See also Land Degradation in Victoria
Potential land degradation in the Wimmera include water erosion (ie: sheet, gully, tunnel and deposition), wind erosion (sheet and deposition) and destruction by pest plants and animals. The Wimmera Catchment Management Authority (external link) has produced a Rabbit Action Plan (WCMA, 1999a) and a Weed Action Plan (WCMA, 1999b).
|Meanwhile, erosion susceptibilities are scored from zero to three and then rated for an erosion potential of nil, low, moderate or high. A class of nil indicates that the susceptibility is predicted to be generally below the limits of detection, and thus comparable to degradation under pre-European conditions. Measurement and description of relevant parameters follows McDonald et al (1990). Data on diagnostic characteristics are generally sufficient for broad predictions of susceptibility. Prediction based on chemical data are less reliable than physical data, and are tentative in areas without laboratory data for soils. Data on soil mottling are also unreliable (Rees, 2000).|
The Wimmera region of Victoria generally has insignificant to low susceptibility to water erosion throughout. However, there are small patches of land in the far south-east of the catchment that are classified as having a medium or high susceptibility to water erosion. These areas are characterised by the steep mountains and hills of the Grampians Ranges and stranded beach ridges. These stranded beach ridge landforms are also susceptible to wind erosion.
Gully erosion near Diapur
|The Susceptibility to Water Erosion map is intended to be used with existing Land Systems data to determine the likely impact of water erosion for areas within the Wimmera region.|
Measurement is based on McDonald et. al.(1990) and uses soil depth (the average depth to solid rock). Rating scores are based on observations in hilly sub-humid areas where water erosion is relatively severe. These scores are rated from nil to high.
Sandier soils in the foreground are most susceptible to wind erosion
Gully erosion near Stawell
|The Susceptibility to Wind Erosion map is intended to be used with existing Land Systems data to determine the likely impact of wind erosion for areas within the Wimmera region.|
Criterion is based on Lorimer (1985) and uses surface texture in semi-arid to sub-humid areas and exposure to particularly strong winds in humid areas. The criterion for susceptibility to wind erosion in semi-arid areas is surface soil texture. Scores are given to rate texture from nil to high.