Dealing with salinity in Wheatbelt Valleys - Department of Water

Commander, Schoknecht, Verboom and Caccetta
HYDRO-AEOLIAN LANDSCAPES
The hydro-aeolian “lakes and lunettes” landscape of
the lower parts of the broad valleys has been formed
by action of both wind and water. It is characterised
by salt lakes and channels, source-bordering and
relict lunettes and flat to undulating plains of clayey
aeolian sediments sourced from salt lakes. This
landscape corresponds to the Baandee and
Nangeenan surfaces (Bettenay & Hingston 1961;
Lantzke & Fulton 1993).
Salt lakes, playas and channels
The soils of the salt lakes are very variable, and have
not been described in any detail across the zone.
The lakes have shallow saline watertables, and may
fill with surface water in wet years. The lakes are
filled with fine and coarse alluvium, plus significant
quantities of mobile salts. Sodium chloride is the
dominant salt, but significant quantities of gypsum
(CaSO4) may also occur.
Soil groups: Salt lake soils, Saline wet soils
Vegetation: Usually bare of vegetation, with
halophytic species such as samphire (Halosarcia spp.),
saltbush (Atriplex spp.) and bluebush (Maireana
brevifolia) on fringing areas.
Lunettes
Lunettes, composed of saline alluvium, occur on the
lee side of the present or ancient salt lakes. The
composition of the lunettes varies considerably, from
gypsum, sand or even clays flocculated to sandy
particle size by the saline conditions.
Soils: variable deposits of sands, clays and gypsum
Vegetation: Variable.
Figure 11: Block diagram showing soil-landscape units in wheatbelt valleys
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