard structures. Further investigation particularly including GIS analysis and site
monitoring should also be carried out.
|Item Type:||Report (Project Report)|
|Publisher:||University of Tasmania|
This report is provided Gratis to State Government,
|Date Deposited:||04 Jan 2011 02:00|
|Last Modified:||18 Nov 2014 04:12|
|Item Statistics:||View statistics for this item|
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