Introduction Riverine Conceptual Models - Statewide

Broad geographic areas such as Queensland can cover a diverse and complex array of ecosystem types which can make understanding aquatic ecosystem processes difficult.  This heterogeneity is related to geographic distance and the presence of different landscape attributes.  Regionalisation is a process used to divide a large area into smaller areas with similar (less variable) ecosystem types.  This reduction in variability is beneficial to condition assessments because it increases the efficiency of the monitoring effort applied within a sampling program.

There are two broad approaches to regionalisation. The first uses patterns of landscape drivers influencing aquatic ecosystems (e.g. stream flow, temperature, soil type) to define areas where systems would be expected to be similar.  The alternative approach uses geographic patterns in ecosystem biota (e.g. fauna such as macroinvertebrates and fish) to regionalise large areas, and has been successfully implemented in Victoria, Australia (Newall and Wells, 2000; Wells et al., 2002).

The riverine systems of Queensland were 'regionalised' using a biota approach.  This resulted in nine Freshwater Biogeographic Provinces with more homogenous biota than the whole State. The approach used macroinvertebrate and freshwater fish data to group similar catchments (Marshall et al., 2006). The resulting provinces provided a practical separation of the state into similar ecosystem types for use as reporting regions, and have been applied as the basis for implementation of the long-term design of the Stream and Estuarine Assessment Program.  These provinces were used as the basis for the construction of both the natural process and stressor Riverine Conceptual Models. 

The riverine conceptual models presented in this section deal solely with naturally occurring processes and do not focus on anthropogenic impacts (that is covered in the stressors section). The major natural processes which drive the physical (e.g. flow regimes, temperature, habitat availability) and chemical (e.g. pH, Nutrient concentrations) composition of the river systems and consequently determine the biota of the province. The major subgroups are: Climate, Geology and Topography, Habitat, Hydrology, and Water Quality (see diagram). More specific information can be found in the Background information section.