This dataset provides a hierarchical framework of geomorphological spatial entities at three tiers (Tier 1 represents the coarsest scale, Tier 3 representing the finest scale). Over the last decade in Victoria, geomorphology has been used to create a hierarchical classification of landforms and landscapes, known as the Victorian Geomorphology Framework (VGF). The VGF is a spatial framework consisting of a hierarchical system of land unit descriptions. The framework hierarchy is a spatial system to assist planning, monitoring and reporting for natural resource management in Victoria and Australia. The VGF describes and defines details of Victorias landscapes and provides a hierarchy to align past and future soil and land information. The upper level (Tier 1) has 8 Divisions and approximates to a scale of 1:1 000 000 to 5 000 000. Tier 2 has 34 categories, approximating to a scale of 1:500 000 to 2 000 000 while Tier 3 has 95 categories approximating to a scale of 1:100 000 to 500 000. Many of the boundaries are derived from the aggregation of soil-landform units/land systems, forming a hierarchical land type, particularly in relation to landform.
The GMU250 layer includes soil erosion susceptibility assessments sourced from soil information contained in underlying regional studies which have been developed at regional scales of 1:100 000 or finer. The regional Land Resource Assessment (LRA) mapping at 1:100 000 scale effectively equates to the fourth tier of GMU mapping detail. As these units have been scaled up for use at the third tier, i.e. GMU250, it has meant a degree of generalisation across the LRA units. In these cases the dominant soil type, based upon maximum spatial extent, has been used for the susceptibility assessments.