Soil/Landform Unit - Mokepilly undulating plains

WLRA Landform Mokepilly undulating plains

Level to gentle plains north of Lake Evans

Area: 3253 ha

0.14% of CMA region

This unit of low-lying terrain of undulating plains consists of two main occurrences. These plains and associated rolling terrain are part of Dissected Western Uplands as part of the residual

Cainozoic

landscapes (2.1.5). These near-level plains lie between the Grampians Ranges and eastern Black Ranges, north of Lake Fyans. The plains and flats are dominant with dunes, rises and drainage depressions as minor landscape components. The plains receive surface drainage from the surrounding upland rises and hills. Yellow and brown

sodic

texture contrast soils with sandy topsoils of varying depth are common (

Sodosols

) with sandy soils on dunes (

Tensosols

) and minor brown and red sodic texture contrast soils (Sodosols). Sheet and rill erosion, as well as compaction, are potential land degradation susceptibilities with a minor susceptibility to wind erosion and waterlogging depending on landform (dune or depression). Remnant native vegetation communities such as Damp Sands Herb-rich Woodland, Heathy Woodland, Plains Grassy Woodland, Red Gum Wetland and Lateritic Woodland have been recorded.

Level plains south of Lake Londsale bordering Mount William Creek
	Lake Fyans

Component	1	2	3	4
Proportion of soil-landform unit	15%	70%	5%	10%
CLIMATE Rainfall (mm)	Annual: 640
CLIMATE Rainfall (mm)	Annual: 640
Temperature (^oC)	Minimum 8, Maximum 20
Precipitation less than potential evapotranspiration	October–March
GEOLOGY Age and lithology	Quaternary fluvial gravel, sand and silt; Cambrian ‘greenstone’ - basalt, andesite, boninite, rhyolite, gabbro, lithic sandstone, chert, shale and breccia
GEOLOGY Age and lithology
Geomorphology	2.1.5 Cainozoic landscapes of the Dissected Western Uplands
LANDUSE	Uncleared areas: water supply; nature conservation; sand extraction Cleared areas: sheep and beef cattle grazing; dryland cropping; sand extraction; water supply
LANDUSE
TOPOGRAPHY Landscape	Undulating plains
TOPOGRAPHY Landscape	Undulating plains
Elevation range (m)	186–215
Local relief (m)	5
Drainage pattern	Dendritic
Drainage density (km/km²)	0.7
Landform	Low dunes	Alluvial plains
Landform element	Dune	Plain	Drainage depression	Low rise slope
Slope and range (%)	3 (1-7)	1 (0-3)	1 (0-2)	2 (1-6)
Slope shape	Convex	Straight	Concave	Convex
NATIVE VEGETATION Ecological Vegetation Class	Plains Grassy Woodland (65.8%), Red Gum Wetland (11.6%), Plains Woodland/Plains Sedgy Woodland/Damp Sands Herb-rich Woodland (10.8%), Other (11.9%)
NATIVE VEGETATION Ecological Vegetation Class
SOIL Parent material	Aeolian dune sand	Fluvial gravel, sand and silt	Fluvial gravel, sand and silt	Fluvial gravel, sand and silt, minor greenstone
SOIL Parent material	Aeolian dune sand	Fluvial gravel, sand and silt	Fluvial gravel, sand and silt	Fluvial gravel, sand and silt, minor greenstone
Description (Corangamite Soil Group)	Shallow and sandy weakly developed soils (13)	Sodic and non-sodic, yellow and brown texture contrast soils (5)	Sodic and non-sodic, yellow and brown texture contrast soils (5)	Sodic and non-sodic, brown and red texture contrast soils (6)
Soil type sites	WLRA54	DOAGW15	DOAGW15	WLRA141, WLRA142, WLRA143
Surface texture	Loamy sand	Sandy clay loam	Sandy clay loam	Sandy loam (silty)
Permeability	High	Moderate - slow	Slow	Moderate
Depth (m)	0.5	> 2	> 2	< 2
LAND CHARACTERISTICS, POTENTIAL AND LIMITATIONS Critical land features, processes, forms	Light sandy soils with weakly coherent surfaces that are subject to severe wind erosion where exposed. Acidic soils with low inherent fertility. Rapid drainage and high soil permeability.	Hardsetting surfaces susceptible to sheet and rill erosion even on gentle slope due to impeding layer (clay or hardpan). Subsurface soil and upper subsoil susceptible to compaction. Extremely prone to gully erosion where sodic subsoils are exposed and vulnerable. Topsoil may be susceptible to acidification.	Subsurface soil and upper subsoil susceptible to compaction. Extremely prone to gully erosion where sodic subsoils are exposed and vulnerable. Topsoil may be susceptible to acidification.	Hardsetting and soft surfaces susceptible to sheet and rill erosion even on gentle slope due to impeding layer (clay or hardpan). Subsurface soil and upper subsoil susceptible to compaction, and also gully erosion where sodic and deep. Topsoil may be susceptible to acidification.

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