Soil/Landform Unit - Mount Cole Creek

Mount Cole Creek and the Wimmera River converging west of Eversley

Area: 20 368 ha

0.87% of CMA region

This unit is an alluvial valley complex associated with the upper Wimmera River and forms part of the alluvial terraces and floodplains subdivision (2.1.7) landscape of the Dissected Western Uplands. This

alluvial

unit is surrounded by many hilly to mountainous units including the Pyrenees Ranges, Mount Langi Ghiran and the Concongella hills from north to south. The alluvial plains/flats occur as elongated valleys that are confined by higher relief. Terrace plains and flats, gentle lower slopes, drainage depressions, valley flats and moderate upper slopes all occur within these valleys. Soil types are predominantly red sodic texture contrast soils (

Sodosols

) with yellow, brown and grey

sodic

gradational (

Dermosols

) and texture contrast soils (

Chromosols

), the latter in the depressions. Soil

compaction

is a potential land degradation susceptibility as is waterlogging on the depressions, broader flats and plains where topsoils are shallow. Fodder production and cereal cropping are common enterprises but grazing (sheep and cattle) is the dominant enterprise. Heathy Dry Forest and Grassy Forest vegetation communities are associated with exposed areas of the landscape, while Herb-rich Foothill Forest and Valley Grassy Forest are more associated with sheltered areas of the landscape. Other remnant vegetation include various woodlands.

Alluvial terraces of the Wimmera River near Crowlands
	Terrace plain railway cutting and Mount Cole Creek

Component	1	2	3	4	5	6	7
Proportion of soil-landform unit	12%	20%	23%	10%	5%	23%	7%
CLIMATE Rainfall (mm)	Annual: 640
CLIMATE Rainfall (mm)	Annual: 640
Temperature (^oC)	Minimum 7, Maximum 19
Precipitation less than potential evapotranspiration	October–April
GEOLOGY Age and lithology	Cambrian marine sandstone, siltstone and biotite schist (St Arnaud Group); Quaternary fluvial gravel, sand and silt; Devonian granite
GEOLOGY Age and lithology
Geomorphology	2.1.5 Terraces and floodplains of the Dissected Western Uplands
LANDUSE	Uncleared areas: water supply; nature conservation Cleared areas: sheep and beef cattle grazing; dryland cropping; pasture production; water supply
LANDUSE
TOPOGRAPHY Landscape	Alluvial plain and valleys
TOPOGRAPHY Landscape	Alluvial plain and valleys
Elevation range (m)	201–840
Local relief (m)	5
Drainage pattern	Dendritic
Drainage density (km/km²)	1.6
Landform	Alluvial terraces, plains and floodplains				Alluvial valleys
Landform element	Gentle slope	Terrace plain	Terrace flat	Drainage depression	Moderate upper slope	Gentle lower slope	Valley flat
Slope and range (%)	3 (1-6)	2 (0-10)	1 (0-2)	2 (0-5)	12 (10-30)	5 (3-20)	2 (1-10)
Slope shape	Straight	Straight	Convex	Straight	Concave	Convex	Straight
NATIVE VEGETATION Ecological Vegetation Class	Plains Woodland (18.4%), Creekline Grassy Woodline (13.6%), Alluvial Terraces Herb-rich Woodland (12.0%)
NATIVE VEGETATION Ecological Vegetation Class
SOIL Parent material	In situ intrusive granite, marine sandstone, siltstone and biotite schist	Fluvial gravel, sand and silt	Fluvial gravel, sand and silt	Fluvial gravel, sand and silt	In situ marine sandstone, siltstone and biotite schist, intrusive granite	Alluvial gravel, sand and silt	Alluvial gravel, sand and silt
SOIL Parent material		Fluvial gravel, sand and silt	Fluvial gravel, sand and silt	Fluvial gravel, sand and silt		Alluvial gravel, sand and silt	Alluvial gravel, sand and silt
Description (Corangamite Soil Group)	Red texture contrast soils (10)	Red texture contrast soils (10) and yellow and brown gradational and texture contrast soils (11)	Red texture contrast soils (10)	Sodic brown, yellow and grey texture contrast soils (12)	Yellow and brown gradational and texture contrast soils (11)	Yellow and brown gradational and texture contrast soils (11)	Sodic brown, yellow and grey texture contrast soils (12)
Soil type sites	DOAGW17, DOAGW2, LP80	DOAGW17, WLRA66, WLRA63	DOAGW17, DOAGW2, LP80	DOAGW12, WLRA144, WLRA145, WLRA148	WLRA66, WLRA63	WLRA66, WLRA63	DOAGW12, WLRA144, WLRA145, WLRA148
Surface texture	Sandy loam	Sandy loam	Sandy loam	Loam, fine sandy (heavy)	Loamy sand	Loamy sand	Loam, fine sandy (heavy)
Permeability	High	High	High	Slow	High	High	Moderate to slow
Depth (m)	> 2	> 2	> 2	> 2	> 2	> 2	> 2
LAND CHARACTERISTICS, POTENTIAL AND LIMITATIONS Critical land features, processes, forms	Light soil surface susceptible to sheet and rill erosion and compaction. Subsoil susceptible to rill and gully erosion where sodic. Lighter soil variants are well drainage. Upper soil susceptible to acidification.	Lighter surface susceptible to compaction and hardsetting with low organic matter levels. Soils are susceptible to sheet and rill erosion where slopes are steeper. Subsoil susceptible to rill and gully erosion. Lighter variants are well drained.	Light soil surface susceptible to sheet and rill erosion and compaction. Subsoil susceptible to rill and gully erosion where sodic. Lighter soil variants are well drainage. Upper soil susceptible to acidification.	Lighter surface susceptible to sheet and rill erosion and compaction. Subject to periodic inundation and waterlogging, especially during flood events. Lighter soil variants are well drained within the depressions. Upper soil susceptible to acidification.	Lighter surface susceptible to sheet and rill erosion and compaction. Subsoil susceptible to rill and gully erosion where sodic and deeper. Lighter variants are well drained.	Lighter surface susceptible to sheet and rill erosion and compaction, especially with low organic matter. Susceptible to rill and gully erosion where sodic subsoils are exposed. Lighter variants are well drained.	Lighter surface susceptible to sheet and rill erosion and compaction. Subject to periodic inundation and waterlogging, especially during flood events. Lighter soil variants are well drained within the depressions. Upper soil susceptible to acidification.

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